PEDF-derived peptide protects against Amyloid-β toxicity in vitro and prevents retinal dysfunction in rats

Amyloid-beta (Aβ), a family of aggregation-prone and neurotoxic peptides, has been implicated in the pathophysiology of age-related macular degeneration (AMD). We have previously shown that oligomeric and fibrillar species of Aβ42 exerted retinal toxicity in rats, but while the consequences of exposure to amyloid were related to intracellular effects, the mechanism of Aβ42 internalization in the retina is not well characterized. In the brain, the 67 kDa laminin receptor (67LR) participates in Aβ-related neuronal cell death. A short peptide derived from pigment epithelium-derived factor (PEDF), formerly designated PEDF-335, was found to mitigate experimental models of ischemic retinopathy via targeting of 67LR. In the present study, we hypothesized that 67LR mediates the uptake of pathogenic Aβ42 assemblies in the retina, and that targeting of this receptor by PEDF-335 may limit the internalization of Aβ, thereby ameliorating its retinotoxicity. To test this assumption ARPE-19 cells in culture were incubated with PEDF-335 before treatment with fibrillar or oligomeric structures of Aβ42. Immunostaining confirmed that PEDF-335 treatment substantially prevented amyloid internalization into ARPE-19 cells and maintained their viability in the presence of toxic oligomeric and fibrillar Aβ42 entities in vitro. FRET competition assay was performed and confirmed the binding of PEDF-335 to 67LR in RPE-like cells. Wild-type rats were treated with intravitreal PEDF-335 in the experimental eye 2 days prior to administration of retinotoxic Aβ42 oligomers or fibrils to both eyes. Retinal function was assessed by electroretinography through 6 weeks post injection. The ERG responses in rats treated with oligomeric or fibrillar Aβ42 assemblies were near-normal in eyes previously treated with intravitreal PEDF-335, whereas those measured in the control eyes treated with injection of the Aβ42 assemblies alone showed pathologic attenuation of the retinal function through 6 weeks. The retinal presence of 67LR was determined ex vivo by immunostaining and western blotting. Retinal staining demonstrated the constitutional expression of 67LR mainly in the retinal nuclear layers. In the presence of Aβ42, the levels of 67LR were increased, although its retinal distribution remained largely unaltered. In contrast, no apparent differences in the retinal expression level of 67LR were noted following exposure to PEDF-335 alone, and its pattern of localization in the retina remained similarly concentrated primarily in the inner and outer nuclear layers. In summary, we found that PEDF-335 confers protection against Aβ42-mediated retinal toxicity, with significant effects noted in cells as well as in vivo in rats. The effects of PEDF-335 in the retina are potentially mediated via binding to 67LR and by at least partial inhibition of Aβ42 internalization. These results suggest that PEDF-335 may merit further consideration in the development of targeted inhibition of amyloid-related toxicity in the retina. More broadly, our observations provide evidence on the importance of extracellular versus intracellular Aβ42 in the retina and suggest concepts on the molecular mechanism of Aβ retinal pathogenicity.

The Surprising Nonlinear Effects of S100A9 Proteins in the Retina

Age-related macular degeneration (AMD) is a complex disease in which inflammation is implicated as a key factor but the precise molecular mechanisms are poorly understood. AMD lesions contain an excess of the pro-inflammatory S100A9 protein, but its retinal significance was yet unexplored. S100A9 was shown to be intrinsically amyloidogenic in vitro and in vivo. Here, we hypothesized that the retinal effects of S100A9 are related to its supramolecular conformation. ARPE-19 cultures were treated with native dimeric and fibrillar S100A9 preparations, and cell viability was determined. Wild-type rats were treated intravitreally with the S100A9 solutions in the right eye and with the vehicle in the left. Retinal function was assessed longitudinally by electroretinography (ERG), comparing the amplitudes and configurations for each intervention. Native S100A9 had no impact on cellular viability in vitro or on the retinal function in vivo. Despite dispersed intracellular uptake, fibrillar S100A9 did not decrease ARPE-19 cell viability. In contrast, S100A9 fibrils impaired retinal function in vivo following intravitreal injection in rats. Intriguingly, low-dose fibrillar S100A9 induced contrasting in vivo effects, significantly increasing the ERG responses, particularly over 14 days postinjection. The retinal effects of S100A9 were further characterized by glial and microglial cell activation. We provide the first indication for the retinal effects of S100A9, showing that its fibrils inflicted retinal dysfunction and glial activation in vivo, while low dose of the same assemblies resulted in an unpredicted enhancement of the ERG amplitudes. These nonlinear responses highlight the consequences of self-assembly of S100A9 and provide insight into its pathophysiological and possibly physiological roles in the retina.

Is there room for prompt routine ophthalmic examination in neonates with congenital cytomegalovirus (CMV) infection during the neonatal period?

PURPOSE

To establish the clinical necessity of routine targeted ophthalmic examination of newborns with congenital cytomegalovirus (CMV) infection during the neonatal period.

METHODS

This retrospective study included consecutive neonates that were referred for ophthalmological screening within the context of a proven congenital CMV infection. The presence of CMV-related ocular and systemic findings was determined.

RESULTS

Among the 91 patients included in this study, 72 (79.12%) were symptomatic with one or more of the following manifestations: abnormal brain ultrasound (42; 46.15%), small for gestational age (29; 31.87%), microcephaly (23; 25.27%), thrombocytopenia (14; 15.38%), sensory neural hearing loss (13; 14.29%), neutropenia (12; 13.19%), anemia (4; 4.4%), skin lesions (4; 4.4%), hepatomegaly (3; 3.3%), splenomegaly (3; 3.3%), direct hyperbilirubinemia (2; 2.2%). Not one single neonate in this cohort had any of the ocular findings surveyed.

CONCLUSION

The presence of ophthalmological findings among neonates with congenital CMV infection during the neonatal period is infrequent, suggesting that routine ophthalmological screening may be safely deferred for the post-neonatal period.

Reduced Electroretinogram Responses in Morphologically Normal Retina in Patients with Primary Hyperoxaluria Type 1

Purpose

To describe ocular findings in individuals with primary hyperoxaluria type 1 (PH1), focusing on the correlations between retinal anatomy and retinal function. To characterize the retinal alterations that occur at different disease stages by evaluating individuals with diverse degrees of renal impairment associated with PH1.

Design

A cross-sectional study.

Participants

Patients diagnosed with PH1 based on clinical criteria and genetic testing, treated in the Pediatric Nephrology Unit of the Ruth Children's Hospital, Rambam Health Care Campus, Haifa, Israel between 2013 and 2021.

Methods

The ophthalmological assessment included a slit-lamp biomicroscopy of the anterior and posterior segment or indirect ophthalmoscopy. Electroretinography was employed for assessment of the retinal function, and retinal imaging included spectral-domain OCT and fundus autofluorescence. A systematic evaluation of the disease stage was based on clinical criteria including physical examination, purposeful imaging (X-ray, echocardiography, and US abdomen), and laboratory tests as needed.

Main Outcome Measures

Anatomical and functional assessment of the retina in patients with PH1, and the relationship between retinal dysfunction and kidney impairment.

Results

A total of 16 eyes were examined in the study of 8 children ranging in age from 4 to 19 years. Four eyes (25%) showed normal structural and functional retinal findings, 8 eyes (50%) presented functional impairment in the absence of pathological structural findings, and 4 eyes (25%) had advanced retinal damage that manifested as significant morphological and functional impairment. There was no direct relationship between the severity of the renal disease and the severity of the retinal phenotype.

Conclusions

Subjects with PH1 present varying severity levels of the retinal phenotype, with possible discrepancy between the clinical retinal morphology and the retinal function noted on electroretinography. These findings raise questions about the molecular basis of the retinal manifestations in PH1. The presence of functional impairment in the absence of evident crystal deposition in the retina suggests that, in addition to oxalate crystal accumulation, other biomolecular processes may play a role in the development of retinopathy.

Changes in chorioretinal flow index after cataract surgery: an optical coherence tomography angiography study

PURPOSE

Pseudophakic cystoid macular edema (CME) occurs in up to 2% of uneventful cataract surgeries. This study evaluates changes in macular blood flow succeeding uneventful phacoemulsification cataract extraction among otherwise visually healthy subjects.

METHODS

This prospective study included 18 eyes of 18 patients undergoing routine phacoemulsification. Optical coherence tomography angiography (OCT-A) was performed using the Angio-Retina 6 × 6 mm protocol with the XR Avanti Angio-Vue system (Optovue Inc., Fremont, California) prior to the surgery and 4-8 weeks thereafter. Exclusion criteria included motion artifacts, segmentation errors and signal strength index (SSI) < 40. The main outcome measure was change in flow index (FI) measured in all 4 retinal segmentation layers within an area of 1 mm diameter around the foveal center.

RESULTS

Following surgery, a significant increase in SSI (46.65 ± 8.62 versus 53.12 ± 8.07, p = 0.01), superficial plexus FI (0.98 ± 0.23 versus 1.16 ± 0.16, p = 0.02) and deep plexus FI (0.54 ± 0.46 versus 0.93 ± 0.39, p = 0.01) was found. No significant changes were noted in the outer retina or the choriocapillaris.

CONCLUSION

The study demonstrates a significant increase in FI in the superficial and deep retinal plexus following uneventful cataract surgery, with the greatest changes occurring in the latter. These findings corroborate evidence from structural imaging and support the vascular etiology of pseudophakic CME.

Autosomal dominant retinitis pigmentosa with incomplete penetrance due to an intronic mutation of the PRPF31 gene

Purpose

To identify the molecular mechanisms of the development of autosomal dominant retinitis pigmentosa (adRP) with incomplete penetrance in an Israeli Muslim Arab family.

Methods

Two patients with adRP underwent a detailed ophthalmic evaluation, including funduscopic examination, visual field testing, optical coherence tomography, and electroretinography. Genetic analysis was performed using a combination of whole exome sequencing (WES) and Sanger sequencing. The pathogenicity of the identified intronic variant was evaluated in silico using several web-based tools, in vitro using a minigene-based assay, and in vivo using reverse transcription PCR analysis of lymphocyte-derived RNA. The relative abundance of alternatively spliced transcripts was evaluated using amplicon-based next-generation sequencing. The relative expression levels of PRPF31 and CNOT3 were measured using quantitative PCR (qPCR) analysis.

Results

The two patients recruited in this study had childhood-onset RP, with night blindness as the initial symptom, followed by concentric restriction of the visual field. The funduscopic findings included narrowed retinal blood vessels and peripheral bone spicule pigmentation. By the third decade of life, the full-field electroretinography findings had been remarkably attenuated. In these patients, we identified a novel heterozygous intronic variant at position +5 of PRPF31 intron 11 (c.1146+5G>T). The same variant was also detected in one asymptomatic family member. Through in silico analysis, the variant was predicted to alter the splicing of intron 11. An in vitro splicing assay and a reverse transcription PCR analysis of lymphocyte-derived RNA revealed that the mutant allele yielded mainly a shorter transcript in which exon 11 was skipped. The skipping of exon 11 was expected to cause a frameshift and an aberrant truncated protein (p.Tyr359Serfs*29). The qPCR analysis revealed reduced PRPF31 expression levels in the mutation carriers, without a significant difference between the affected patient and his asymptomatic brother. We evaluated several factors that have been suggested to correlate with non-penetrance of PRPF31 mutations, including the number of cis-acting MSR1 elements adjacent to the PRPF31 core promoter, CNOT3 expression level, and CNOT3 rs4806718 single-nucleotide polymorphism. None of these factors correlated with non-penetrance in the family in this study.

Conclusions

We report a novel intronic mutation in PRPF31 underlying adRP. This report expands the spectrum of pathogenic mutations in PRPF31 and further demonstrates the importance of intronic mutations. Moreover, it demonstrates the phenomenon of incomplete penetrance previously associated with PRPF31 mutations. The fact that the non-penetrance in the family in this study could not be explained by any of the known mechanisms suggests the possible contribution of a novel modifier of PRPF31 penetrance.

Predicting Post-Cataract Surgery Visual Acuity in Vitrectomized Eyes: The Efficacy and Accuracy of "Lambda" Retinometry

BACKGROUND AND OBJECTIVE

Determine the ability of Lambda retinometry to predict post-cataract surgery visual acuity in vitrectomized eyes.

PATIENTS AND METHODS

Prospective study including 47 cataract surgery candidates with a history of pars plana vitrectomy (PPV). Lambda retinometry using a hand-held Lambda retinometer and best-corrected visual acuity (BCVA) were measured preoperatively, and BCVA was reassessed postoperatively.

RESULTS

Lambda predictions strongly correlated with postoperative BCVA (logarithm of the minimum angle of resolution [logMAR]) (P < .001, r² = 0.57), especially combined with preoperative BCVA (logMAR) (P < .001, r² = 0.65). In 89% of cases, postoperative BCVA was equal to or higher than the prediction. Neither cataract grades nor indications for PPV were associated with the accuracy of Lambda predictions (P = .882 and P = .790, respectively). Underestimation of visual outcome was more common than overestimation. A Lambda prediction of ≥ 20/40 (Snellen) had a positive predictive value of 85.7% and a negative predictive value of 73.6% for the postoperative outcome.

CONCLUSIONS

Lambda retinometry can reliably predict the postoperative BCVA in cataract patients who previously underwent PPV, with a tendency towards underestimation. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:535-542.].

PERSISTENT LOCULATED SUBRETINAL FLUID AFTER RHEGMATOGENOUS RETINAL DETACHMENT SURGERY

PURPOSE

To identify factors associated with persistent subretinal fluid (SRF) after small-gauge pars plana vitrectomy for primary rhegmatogenous retinal detachment.

METHODS

This retrospective study included patients from 2 tertiary centers who underwent pars plana vitrectomy for repair of rhegmatogenous retinal detachment between 2013 and 2016. Preoperative and intraoperative parameters were examined for association with development of SRF.

RESULTS

Overall, 153 eyes of 153 patients, mean age of 55.2 ± 17.9 years were included. Persistent SRF occurred in 15.0% (n = 23) and was associated with high myopia (65.22 vs. 26.15%, P < 0.001), macula-involving retinal detachment (91.30 vs. 66.15%, P = 0.02), phakic lens status (86.96 vs. 66.15%, P = 0.04), and younger age (47.8 ± 18.7 vs. 56.5 ± 17.5, P = 0.04) while drainage retinotomy was protective (13.04 vs. 34.11%, P = 0.04). In multivariate analysis, high myopia (P = 0.009) and macula-involving retinal detachment (P = 0.004) were associated with SRF, while drainage retinotomy was protective (P = 0.03). Persistent SRF was associated with outer retinal band irregularity (30.4 vs. 9.3%, P = 0.005). There were no significant differences in terms of change in best-corrected visual acuity from presentation (P = 0.70), or final best-corrected visual acuity (P = 0.54).

CONCLUSION

Eyes with preoperative high myopia and macular involvement, and those in which a drainage retinotomy was not performed, were more likely to develop persistent SRF.

Inhibition of amyloid fibrillation of γD-crystallin model peptide by the cochineal Carmine

γD-crystallin is among the most abundant γ-crystallins in the human eye lens which are essential for preserving its transparency. Aging, and environmental changes, cause crystallins to lose their native soluble structure and aggregate, resulting in the formation of cataract. Current treatment of cataract is surgical removal which is costly. Pharmaceutical therapeutics of cataract is an unmet need. We report a screen for small molecules capable of inhibiting aggregation of human γD-crystallin. Using a highly amyloidogenic hexapeptide model ⁴¹GCWMLY⁴⁶ derived from the full-length protein, we screened a library of 68 anthraquinone molecules using ThT fluorescence assay. A leading hit, the cochineal Carmine, effectively reduced aggregation of the model GDC6 peptide in dose dependent manner. Similar effect was observed toward aggregation of the full-length γD-crystallin. Transmission electron microscopy, intrinsic Tryptophan fluorescence and ANS fluorescence assays corroborated these results. Insights obtained from molecular docking suggested that Carmine interaction with monomeric GDC6 involved hydrogen bonding with Ace group, Cys, Met residues and hydrophobic contact with Trp residue. Carmine was non-toxic toward retinal cells in culture. It also reduced ex vivo the turbidity of human extracted cataract material. Collectively, our results indicate that Carmine could be used for developing new therapeutics to treat cataract.

The effect of contact lens wear on retinal spectral domain optical coherence tomography

BACKGROUND

This study assessed the impact of contact lens wear on retinal spectral domain optical coherence tomography (SD-OCT) image quality and macular thickness measurements, among subjects with myopia.

METHODS

This was a prospective study including 34 subjects (26.59 ± 3.19 years) with myopia or myopic astigmatism. Twelve were imaged wearing spherical soft contact lenses, eight non-contact lens wearers were imaged with a plano soft contact lens, and 14 with significant astigmatism were fitted with a rigid gas permeable (RGP) contact lens. For each group of contact lens types, the average image quality index (Q-index), and the average macular thickness measurements were compared between macular OCT scans obtained from the same eyes with and without a contact lens.

RESULTS

Among the subjects assessed with their habitual spherical soft lenses, the average Q-index was similar for scans acquired with and without a contact lens (30.10 ± 1.94 versus 31.03 ± 2.55; p = 0.18). Among non-contact lens wearers, the average Q-index was slightly higher for scans acquired without a contact lens, compared to scans with a plano contact lens (31.99 ± 2.06 versus 29.51 ± 1.56; p = 0.006). Among 14 subjects imaged wearing a fitted RGP contact lens, the Q-index was similar for scans acquired with and without a contact lens (29.04 ± 2.73 versus 28.75 ± 2.86; p = 0.78). In all groups, there were no correlations between the power of the sphere and change in the Q-index (that is, post- minus pre-contact lens Q-index), and no differences were found between OCT-derived macular thickness measurements from scans with and without a contact lens. The magnitude of cylinder was not correlated with the change in the Q-index in the habitual and RGP contact lens groups. However, an inverse correlation between cylinder power and change in the Q-index was found in the plano contact lens group.

CONCLUSION

In low to intermediate levels of myopia, with or without regular astigmatism, macular SD-OCT imaging does not merit placement of a soft or rigid contact lens, nor is there an added benefit from removing a habitual spherical soft lens prior to scanning.

Cone Spacing Correlates With Retinal Thickness and Microperimetry in Patients With Inherited Retinal Degenerations

Purpose

To determine whether high-resolution retinal imaging measures of macular structure correlate with visual function over 36 months in retinal degeneration (RD) patients and normal subjects.

Methods

Twenty-six eyes of 16 RD patients and 16 eyes of 8 normal subjects were studied at baseline; 15 eyes (14 RD) and 11 eyes (6 normal) were studied 36 months later. Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO) was used to identify regions of interest (ROIs) with unambiguous cones at baseline to measure cone spacing. AOSLO images were aligned with spectral-domain optical coherence tomography (SD-OCT) and fundus-guided microperimetry results to correlate structure and function at the ROIs. SD-OCT images were segmented to measure inner segment (IS) and outer segment (OS) thickness. Correlations between cone spacing, IS and OS thickness and sensitivity were assessed using Spearman correlation coefficient ρ with bootstrap analyses clustered by person.

Results

Cone spacing (ρ = 0.57, P < 0.001) and macular sensitivity (ρ = 0.19, P = 0.14) were significantly correlated with eccentricity in patients. Controlling for eccentricity, cone spacing Z-scores were inversely correlated with IS (ρ = −0.29, P = 0.002) and OS thickness (ρ = −0.39, P < 0.001) in RD patients only, and with sensitivity in normal subjects (ρ = −0.22, P < 0.001) and RD patients (ρ = −0.38, P < 0.001). After 36 months, cone spacing increased (P < 0.001) and macular sensitivity decreased (P = 0.007) compared to baseline in RD patients.

Conclusions

Cone spacing increased and macular sensitivity declined significantly in RD patients over 36 months. High resolution images of cone structure correlated with retinal sensitivity, and may be appropriate outcome measures for clinical trials in RD.

Laser Pointer-Induced Maculopathy: More Than Meets the Eye

PURPOSE

To describe the clinical findings in patients with laser-induced retinal injury.

METHODS

Consecutive patients presenting to a tertiary center between January 2014 and December 2015 following inadvertent ocular exposure to a laser pointer were included. Evaluation included a full ophthalmic examination and spectral-domain optical coherence tomography (SD-OCT).

RESULTS

Seven young patients (8 eyes) were identified. Their mean age was 18.7 years (median: 16 years; range: 12 to 36 years). In most cases, patients were exposed for several seconds to a 5-mW green laser. At presentation, all patients complained of a central/paracentral scotoma. Snellen best corrected visual acuity (BCVA) at presentation ranged from counting fingers to 6/6. In 5 eyes, a round, well-defined deep yellowish-orange discoloration at the level of the retinal pigment epithelium in the foveola, ranging from 150 to 350 μm in diameter, was noted on ophthalmoscopic examination. Additional findings were macular subhyaloid hemorrhage in 2 eyes and a full-thickness macular hole with cystoid macular edema in 1 eye. In all cases, baseline SD-OCT revealed disruption involving the photoreceptor inner segment/outer segment junction/ellipsoid zone band, and extended toward the inner aspect of the retinal pigment epithelium band, ranging from focal interruption to extensive full-thickness macular hole. All patients received oral corticosteroid treatment with prednisone (0.5 to 1 mg/kg). Follow-up ranged between 2 and 12 months. Over time, improvement in visual acuity to 6/8 and 6/6 was noted in all eyes but one, which remained poor at counting fingers from 2 meters. The visual improvement was associated with complete or near-complete restoration of the integrity of macular structure noted on SDOCT.

CONCLUSIONS

Commercial handheld laser pointers may inflict notable macular injury and damage vision permanently. Although good visual recovery was often noted, access to commercially available laser devices is potentially hazardous, especially to minors, and public awareness should be raised. [J Pediatr Ophthalmol Strabismus. 2018;55(5):312-318.].

Rosmarinic Acid Restores Complete Transparency of Sonicated Human Cataract Ex Vivo and Delays Cataract Formation In Vivo

Cataract, the leading cause of vision impairment worldwide, arises from abnormal aggregation of crystallin lens proteins. Presently, surgical removal is the only therapeutic approach. Recent findings have triggered renewed interest in development of non-surgical treatment alternatives. However, emerging treatments are yet to achieve full and consistent lens clearance. Here, the first ex vivo assay to screen for drug candidates that reduce human lenticular protein aggregation was developed. This assay allowed the identification of two leading compounds as facilitating the restoration of nearly-complete transparency of phacoemulsified cataractous preparation ex vivo. Mechanistic studies demonstrated that both compounds reduce cataract microparticle size and modify their amyloid-like features. In vivo studies confirmed that the lead compound, rosmarinic acid, delays cataract formation and reduces the severity of lens opacification in model rats. Thus, the ex vivo assay may provide an initial platform for broad screening of potential novel therapeutic agents towards pharmacological treatment of cataract.

Infliximab exerts a dose-dependent effect on retinal safety in the albino rabbit

PURPOSE

To assess the retinal toxicity of an intravitreal injection of infliximab, a monoclonal antibody to tumor necrosis factor α, in a rabbit model.

MATERIALS AND METHODS

Two groups of adult albino rabbits (n = 5) received intravitreal injections of infliximab (0.1 ml) in the study eye and balanced salt solution (BSS, 0.1 ml) in the control eye at baseline. Group 1 was administered with 1.5 mg/0.1 ml, and group 2 was injected with 7.5 mg/0.1 ml of infliximab solution. Electroretinography (ERG) was performed at baseline and at 1, 7, 30, and 45 days after the injection. Visual evoked potentials (VEPs) were recorded at 7 and 45 days after the injection. After the last electrophysiological assessment, the rabbits were euthanized and retinal histopathology and immunhistochemistry for glial fibrillary acidic protein (GFAP) were performed.

RESULTS

ERG responses demonstrated no significant deficit in retinal function in eyes injected with infliximab. Mean dark-adapted a-wave and b-wave maximal amplitude and semi-saturation constant values at baseline and throughout the 45 days of follow-up after the injection indicated no remarkable difference in outer retinal function between the control and experimental eyes. VEP responses were similar at each time point (7 and 45 days). No difference was seen in retinal histopathology and immunocytochemistry sections in eyes receiving the 1.5 mg/0.1 ml dose compared to the control eyes. However, increased GFAP labeling in retinal Müller cells was detected in rabbit eyes treated with the 7.5 mg/0.1 ml dose.

CONCLUSIONS

Intravitreal injection of 1.5 mg/0.1 ml infliximab dose has no toxic effect on the integrity (functional or structural) of the retina in rabbits. A higher dose of 7.5 mg/0.1 ml may be slightly toxic as suggested by positive Müller cell GFAP expression. Additional studies of retinal toxicity at higher doses and after multiple injections are needed to establish the retinal safety of intravitreal infliximab therapy in humans.

Qualifying to Use a Home Monitoring Device for Detection of Neovascular Age-Related Macular Degeneration

IMPORTANCE

Patients with intermediate age-related macular degeneration (AMD) using a home monitoring device have less loss of visual acuity, on average, at detection of choroidal neovascularization than do individuals using standard care monitoring techniques. Understanding the frequency with which patients are likely to initiate using a home monitoring device successfully is important in planning implementation of the device into practice.

OBJECTIVES

To determine the frequency with which patients with intermediate AMD qualify to use a home monitoring device and to establish a reliable baseline reference value with the device to monitor their AMD for progression to choroidal neovascularization.

DESIGN, SETTING, AND PARTICIPANTS

Between October 8, 2010, and May 20, 2011, a total of 131 eligible participants within a university-based retina practice with intermediate AMD in the study eye and visual acuity of 20/63 or better completed an in-clinic qualification test for the home device. Intermediate AMD was defined as multiple intermediate-sized drusen or at least 1 large druse. If both eyes were eligible, the eye with better visual acuity was selected as the study eye. If both eyes had the same visual acuity, the patient used the eye with subjectively better vision. Analysis was performed between August 1, 2011, and January 11, 2014.

MAIN OUTCOMES AND MEASURES

The proportion of patients with reliable qualification test results and a test score predictive of successful home use of a monitoring device for detecting neovascular AMD, and the proportion who established a baseline reference value at home.

RESULTS

A total of 129 participants (98.5%; 95% CI, 96.4%-99.9%) had reliable qualification test results; 91 participants (69.5%; 95% CI, 61.6%-77.4%) who completed this test attained a score that suggested they would be able to successfully use the home device. Among the 91 participants who could initiate home testing, 83 did so, including 80 participants (87.9%; 95% CI, 81.2%-94.6%) who established a baseline value that could be used as a reference for future monitoring. Younger participants were more likely to qualify for home testing (mean [SD] age, 73.1 [8.4] vs 81.1 [7.1] years; P < .001). Visual acuity at study enrollment did not appear to be associated with successful qualification (mean visual acuity for those who did and did not qualify was 20/28 and 20/31, respectively; P = .10).

CONCLUSIONS AND RELEVANCE

These data suggest that the in-office qualification test is a useful screening tool to identify patients who may benefit from the home device. In any given retina practice, our data suggest an estimated 61.6% to 77.4% of patients with intermediate AMD should be able to produce reliable initial test results in the office test using the home monitoring device and pass a qualification test to initiate home monitoring. Subsequently, 81.2% to 94.6% of patients should be able to establish a home baseline reference value for future monitoring.

Correlation of outer nuclear layer thickness with cone density values in patients with retinitis pigmentosa and healthy subjects

PURPOSE

We studied the correlation between outer nuclear layer (ONL) thickness and cone density in normal eyes and eyes with retinitis pigmentosa (RP).

METHODS

Spectral-domain optical coherence tomography (SD-OCT) scans were acquired using a displaced pupil entry position of the scanning beam to distinguish Henle's fiber layer from the ONL in 20 normal eyes (10 subjects) and 12 eyes with RP (7 patients). Cone photoreceptors were imaged using adaptive optics scanning laser ophthalmoscopy. The ONL thickness and cone density were measured at 0.5° intervals along the horizontal meridian through the fovea nasally and temporally. The ONL thickness and cone density were correlated using Spearman's rank correlation coefficient r.

RESULTS

Cone densities averaged over the central 6° were lower in eyes with RP than normal, but showed high variability in both groups. The ONL thickness and cone density were significantly correlated when all retinal eccentricities were combined (r = 0.74); the correlation for regions within 0.5° to 1.5° eccentricity was stronger (r = 0.67) than between 1.5° and 3.0° eccentricity (r = 0.23). Although cone densities were lower between 0.5° and 1.5° in eyes with RP, ONL thickness measures at identical retinal locations were similar in the two groups (P = 0.31), and interindividual variation was high for ONL and cone density measures. Although ONL thickness and retinal eccentricity were important predictors of cone density, eccentricity was over 3 times more important.

CONCLUSIONS

The ONL thickness and cone density were correlated in normal eyes and eyes with RP, but both were strongly correlated with retinal eccentricity, precluding estimation of cone density from ONL thickness. (ClinicalTrials.gov number, NCT00254605.).

Cone structure imaged with adaptive optics scanning laser ophthalmoscopy in eyes with nonneovascular age-related macular degeneration

PURPOSE

To evaluate cone spacing using adaptive optics scanning laser ophthalmoscopy (AOSLO) in eyes with nonneovascular AMD, and to correlate progression of AOSLO-derived cone measures with standard measures of macular structure.

METHODS

Adaptive optics scanning laser ophthalmoscopy images were obtained over 12 to 21 months from seven patients with AMD including four eyes with geographic atrophy (GA) and four eyes with drusen. Adaptive optics scanning laser ophthalmoscopy images were overlaid with color, infrared, and autofluorescence fundus photographs and spectral domain optical coherence tomography (SD-OCT) images to allow direct correlation of cone parameters with macular structure. Cone spacing was measured for each visit in selected regions including areas over drusen (n = 29), at GA margins (n = 14), and regions without drusen or GA (n = 13) and compared with normal, age-similar values.

RESULTS

Adaptive optics scanning laser ophthalmoscopy imaging revealed continuous cone mosaics up to the GA edge and overlying drusen, although reduced cone reflectivity often resulted in hyporeflective AOSLO signals at these locations. Baseline cone spacing measures were normal in 13/13 unaffected regions, 26/28 drusen regions, and 12/14 GA margin regions. Although standard clinical measures showed progression of GA in all study eyes, cone spacing remained within normal ranges in most drusen regions and all GA margin regions.

CONCLUSIONS

Adaptive optics scanning laser ophthalmoscopy provides adequate resolution for quantitative measurement of cone spacing at the margin of GA and over drusen in eyes with AMD. Although cone spacing was often normal at baseline and remained normal over time, these regions showed focal areas of decreased cone reflectivity. These findings may provide insight into the pathophysiology of AMD progression. (ClinicalTrials.gov number, NCT00254605).

High-resolution images of retinal structure in patients with choroideremia

PURPOSE

To study retinal structure in choroideremia patients and carriers using high-resolution imaging techniques.

METHODS

Subjects from four families (six female carriers and five affected males) with choroideremia (CHM) were characterized with best-corrected visual acuity (BCVA), kinetic and static perimetry, full-field electroretinography, and fundus autofluorescence (FAF). High-resolution macular images were obtained with adaptive optics scanning laser ophthalmoscopy (AOSLO) and spectral domain optical coherence tomography (SD-OCT). Coding regions of the CHM gene were sequenced.

RESULTS

Molecular analysis of the CHM gene identified a deletion of exons 9 to 15 in family A, a splice site mutation at position 79+1 of exon 1 in family B, deletion of exons 6 to 8 in family C, and a substitution at position 106 causing a premature stop in family D. BCVA ranged from 20/16 to 20/63 in carriers and from 20/25 to 5/63 in affected males. FAF showed abnormalities in all subjects. SD-OCT showed outer retinal layer loss, outer retinal tubulations at the margin of outer retinal loss, and inner retinal microcysts. Patchy cone loss was present in two symptomatic carriers. In two affected males, cone mosaics were disrupted with increased cone spacing near the fovea but more normal cone spacing near the edge of atrophy.

CONCLUSIONS

High-resolution retinal images in CHM carriers and affected males demonstrated RPE and photoreceptor cell degeneration. As both RPE and photoreceptor cells were affected, these cell types may degenerate simultaneously in CHM. These findings provide insight into the effect of CHM mutations on macular retinal structure, with implications for the development of treatments for CHM. (ClinicalTrials.gov number, NCT00254605.).

Unilateral Idiopathic Macular Telangiectasia with Choroidal Neovascularization

A 40-year-old man with decreasing visual acuity in his left eye over 1 year, diagnosed elsewhere as vein occlusion and treated unsuccessfully by systemic steroids was reported. Retrospective analysis of available previous imaging studies was undertaken, and a retrospective diagnosis of idiopathic macular telangiectasia (IMT) was made. Examination revealed subfoveal neovascularization and retinochoroidal anastomosis (RCA) in his left eye with macular edema and exudates surrounding it. The right eye was normal. Current fluorescein angiography (FA) confirmed the presence of choroidal neovascularization and RCA, and optical coherence tomography (OCT) demonstrated cystoid macular edema and subfoveal neovascularization.The patient was diagnosed with unilateral idiopathic macular telangiectasia complicated by subretinal neovascularization. The presences of a choroidal neovascularization process and an RCA have not, to our knowledge, been reported in this type of IMT.

Idiopathic intracranial hypertension after 40 years of age: clinical features in 23 patients

PURPOSE

Idiopathic intracranial hypertension (IIH) is a well-recognized disorder of unknown etiology associated with elevated intracranial pressure (ICP), normal neuroimaging, and normal cerebrospinal fluid (CSF) composition, found mostly among obese females of childbearing age. The aim of this study is to investigate the clinical features of IIH in patients older than 40 years.

METHODS

This is a retrospective chart review (1998-2007) of all consecutive patients older than 40 years who were diagnosed with IIH based on the Modified Dandy Criteria.

RESULTS

Twenty three of the 200 IIH patients in the institutional database fulfilled study entry criteria. They included 22 females and one male whose mean age was 51.4 years (range 41-79). Coexisting systemic arterial hypertension was found in 13 (56.5%) patients. Seventeen patients (73.9%) had symptoms attributable to elevated ICP. The most common presenting symptoms were visual; mainly blurred vision and transient visual obscuration (15/17 patients, 88.23%). Eleven patients (64.7%) complained of headache, and another 4 (23.5%) of pulsatile intracranial noise. The average follow up period was 21.8 months.

CONCLUSIONS

The findings indicate that IIH among individuals older than 40 years of age may be underreported. These patients are more likely to present with systemic hypertension and with more visual disturbances, but with fewer complaints of headache than the younger IIH population.

Ocular central nervous system lymphoma mimicking choroidal neovascularization

Two patients evaluated for metamorphopsia were noted to have inferotemporal retinal pigment epithelium elevations formed by a yellowish lesion. Fluorescein angiography showed granular hyperfluorescence with late leakage, which was interpreted as an occult choroidal neovascularization. One patient underwent photodynamic therapy. In both patients, neither vitreous cells nor neurologic manifestations were evident on presentation. Subsequent neurological signs appeared that prompted performance of brain imaging, which confirmed a space-occupying lesion. In both patients, the tumor was proven on histopathologic examination of brain tissue to be central nervous system lymphoma. Awareness of other possible underlying pathologies is warranted in cases of atypical choroidal neovascularization.

VARIABILITY AMONG RETINA SPECIALISTS IN EVALUATING FLUORESCEIN ANGIOGRAMS OF PATIENTS WITH NEOVASCULAR AGERELATED MACULAR DEGENERATION

PURPOSE

To determine the rate of agreement among five retina specialists in classifying various angiographic features of subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD), as evaluated on printed digital fluorescein angiogram (FA) frames, as well as determination of eligibility for photodynamic treatment (PDT) according to established guidelines.

METHODS

Ninety-two digital FAs demonstrating subfoveal CNV secondary to AMD were evaluated independently by five retina specialists. The pattern of classic component could be classified as no classic component, minimally classic, predominantly classic, or classic only. Each grader was asked to determine eligibility of each case to PDT according to established treatment guidelines, national health insurance guidelines, and one's own personal judgment.

RESULTS

The kappa coefficient of concordance calculated for all five observers regarding CNV localization was 0.285, indicating fair overall agreement, and was 0.295, indicating fair agreement, regarding classification of leakage pattern. The kappa coefficient of agreement calculated for all five graders regarding eligibility for treatment according to established international guidelines, national health insurance, and each grader's own personal judgment was 0.163, 0.33, and 0.164, respectively, indicating slight to fair overall agreement.

CONCLUSION

Considerable variability may exist among retina specialists interpreting FAs and should be considered in the assessment of treatment guidelines.

Retinal pigment epithelial detachment

Detachment of the retinal pigment epithelium is a prominent feature of many chorio-retinal disease processes, the most prevalent of which is age-related macular degeneration (AMD). Detachment of the retinal pigment epithelium may or may not be associated with choroidal neovascularization and may be caused by different types of pathogenesis, each associated with distinct angiographic features, natural course, visual prognosis, and response to treatment. The phrase "detachment of the retinal pigment epithelium" is used quite often, not always in the correct association and with no clear differentiation between its various types. It is important to identify the specific nature of detachment of the retinal pigment epithelium, and to establish an accurate diagnosis and treatment plan. Therefore, we present a review of the existing types of detachment of the retinal pigment epithelium with what we propose as being appropriate nomenclature and classification, and potential treatment recommendations.

Endogenous Phialemonium curvatum endophthalmitis

PURPOSE

To report a case of bilateral endogenous Phialemonium curvatum endophthalmitis, secondary to intrapenile injections for erectile dysfunction.

DESIGN

Observational case report.

METHODS

A 71-year-old man with P. curvatum endocarditis and bilateral decreased vision was diagnosed as having bilateral endogenous endophthalmitis. P. curvatum was identified in cultures that were performed on samples of the vitreous. Treatment consisted of bilateral vitrectomy and intraocular and systemic antifungals.

RESULTS

Despite resolution of the systemic infection, the patient's postoperative visual acuity remained limited to hand movement, and the ophthalmic clinical picture remained unchanged.

CONCLUSIONS

P. curvatum is a pathogen that can be readily isolated from the vitreous. The authors are unaware of previous reported cases of ocular infection that was caused by P. curvatum.