Objective analysis of retinal damage in HIV-positive patients in the HAART era using OCT

Inflammatory mechanisms contributing to retinal alterations in HIV infection and long-term ART

People living with HIV (PLWH) may face an increased risk of eye complications associated with ageing, chronic inflammation, and the toxicity arising from long-term antiretroviral therapy (ART). This review aims to understand how inflammatory pathways contribute to retinal alterations observed in PLWH on long-term ART. This review was conducted using four electronic database searches, namely Scopus, Hinari, Google Scholar, and PubMed; from 1996 (when ART became available) until January 2022, without language restriction. Sources from clinical trials, meta-analyses, randomised controlled trials, and systematic reviews were used. Dysregulated para-inflammation (chronic inflammation) damages the blood-retina barrier, resulting in the altered retinal immune privilege and leading to the development of retinal and blood vessel changes. There is an interplay between the effects of the disease versus ART. ART causes mitochondrial toxicity, which affects the retinal ganglion cells and retinal pigment epithelium (RPE) due to oxidative stress. Infection by HIV also affects retinal microglia, which contributes to RPE damage. Both of these mechanisms affect the blood vessels. Assessing the integrity of the inner and outer blood-retina barrier is a pivotal point in pinpointing the pathogenesis of inner retinal alterations. Optical coherence tomography is a valuable tool to assess these changes. There is a paucity of research to understand how these structural changes may affect visual function, such as contrast sensitivity and colour vision.

Comparison of retinochoroidal and optic nerve head microvascular circulation between HIV-positive patients and healthy subjects using optical coherence tomography angiography

PURPOSE

To evaluate the retinal, choroidal, and optic disc head microvascular circulation in human immunodeficiency virus (HIV)-infected individuals without retinopathy receiving highly active antiretroviral therapy (HAART) using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

This cross-sectional study included 100 eyes of 100 patients with HIV infection but no HIV-related ocular disease and 108 eyes of 108 age- and sex-matched healthy subjects as the control group. SS-OCTA was used to assess foveal avascular zone (FAZ) area, retinal nerve fiber layer thickness (RNFL), choriocapillaris (CC) flow area, outer retinal (OR) thickness, radial peripapillary capillary (RPC) vessel density (VD), ONH VD, and choroidal thickness.

RESULTS

No statistically significant difference was found between the two groups except in the foveal VD of the deep capillary plexus (DCP). The foveal VD of the DCP was lower in the HIV-positive group (P=0.011). The mean FAZ area (mm2), perimeter (mm), and CC flow area (mm) values were higher in the HIV-positive group at statistically significant levels (P=0.021, P=0.02, and P=0.039, respectively). However, no statistically significant differences were found between the two groups concerning the OR flow area, subfoveal choroidal thickness, or the VDs of the RPC or ONH.

CONCLUSIONS

This is the first study in the literature to evaluate the microvascular circulation of the ONH in HIV-positive patients. Although retinal and choroidal microvascular circulation decreased in HIV-positive patients receiving HAART treatment, we found no effect on the microvascular circulation of the ONH or RPC microvascular circulation. Our findings suggest that retinochoroidal microvascular circulation is affected in HIV-positive patients over time.

Significant loss of retinal nerve fibre layer and contrast sensitivity in people with well controlled HIV disease: implications for aging with HIV

Objective

Antiretroviral therapy has decreased the prevalence of retinal opportunistic infections in people living with HIV (PLWH). However, abnormalities in visual function are evident and may be associated with an early onset of aging in PLWH. In this study, we examined the Retinal Nerve Fibre Layer (RNFL) thickness and visual function in PLWH and HIV non-infected controls in Malaysia.

Design

Cross-sectional study.

Methods

Two hundred and two (202) PLWH without retinal opportunistic infection and 182 age-matched, HIV seronegative individuals were enrolled. PLWH were recruited from the Infectious Disease clinic at the University Malaya Medical Centre. Controls were recruited among the hospital staff and community volunteers. RNFL thickness was measured with spectral domain optical coherence tomography (SDOCT). Visual functions include visual acuity using LogMAR chart and contrast sensitivity using Pelli- Robson Chart.

Results

All PLWH (mean age 46.1 years ± 9.9 years) in the study were on ART and 61.2% had a CD4+ T-cell count more than 500 cell/μl. The mean visual acuity was similar between the two groups (LogMAR 0.05 vs. 0.07, p = 0.115). Contrast sensitivity was lower in PLWH compared to HIV seronegative individuals (1.90 vs 1.93, p = 0.032). RNFL thickness was significantly thinner in the temporal quadrant for PLWH compared to controls (68.89 μm vs 74.08 μm, p = 0.001).

Conclusion

Changes in RNFL thickness and contrast sensitivity were seen in PLWH despite their relatively young age and well controlled HIV disease. The changes reflect structural and functional deficits, and could have long-term implications on their health trajectory.

Development of retinal structure in perinatally HIV-infected children and adolescents: A longitudinal and cross-sectional assessment

In perinatally HIV-infected (PHIV) children, cross-sectional studies reported on subtle structural retinal differences and found associations between the retina and structural brain changes. Our objective is to investigate whether neuroretinal development in PHIV children is similar to the development in healthy matched controls and to explore associations with the brain structure. We measured RT using optical coherence tomography (OCT) on two occasions in 21 PHIV children or adolescents and 23 matched controls-all with good visual acuity-with a mean interval of 4.6 years (SD 0.3). We also included 22 participants (11 PHIV children and 11 controls) together with the follow-up group for a cross-sectional assessment using a different OCT device. Magnetic resonance imaging (MRI) was used to assess the white matter microstructure. We used linear (mixed) models to assess changes in RT and its determinants (over time), adjusting for age and sex. The development of the retina was similar between the PHIV adolescents and controls. In our cohort, we found that changes in the peripapillary RNFL was significantly associated with changes in WM microstructural makers: fractional anisotropy (coefficient = 0.030, p = 0.022) and radial diffusivity (coefficient = -0.568, p = 0.025). We found comparable RT between groups. A thinner pRNFL was associated with lower WM volume (coefficient = 0.117, p = 0.030). PHIV children or adolescents appear to have a similar development of the retinal structure. In our cohort, the associations between RT and MRI biomarkers underscore the relation between retina and brain.

Retinal Thinning in People With Well-Controlled HIV Infection

BACKGROUND

Retinal measurements correlate with disease progression in patients with multiple sclerosis; however, whether they associate with neurologic disease in people with controlled HIV is unknown. Using spectral domain optical coherence tomography, we evaluated retinal differences between people with HIV and HIV-negative controls and investigated clinical correlates of retinal thinning.

METHODS

People with HIV on antiretroviral therapy for at least 1 year and HIV-negative controls recruited from the same communities underwent spectral domain optical coherence tomography, ophthalmic examination, brain MRI, and neuropsychological testing. Retinal nerve fiber layer (RNFL) and ganglion cell inner plexiform layer (GC-IPL) thicknesses were compared between groups using analysis of covariance with relevant clinical variables as covariates. Linear regression was used to explore associations of HIV history variables, cognitive domain scores, and MRI volume measurements within the HIV group.

RESULTS

The HIV group (n = 69), with long-duration HIV infection (median time from diagnosis 19 years) and outstanding viral control have thinner retinal layers than HIV-negative controls (n = 28), after adjusting for covariates (GC-IPL: P = 0.002; RNFL: P = 0.024). The effect of HIV on GC-IPL thickness was stronger in women than in men (Women: P = 0.011; Men: P = 0.126). GC-IPL thickness is associated with information processing speed in the HIV group (P = 0.007, semipartial r = 0.309). No associations were found with retinal thinning and MRI volumes or HIV factors.

CONCLUSIONS

People with HIV on antiretroviral therapy have thinning of the RNFL and GC-IPL of the retina, and women particularly are affected to a greater degree. This retinal thinning was associated with worse performance on tests of information processing speed.

Macular Changes Observed on Optical Coherence Tomography Angiography in Patients Infected With Human Immunodeficiency Virus Without Infectious Retinopathy

Purpose

As the human immunodeficiency virus (HIV) pandemic is far from over, whether there are subclinical macular changes in HIV-positive patients is something that should not be overlooked. We aimed to apply optical coherence tomography angiography (OCTA) to assess the macular structure and microvasculature changes in patients with HIV without infectious retinopathy.

Methods

HIV-positive and -negative participants were included and classified into three groups: HIV-negative, HIV-positive, and HIV-positive with microvasculopathy. OCTA parameters regarding macular structure and microvasculature were analyzed.

Results

Compared with the HIV-negative group, the superficial retinal vessel density (VD) in the parafovea sectors and the whole Early Treatment of Diabetic Retinopathy Study (ETDRS) grid and the choroidal vascularity index (CVI) in the whole ETDRS grid were significantly decreased in the HIV-positive and HIV-positive with microvasculopathy groups (p < 0.05). No differences were found in OCTA parameters between the HIV-positive and HIV-positive with microvasculopathy groups. Retinal, retinal nerve fiber layer-ganglion cell layer-inner plexiform layer (RNFL-GCL-IPL), RNFL, GCL-IPL, and INL thickness showed a negative association with the duration of HIV diagnosis or antiretroviral therapy (ART) (all p < 0.05). All OCTA microvasculature parameters showed no association with HIV-related clinical variables (all p > 0.05).

Conclusions

Subclinical macular changes existed in HIV-infected patients without clinical infectious retinopathy. Substructures from inner retinal layers might be associated with HIV infection or ART duration.

The Integrity of Retinal Morphology in Non-immunocompromised People Living with HIV on Antiretroviral Therapy

SIGNIFICANCE

Non-immunocompromised people living with HIV (NIPLHIV) share a similar immunocompetence to non-HIV (HIV) people with an elevated cluster of differentiation 4 (CD4) count in the era of antiretroviral therapy (ART). This has reduced the incidence of HIV retinopathy, thus raising the question of the integrity of the retinal morphology in NIPLHIV with longer life expectancy.

PURPOSE

The study assessed the retinal thickness and volume of NIPLHIV without retinitis on ART and attempted to find associations with linear parameters of cerebral atrophy.

METHODS

The study was conducted at a public hospital in South Africa. All people living with HIV were on ART with CD4 counts above 350 cells/mm3 and viral loads less than 10,000 copies/mL. The Heidelberg Spectralis ocular coherence tomographer assessed the retinal thickness and volume for comparison between 30 NIPLHIV and 30 HIV-negative participants. A subset of the HIV group obtained a computed tomography scan to determine the bicaudate ratio and the sylvian fissure ratio to assess cerebral atrophy. Independent t tests were performed to identify differences in retinal thickness and volume. Multivariate linear regressions measured associations between retinal thickness and volume with cerebral atrophy.

RESULTS

The NIPLHIV group had a thicker mean global temporal subfields at Early Treatment Diabetic Retinopathy Study (ETDRS) 3 mm (P = .047) and ETDRS 6 mm (P = .03). The mean global temporal subfield volume at ETDRS 3 mm was also increased in the NIPLHIV group (P = .02). Nasal macula retinal nerve fiber layer thickness and the inferior inner nuclear layer macula volume were directly related to the bicaudate ratio, whereas the volumes at the outer retinal layer subfields of the macula were inversely related to sylvian fissure ratio in NIPLHIV.

CONCLUSIONS

Macula thickness and volumetric differences do exist in NIPLHIV. Practitioners should keep NIPLHIV under retinal morphometric surveillance because they live longer. Associations of cerebral atrophy with retinal morphology may be used to monitor cerebral atrophy in NIPLIV on ART.

THE THICKNESSES OF CHOROID, MACULAR SEGMENTS, PERIPAPILLARY RETINAL NERVE FIBER LAYER, AND RETINAL VASCULAR CALIBER IN HIV-1-INFECTED PATIENTS WITHOUT INFECTIOUS RETINITIS

PURPOSE

To evaluate choroidal, macular, peripapillary retinal nerve fiber layer (RNFL) thicknesses and retinal vascular caliber alterations in HIV-1-infected patients without opportunistic infections.

METHODS

This cross-sectional study included 45 HIV-1-infected patients and 47 healthy subjects. Spectral domain optical coherence tomography was used for assessment of choroidal, macular, peripapillary RNFL thicknesses and retinal vascular caliber alterations.

RESULTS

The mean CD4 count was 426 ± 226 cells per milliliter and the mean HIV-1 RNA level was 1.8 × 10 ± 3.6 × 10 copies/mL in HIV-infected group. Central inner plexiform, superior photoreceptor, superior and nasal retinal pigment epithelium layers were thinner in HIV-infected patients compared with control subjects (P < 0.05). The differences in sectoral retinal thicknesses lost their significance after Bonferroni correction (P < 0.01). The average thickness of pericentral retina within 3 mm was thinner in the photoreceptor layer in HIV-infected patients compared with control subjects (P = 0.033). The differences in peripapillary RNFL thickness, choroidal thickness, and retinal vascular caliber were not significant between the groups. Choroidal thickness and pericentral outer plexiform were thinner, whereas peripapillary RNFL was thicker in newly diagnosed cases (16 patients) compared with patients having treatment for at least 4 months or longer (27 patients, P < 0.05, Mann-Whitney U test). HIV-1 RNA showed negative correlation with choroidal thickness (r = -0.435, P = 0.003) and positive correlation with peripapillary RNFL in central (r = 0.323, P = 0.032) and superonasal (r = 0.369, P = 0.014) sectors.

CONCLUSION

Choroidal thickness was thinner in newly diagnosed patients compared with patients on treatment. Viral load showed negative correlation with choroidal thickness. Retinal segmental alterations occurred in HIV-infected patients compared with control subjects.

Factors Affecting Vision and Visio-Spatial Intelligence (VSI) in Sport: A Review of the Literature

: Sport has become increasingly competitive, prompting the need to determine, as far as possible, any likely performance advantage. While the focus of athletic research, testing, and training is on the physiological and physical characteristics of the sport, visual abilities not only affect sport performance directly, but also affect the acquisition of motor skills. Vision, and visual-spatial intelligence (VSI), are a relatively new and underexplored area of athletic performance. As with physiological and physical parameters, a range of factors affect vision and VSI in sporting activities. This review of the literature is a first attempt to summarize and compile an overview of the factors affecting vision and VSI in athletes, covering those previously connected with sport, as well as those hitherto not associated with athletic activities, but that could also play a part in sports performance. The evidence from this review suggests that while current research still tends to focus on single factors affecting vision and VSI, a large number of such factors have been identified that could affect vision and VSI. This offers new opportunities for researchers to investigate the effects of a combination of factors, and for conditioning and/or sports vision specialists to explore further possibilities for competitive advantage.

Absence of peripapillary retinal nerve-fiber-layer thinning in combined antiretroviral therapy-treated, well-sustained aviremic persons living with HIV

Purpose

To compare peripapillary retinal nerve-fiber–layer (pRNFL) thickness, total retina macular volume, and ganglion-cell-layer (GCL) macular volume and thickness between persons living with HIV (PLHIVs) with well-controlled infections and good immune recovery, and sex- and age-matched HIV-uninfected controls (HUCs).

Methods

This prospective cross-sectional study (www.clinicaltrials.gov identifier: NCT02003989) included 56 PLHIVs, infected for ≥10 [median 20.2] years and with sustained plasma HIV-load suppression on combined antiretroviral therapy (cART) for ≥5 years, and 56 matched HUCs. Participants underwent spectral-domain optical coherence tomography (SD-OCT) with thorough ophthalmological examinations and brain magnetic resonance imaging (MRI). Their overall and quadrant pRNFL thicknesses, total macular volumes, and GCL macular volumes and thicknesses were compared. Cerebral small-vessel diseases (CSVD) complied with STRIVE criteria.

Results

Median [interquartile range, IQR] ages of PLHIVs and HUCs, respectively, were 52 [46–60] and 52 [44–60] years. Median [IQR] PLHIVs’ nadir CD4+ T-cell count and current CD4/CD8 T-cell ratio were 249/μL [158–350] and 0.95 [0.67–1.10], respectively; HIV-seropositivity duration was 20.2 [15.9–24.5] years; cART duration was 16.8 [12.6–18.6] years; and aviremia duration was 11.4 [7.8–13.6] years. No significant between-group pRNFL thickness, total macular volume, macular GCL-volume and -thickness differences were found. MRI-detected CSVD in 21 (38%) PLHIVs and 14 (25%) HUCs was associated with overall thinner pRNFLs, and smaller total retina and GCL macular volumes, independently of HIV status.

Conclusions

SD-OCT could not detect pRNFL thinning or macular GCL-volume reduction in well-sustained, aviremic, cART-treated PLHIVs who achieved good immune recovery. However, CSVD was associated with thinner pRNFLs and GCLs, independently of HIV status.

Meibomian gland dropout is associated with immunodeficiency at HIV diagnosis: Implications for dry eye disease

AIM

To characterize anterior eye health and tear film characteristics in individuals with human immunodeficiency virus (HIV) undergoing anti-retroviral therapy.

METHODS

This cross-sectional study involved 35 adults, categorized as healthy controls (n = 18) or as HIV-positive patients (n = 17), with no history of opportunistic infection or current ocular fundus abnormalities. Participants underwent a comprehensive anterior eye assessment. Primary outcome measures were dry eye symptoms (Ocular Surface Disease Index survey), tear film osmolarity, and extent of meibomian gland dropout. Secondary outcomes measures were ocular redness, tear film stability, and ocular surface staining. Levels of 36 cytokines were assayed from basal tears using a multiplex bead array.

RESULTS

The HIV-positive group showed more extensive meibomian gland dropout relative to controls (mean ± SD, controls: 29.6 ± 5.8 versus 37.0 ± 13.9%, p = 0.045). The extent of meibomian gland dropout was negatively correlated with blood CD4 T-cell count (a marker of immunodeficiency) at diagnosis (r = -0.69, p = 0.006). All other tests of anterior ocular health, including dry eye symptom levels, were not significantly different between the groups. There were no significant inter-group differences for the 36 cytokines assayed in the tear film.

CONCLUSIONS

We find greater meibomian gland dropout in HIV-positive individuals that is related to disease severity at diagnosis. Given this feature predisposes to dry eye disease, it suggests the need for long-term studies of anterior eye health in people with HIV.

Endogenous endophthalmitis and other ocular manifestations of injection drug use

PURPOSE OF REVIEW

The United States has experienced a dramatic rise in opioid and injection drug use over the past 2 decades. A public health emergency was declared in 2017 and subsequently, there have been several new reports on the rise of endogenous endophthalmitis specifically associated with injection drug use. The purpose of this review is to provide a current perspective of the ocular harms posed by injection drug use.

RECENT FINDINGS

The opioid epidemic has prompted several new studies from New England, one of the US regions most heavily affected, that examine the trends and characteristics of injection drug use-associated endogenous endophthalmitis. Patients may delay seeking care and may be infected with a variety of rare and atypical microbes, and as a result clinical appearance may vary widely. Injection drug use also leads to embolic phenomena such as talc retinopathy and septic emboli from endocarditis. HIV is highly associated with injection drug use and although HAART has drastically reduced the morbidity and mortality of HIV-associated infections, a variety of ocular disease may accompany an immunocompromised patient.

SUMMARY

Healthcare providers must remain vigilant in the recognition of injection drug use patients with vision loss and ocular inflammation to ensure prompt medical and/or surgical treatment.

Retinal nerve fiber layer changes based on historic CD4 nadir among HIV positive patients undergoing glaucoma evaluation

AIM

To determine relationships between retinal nerve fiber layer (RNFL) thickness and nadir CD4 cell count in human immunodeficiency virus (HIV) positive patients evaluated for glaucoma suspicion.

METHODS

Data were reviewed for 329 HIV positive patients evaluated for glaucoma suspicion. High-definition optical coherence tomography (OCT) RNFL measurements were obtained at least 6mo apart. Analyses were performed to identify relationships between nadir CD4 count and RNFL thickness.

RESULTS

Totally 110 eyes of 55 patients met inclusion criteria, of which 46 eyes were from subjects with nadir CD4<200 cells/mm³ and 64 had nadir CD4≥200 cells/mm³. Patients with nadir CD4<200 cells/mm³ had significantly thicker superior (119.7±18.6 µm) and temporal (63.8±11.7 µm) quadrants at time of initial OCT compared to the superior (112.8±16.8 µm, P=0.048) and temporal (57.1±11.9 µm, P=0.004) quadrants of patients with higher nadir CD4. This trend toward thicker RNFL among subjects with lower nadir CD4 cell counts persisted at the time of follow up OCT where participants with nadir CD4<200 cells/mm³ showed average RNFL thickness in the superior and temporal quadrants of 117.9±18.3 µm and 63.8±12.8 µm, respectively, compared to a superior thickness of 110.5±16.9 µm (P=0.034) and temporal thickness of 57.3±11.6 µm (P=0.007) among those with higher nadir CD4.

CONCLUSION

Patients with lower nadir CD4 cell counts have thicker RNFL in the superior and temporal quadrants compared to those with higher nadir CD4 counts. RNFL thickness in HIV positive patients may be affected by historic HIV disease control and should be considered when evaluating HIV positive patients for glaucoma.

Visual Acuity Change Over 24 Months and Its Association With Foveal Phenotype and Genotype in Individuals With Stargardt Disease: ProgStar Study Report No. 10

Importance

Limited data from prospective studies are available to understand the natural history of ABCA4-related Stargardt disease (STGD1). Such data are important for determining appropriate outcome measures for future STGD1 trials.

Objective

To estimate the rate of loss of best-corrected visual acuity (BCVA) during 2 years and to estimate the associations of BCVA loss with foveal phenotype and genotype in patients with STGD1.

Design, Setting, and Participants

This multicenter prospective cohort study included 259 participants (489 study eyes) with molecularly confirmed STGD1 who were 6 years or older. The participants were enrolled at 9 centers in the United States and Europe and were followed up every 6 months for 2 years.

Exposures

Baseline BCVA and presence and type of foveal lesion (determined via fundus autofluorescence images) and genotype (classified into 4 groups based on the number and pathogenicity of ABCA4 mutations).

Main Outcomes and Measures

Rate of BCVA change per year.

Results

The mean (SD) age was 33 (15) years. Of 259 the participants, 141 (54%) were female, and 222 (85%) were white. The overall rate of BCVA loss was 0.55 (95% CI, 0.20-0.90) letters per year during the 2 years. Eyes with baseline BCVA worse than 20/200 showed an improvement of 0.65 (95% CI, 0.1-1.2) letters per year. At baseline, the mean BCVA for eyes without foveal lesion was 20/32, and their BCVA change rate over time was 0.1 (95% CI, -1.2 to 1.35) letters per year (P = .89). Eyes with a foveal lesion but having BCVA of 20/70 or better at baseline lost BCVA at a rate of 3 (95% CI, 1.5-4.4) letters per year (P < .001). Genotype was neither associated with baseline BCVA nor with the rate of BCVA change during the follow-up.

Conclusions and Relevance

A clinically small BCVA loss was observed during 2 years, and the change rate varied depending on baseline BCVA. Eyes without lesion in the fovea had better BCVA at baseline and showed minimal change of BCVA throughout 2 years. Eyes with no or modest acuity impairment but with a foveal lesion at baseline had the fastest loss rate. For trials of STGD1 with 2 years of duration, it may be difficult to show efficacy using BCVA as an end point owing to its slow rate of change over this time.

Characterization of cytokine gene expression associated with noninfectious human immunodeficiency virus retinopathy in human autopsy eyes

PURPOSE

The purpose of this study was to determine the cytokine-related pathogenesis of human immunodeficiency virus retinopathy in human autopsy eyes.

METHODS

Fresh autopsy eyes were procured from clinically diagnosed patients with acquired immunodeficiency syndrome who had died as a result of disease-related complications; eyes were immediately immersed in RNAlater. Clean 2-mm trephines were used to punch individual pathologic retina in areas of cotton-wool spots and control punches. Total RNA was extracted using the TRIzol extraction protocol, and the optimal density of the RNA was measured at an optical density of 260 nm. [Delta]Ct (cytokine) values were calculated using the comparative cytokine analysis method. The results are expressed as a mean fold modulation and as a statistical comparison of Ct values controlling for retinal areas without a lesion in the same eye.

RESULTS

The fold modulations and the statistical comparisons of the cytokines studied in tissues from cotton-wool spots and control retina, respectively, regulated on activation normal T cell expressed and secreted (RANTES), macrophage inflammatory protein 1beta, macrophage inflammatory protein 1alpha (5.32x, P = 0.04), and Bcl-2-associated X protein (1.24x, P = 0.05) had a marked elevation of fold modulation and were statistically significant compared with control tissue. Interleukin-8 (1.09x, P = 0.18), interleukin-4, and interleukin-10 (2.7x, P = 0.30) were not significantly expressed in cotton-wool spots.

CONCLUSION

Certain inflammatory human immunodeficiency virus-associated and apoptotic cytokines are expressed in cotton-wool spots in eyes with human immunodeficiency virus retinopathy.

Neuroretinal Degeneration in HIV Patients Without Opportunistic Ocular Infections in the cART Era

Subtle structural and functional retinal abnormalities, termed 'HIV-associated Neuroretinal Disorder (HIV-NRD)', have been reported in HIV patients receiving combination antiretroviral therapy (cART), without infectious retinitis or any apparent fundus abnormalities otherwise. In this review, we provide an overview of studies investigating HIV-NRD in HIV patients without opportunistic ocular infections in the cART era, and try to elucidate underlying mechanisms and associated risk factors. Most studies focused on patients with severe immune-deficiency and demonstrated that patients with nadir CD4 counts<100 cells/μL are most at risk for neuroretinal damage, with a thinner retinal nerve fiber layer, subtle loss of color vision and/or contrast sensitivity, visual field deficits, and subnormal electrophysiological responses. In contrast, alterations in retinal vascular calibers and retinal blood flow were not associated with nadir CD4 counts, but instead with detectable viremia, suggesting a role for (chronic) inflammation in microvascular damage. Although the alterations in visual function are subtle, they can lead to difficulties in activities, such as reading or driving, thereby affecting quality of life. Since HIV has become a chronic disease, its long-term effects with respect to visual function loss become more important, as is recently emphasized by a longitudinal study, reporting that AIDS patients with HIV-NRD have higher risks of developing bilateral visual impairment and even blindness than patients without HIV-NRD. The question remains whether patients with high (>350 cells/μL) nadir CD4 counts and well-suppressed HIV infection on cART remain at risk for HIV-NRD, as this group constitutes a growing part of the aging HIV-infected population.

Retinal Nerve Fiber and Optic Disc Morphology in Patients with Human Immunodeficiency Virus Using the Heidelberg Retina Tomography 3

PURPOSE

To use novel confocal scanning ophthalmoscopy technology to test hypothesis that HIV-seropositive patients without history of retinitis with a history of a low CD4 count are more likely to have damage to their retinal nerve fiber layer (RNFL) when compared to patients with high CD4 count. In addition, we compared optic disc morphologic changes with glaucoma.

DESIGN

Cross-sectional study.

PARTICIPANTS AND CONTROLS

171 patients were divided into four groups. The control group consisted of 40 eyes of 20 HIV-seronegative patients. The second group consisted of 80 eyes of 41 HIV-positive patients whose CD4 cell count never dropped below 100 (1.0 x 10(9)/L). The third group consisted of 44 eyes of 26 HIV-positive patients with a history of low CD4 counts <100. Fourth group consisted of 79 eyes of 79 patients with confirmed glaucoma who served as positive controls.

TESTING

Confocal scanning laser ophthalmoscopy was performed with the Heidelberg Retina Tomograph (HRT3) and data were analyzed with HRT3, software (Heyex version 1.5.10.0).

MAIN OUTCOME MEASURES

Disc area, cup area, cup volume, rim volume, mean cup depth, maximum cup depth, cup-to-disc ration, mean RNFL thickness, and RNFL cross-sectional area.

RESULTS

Analysis of the global optic nerve and cup parameters showed no difference in disk area among the four groups. There was also no difference in cup, rim volume, mean cup depth, or maximum cup depth among the first three groups but they were all different from glaucoma group. The RNFL was thinner in glaucoma and both HIV-positive groups compared to HIV-seronegative subjects. The cross sectional RNFL area was thinner in both high and low CD4 HIV-positive groups compared to HIV-seronegative group in the nasal and temporal/inferior sectors, respectively. Glaucoma group showed thinning in all sectors.

CONCLUSIONS

HIV retinopathy results in retinal nerve fiber layer loss without structural optic nerve supportive tissue change. RNFL damage may occur early in HIV disease by mechanism different than in glaucoma.

Retinal Thickening and Photoreceptor Loss in HIV Eyes without Retinitis

Purpose

To determine the presence of structural changes in HIV retinae (i.e., photoreceptor density and retinal thickness in the macula) compared with age-matched HIV-negative controls.

Methods

Cohort of patients with known HIV under CART (combination Antiretroviral Therapy) treatment were examined with a flood-illuminated retinal AO camera to assess the cone photoreceptor mosaic and spectral-domain optical coherence tomography (SD-OCT) to assess retinal layers and retinal thickness.

Results

Twenty-four eyes of 12 patients (n = 6 HIV-positive and 6 HIV-negative) were imaged with the adaptive optics camera. In each of the regions of interest studied (nasal, temporal, superior, inferior), the HIV group had significantly less mean cone photoreceptor density compared with age-matched controls (difference range, 4,308–6,872 cones/mm²). A different subset of forty eyes of 20 patients (n = 10 HIV-positive and 10 HIV-negative) was included in the retinal thickness measurements and retinal layer segmentation with the SD-OCT. We observed significant thickening in HIV positive eyes in the total retinal thickness at the foveal center, and in each of the three horizontal B-scans (through the macular center, superior, and inferior to the fovea). We also noted that the inner retina (combined thickness from ILM through RNFL to GCL layer) was also significantly thickened in all the different locations scanned compared with HIV-negative controls.

Conclusion

Our present study shows that the cone photoreceptor density is significantly reduced in HIV retinae compared with age-matched controls. HIV retinae also have increased macular retinal thickness that may be caused by inner retinal edema secondary to retinovascular disease in HIV. The interaction of photoreceptors with the aging RPE, as well as possible low-grade ocular inflammation causing diffuse inner retinal edema, may be the key to the progressive vision changes in HIV-positive patients without overt retinitis.

Spectral domain optical coherence tomography in the evaluation and management of infectious retinitis

PURPOSE

To describe spectral domain optical coherence tomography (SD-OCT) findings of infectious retinitis, including affected layer of retinal involvement, changes at the vitreoretinal interface, and response to therapy.

METHODS

Observational case series. A retrospective review of five patients with infectious retinitis: one with toxoplasmosis, three with herpetic retinitis secondary to cytomegalovirus, and one with herpetic retinitis secondary to varicella zoster virus. Each patient underwent a complete ophthalmologic examination, fundus photography, and SD-OCT imaging (Heidelberg Spectralis; Heidelberg Engineering, Heidelberg, Germany) of the affected retina at the initial visit with serial fundus photography and SD-OCT imaging at follow-up visits. Approval was obtained from the Institutional Review Board of Northwestern University.

RESULTS

Spectral domain ocular coherence tomography of retinitis associated with Toxoplasma, cytomegalovirus, or varicella zoster virus demonstrates full-thickness disruption of the retinal architecture and overall thickening. This was in contrast to clinically imitating lesions such as cotton-wool spots, which only showed focal swelling of the inner retina. There was a clear demarcation between the area of active retinitis and unaffected retina. Inactivity was apparent when the previously affected thickened area became atrophic. The SD-OCT also demonstrated changes at the vitreoretinal interface where there was frequently a detachment of the posterior hyaloid (four of five cases) associated with overlying vitreous debris and formation of tractional changes. In the case of varicella zoster virus retinitis, this traction subsequently led to a total retinal detachment.

CONCLUSION

In the assessment of infectious retinitides, SD-OCT is a helpful adjunct to clinical examination and fundus photography. It provides high-resolution detail regarding the border of infectious activity, the vitreoretinal interface, and the differentiation of lesions that can clinically mimic active retinitis. Serial SD-OCT also provides further insight into response to therapy and postinfectious retinal changes by highlighting areas that are at greater risk for complications such as retinal detachment.

Incidence and long-term outcomes of the human immunodefıciency virus neuroretinal disorder in patients with AIDS

PURPOSE

Patients with AIDS have an abnormality of retina/optic nerve function, manifested as decreased contrast sensitivity (in the absence of ocular opportunistic infections or media opacity), abnormalities on automated perimetry, and loss of retinal nerve fiber layer, even among those with good visual acuity, termed the "human immunodeficiency virus (HIV) neuroretinal disorder." The objectives of this study were to determine the prevalence, incidence, risk factors, and outcomes of HIV neuroretinal disorder.

DESIGN

Prospective cohort study.

PARTICIPANTS

A total of 1822 patients with AIDS without ocular infections or media opacities.

METHODS

Patients with HIV neuroretinal disorder were identified by a contrast sensitivity <1.50 log units in either eye in the absence of ocular opportunistic infections or media opacity.

MAIN OUTCOME MEASURES

Incidence of HIV neuroretinal disorder, mortality, visual impairment (visual acuity ≤20/50), and blindness (≤20/200) on logarithmic visual acuity charts.

RESULTS

Sixteen percent of participants had HIV neuroretinal disorder at enrollment. The estimated cumulative incidence by 20 years after AIDS diagnosis was 51% (95% confidence interval [CI], 46-55). Human immunodeficiency virus neuroretinal disorder was more common in women and African Americans. Risk factors for HIV neuroretinal disorder included hepatitis C infection, low CD4+ T cells, and detectable HIV RNA in the blood. Patients with HIV neuroretinal disorder had a 70% excess mortality versus those without it, even after adjusting for CD4+ T cells and HIV load (hazard ratio [HR], 1.7; 95% CI, 1.3-2.1; P < 0.0001). Patients with HIV neuroretinal disorder had increased risks of bilateral visual impairment (HR, 6.5; 95% CI, 2.6-10.6; P < 0.0001) and blindness (HR, 5.9; 95% CI, 2.8-13.7; P = 0.01) versus those without HIV neuroretinal disorder.

CONCLUSIONS

Human immunodeficiency virus neuroretinal disorder is a common finding among patients with AIDS, and it is associated with an increased mortality and an increased risk of visual impairment. Successful antiretroviral therapy decreases but does not eliminate the risk of HIV neuroretinal disorder.

Visual function assessment in simulated real-life situations in HIV-infected subjects

Visual function abnormalities are common in people living with HIV disease (PLWH) without retinitis, even after improvement in immune status. Abnormalities such as reduced contrast sensitivity, altered color vision, peripheral visual field loss, and electrophysiological changes are related to a combination of retinal dysfunctions, involving inner and outer retinal structures. The standard protocol for testing vision performance in clinical practice is the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. However, this method poorly correlates with activities of daily living that require patients to assess visual stimuli in multiple light/contrast conditions, and with limited time. We utilized a novel interactive computer program (Central Vision Analyzer) to analyze vision performance in PLWH under a variety of light/contrast conditions that simulate stressful and real-world environments. The program tests vision in a time-dependent way that we believe better correlates with daily living activities than the non-timed ETDRS chart. We also aimed to correlate visual scores with retinal neuro-fiber layer thickness on optical coherence tomography. Here we show that visual acuity is more affected in PLWH in comparison to HIV-seronegative controls in varying contrast and luminance, especially if the nadir CD4+ T-cell count was lower than 100 cells/mm³. Visual impairment reflects the loss of retinal nerve fiber layer thickness especially of the temporal-inferior sector. In PLWH the ETDRS chart test led to better visual acuity compared to the Central Vision Analyzer equivalent test, likely because patients had indefinite time to guess the letters. This study confirms and strengthens the finding that visual function is affected in PLWH even in absence of retinitis, since we found that the HIV serostatus is the best predictor of visual loss. The Central Vision Analyzer may be useful in the diagnosis of subclinical HIV-associated visual loss in multiple light/contrast conditions, and may offer better understanding of this entity called “neuroretinal disorder”.

Retinal nerve fibre layer thickness and contrast sensitivity in HIV-infected individuals in South Africa: a case-control study

Background

Antiretroviral treatment (ART) has altered the spectrum of HIV-related eye disease, resulting in a lower prevalence of retinal opportunistic infections (OIs). However, abnormalities in visual function have been reported in HIV-infected individuals despite effective viral suppression and the absence of retinal OIs. These changes may be mediated by an HIV-associated ‘neuroretinal disorder’, characterized by changes in the retinal nerve fibre layer (RNFL). HIV infection may also be associated with accelerated biological aging. The aim of this study was to investigate the relationships between contrast sensitivity, RNFL thickness, HIV infection and frailty in South African adults.

Methods

Case-control study of 225 HIV-infected individuals without retinal OIs and 203 gender/age-matched HIV-seronegative individuals. Peri-papillary RNFL thickness was determined with spectral domain optical coherence tomography in four quadrants. CS was measured using a Pelli-Robson chart. Frailty was assessed using standard criteria. Multivariable linear and logistic regression were used to assess associations between HIV status and RNFL/CS and frailty.

Results

The median age of both groups was similar (41.2 vs. 41.9 years, p = 0.37). 88% of HIV-infected individuals were receiving ART and their median CD4 count was 468 cells/μl. Adjusted CS score was lower in HIV-infected participants compared to HIV-seronegative individuals (1.76 vs. 1.82, p = 0.002). Independent predictors of poor CS in the HIV-infected group were positive frailty status and current HIV viral load >2 log copies/ml. Lower CS score was also associated with thin temporal RNFL in HIV-infected individuals (p = 0.04). Superior quadrant RNFL thickness was greatest in ART-naïve participants relative to the HIV-uninfected group (p-trend = 0.04). Longer ART duration was associated with thinning of inferior and nasal RNFL quadrants (p-trend = 0.03 and 0.04, respectively).

Conclusions

Contrast sensitivity is reduced in HIV-infected individuals and functionally associated with frailty and unsuppressed viraemia. This may reflect structural changes in the RNFL that are evident despite the absence of OIs.

A degenerative retinal process in HIV-associated non-infectious retinopathy

HIV retinopathy is the most common non-infectious complication in the eyes of HIV-positive individuals. Oncotic lesions in the retinal nerve fiber layer, referred to as cotton wool spots (CWS), and intraretinal (IR) hemorrhages are frequently observed but are not unique to this pathology. HIV-positive patients have impaired color vision and contrast sensitivity, which worsens with age. Evidence of inner-retinal lesions and damage have been documented ophthalmoscopically, however their long term structural effect has not been investigated. It has been hypothesized that they may be partially responsible for loss of visual function and visual field. In this study we utilized clinical data, retinal imaging and transcriptomics approaches to comprehensively interrogate non-infectious HIV retinopathy. The methods employed encompassed clinical examinations, fundus photography, indirect ophthalmoscopy, Farmsworth-Munsell 100 hue discrimination testing and Illumina BeadChip analyses. Here we show that changes in the outer retina, specifically in the retinal pigment epithelium (RPE) and photoreceptor outer segments (POS) contribute to vision changes in non-infectious HIV retinopathy. We find that in HIV-positive retinae there is an induction of rhodopsin and other transcripts (including PDE6A, PDE6B, PDE6G, CNGA1, CNGB1, CRX, NRL) involved in visual transduction, as well as structural components of the rod photoreceptors (ABCA4 and ROM1). This is consistent with an increased rate of renewal of rod outer segments induced via increased phagocytosis by HIV-infected RPE previously reported in culture. Cone-specific transcripts (OPN1SW, OPN1LW, PDE6C, PDE6H and GRK7) are uniformly downregulated in HIV positive retina, likely due to a partial loss of cone photoreceptors. Active cotton wool spots and intraretinal hemorrhages (IRH) may not affect photoreceptors directly and the interaction of photoreceptors with the aging RPE may be the key to the progressive vision changes in HIV-positive patients.

The eye as a model of ageing in translational research--molecular, epigenetic and clinical aspects

The eye and visual system are valuable in many areas of translational research such as stem cell therapy, transplantation research and gene therapy. Changes in many ocular tissues can be measured directly, easily and objectively in vivo (e.g. lens transparency; retinal blood vessel calibre; corneal endothelial cell counts) and so the eye may also be a uniquely useful site as a model of ageing. This review details cellular, molecular and epigenetic mechanisms related to ageing within the eye, and describes ocular parameters that can be directly measured clinically and which might be of value in ageing research as the translational "window to the rest of the body". The eye is likely to provide a valuable model for validating biomarkers of ageing at molecular, epigenetic, cellular and clinical levels. A research agenda to definitively establish the relationship between biomarkers of ageing and ocular parameters is proposed.

Optic nerve head morphology and visual field function in patients with AIDS and without infectious retinitis

PURPOSE

To evaluate morphology of the optic nerve head and visual field in AIDS patients without retinitis.

METHODS

One randomly selected eye from 246 patients with AIDS without retinitis was evaluated from prospective multicenter Longitudinal Studies of Ocular Complications of AIDS. Stereo fundus photographs of OHN and serial VF data over 5-years were analyzed. Main outcomes included vertical cup-to-disc ratio (CDR), mean deviation, and pattern standard deviation scores on VF testing.

RESULTS

The median CDR was 0.39 at enrollment and 0.40 at 5-year follow-up. An unadjusted linear regression model revealed a mean change in CDR of 0.004 after 5-years (P = 0.04). After adjustment for practice effect, there were no statistically significant changes in VF performance observed during the 5 years of follow-up.

CONCLUSIONS

We detected clinically minimal, but statistically significant changes in ONH morphology and no change in VF performance among eyes of patients with AIDS and without retinitis.

Association between retinal nerve fiber layer thickness and abnormalities of vision in people with human immunodeficiency virus infection

PURPOSE

To investigate relationships between contrast sensitivity (CS), color vision, and retinal nerve fiber layer (RNFL) among people with human immunodeficiency virus (HIV) infection; to evaluate the effect of time since diagnosis of HIV infection on RNFL thickness.

DESIGN

Noninterventional cross-sectional study.

METHODS

We evaluated 102 eyes of 57 HIV-infected individuals without ocular opportunistic infections. Peripapillary RNFL thickness was determined with spectral-domain optical coherence tomography in 4 quadrants. CS was measured with the Pelli-Robson technique (expressed as logCS); color vision was measured with the Lanthony desaturated 15-hue technique (expressed as color confusion index [C-index], with higher scores indicating worse color vision). Correlations between values were assessed using Spearman correlation coefficients.

RESULTS

Median RNFL thickness (average of 4 quadrants) was 102.9 μm (range, 75.0-134.7 μm). Median logCS was 1.90 (range, 1.25-1.95). Median C-index was 1.58 (range, 0.96-4.07). Temporal RNFL thickness was correlated with logCS (r=0.295, P=.003) and C-index (r=-0.338, P=.0005). Time since diagnosis of HIV infection was shorter for those with thick average RNFL than for those with thin average RNFL (P=.18).

CONCLUSIONS

Both worse CS and worse color vision are correlated with thinning of the temporal RNFL, with possible threshold effects. Increased prevalences of abnormal CS and abnormal color vision in this population are therefore likely attributable to neuroretinal compromise. This pattern of structural and functional losses may reflect preferential damage to small-caliber axons in the maculopapillary bundle, possibly associated with mitochondrial dysfunction, providing a potential disease mechanism for HIV-associated "neuroretinal disorder."

Human immunodeficiency virus and its effects on the visual system

During the first 15 years of the AIDS epidemic patients experienced a high incidence of blindness due to cytomegalovirus (CMV) retinitis and other severe ocular opportunistic infections. Highly active anti-retroviral therapy, introduced in 1996, dramatically decreased the incidence of CMV retinitis. Though CMV retinitis still causes 40% of vision loss in AIDS patients, other conditions such as immune reconstitution uveitis, cataracts, and a significant othercategory -which most investigators believe is directly due to HIV - comprise the majority of cases. HIV causes vascular abnormalities of the conjunctiva and retina in the majority of AIDS patients, as well as retinitis, anterior and posterior uveitis and vasculitis. HIV frequently causes an optic neuropathy and is responsible for the majority of eye movement disorders among HIV patients. Physicians need to be aware that these problems may be the initial manifestation of HIV infections or a sign of highly active anti-retroviral therapy (HAART) failure. Therefore, patients with identifiable risk factors for AIDS who present with ophthalmologic conditions of unknown etiology should be considered for HIV testing. Finally, anti-retroviral therapy has been reported to cause asymptomatic deposits as well as degenerative conditions of both the anterior and posterior segments of the eye.

Relationship between retinal nerve fiber layer thickness and driving ability in patients with human immunodeficiency virus infection

BACKGROUND

The aim of this work is to study the possible association between retinal nerve fiber layer (NFL) thickness and driving ability.

METHODS

Thirty-eight drivers including 22 HIV-positive (HIV+) and 16 age-matched HIV-negative controls participants underwent a full ophthalmologic evaluation, including assessment of retinal NFL thickness. In the undilated state with standard optical correction and under standard illumination they also completed a computer-based, wide field-of-view driving simulation in which they were to obey traffic laws, engage in crash avoidance, and pass slower automobiles. Crashes, speeding and traffic light tickets, and off-road excursions contributed to a weighted score of driving errors.

RESULTS

HIV-seropositive participants had a significantly higher weighted error score than control participants (18.4 [9.2] vs. 11.1 [4.5], p = 0.006). NFL thickness was significantly correlated with driving errors (r = -0.51, p = 0.025); there was a trend for participants with a CD4 nadir <100 to have more errors than those with a nadir >100 (29.7 [13.2] vs. 19.3 [8.4], p = 0.056). The highest number of driving errors occurred in individuals with both CD4 <100 and NFL thickness <80.

CONCLUSIONS

Driving ability may be impacted by reductions in retinal nerve fiber layer thickness. Physicians should consider the potential impact that more complex ophthalmologic conditions in HIV-infected patients may have on driving performance.

Pathogenesis and treatment of human immunodeficiency virus-associated cytomegalovirus retinitis

In the era of HAART, human cytomegalovirus (HCMV) retinitis remains the leading opportunistic ocular infection and the major cause of blindness in patients with AIDS. The virus has been subjected to selection and presented with the opportunity to occupy a niche to which it is highly adapted in order to escape from host immune recognition and establish persistent infection in the retina. The imbalance between host immune protection and viral immune evasion results in retinitis progression. Moreover, a synergistic interaction between HCMV and HIV in the pathogenesis of retinitis has been proposed. HAART has had a major beneficial impact on the prognosis for HIV-infected individuals. Both HAART and specific anti-HCMV treatment contribute to therapeutic success against HCMV retinitis in AIDS patients. The improved prognosis for AIDS patients with respect to the development of HCMV retinitis has been welcomed; however, we should bear in mind the occurrence of HIV drug resistance, relapse of retinitis and immune recovery uveitis after treatment, which mean that this complication of HIV infection remains a threat.

[Visual function evaluation in human immunodeficiency virus carriers]

OBJECTIVE

To determine whether there are changes in the peripapillary nerve fibre layer, in colour vision, contrast sensitivity, dark adaptation and electroretinography changes in these patients who do not have infectious retinitis.

METHODS

We studied 52 patients without ocular pathology; the mean age was 35.88 years old.

RESULTS

We observed less thickness in all quadrants, except the nasal. The colour vision was altered in 27.77% of the patients. The contrast sensitivity test showed high frequency alterations. There was no statistically significant difference in the electroretinography test or in dark adaptation.

CONCLUSIONS

There are changes in the peripapillary nerve fibre layer thickness; also we found changes in colour vision, contrast sensitivity and a decreasing trend of the B wave in the electroreninogram.

Pattern recognition can detect subtle field defects in eyes of HIV individuals without retinitis under HAART

Objectives

To use machine learning classifiers (MLCs) to seek differences in visual fields (VFs) between normal eyes and eyes of HIV+ patients; to find the effect of immunodeficiency on VFs and to compare the effectiveness of MLCs to commonly-used Statpac global indices in analyzing standard automated perimetry (SAP).

Methods

The high CD4 group consisted of 70 eyes of 39 HIV-positive patients with good immune status (CD4 counts were never <100/ml). The low CD4 group had 59 eyes of 38 HIV-positive patients with CD4 cell counts <100/ml at some period of time lasting for at least 6 months. The normal group consisted of 61 eyes of 52 HIV-negative individuals. We used a Humphrey Visual Field Analyzer, SAP full threshold program 24-2, and routine settings for evaluating VFs. We trained and tested support vector machine (SVM) machine learning classifiers to distinguish fields from normal subjects and high and CD4 groups separately. Receiver operating characteristic (ROC) curves measured the discrimination of each classifier, and areas under ROC were statistically compared.

Results

Low CD4 HIV patients: with SVM, the AUROC was 0.790 ± 0.042. SVM and MD each significantly differed from chance decision, with p < .00005. High CD4 HIV patients: the SVM AUROC of 0.664 ± 0.047 and MD were each significantly better than chance (p = .041, p = .05 respectively).

Conclusions

Eyes from both low and high CD4 HIV+ patients have VFs defects indicating retinal damage. Generalized learning classifier, SVM, and a Statpac classifier, MD, are effective at detecting HIV eyes that have field defects, even when these defects are subtle.

Structural and functional assessment in HIV-infected patients using optical coherence tomography and frequency-doubling technology perimetry

PURPOSE

To assess retinal nerve fiber layer (RNFL) and macular thickness using optical coherence tomography (OCT) on HIV-infected patients without ocular manifestations and to correlate these findings with frequency-doubling technology perimetry (FDT).

DESIGN

Cross-sectional study.

METHODS

setting: Single center. study population: Seventy-three patients (146 eyes) with clinically normal examination classified in 3 groups: group A, HIV-infected patients with CD4 count <100 cells/mm(3) for at least 6 months; group B, HIV-infected patients with CD4 count >100 cells/mm(3) since diagnosis; and group C, HIV-negative control subjects. observation procedures: Fast RNFL and fast macula scan strategies on Stratus OCT and Humphrey Matrix 24-2 full-threshold program. main outcome measures: OCT RNFL and macular thicknesses and FDT indices (mean deviation [MD], pattern standard deviation [PSD], and glaucoma hemifield test [GHT]).

RESULTS

Group A had a significantly thinner average RNFL, temporal outer macula, and inferior outer macula thicknesses when compared to groups B and C (P < .05). Statistically significant differences were observed in the FDT MD between groups A and C (P = .034) and in PSD in group A compared to groups B and C (P = .011). Eyes of HIV patients with GHT and PSD results outside normal confidence limits had thinner average RNFL thickness measures than eyes with results within normal limits in the same group of patients (P < .05).

CONCLUSIONS

HIV-infected patients with low CD4 count have a significant RNFL and macular thinning. Functional loss detected by FDT is related to RNFL thinning in HIV-infected patients.

Imaging of long-term retinal damage after resolved cotton wool spots

PURPOSE

Patients infected with the human immunodeficiency virus (HIV) develop noninfectious retinopathy characterized by retinal cotton wool spots (CWS) and microvascular abnormalities. Ophthalmoscopically, CWS fade with time. We hypothesized that structural changes should be permanent and possibly visible well after ophthalmoscopic resolution. We used simultaneous spectral domain optical coherence tomography (SD-OCT)/scanning laser ophthalmoscope (SLO) to allow colocalization of the lesions and determine the extent and location of residual damage after ophthalmoscopic resolution of the lesions.

DESIGN

Retrospective, noninterventional case series.

PARTICIPANTS

Eight eyes of 7 HIV patients with 19 resolved retinal CWS.

METHODS

Nineteen retinal CWS were imaged between 2 and 16 years (median, 7.84) after the acute lesions using simultaneous SD-OCT and SLO examinations. The areas of the previous CWS were scanned by overlaying the color retinal image over the SLO image and scanning at high resolution in the horizontal plane through the resolved lesion. Each CWS lesion had a control area taken from the same eye within 2 disc diameters of the lesion. The thickness of each of the retinal layers was compared between lesions and control areas using a paired t-test with multitest correction.

MAIN OUTCOME MEASURES

Thickness of the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL).

RESULTS

The greatest loss of thickness was seen in the retinal GCL with a 43% reduction in thickness. There was a statistically significant thinning of the RNFL, GCL, IPL, INL, and OPL. The median thickness differences ranged from 5 to 7 microns. This difference was highly significant. Another striking finding was the displacement of the ONL toward the retinal surface resulting in an apparent increase in thickness of the ONL by >15% (median difference, 12 microns).

CONCLUSIONS

Our data, using ultrahigh resolution and high-speed SD-OCT/SLO, show and quantify the presence of permanent retinal destruction associated with retinal CWS in HIV disease.

Multifocal electroretinography in HIV-positive patients without infectious retinitis

PURPOSE

To evaluate early changes in the central retinal response in human immunodeficiency virus (HIV)-positive patients without infectious retinitis using multifocal electroretinography (mfERG).

DESIGN

Case control study.

METHODS

We evaluated three cohorts: HIV-negative controls and two groups of HIV-positive patients separated according to their nadir CD4 counts (>or= 100 cells/mm(3) and < 100 cells/mm(3) for a minimum of six months). mfERG first-order kernels (FOKs) and second-order kernels (SOKs) were analyzed separately by areas of rings, quadrants, and individual hexagons for each cohort.

RESULTS

Of 103 hexagon locations of FOK results, there were no significant differences in amplitudes of P1 and N1 across the groups (.05 < P < .50), although there was a trend for an overall reduction in the amplitudes. Similarly, latency N1 did not differ (.28 < P < .95). There were significantly delayed latencies of P1 between cohorts across 103 hexagons in both kernels. SOK results also showed significant delay in latencies of P1 and a trend of reduced P1 amplitudes across studied locations among cohorts (.24 < P < .08).

CONCLUSIONS

The results demonstrate widespread delay in latency in HIV-positive patients, especially in those with prolonged low (below 100 cells/mm(3)) CD4 nadir counts. These findings suggest early diffuse dysfunction of the inner retina results from severe HIV disease even in the HAART era.

Vision function in HIV-infected individuals without retinitis: report of the Studies of Ocular Complications of AIDS Research Group

PURPOSE

To evaluate the prevalence and risk factors for vision loss in patients with clinical or immunologic AIDS without infectious retinitis.

DESIGN

A prospective, multicenter cohort study of patients with AIDS.

METHODS

One thousand three hundred and fifty-one patients (2,671 eyes) at 19 clinical trials centers diagnosed with AIDS but without major ocular complications of HIV. Standardized measurements of visual acuity, automated perimetry, and contrast sensitivity were analyzed and correlated with measurements of patients' health and medical data relating to HIV infection. We evaluated correlations between vision function testing and HIV-related risk factors and medical testing.

RESULTS

There were significant (P<.05) associations between measures of decreasing vision function and indices of increasing disease severity, including Karnofsky score and hemoglobin. A significant relationship was seen between low-contrast sensitivity and decreasing levels of CD4+ T-cell count. Three percent of eyes had a visual acuity worse than 20/40 Snellen equivalents, which was significantly associated with a history of opportunistic infections and low Karnofsky score. When compared with external groups with normal vision, 39% of eyes had abnormal mean deviation on automated perimetry, 33% had abnormal pattern standard deviation, and 12% of eyes had low contrast sensitivity.

CONCLUSIONS

This study confirms that visual dysfunction is common in patients with AIDS but without retinitis. The most prevalent visual dysfunction is loss of visual field; nearly 40% of patients have some abnormal visual field. There is an association between general disease severity and less access to care and vision loss. The pathophysiology of this vision loss is unknown but is consistent with retinovascular disease or optic nerve disease.

Analysis with support vector machine shows HIV-positive subjects without infectious retinitis have mfERG deficiencies compared to normal eyes

PURPOSE

To test the following hypotheses: (1) eyes from individuals with human immunodeficiency virus (HIV) have electrophysiologic abnormalities that manifest as multifocal electroretinogram (mfERG) abnormalities; (2) the retinal effects of HIV in immune-competent HIV individuals differ from the effects in immune-incompetent HIV individuals; (3) strong machine learning classifiers (MLCs), like support vector machine (SVM), can learn to use mfERG abnormalities in the second-order kernel (SOK) to distinguish HIV from normal eyes; and (4) the mfERG abnormalities fall into patterns that can be discerned by MLCs. We applied a supervised MLC, SVM, to determine if mfERGs in eyes from patients with HIV differ from mfERGs in HIV-negative controls.

METHODS

Ninety-nine HIV-positive patients without visible retinopathy were divided into 2 groups: (1) 59 high-CD4 individuals (H, 104 eyes), 48.5 +/- 7.7 years, whose CD4 counts were never observed below 100, and (2) 40 low-CD4 individuals (L, 61 eyes), 46.2 +/- 5.6 years, whose CD4 counts were below 100 for at least 6 months. The normal group (N, 82 eyes) had 41 age-matched HIV-negative individuals, 46.8 +/- 6.2 years. The amplitude and latency of the first positive curve (P1, hereafter referred to as a) and the first negative curve (N1, referred to as b) in the SOK of 103 hexagon patterns of the central 28 degrees of the retina were recorded from the eyes in each group. SVM was trained and tested with cross-validation to distinguish H from N and L from N. SOK was chosen as a presumed detector of inner retinal abnormalities. Classifier performance was measured with the area under the receiver operating characteristic (AUROC) curve to permit comparison of MLCs. Improvement in performance and identification of subsets of the most important features were sought with feature selection by backward elimination.

RESULTS

In general, the SOK b-parameters separated L from N and H from N better than a-parameters, and latency separated L from N and H from N better than amplitude. In the HIV groups, on average, amplitude was diminished and latency was extended. The parameter that most consistently separated L from N and H from N was b-latency. With b-latency, SVM learned to distinguish L from N (AUROC = 0.7.30 +/- 0.044, P = .001 against chance [0.500 +/- 0.051]) and H from N (0.732 +/- 0.038, P = .0001 against chance) equally well. With best-performing subsets (21 out of 103 hexagons) derived by backward elimination, SVM distinguished L from N (0.869 +/- 0.030, P < .00005 against chance) and H from N (0.859 +/- 0.029, P <.00005 against chance) better than SVM with the full set of hexagons. Mapping the top 10 hexagon locations for L vs N and H vs N produced no apparent pattern.

CONCLUSIONS

This study confirms that mfERG SOK abnormalities develop in the retina of HIV-positive individuals. The new finding of equal severity of b-latency abnormalities in the low- and high-CD4 groups indicates that good immune status under highly active antiretroviral therapy may not protect against retinal damage and, by extension, damage elsewhere. SOKs are difficult for human experts to interpret. Machine learning classifiers, such as SVM, learn from the data without human intervention, reducing the need to rely on human skills to interpret this test.

What you can see in your patient's eyes? Review of ocular manifestations of HIV in HAART era

The early diagnosis and treatment of ocular disease to prevent morbidity and mortality of patients with human immunodeficiency virus (HIV) is of paramount importance. Since the advent of highly active antiretroviral therapy (HAART), the incidence of ocular complications of HIV has decreased and their manifestations and natural course are also modified. This has been observed in the face of emerging immune recovery, which per se has brought new difficulties in the process of diagnosing and management of the ocular disease. Conditions such as immune recovery uveitis could affect eyes with history of opportunistic disease with a potential to cause vision loss; with this regard, differentiation of the inflammatory process from infective causes is essential. The other sexually contracted diseases are also to be included in this complex picture because of their contribution to the clinical picture and also sharing common routes of transmission with HIV. There is very little doubt that visual deterioration would further deteriorate the already compromised quality of life of this group of patients. In this review, authors wish to provide evidence available in the medical literature around the visual health issues in HIV-infected patients and raise awareness towards the changing pattern of the ocular disease in the HAART era.

Objective analysis of retinal function in HIV-positive children without retinitis using optical coherence tomography

PURPOSE

To assess the retinal nerve fiber layer thickness in children with human immunodeficiency virus disease without cytomegalovirus retinitis or visual symptoms.

METHODS

Thirty-eight eyes of 19 human immunodeficiency virus-positive children (group A) with visual acuity of 20/20 or better, normal color vision testing and no ophthalmoscopically detectable disorders were prospectively examined. All subjects of group A had no history of cytomegalovirus retinitis and CD4 counts consistently above 100. Patients in group B (40 eyes of 21 patients) were human immunodeficiency virus-negative age-matched control subjects. Thickness of retinal nerve fiber layer along a 3.4-mm-diameter circle centered on the optic nerve head was evaluated using third-generation optical coherence tomography. CD8 T-lymphocyte count, presence of systemic infection, hemoglobin, hematocrit and serum beta-microglobulin levels were also recorded.

RESULTS

The mean overall retinal nerve fiber layer thickness in groups A and B were 89.2 +/- 24.01 microm and 102.82 +/- 29.168 microm (SD) respectively. The difference was considered extremely significant (P < 0.0001). Group A had significantly thinner average nerve fiber layer in temporal, nasal, superior and inferior retinal areas.

CONCLUSIONS

Significant retinal nerve fiber layer thinning occurs in human immunodeficiency virus-positive children with no visual impairment or ophthalmologic evidence or retinitis.

Laser Scanning Confocal Ophthalmoscopy and Polarimetry of Human Immunodeficiency Virus Patients Without Retinopathy, Under Antiretroviral Therapy

PURPOSE

Confocal laser scanning ophthalmoscopy (HRT; Heidelberg retinal tomograph II) and scanning laser polarimetry (GDx-variable corneal compensator [VCC]) were used to investigate whether early indicators of retinal nerve fiber layer (RNFL) thickness loss could be observed in patients infected with the human immunodeficiency virus (HIV) that had no associated retinopathy or optic neuropathy and were concomitantly receiving antiretroviral medications.

METHODS

HRT and GDx-VCC parameters obtained from a group of 13 HIV-positive subjects (n=26 eyes) on antiretroviral therapy examined with HRT, with a subgroup of six subjects (n=12 eyes) examined with both HRT and GDx-VCC, were compared with those of a matched HIV-negative control cohort (13 subjects, n=26 eyes) examined with HRT, with a subgroup of five subjects (n=10 eyes) examined with both HRT and GDx-VCC. We employed generalized estimating equations for statistical analysis.

RESULTS

Reduced mean values for the HRT height variation contour (p<0.045) and HRT mean RNFL thickness (p<0.023) were observed in HIV-positive subjects controlling for age, sex, and race. A significantly reduced mean value corresponding to the GDx-VCC superior maximum (p<0.014) and inferior maximum (p<0.016) were also observed for the HIV-positive cohort analyzed controlling for age, sex, and race.

CONCLUSION

HRT and GDx-VCC indicators of RNFL thickness appear to be significantly reduced in HIV-positive subjects without retinopathy or optic nerve disease using antiretroviral medication, suggesting RNFL loss occurs in this population of HIV-positive patients. The lack of correlation between CD4 counts, viral load, number of antiretroviral medications used, or years from diagnosis of HIV and RNFL thinning, suggests that possibly other factors associated with HIV infection may contribute to the apparent RNFL thickness loss.

Effect of Cytomegalovirus Retinitis on the Risk of Visual Acuity Loss among Patients with AIDS

PURPOSE

To describe the prevalence and incidence of reduced visual acuity in eyes of patients with AIDS and without cytomegalovirus (CMV) retinitis at enrollment and estimate the proportion of incident vision loss attributable to new-onset CMV retinitis in this cohort.

DESIGN

Multicenter prospective observational study.

PARTICIPANTS

Three thousand fourteen eyes of 1507 patients with AIDS and without CMV retinitis at enrollment.

METHODS

Medical history, ophthalmologic examination, and laboratory testing collected at enrollment and at follow-up visits every 6 months thereafter.

MAIN OUTCOME MEASURES

Loss of visual acuity across the < or =20/50 and < or =20/200 thresholds and doubling of the visual angle; potential causes of this vision loss.

RESULTS

For eyes of patients without CMV retinitis at enrollment, the proportions with best-corrected visual acuity of < or =20/50 and of < or =20/200 were 3.9% and 1.8%, respectively. The incidence rates of vision loss to < or =20/50, < or =20/200, and to a doubling of the visual angle were 1.5/100 eye-year (EY), 0.8/100 EY, and 2.1/100 EY, respectively. Approximately 40% of the incident vision loss was attributable to CMV retinitis diagnosed during the follow-up period, and approximately 25% was attributable to cataract.

CONCLUSIONS

Although the development of CMV retinitis was the most common reason for visual acuity loss in eyes of our patients with AIDS, it accounted for less than half of the vision loss in our population (approximately 40%). Newly diagnosed cataract during the follow-up period accounted for a substantial amount of incident vision loss as well.

Hyperreflective Sign in Resolved Cotton Wool Spots Using High-Resolution Optical Coherence Tomography and Optical Coherence Tomography Ophthalmoscopy

PURPOSE

To characterize retinal changes in areas of cotton wool spots (CWSs) using optical coherence tomography (OCT) and to determine the optical density changes of the retina after CWSs have disappeared clinically.

DESIGN

Prospective, noninterventional, observational study.

PARTICIPANTS

Thirty-one patients with CWSs who underwent imaging studies.

METHODS

The study groups included patients with CWSs resulting from diabetic retinopathy (n = 12), human immunodeficiency virus (HIV) retinopathy (n = 10), hypertensive retinopathy (n = 3), branch retinal vein occlusion (n = 3), uveitis (n = 2), and radiation retinopathy (n = 1). The single line scan mode of the StratusOCT Model 3000 (Carl Zeiss Meditec, Dublin, CA) was used for imaging of acute CWSs, CWSs 3 months after their resolution, and adjacent normal retina. A fundus photograph served as a template for localization of OCT scanning of CWSs. Retinal tissue reflectivity images were compared across lesion types and time. Additional imaging in 14 patients was performed to localize lesions better and to provide coronal OCT sections using the combined OCT and scanning laser ophthalmoscope.

MAIN OUTCOME MEASURES

Changes in retinal reflectivity in areas of normal retina and retina with acute and resolved CWSs.

RESULTS

The average reflectivity of normal retina was 58.4+/-2.1 dB, the average reflectivity in the area of active CWSs was 62.6+/-2.5 dB, and the average reflectivity in the same area after CWSs resolved was 61.0+/-2.4 dB. A significant difference (P<0.05) exists between reflectivity of normal retina and acute CWSs as well as normal retina and resolved CWSs.

CONCLUSIONS

Acute CWSs show a hyperreflective pattern on OCT. As they become ophthalmoscopically invisible, the OCT still shows signs of hyperreflectivity in the areas of previous CWSs (hyperreflective sign). The authors observed the same phenomenon using 2 imaging machines.

Machine learning classifiers detect subtle field defects in eyes of HIV individuals

PURPOSE

To test the following hypotheses: (1) eyes from patients with human immunodeficiency virus (HIV) have retinal damage that causes subtle field defects, (2) sensitive machine learning classifiers (MLCs) can use these field defects to distinguish fields in HIV patients and normal subjects, and (3) the subtle field defects form meaningful patterns. We have applied supervised MLCs--support vector machine (SVM) and relevance vector machine (RVM)--to determine if visual fields in patients with HIV differ from normal visual fields in HIV-negative controls.

METHODS

HIV-positive patients without visible retinopathy were divided into 2 groups: (1) 38 high-CD4 (H), 48.5 +/- 8.5 years, whose CD4 counts were never below 100; and (2) 35 low-CD4 (L), 46.1 +/- 8.5 years, whose CD4 counts were below 100 at least 6 months. The normal group (N) had 52 age-matched HIV-negative individuals, 46.3 +/- 7.8 years. Standard automated perimetry (SAP) with the 24-2 program was recorded from one eye per individual per group. SVM and RVM were trained and tested with cross-validation to distinguish H from N and L from N. Area under the receiver operating characteristic (AUROC) curve permitted comparison of performance of MLCs. Improvement in performance and identification of subsets of the most important features were sought with feature selection by backward elimination.

RESULTS

SVM and RVM distinguished L from N (L: AUROC = 0.804, N: 0.500, P = .0002 with SVM and L: .800, P = .0002 with RVM) and H from N (H: 0.683, P = .022 with SVM and H: 0.670, P = .038 with RVM). With best-performing subsets derived by backward elimination, SVM and RVM each distinguished L from N (L: 0.843, P < .00005 with SVM and L: 0.870, P < .00005 with RVM) and H from N (H: 0.695, P = .015 with SVM and H: 0.726, P = .007 with RVM). The most important field locations in low-CD4 individuals were mostly superior near the blind spot. The location of important field locations was uncertain in high-CD4 eyes.

CONCLUSIONS

This study has confirmed that low-CD4 eyes have visual field defects and retinal damage. Ranking located important field locations superiorly near the blind spot, implying damage to the retina inferiorly near the optic disc. Though most fields appear normal in high-CD4 eyes, SVM and RVM were sufficiently sensitive to distinguish these eyes from normal eyes with SAP. The location of these defects is not yet defined. These results also validate the use of sensitive MLC techniques to uncover test differences not discernible by human experts.

ASSESSMENT OF RETINAL FUNCTION IN PATIENTS WITH HIV WITHOUT INFECTIOUS RETINITIS BY MULTIFOCAL ELECTRORETINOGRAM AND AUTOMATED PERIMETRY

PURPOSE

To determine if multifocal electroretinogram (mfERG) testing shows abnormalities that correspond to perimetric defects in HIV positive patients without infectious retinitis.

METHODS

We studied three groups of patients: HIV negative controls, HIV high CD4 nadir patients (lowest CD4 T cell count is over 100) and low CD4 nadir patients (below 100 for over 6 months). Twenty-six HIV positive eyes and 16 HIV negative control eyes were studied by mfERG. A subset of 10 eyes also underwent computerized perimetry for comparison. We analyzed mfERG by hexagons as well as by quadrants and rings.

RESULTS

Of 103 hexagon locations there was no significant difference in the amplitudes P1 and N1 (nV/degree) between the three studied groups (p>0.05), similarly, the latencies were not different (p>0.05). All eyes with significant visual field defects at the 0.01 and 0.005 level (Humphrey pattern deviation; 24-2) were compared to mfERG amplitudes and latencies at those locations-there were no corresponding defects in mfERG data (p>0.2).

CONCLUSION

In the era of HAART there are still demonstrable visual field defects and other evidence of damage to the retinal nerve fiber layer in HIV patients. Our mfERG studies show that the damage appears to affect the inner retina, the outer retina is spared. Further studies of inner retinal structure and function are indicated to elucidate this process.