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.

Antarctica eye study: a prospective study of the effects of overwintering on ocular parameters and visual function

BACKGROUND

In 2013 five polar explorers attempted to complete the first Trans-Antarctic Winter Traverse (TAWT). This study presents the ophthalmological findings for this group, who overwintered in Antarctica as part of the White Mars Human Science Protocol. Antarctic crews are exposed to extreme cold, chronic hypoxia and altered day-night cycles. Previous studies of Antarctic explorers have focused on the prolonged effect of ultraviolet radiation including the development of ultraviolet keratitis and accelerated cataract formation. This is the first study of its kind to investigate the effect of overwintering in Antarctica on the human eye.

METHODS

Pre and post-expedition clinical observations were made including visual acuity, contrast sensitivity, colour vision, auto-refraction, subjective refraction, retinal examination, retinal autofluoresence and retinal thickness, which were graded for comparison. During the expedition additional observations were made on a monthly basis including LogMAR visual acuity, autorefraction and intraocular pressure.

RESULTS

No significant differences between pre and post-expedition observations were found, including visual acuity, contrast sensitivity, colour vision, refraction, visual fields, intraocular pressure and retinal examination. There was a small but statistically significant decrease in retinal thickness across all regions of the retina, except for the macular and fovea, in all explorers. Intra-expedition observations remained within normal limits.

CONCLUSION

Reassuringly, the human eye remains largely unchanged by exposure to the extreme conditions encountered during the Antarctic winter, however, further research is needed to investigate changes in retinal thickness. This may have implications for scientists who spend prolonged periods of time in the polar regions, as well as those who have prolonged exposure to the extreme cold or chronic hypoxia in other settings.

Optical coherence tomography automated layer segmentation of macula after retinal detachment repair

Purpose

To investigate the thickness of retinal layers and association with final visual acuity using spectral-domain optical coherence tomography (SD-OCT) in macular area of macula-off rhegmatogenous retinal detachment (RRD) patients after a successful macular re-attachment.

Methods

In retrospective study, a total 24 eyes with macula-off RRD were enrolled. All patients underwent vitrectomy to repair RRD. Outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptor layer (PR), retinal pigment epithelium (RPE) thicknesses were measured by the Spectralis (Heidelberg Engineering, Heidelberg, Germany) SD-OCT with automated segmentation software. The relationship between the thicknesses of each retinal layer and postoperative logarithm of the minimum angle of resolution scale (LogMAR) visual acuity was analyzed.

Results

OPL and RPE thicknesses were not significantly different between the retinal detachment eyes and fellow eyes (P = 0.839, 0.999, respectively). The ONL and photoreceptor thickness were significantly thinner in the retinal detachment eyes (P <0.001 and 0.001, respectively). In the univariate regression analysis, preoperative best corrected visual acuity (BCVA), ONL thickness and photoreceptor thickness showed association with the postoperative BCVA (P = 0.003, <0.001 and 0.024, respectively). In final multiple linear regression model, ONL thickness was the only variable significantly associated with postoperative BCVA (P = 0.044).

Conclusions

Segmented ONL and photoreceptor thickness of retinal detachment eyes were significantly thinner than fellow eyes. Segmental analysis of the retinal layer in macular region may provide valuable information for evaluation RRD. And ONL thickness can be used as a potential biomarker to predict visual outcome after RRD repair.

Optical Coherence Tomography in Children With Microtropia

PURPOSE

To assess whether optical coherence tomography (OCT) could be useful for detecting and documenting fixation in patients with microtropia.

METHODS

Retinal fixation observation was performed using spectral-domain OCT on amblyopic children with microtropia. The position between the retinal fixation point and the anatomical fovea was measured, in microns, using the system software tools. Only patients with a high level of cooperation, OCT scan quality signal of 7 or better, and visual acuity of 0.70 logarithm of the minimum angle of resolution (logMAR) or worse in the amblyopic eye were included.

RESULTS

A total of 25 patients were included: 15 with microtropia (study group) and 10 without tropia and with foveal fixation and stereopsis (control group). In the study group, microtropia was previously diagnosed in 67% of cases through the cover test, and was predominantly in the left eye (73%). The average visual acuity of the sound eye was 0.03 decimal and 0.18 logMAR in the amblyopic eye. The microtropia was 3.73 ± 3.34 prism diopters and eccentric fixation (387 ± 199 µm) with OCT was observed in all cases except one. Eccentricity was predominantly in the superonasal quadrant (57%). Both eyes in the control group and the contralateral eyes of the study group showed foveal fixation.

CONCLUSIONS

OCT can play an important role in the diagnosis and measurement of eccentric fixation in eyes with microtropia, providing high sensitivity. [J Pediatr Ophthalmol Strabismus. 2018;55(3):171-177.].

Monitoring foveal sparing in geographic atrophy with fluorescence lifetime imaging ophthalmoscopy - a novel approach

PURPOSE

To investigate fundus autofluorescence (FAF) lifetimes in geographic atrophy (GA) with a focus on macular pigment (MP) and foveal sparing.

METHODS

The study included 35 eyes from 28 patients (mean age 79.2 ± 8.0 years) with GA. A 30° retinal field, centred at the macula, was investigated using fluorescence lifetime imaging ophthalmoscopy (FLIO). The FLIO technology is based on a Heidelberg Engineering Spectralis system. Decays of FAF were detected in a short (498-560 nm, SSC) and long (560-720 nm, LSC) spectral channel. The mean fluorescence lifetime, τ_m , was calculated from a three-exponential approximation of the FAF decays. Macular optical coherence tomography (OCT) scans as well as fundus photography were recorded.

RESULTS

Review of FLIO data reveals specific patterns of significantly prolonged τ_m in regions of GA (SSC 616 ± 343 ps, LSC 615 ± 154 ps) as compared to non-atrophic regions. Large τ_m differences between the fovea and atrophic areas correlate with better visual acuity (VA). Shorter τ_m at the fovea than within other non-atrophic regions indicates sparing, which was identified in 16 eyes. Seventy per cent of patients treated with lutein supplementation showed foveal sparing, whereas the rate among non-supplemented patients was 22%.

CONCLUSION

Using FLIO, we present a novel way to detect foveal sparing, investigate MP, and analyse variability of τ_m in different foveal regions (including the prognostic valuable border region) in GA. These findings support the potential utility of FLIO in monitoring disease progression. The findings also highlight the possibly protective effect of lutein supplementation, with implication in recording the presence and distributional pattern of MP.

Age-Dependent Phenotypic Expression of a Pattern Dystrophy of the Retina

We studied a family with pattern dystrophy of the retina (PDR) in order to elucidate the clinical course of the disorder, relations between the different forms, and the mode of inheritance. Thirty-nine family members, representing three generations, underwent a thorough ophthalmological examination, with fluorescein angiography whenever a macular abnormality was suspected. Of family members over the age of 32 years, 46.7% showed signs of PDR. We classified the clinical forms of PDR in this family into four types: minimal lesion, pseudovitelliform type, butterfly-spider type, and late-stage lesion. These forms were predominant in the order cited in age groups 31-40 years, 41-50, 51-60, and > 60 years. Significant visual loss occurred only after the age of 50 years, when 8 of 14 eyes had visual acuity of less than 20/25. Inheritance was autosomal dominant. PDR presented different clinical forms in members of this family, and in successive age classes patterns of increasing severity prevailed. Thus, the different phenotypic forms apparently represent transient stages related to the age of the patient.

Association between characteristics of foveal cystoid spaces and short-term responsiveness to ranibizumab for diabetic macular edema

PURPOSE

To investigate the association between the characteristics of foveal cystoid spaces and short-term responsiveness to ranibizumab treatment for diabetic macular edema (DME) at 3 months from the initial injection.

METHODS

We retrospectively reviewed 66 eyes of 61 patients with center-involved DME who received three consecutive ranibizumab injections and following as-needed administrations. We evaluated the relationship between visual improvement at 3 months and the preoperative optical coherence tomography (OCT) parameters including hyperreflective foci, heterogeneous OCT reflectivity, mean levels of OCT reflectivity and height of foveal cystoid spaces.

RESULTS

Twenty-three eyes without preoperative hyperreflective foci in the foveal cystoid spaces had significantly greater improvement in the logarithm of the minimum angle of resolution visual acuity (logMAR VA) at 3 months than 43 eyes with foci (P = 0.006). That was similar to the greater reduction in CSF thickness in eyes without lesions after treatment at the same time point (P < 0.001). VA improvement at 3 months was not associated with the height (R = 0.215, P = 0.083) or the reflectivity levels (R = -0.079, P = 0.538) of foveal cystoid spaces. There were no differences in VA changes between eyes with and without heterogeneous reflectivity in foveal cystoid spaces (P = 0.297). Multivariate analyses showed that logMAR VA and the absence of hyperreflective foci in foveal cystoid spaces were associated with VA improvement at 3 months.

CONCLUSION

Hyperreflective foci in foveal cystoid spaces at baseline predict poorer short-term responsiveness to ranibizumab injections for DME.

Vitrectomy with a modified temporal inverted limiting membrane flap to reconstruct the foveolar architecture for macular hole retinal detachment in highly myopic eyes

PURPOSE

We investigated the surgical results of macular hole retinal detachment (MHRD) with a modified C-shaped temporal inverted internal limiting membrane (ILM) flap to reconstruct the foveolar architecture in highly myopic eyes.

METHODS

Eighteen highly myopic eyes with MHRD in 17 patients who underwent a vitrectomy with a modified C-shaped temporal inverted ILM flap were followed for 12 months. Anatomic outcomes were evaluated by fundus examinations and optical coherence tomography. The preoperative and postoperative best-corrected visual acuities (BCVAs) were compared as functional outcomes.

RESULTS

Women accounted for 88% of the MHRD patients. The mean age was 60.2 ± 8.2 years. The mean axial length was 29.25 ± 2.10 mm. Type 1 and type 2 MHRD was present in four eyes and 14 eyes, respectively. After a single surgery, the hole was closed in 18 eyes (100%). Retinal attachment was achieved in 95%. Persistent shallow subretinal fluid (SRF) was noted in one case, which was resolved at follow-up. The surgery significantly improved BCVAs (from 1.7 ± 0.6 to 0.72 ± 0.4 logarithm of the minimum angle of resolution units [p < 0.001]) at the last visit. In total, 94.4% of the eyes had restored foveolar architecture. Ellipsoid zone recovery within the foveola was found in 77.8% of the eyes.

CONCLUSION

A vitrectomy and modified C-shaped inverted temporal ILM flap is effective for closing MHs, reattaching the retina, restoring the foveolar architecture and significantly improving the postoperative BCVA in MHRD patients. This technique is feasible, and we propose 'presumed' Müller cell cone repair in MHRD surgery.

Bevacizumab for Occult Subfoveal Neovascularization in Age-Related Macular Degeneration

Purpose

To report on the treatment of exudative age-related macular degeneration by intravitreal bevacizumab (Avastin).

Methods

A 78-year-old patient experienced a progressive loss of visual acuity in her right eye due to an occult subfoveal neovascular membrane in age-related macular degeneration. She received an intravitreal injection of 1.5 mg bevacizumab.

Results

Within 4 weeks after the injection, visual acuity improved from 0.40 to 0.60 with complete resolution of subretinal and intraretinal leakage and edema as shown on optical coherence tomography. Pre-existing metamorphopsias disappeared. Intraocular pressure remained in the normal range. During the follow-up, there were no sings of intraocular inflammation or any other intraocular pathology induced by the intravitreal injection.

Conclusions

Intravitreal bevacizumab may potentially be helpful in the treatment of exudative age-related macular degeneration and may deserve further evaluation.

Pars Plana Vitrectomy and Removal of the Internal Limiting Membrane in Diabetic Macular Edema Unresponsive to Grid Laser Photocoagulation

PURPOSE

To evaluate the effectiveness of pars plana vitrectomy (PPV) with removal of the internal limiting membrane (ILM) in diabetic patients with macular edema unresponsive to grid laser photocoagulation.

METHODS

In this randomized controlled study, 20 eyes of 10 patients with diabetic macular edema unresponsive to grid laser photocoagulation were evaluated. PPV with ILM removal was performed randomly in one eye each of 10 patients and taken as the study group; the untreated fellow eyes were taken as the control group. Main outcome measures were foveal thickness changes measured with optical coherence tomography and preoperative and post-operative visual acuity. Mann-Whitney U, Wilcoxon, and chi-square tests were used in statistical analysis.

RESULTS

The mean age of the patients was 61.5+/-6 years (range 51 to 71). All patients were followed up for 12 months. In the study group, mean foveal thickness was 391.3+/-91.6 microm preoperatively and 225.5+/-49.4 microm postoperatively (p=0.009). In the control group, mean foveal thickness was 356.2+/-140 microm at baseline and 318.4+/-111.1 microm at 12-month follow-up (p=0.138). Mean decrease in foveal thickness was 165.8+/-114.8 microm in the study group and 37.8+/-71.2 microm in the control group (p=0.016). In the study group, best-corrected log-MAR visual acuity was 0.71+/-0.43 preoperatively and 0.54+/-0.45 postoperatively (p=0.125). In the control group, best-corrected logMAR visual acuity was 0.43+/-0.44 at baseline and 0.59+/-0.55 at 12-month follow-up (p=0.235). In the study group, visual acuity improved by two or more lines in 4 eyes (40%) and remained stable in 6 eyes (60%). In the control group, visual acuity improved by two or more lines in 1 eye (10%) and decreased by two or more lines in 3 eyes (30%).

CONCLUSIONS

PPV with ILM removal appears to be an effective procedure for reducing diabetic macular edema unresponsive to grid laser photocoagulation. A further study with a large number of patients is required to assess the effectiveness and safety of this procedure.

Human L- and M-opsins restore M-cone function in a mouse model for human blue cone monochromacy

Purpose

Blue cone monochromacy (BCM) is an X-linked congenital vision disorder characterized by complete loss or severely reduced L- and M-cone function. Patients with BCM display poor visual acuity, severely impaired color discrimination, myopia, nystagmus, and minimally detectable cone-mediated electroretinogram. Recent studies of patients with BCM with adaptive optics scanning laser ophthalmoscopy (AOSLO) showed that they have a disrupted cone mosaic with reduced numbers of cones in the fovea that is normally dominated by L- and M-cones. The remaining cones in the fovea have significantly shortened outer segments but retain sufficient structural integrity to serve as potential gene therapy targets. In this study, we tested whether exogenously expressed human L- and M-opsins can rescue M-cone function in an M-opsin knockout (Opn1mw-/- ) mouse model for BCM.

Methods

Adeno-associated virus type 5 (AAV5) vectors expressing OPN1LW, OPN1MW, or C-terminal tagged OPN1LW-Myc, or OPN1MW-HA driven by a cone-specific promoter were injected subretinally into one eye of Opn1mw-/- mice, while the contralateral eye served as the uninjected control. Expression of cone pigments was determined with western blotting and their cellular localization identified with immunohistochemistry. M-cone function was analyzed with electroretinogram (ERG). Antibodies against cone phototransduction proteins were used to study cone outer segment (OS) morphology in untreated and treated Opn1mw-/- eyes.

Results

We showed that cones in the dorsal retina of the Opn1mw-/- mouse do not form outer segments, resembling cones that lack outer segments in the human BCM fovea. We further showed that AAV5-mediated expression of either human M- or L-opsin individually or combined promotes regrowth of cone outer segments and rescues M-cone function in the treated Opn1mw-/- dorsal retina.

Conclusions

Exogenously expressed human opsins can regenerate cone outer segments and rescue M-cone function in Opn1mw-/- mice, thus providing a proof-of-concept gene therapy in an animal model of BCM.

High-resolution Imaging in Male Germ Cell-Associated Kinase (MAK)-related Retinal Degeneration

PURPOSE

To describe the characteristics of MAK-related retinal degeneration using optical coherence tomography angiography (OCTA) and adaptive optics scanning laser ophthalmoscopy (AOSLO).

DESIGN

Cross-sectional study.

METHODS

Six patients with rod-cone degeneration and disease-causing mutations in MAK were evaluated with visual acuity, spectral-domain OCT, confocal AOSLO, and OCTA. Foveal avascular zone (FAZ) area, vessel densities, and perfusion densities of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the central macula in all 6 patients were compared with 5 normal subjects. Cone spacing was measured in 4 patients from AOSLO images and compared with 37 normal subjects.

RESULTS

Patients ranged from 25 to 81 years of age (mean, 52 years). Visual acuity varied from 20/13 to 20/40+2, except in 1 patient with cystoid macular edema whose vision was 20/60- and 20/70+1. The SCP (P = .012) and DCP (P = .013) vessel density and perfusion density (P =.015 and .013, respectively) were significantly lower in patients compared to normal subjects in the parafoveal region 1.0-3.0 mm from the fovea, but were similar to normal subjects within 1.0 mm of the fovea. The FAZ area was not significantly different from normal (all P ≥ .24). Cone spacing was normal at almost all locations in 2 patients with early disease and increased in 2 patients with advanced disease.

CONCLUSIONS

Although retinal vascular densities are reduced and cone spacing is increased in advanced disease, central foveal structure is maintained until late stages of disease, which may contribute to preservation of foveal vision in eyes with MAK-related retinal degeneration.

Effect of optical correction on subfoveal choroidal thickness in children with anisohypermetropic amblyopia

The purpose of this study was to determine the effect of optical correction on the best-corrected visual acuity (BCVA) and subfoveal choroidal thickness (CT) in the eyes of children with anisohypermetropic amblyopia. Twenty-four anisohypermetropic amblyopic eyes and their fellow eyes of 24 patients and twenty-three eyes of 23 age-matched control children were studied. After one year of optical correction, the BCVA in the anisohypermetropic amblyopic eyes was significantly improved. Before the treatment, the mean subfoveal CT in the amblyopic eyes was 351.9 ± 59.4 μm which was significantly thicker than that of control eyes at 302.4 ± 63.2 μm. After the treatment, the amount of change in the subfoveal CT in the amblyopic and fellow eyes was greater than that in the control eyes. The amblyopic and fellow eyes with thicker choroids had a greater thinning of the choroid whereas eyes with thinner choroids had a greater thickening of the choroid. We conclude that wearing corrective lenses improves the visual acuity, and induces changes of the subfoveal CT in eyes with anisohypermetropic amblyopia.

Aflibercept in Serous Foveal Detachment in Dome-Shaped Macula: Short-Term Results in a Retrospective Study

BACKGROUND AND OBJECTIVE

To evaluate short-term efficacy of intravitreal aflibercept (Eylea; Regeneron, Tarrytown, NY) in serous foveal detachment (SFD) in dome-shaped macula (DSM).

PATIENTS AND METHODS

A retrospective, noncomparative case series. Three monthly aflibercept injections were administered. Early Treatment Diabetic Retinopathy Study best-corrected visual acuity (BCVA), optical coherence tomography central subfield thickness (CST), and subretinal fluid (SRF) at baseline and at 2 months and 4 months after the last injection were considered for statistical analysis.

RESULTS

The authors reviewed nine eyes affected by SFD in DSM. Mean BCVA improved from 0.42 LogMAR at baseline to 0.33 LogMAR at final follow-up (P = .06), and mean CST and SRF reduced from 347 μm to 295 μm (P = .09) and from 146 μm to 99 μm (P < .01), respectively. None of the considered eyes had resolution of the SRF.

CONCLUSIONS

Three monthly aflibercept injections may improve BCVA and reduce CST and SRF in SFD of DSM. Further prospective studies are necessary to state the real efficacy of this approach. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:822-828.].

Quantitative and Qualitative Features of Spectral-Domain Optical Coherence Tomography Provide Prognostic Indicators for Visual Acuity in Patients With Choroideremia

BACKGROUND AND OBJECTIVE

To identify qualitative and quantitative features of spectral-domain optical coherence tomography (SD-OCT) as prognostic indicators of visual acuity (VA) loss in patients with choroideremia (CHM).

PATIENTS AND METHODS

Retrospective study of 57 male patients with CHM. Central foveal thickness (CFT), subfoveal choroidal thickness (SCT), fundus autofluorescence area, and evidence of outer retinal and choroidal degeneration were analyzed by SD-OCT.

RESULTS

Best-corrected VA logMAR at baseline was associated with CFT at baseline (r = -0.47; P < .01), CFT at most recent follow-up (r = -0.27; P < .01), and SCT at baseline (r = -0.31; P < .01). Ellipsoid zone (EZ) rupture was associated with a higher CFT loss (r = 0.33; P < .01) and macular cystic spaces (MCS) with a reduction in VA over time (hazard risk = 0.48; P = .05).

CONCLUSION

Reduced CFT at baseline, EZ rupture, and MCS are poor prognostic indicators for VA outcome. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:711-716.].

Optical Coherence Tomography Protocols for Screening of Hydroxychloroquine Retinopathy in Asian Patients

PURPOSE

To investigate the distribution of outer retinal changes in hydroxychloroquine (HCQ) retinopathy and explore optical coherence tomography (OCT) protocols to maximize the sensitivity of HCQ retinopathy detection in Asian patients.

DESIGN

Diagnostic validity assessment.

METHODS

Setting: Institutional.

PATIENT POPULATION

Forty-eight eyes (24 patients) with HCQ retinopathy underwent 6-mm horizontal and vertical line scans and 6 × 6-mm² volume scans using spectral-domain OCT (SD-OCT), and 9-mm line scans and 6 × 6-mm² and 12 × 9-mm² volume scans using swept-source OCT (SS-OCT).

OBSERVATION PROCEDURES

Distances from the fovea to the defective photoreceptors were measured in the temporal, nasal, superior, and inferior directions from line scan OCT images. The sensitivity of retinopathy detection, indicated by photoreceptor defects, was compared among protocols.

MAIN OUTCOME MEASURES

Detection of photoreceptor defects and distances from the fovea to the defects.

RESULTS

The average minimum distance from the fovea to an area of photoreceptor defects was 1.84 ± 1.26 mm (mean ± standard deviation). The distances were greater than 3 mm horizontally and vertically in 15 (31.3%) and 17 (35.4%) eyes with HCQ retinopathy, respectively, and only wide-field line or volume scans could detect defects in the eyes. The 9-mm line scans detected HCQ retinopathy significantly better than 6-mm scans (P < .001); the sensitivity of the wide volume scan was significantly greater than the standard volume scan (P = .001). The 12 × 9-mm² volume scan detected retinopathy with the greatest sensitivity (100%).

CONCLUSIONS

Our study recommends a wide-field OCT scan to screen Asian patients taking HCQ medications.

Foveal Development in Infants Treated with Bevacizumab or Laser Photocoagulation for Retinopathy of Prematurity

PURPOSE

To characterize and quantify early foveal development in preterm infants and to compare this development between eyes treated with intravitreal bevacizumab or laser photocoagulation (LPC) and untreated eyes.

DESIGN

Observational case series.

PARTICIPANTS

One hundred thirty-one preterm infants undergoing retinopathy of prematurity (ROP) screenings.

METHODS

Handheld OCT imaging was performed longitudinally on all patients. Thickness measurements of the inner and outer retinal layers were obtained at the foveal center and the nasal and temporal foveal rims. Comparisons between treated and untreated eyes were adjusted for age and other confounding variables.

MAIN OUTCOME MEASURES

Weekly change in inner and outer retinal thickness and presence of inner retinal layers, ellipsoid zone (EZ), and cystoid macular changes (CMCs).

RESULTS

Outer retinal thickness at the foveal center increased by 3.1 μm/week in untreated eyes and 7.2 μm/week in bevacizumab-treated eyes (P = 0.038). Eyes treated with LPC had a lower probability of having all inner retinal layers present at the foveal center (odds ratio, 0.04; P = 0.001) and a lower probability of having the EZ present at the foveal center (odds ratio, 0.07; P = 0.024) compared with untreated eyes. Cystoid macular changes were found in 53% of patients and 22% of imaging sessions. The age-adjusted incidence of CMCs was not correlated with bevacizumab or LPC treatment.

CONCLUSIONS

Intravitreal bevacizumab therapy for ROP is associated with more rapid outer retinal thickening at the foveal center, whereas LPC is associated with earlier extrusion of the inner retinal layers and delayed development of the EZ at the foveal center. Long-term follow-up is needed to determine the visual significance of these findings.

Left-right asymmetry of the Maxwell spot centroids in adults without and with dyslexia

In human vision, the brain has to select one view of the world from our two eyes. However, the existence of a clear anatomical asymmetry providing an initial imbalance for normal neural development is still not understood. Using a so-called foveascope, we found that for a cohort of 30 normal adults, the two blue cone-free areas at the centre of the foveas are asymmetrical. The noise-stimulated afterimage dominant eye introduced here corresponds to the circular blue cone-free area, while the non-dominant eye corresponds to the diffuse and irregular elliptical outline. By contrast, we found that this asymmetry is absent or frustrated in a similar cohort of 30 adults with normal ocular status, but with dyslexia, i.e. with visual and phonological deficits. In this case, our results show that the two Maxwell centroid outlines are both circular but lead to an undetermined afterimage dominance with a coexistence of primary and mirror images. The interplay between the lack of asymmetry and the development in the neural maturation of the brain pathways suggests new implications in both fundamental and biomedical sciences.

Cellular Characterization of OCT and Outer Retinal Bands Using Specific Immunohistochemistry Markers and Clinical Implications

PURPOSE

OCT has been a technological breakthrough in the diagnosis, treatment, and follow-up of many ocular diseases, especially retinal and neuro-ophthalmologic pathologic conditions. Until now, several controversies have arisen over the specific cell types that the bands observed in the OCT represent, especially over the 4 outer retinal bands.

DESIGN

To correlate the 4 outer hyperreflective bands observed in the OCT with the histologic structures using human retinal sections and immunocytochemistry at the fovea level.

PARTICIPANTS

Eyes from human donors.

METHODS

Vertical cryosections of human retinas were immunostained with antibodies specific for cones photoreceptors, bipolar cells, mitochondria, Müller cells, and retinal pigment epithelium (RPE) cells and were visualized using confocal microscopy.

MAIN OUTCOME MEASURES

Morphological correlation between histology and OCT at the fovea level.

RESULTS

Triple immunolabeling allowed distinguishing between cells types and different cell compartments. Immunostaining with guanine nucleotide-binding protein β 3 (GNB3) and cellular retinaldehyde-binding protein (CRALBP) antibodies showed all retinal layers at the foveola, especially the separation between the outer nuclear layer and the Henle fiber layer. CRALBP and cytochrome C (Cyt C) immunolabeling revealed that hyperreflective bands 1 and 2, observed in the OCT, correspond to the outer limiting membrane and the cone ellipsoids, respectively, separated by the cone myoids. CRALBP, cytochrome C, and GNB3 showed that the RPE interdigitations extend along the entire external segment of the cones, we do not believe them to be the structure responsible for forming the third band. However, the identification of small fragments of cone outer segments within the RPE led us to characterize the third band as the cone phagosomes located in the top of the RPE. Finally, we propose that the fourth band corresponds to the accumulation of mitochondria at the basal portion of the RPE, as identified by cytochrome C immunoreactivity, and that the hyporeflective band between bands 3 and 4 corresponds to the RPE nuclei and melanosomes zone.

CONCLUSIONS

This study proposes a new interpretation of the outer retinal bands that leads to a more accurate interpretation of OCT images, providing information about the health of cones and their relationship with the RPE, and could help to form a better understanding of retinal disease diagnosis and prognosis.

REPEATABILITY AND LONGITUDINAL ASSESSMENT OF FOVEAL CONE STRUCTURE IN CNGB3-ASSOCIATED ACHROMATOPSIA

PURPOSE

Congenital achromatopsia is an autosomal recessive disease causing substantial reduction or complete absence of cone function. Although believed to be a relatively stationary disorder, questions remain regarding the stability of cone structure over time. In this study, the authors sought to assess the repeatability of and examine longitudinal changes in measurements of central cone structure in patients with achromatopsia.

METHODS

Forty-one subjects with CNGB3-associated achromatopsia were imaged over a period of between 6 and 26 months using optical coherence tomography and adaptive optics scanning light ophthalmoscopy. Outer nuclear layer (ONL) thickness, ellipsoid zone (EZ) disruption, and peak foveal cone density were assessed.

RESULTS

ONL thickness increased slightly compared with baseline (0.184 μm/month, P = 0.02). The EZ grade remained unchanged for 34/41 subjects. Peak foveal cone density did not significantly change over time (mean change 1% per 6 months, P = 0.126).

CONCLUSION

Foveal cone structure showed little or no change in this group of subjects with CNGB3-associated achromatopsia. Over the time scales investigated (6-26 months), achromatopsia seems to be a structurally stable condition, although longer-term follow-up is needed. These data will be useful in assessing foveal cone structure after therapeutic intervention.

Quantitative optical coherence tomography angiography of macular vascular structure and foveal avascular zone in glaucoma

Objective

The study aimed to evaluate the quantitative characteristics of the macular vessel density (VD) and foveal avascular zone (FAZ) in glaucoma using optical coherence tomography angiography (OCT-A).

Design

Cross-sectional, age- and sex-matched case–control study.

Methods

Fifty-two eyes of 52 patients with primary open angle glaucoma and 52 eyes from 52 healthy participants were recruited retrospectively. OCT-A was performed on a 3 x 3-mm macular region centered on the fovea. OCT-A scans were manually graded to define the FAZ. Parafoveal VD in superficial and deep retina were analyzed in the circular- and quadrant-segmented zone. The FAZ parameters included size, perimeter, and circularity index. The regression analysis among VD and FAZ-related parameters and ocular parameters was performed, and the diagnostic ability was calculated with refractive error adjusted.

Results

For both groups, the mean age and the sex ratio was not different between groups. With refractive error adjusted, the average macular VD was lower in glaucoma than in the control group for superficial (P = 0.013), deep (P<0.001), and the whole retina (P = 0.002). There were increased FAZ perimeter and decreased FAZ circularity index in glaucoma when compared with controls (P<0.001). In the multivariate regression models, FAZ circularity index were significantly associated with decreased peripapillary RNFL thickness (P = 0.007) and macular GCIPL thickness (P = 0.009) measured by OCT. The refractive-error adjusted area under receiver operating characteristics was highest for FAZ circularity index (0.905; 95% CI, 0.844–0.966), followed by temporal deep retinal VD (0.870; 95% CI, 0.803–0.937) and FAZ perimeter (0.858; 95% CI, 0.784–0.932).

Conclusions

Decreased macular VD, increased FAZ perimeter, and decreased FAZ circularity index were observed in eyes with glaucoma using OCT-A. With refractive error adjusted, these parameters showed considerable diagnostic value for glaucoma. FAZ circularity index may be a novel biomarker representing disruption of the parafoveal capillary network in glaucoma, as supported by its association with structural parameters.

Relationships Between Spatial Contrast Sensitivity and Parafoveal Cone Density in Normal Subjects and Patients With Retinal Degeneration

BACKGROUND AND OBJECTIVE

To investigate the relationship between spatial contrast sensitivity (CS) and parafoveal cone density (PCD).

PATIENTS AND METHODS

Fifteen healthy individuals (mean age: 26.1 years ± 4.5 years) and nine patients with hereditary retinal degeneration (mean age: 31.6 years ± 13.4 years) without media opacities were studied. The CS was measured by CSV-1000 (VectorVision, Greenville, OH). The cone mosaic was photographed with an adaptive optics scanning laser ophthalmoscope (AOSLO) with a 1° × 1° field of view centered on the fovea. The PCD was calculated in an annular area with radii of 0.38° and 0.43°. The CS was converted to the logarithm (logCS), and the area under the logCS function (AULCSF) was determined.

RESULTS

The AULCSF was significantly and positively correlated with the PCD in the control (R² = 0.522; P = .003) and retinal degeneration (R² = 0.514; P = .03) groups.

CONCLUSION

PCD can predict the spatial contrast sensitivity in normal subjects or patients with retinal degeneration without media opacities. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:106-113.].

Optical Coherence Tomography Angiography in Foveal Hypoplasia

BACKGROUND AND OBJECTIVE

A retrospective case series reporting optical coherence tomography angiography (OCTA) findings in foveal hypoplasia.

PATIENTS AND METHODS

Patients with foveal hypoplasia who presented to the authors' tertiary eye center. Cases of foveal hypoplasia that underwent OCTA were reviewed, and the clinical histories as well as imaging findings were summarized.

RESULTS

Three patients presented to the authors' eye center for evaluation of foveal hypoplasia and underwent OCTA: a 5-year-old girl, a 40-year-old woman, and a 22-year-old man. OCTA images were taken for both eyes of all patients. Four of five eyes with foveal hypoplasia had a small but present foveal avascular zone in the deep capillary plexus, whereas all eyes had an absent or severely reduced superficial capillary plexus.

CONCLUSION

OCTA can be helpful in the diagnosis of foveal hypoplasia and can aid in the anatomical characterization of disease. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:1127-1131.].

Bilateral Prefoveal Sub-Internal Limiting Membrane Hemorrhage in Autoimmune Hemolytic Anemia

Severe anemia can cause multilayered retinal hemorrhages. A 65-year-old woman noted "red spheres" in the central vision of both eyes during a hospital admission for autoimmune hemolytic anemia. Examination revealed extensive multilayered retinal hemorrhages, including bilateral foveal preretinal hemorrhage. Spectral-domain optical coherence tomography localized the preretinal blood to the sub-internal limiting membrane (ILM) space. Various options are available for management of such hemorrhage, including observation for spontaneous resolution, YAG laser membranotomy, or pars plana vitrectomy with ILM peeling. In the authors' patient, the size of the sub-ILM hemorrhage spontaneously improved during the course of 1 month, with both subjective and objective visual improvement. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:1151-1153.].