Static Perimetry in the Rate of Progression in USH2A-related Retinal Degeneration (RUSH2A) Study: Assessment Through 2 Years.

PURPOSE: To evaluate disease progression using static perimetry (SP) in patients with USH2A-related retinal degeneration, including Usher syndrome type 2 (USH2) and nonsyndromic autosomal recessive retinitis pigmentosa. DESIGN: Prospective, observational cohort study. METHODS: A total of 102 patients with biallelic disease-causing sequence variants in USH2A with baseline best-corrected visual acuity (BCVA) letter score ≥54 were recruited from 16 clinical sites in Europe and North America. SP, BCVA, full-field stimulus thresholds, spectral domain optical coherence tomography macular scans, and fundus-guided mesopic microperimetry were performed at baseline and annually. The main outcome measures were total hill of vision (VTOT), hill of vision in the central 30° (V30), VTOT minus V30 (VPERIPH), and mean sensitivity. RESULTS: The average decline (95% CI) was 2.05 (1.40, 2.70) decibel-steradian (dB-sr)/y for VTOT, 0.48 (0.32, 0.65) dB-sr/y for V30, 1.53 (0.97, 2.08) dB-sr/y for VPERIPH, and 0.55 (0.40, 0.71) dB/y for mean sensitivity. Average percentage decline per year was 8.3 (5.5, 11.1) for VTOT, 5.2 (3.0, 7.4) for V30, 16.0 (9.5, 22.0) for VPERIPH, and 5.1 (3.5, 6.7) for mean sensitivity. Changes from baseline to year 2 in all SP measures were highly correlated (r's ranging from 0.52 [V30 vs VPERIPH] to 0.98 [VTOT vs VPERIPH]). CONCLUSIONS: Quantitative measures of SP declined significantly over 2 years in USH2A-related retinal degeneration. The annual percentage rate of change was greatest for VTOT and VPERIPH, whereas V30 and mean sensitivity changed least, reflecting earlier and more severe peripheral degeneration compared with central loss.

Computer-assisted photoreceptor assessment on Heidelberg Engineering Spectralis™ High Magnification Module™ images.

PURPOSE: To evaluate reliability and repeatability of computer-assisted measurements of cone photoreceptor metrics on Heidelberg Engineering Spectralis™ High Magnification Module (HMM™) Automatic Real-time Tracking (ART™) images. METHODS: We analyzed HMM™ images in three separate study arms. Computer-assisted cone identification software was validated using an open-access adaptive optics (AO) dataset. We compared results of the first arm to data from AO and histology. We evaluated intersession repeatability of our computer-assisted cone analysis in the second arm. We assessed the capability of HMM™ to visualize cones in the presence of pathology in the third arm. RESULTS: We included 10 healthy subjects in the first arm of our study, 5 additional healthy participants in the second arm and 5 patients in the third arm. In total, we analyzed 225 regions of interest on HMM™ images. We were able to automatically identify cone photoreceptors and assess corresponding metrics at all eccentricities between 2 and 9° from the fovea. Cone density significantly declined with increasing eccentricity (p = 4.890E-26, Friedman test). With increasing eccentricity, we found a significant increase in intercell distance (p = 2.196E-25, Friedman test) and nearest neighbor distance (p = 1.997E-25, Friedman test). Cone hexagonality ranged between 71 and 85%. We found excellent automated intersession repeatability of cone density counts and spacing measurements. In pathology, we were also able to repeatedly visualize photoreceptors. CONCLUSION: Computer-assisted cone photoreceptor analysis on Spectralis™ HMM™ images is feasible, and most cone metrics show excellent repeatability. HMM™ imaging may be useful for photoreceptor analysis as progression marker in outer retinal disease.

PRPH2 mutation update: In silico assessment of 245 reported and 7 novel variants in patients with retinal disease.

Mutations in PRPH2, encoding peripherin-2, are associated with the development of a wide variety of inherited retinal diseases (IRDs). To determine the causality of the many PRPH2 variants that have been discovered over the last decades, we surveyed all published PRPH2 variants up to July 2020, describing 720 index patients that in total carried 245 unique variants. In addition, we identified seven novel PRPH2 variants in eight additional index patients. The pathogenicity of all variants was determined using the ACMG guidelines. With this, 107 variants were classified as pathogenic, 92 as likely pathogenic, one as benign, and two as likely benign. The remaining 50 variants were classified as variants of uncertain significance. Interestingly, of the total 252 PRPH2 variants, more than half (n = 137) were missense variants. All variants were uploaded into the Leiden Open source Variation and ClinVar databases. Our study underscores the need for experimental assays for variants of unknown significance to improve pathogenicity classification, which would allow us to better understand genotype-phenotype correlations, and in the long-term, hopefully also support the development of therapeutic strategies for patients with PRPH2-associated IRD.

The cost-effectiveness of bevacizumab, ranibizumab and aflibercept for the treatment of age-related macular degeneration-A cost-effectiveness analysis from a societal perspective.

BACKGROUND: The discussion on the use of bevacizumab is still ongoing and often doctors are deterred from using bevacizumab due to legal or political issues. Bevacizumab is an effective, safe and inexpensive treatment option for neovascular age-related macular degeneration (AMD), albeit unregistered for the disease. Therefore, in some countries ophthalmologists use the equally effective but expensive drugs ranibizumab and aflibercept. We describe the economic consequences of this dilemma surrounding AMD treatment from a societal perspective. METHODS: We modelled cost-effectiveness of treatment with ranibizumab (as-needed), aflibercept (bimonthly) and bevacizumab (as-needed). Effectiveness was estimated by systematic review and meta-analysis. The drug with the most favourable cost-effectiveness profile compared to bevacizumab was used for threshold analyses. First, we determined how much we overspend per injection. Second, we calculated the required effectiveness to justify the current price and the reasonable price for a drug leading to optimal vision. Finally, we estimated how much Europe overspends if bevacizumab is not first choice. RESULTS: Bevacizumab treatment costs €27,087 per year, about €4,000 less than aflibercept and €6,000 less than ranibizumab. With similar effectiveness for all drugs as shown by meta-analysis, bevacizumab was the most cost-effective. Aflibercept was chosen for threshold analyses. Aflibercept costs €943 per injection, but we determined that the maximum price to be cost-effective is €533. Alternatively, at its current price, aflibercept should yield about twice the visual gain. Even when optimal vision can be achieved, the maximum price for any treatment is €37,453 per year. Most importantly, Europe overspends €335 million yearly on AMD treatment when choosing aflibercept over bevacizumab. CONCLUSION: Bevacizumab is the most cost-effective treatment for AMD, yet is not the standard of care across Europe. The registered drugs ranibizumab and aflibercept lead to large overspending without additional health benefits. Health authorities should consider taking steps to implement bevacizumab into clinical practice as first choice.

Automatic drusen quantification and risk assessment of age-related macular degeneration on color fundus images.

PURPOSE: To evaluate a machine learning algorithm that allows for computer-aided diagnosis (CAD) of nonadvanced age-related macular degeneration (AMD) by providing an accurate detection and quantification of drusen location, area, and size. METHODS: Color fundus photographs of 407 eyes without AMD or with early to moderate AMD were randomly selected from a large European multicenter database. A machine learning system was developed to automatically detect and quantify drusen on each image. Based on detected drusen, the CAD software provided a risk assessment to develop advanced AMD. Evaluation of the CAD system was performed using annotations made by two blinded human graders. RESULTS: Free-response receiver operating characteristics (FROC) analysis showed that the proposed system approaches the performance of human observers in detecting drusen. The estimated drusen area showed excellent agreement with both observers, with mean intraclass correlation coefficients (ICC) larger than 0.85. Maximum druse diameter agreement was lower, with a maximum ICC of 0.69, but comparable to the interobserver agreement (ICC = 0.79). For automatic AMD risk assessment, the system achieved areas under the receiver operating characteristic (ROC) curve of 0.948 and 0.954, reaching similar performance as human observers. CONCLUSIONS: A machine learning system capable of separating high-risk from low-risk patients with nonadvanced AMD by providing accurate detection and quantification of drusen, was developed. The proposed method allows for quick and reliable diagnosis of AMD, opening the way for large dataset analysis within population studies and genotype-phenotype correlation analysis.

Genetic, behavioral, and sociodemographic risk factors for second eye progression in age-related macular degeneration.

PURPOSE: This study was conducted to investigate the correlation of genetic, sociodemographic, and behavioral risk factors with second eye progression to end-stage AMD. METHODS: One hundred and eight patients with end-stage AMD in one or both eyes were included in a retrospective time-to-event analysis of the onset of end-stage AMD in the second eye. Multivariate Cox regression survival analysis was performed for sex, age, smoking, body mass index (BMI), education, and 16 single nucleotide polymorphisms (SNPs) associated with AMD. RESULTS: Except for education, all sociodemographic and behavioral risk factors analyzed were significantly associated with a more rapid progression toward second eye involvement. Hazard ratios (HRs) were 2.6 (95% confidence interval [CI], 1.4-5.0) for female sex; 5.0 (95% CI, 2.0-12.5) for age >80; 2.2 (95% CI, 1.1-4.1) for BMI >30; and 4.4 (95% CI, 1.4-14.3) for >40 pack years, compared with the referent groups. Carriers of the lipoprotein lipase (LPL; rs12678919) risk alleles were at risk for more rapid progression to end-stage AMD in the second eye compared with the referent wild-type genotype (HR 2.0; 95% CI, 1.0-3.6). For complement factor I (CFI; rs10033900), homozygous carriers of the risk allele progressed faster than wild-type individuals (HR 2.2; 95% CI, 1.1-4.3). CONCLUSIONS: Sociodemographic, behavioral, and genetic risk factors are associated with the rate of second eye progression toward end-stage AMD. The findings of this study underline the importance of lifestyle factors and the complement pathway in AMD progression and suggest a role of the high-density-lipoprotein metabolism in second eye progression.

Genomic structure and assessment of the retinally expressed RFamide-related peptide gene in dominant cystoid macular dystrophy.

PURPOSE: Computer-assisted sampling of EST data contained within the UniGene human sequences collection is being used to establish a catalog of novel genes that are expressed exclusively or predominantly in the human retina. This provides a valuable source for candidate genes possibly involved in retinal degeneration. In this report we present the characterization of the C7orf9 gene locus encoding RFamide-related peptides (RFRPs) and its evaluation in dominant cystoid macular dystrophy (CYMD). METHODS: Bioinformatics and cDNA library screening were used to isolate the full-length cDNA sequence and to determine the genomic organization of C7orf9. Expression profiling was done by RT-PCR and Northern blot analysis. C7orf9 was evaluated as a candidate gene for CYMD by DNA sequencing and Southern blot analysis in two affected individuals from an extended Dutch CYMD family. RESULTS: The C7orf9 cDNA transcript consists of 1190 bp and is organized into 3 exons on the short arm of chromosome 7 within the critical region for CYMD. The transcript is specifically expressed in the retina but not in a large range of other human tissues. No disease-causing mutations or larger gene rearrangements were found. CONCLUSIONS: We provide the genomic organization of the RFamide-related peptide gene, C7orf9, which encodes a precursor protein for at least two small neuropeptides, referred to as NPSF (alias RFRP-1) and NPVF (alias RFRP-3) and show that it is abundantly expressed in the human retina. Results of our comprehensive mutation analysis suggests that C7orf9 is not the CYMD gene.