Spectrum of Disease Severity in Nonsyndromic Patients With Mutations in the CEP290 Gene: A Multicentric Longitudinal Study

PurposeThe purpose of this study was to perform a detailed longitudinal phenotyping and genetic characterization of 32 Italian patients with a nonsyndromic retinal dystrophy and mutations in the CEP290 gene.MethodsWe reviewed the clinical history and examinations of 32 patients with a nonsyndromic retinal dystrophy due to mutations in the CEP290 gene, followed up (mean follow-up: 5.9 years) at 3 Italian centers. The clinical examinations included: best corrected visual acuity (BCVA), optical coherence tomography (OCT), and full-field electroretinogram (ERG).ResultsPatients (mean age = 19.0 ± 3.4 years) had a mean BCVA of 1.73 ± 0.20 logMAR. Longitudinal analysis of BCVA showed a nonsignificant decline. Central retinal thickness (CRT) declined significantly with age at an exponential rate of 1.0%/year (P = 0.001). At disease onset, most patients (19/32; 49.4%) had nystagmus. The absence of nystagmus was significantly associated with better BCVA and more preserved CRT (P < 0.05). ERG showed undetectable responses in most patients (64.0%), whereas reduced scotopic and photopic responses were observed in four patients (16.0%) who had no nystagmus. We identified 35 different variants, among which 12 were novel. Our genotype-phenotype correlation analysis shows a significantly worse BCVA in patients harboring a loss-of-function mutation and the deep-intronic variant c.2991+1655A>G.ConclusionsOur study highlights a mild phenotype of the disease, characterized by absence of nystagmus, good visual acuity, considerably preserved retinal morphology, and recordable ERG, confirming the wide spectrum of CEP290-related retinal dystrophies. Finally, in our cohort, the deep intronic variant c.2991+1655A>G was associated with a more severe phenotype.     

Spectrum of Disease Severity in Patients With X-Linked Retinitis Pigmentosa Due to RPGR Mutations

PurposeThe purpose of this study was to perform a detailed longitudinal phenotyping of X-linked retinitis pigmentosa (RP) caused by mutations in the RPGR gene during a long follow-up period.MethodsAn Italian cohort of 48 male patients (from 31 unrelated families) with RPGR-associated RP was clinically assessed at a single center (mean follow-up = 6.5 years), including measurements of best-corrected visual acuity (BCVA), Goldmann visual field (GVF), optical coherence tomography (OCT), fundus autofluorescence (FAF), microperimetry, and full-field electroretinography (ERG).ResultsPatients (29.6 ± 15.2 years) showed a mean BCVA of 0.6 ± 0.7 logMAR, mostly with myopic refraction (79.2%). Thirty patients (62.5%) presented a typical RP fundus, while the remaining sine pigmento RP. Over the follow-up, BCVA significantly declined at a mean rate of 0.025 logMAR/year. Typical RP and high myopia were associated with a significantly faster decline of BCVA. Blindness was driven primarily by GVF loss. ERG responses with a rod-cone pattern of dysfunction were detectable in patients (50%) that were significantly younger and more frequently presented sine pigmento RP. Thirteen patients (27.1%) had macular abnormalities without cystoid macular edema. Patients (50%) with a perimacular hyper-FAF ring were significantly younger, had a higher BCVA and a better-preserved ellipsoid zone band than those with markedly decreased FAF. Patients harboring pathogenic variants in exons 1 to 14 showed a milder phenotype compared to those with ORF15 mutations.ConclusionsOur monocentric, longitudinal retrospective study revealed a spectrum disease progression in male patients with RPGR-associated RP. Slow disease progression correlated with sine pigmento RP, absence of high myopia, and mutations in RPGR exons 1 to 14.     

Axial Length Distributions in Patients With Genetically Confirmed Inherited Retinal Diseases

PurposeWe investigated axial length (AL) distributions in inherited retinal diseases (IRDs), comparing them with reference cohorts.MethodsAL measurements from IRD natural history study participants were included and compared with reference cohorts (TwinsUK, Raine Study Gen2-20, and published studies). Comparing with the Raine Study cohort, formal odds ratios (ORs) for AL ≥ 26 mm or AL ≤ 22 mm were derived for each IRD (Firth''s logistic regression model, adjusted for age and sex).ResultsMeasurements were available for 435 patients (median age, 19.5 years). Of 19 diseases, 10 had >10 participants: ABCA4 retinopathy; CNGB3- and CNGA3-associated achromatopsia; RPGR-associated disease; RPE65-associated disease; blue cone monochromacy (BCM); Bornholm eye disease (BED); TYR- and OCA2-associated oculocutaneous albinism; and GPR143-associated ocular albinism. Compared with the TwinsUK cohort (n = 322; median age, 65.1 years) and Raine Study cohort (n = 1335; median age, 19.9 years), AL distributions were wider in the IRD groups. Increased odds for longer ALs were observed for BCM, BED, RPGR, RPE65, OCA2, and TYR; increased odds for short AL were observed for RPE65, TYR, and GPR143. In subanalysis of RPGR-associated disease, longer average ALs occurred in cone–rod dystrophy (n = 5) than rod–cone dystrophy (P = 0.002).ConclusionsSeveral diseases showed increased odds for longer AL (highest OR with BCM); some showed increased odds for shorter AL (highest OR with GPR143). Patients with RPE65- and TYR-associated disease showed increased odds for longer and for shorter eyes. Albinism genes were associated with different effects on AL. These findings add to the phenotype of IRDs and may yield insights into mechanisms of refractive error development.     

A clinical study of patients with novel CDHR1 genotypes associated with late-onset macular dystrophy

PurposeTo describe the clinical and electrophysiological features of adult-onset macular dystrophy, due to novel combinations of CDHR1 alleles, and compare the associated phenotypes with previous reports.MethodsThe clinical records of patients with macular dystrophy and biallelic variants in CDHR1 were reviewed. Data analysed included best corrected visual acuity (BCVA), fundus images: autofluorescence (AF) and optical coherence tomography (OCT); full field electroretinography (ERG) and pattern ERG (PERG).ResultsSeven patients from six pedigrees were ascertained. One patient was homozygous for a known synonymous variant p.(Pro261=), four were compound heterozygous for the p.(Pro261=) variant and a novel allele of CDHR1: p.(Gly188Ser), p.(Met1?), or p.(Val458Asp); one patient was compound heterozygous for two previously unreported variants: c.297+1G>T in trans with p.(Pro735Thr). The range of BCVA at the last clinic review was (6/5–6/60). Autofluorescence showed macular flecks of increased AF in mild cases and patches of reduced AF in severe cases. The OCT showed attenuation of the ellipsoid zone (EZ) in mild cases and loss of the EZ and the outer nuclear layer in severe cases; one patient had subfoveal hyporeflective region between the EZ and the retinal pigment epithelium. The full field ERG was normal or borderline subnormal in all cases, and the PERG was subnormal in mild cases or undetectable in severe cases.ConclusionsThis report corroborates previous observations that genotypes distinct from those causing pan-retinal dystrophy can cause a milder phenotype, predominantly affecting the macula, and expands the spectrum of these genotypes. The findings in this cohort suggest a potential macular susceptibility to mild perturbations of the photoreceptor cadherin.Subject terms: Hereditary eye disease, Disease genetics     

The relationship between pigment epithelial detachment and visual outcome in neovascular age-related macular degeneration and polypoidal choroidal vasculopathy

Background/objectivesTo compare the detailed optical coherence tomography (OCT)-based morphological parameters of pigment epithelial detachment (PED) in eyes presenting with neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV), and to assess whether these PED-associated parameters influence 1-year visual outcomes.Subject/methodsWe analysed images from a prospective observational study of treatment-naive Asian participants with nAMD or PCV. An independent reading centre graded baseline morphological features of PED on spectral-domain OCT, including greatest height, greatest width, greatest volume, morphology (predominantly dome shaped versus peaked), presence of retinal pigment epithelium (RPE) tear and cholesterol bands. The influence of these baseline features on 12 months best corrected visual acuity (BCVA) was evaluated.ResultsSeventy-eight eyes of 78 participants with PED were studied. In total, 40 (51.3%) participants had nAMD and 38 (48.7%) had PCV. Eyes with PCV, compared with nAMD, had PED of greater height (455.9 µm versus 389.9 µm; P = 0.035) and had higher prevalence of RPE tear (22.9 versus 5.3%; P = 0.041). In the multivariate analysis, only baseline BCVA was significantly associated with month 12 BCVA, but none of the PED-associated OCT parameters at baseline influenced month 12 BCVA.ConclusionsDespite the differences in PED height and prevalence of RPE tear between nAMD and PCV, none of these PED morphological factors on OCT at baseline significantly influenced visual outcome at 12 months.Subject terms: Predictive markers, Medical imaging     

Long-term clinical outcomes of submacular blood removal with isolated autologous retinal pigment epithelium-choroid patch graft transplantation in long-standing large-sized submacular hematomas: An Indian experience

Purpose:To study the outcomes of submacular blood removal with isolated autologous full-thickness retinal pigment epithelial (RPE)-choroid patch graft transplantation in long-standing large-sized submacular hematomas in Indian population.Methods:A retrospective study was done on eight consecutive patients of long-standing large-sized submacular hematoma from east India. In all cases, 23G vitrectomy was performed with the induction of retinal detachment (performed with or without 38G or 41G subretinal cannula) and a temporal 180° retinectomy was done. Submacular blood along with choroidal neovascular tissue was removed. A full-thickness RPE-choroid autologous patch graft was taken from a relatively healthy quadrant at the mid periphery and then the graft transferred under perfluorocarbon liquid (PFCL) to place it in the subfoveal area. Then, retina was re-attached using PFCL and laser completed. Silicone oil (5000 cst) was used as a tamponade. Post-operatively, wide-field fundus photographs (Optos), serial optical coherence tomography (OCT), indocyanine green angiography (ICGA), and multifocal electroretinography (ERG) were done.Results:The mean age of the patients at presentation was 67.88 ± 10.03 years. Mean pre-operative best corrected visual acquity (BCVA) was 2.64 ± 0.3 log MAR and mean postoperative BCVA was 1.095 ± 0.27 log MAR (P < 0.05). The mean follow-up was 20 ± 16.57 months. ICG showed re-vascularization of translocated graft in all at 2 months. Multifocal ERG (after 6 months) showed some waveform in all. None of the cases developed re-bleed.Conclusion:Removal of submacular blood and neovascular membrane with autologous RPE-choroid graft is a viable option in cases with long-standing large submacular hematomas.     

Clinical and molecular genetics of Leber's congenital amaurosis: a multicenter study of Italian patients

PURPOSE: To identify the molecular basis of Leber's congenital amaurosis (LCA) in a cohort of Italian patients and to perform genotype-phenotype analysis. METHODS: DNA samples from 95 patients with LCA were analyzed by using a microarray chip containing disease-associated sequence variants in eight LCA genes. In addition, all patients in whom no mutations were identified by microarray were subjected to sequence analysis of the CEP290 gene. Patients with mutations identified underwent a detailed ophthalmic evaluation. RESULTS: Disease-causing mutations were identified in 28% of patients, and twelve novel variants were identified. Mutations occurred more frequently in the RPE65 (8.4%), CRB1 (7.4%), and GUCY2D (5.2%) genes. Mutations in CEP290 were found in only 4.2% of the patients analyzed. Clinical assessment of patients carrying RPE65 or CRB1 mutations revealed the presence of retained visual capabilities in the first decade of life. RPE65 mutations were almost always associated with normal macular thickness, as assessed by optical coherence tomography (OCT), whereas CRB1 mutations were associated with reduced retinal thickness and a coarsely laminated retina. Fundus autofluorescence was mostly observed in patients with RPE65 and GUCY2D mutations and was not elicitable in patients carrying CRB1. CONCLUSIONS: RPE65 gene mutations represented a significant cause of LCA in the Italian population, whereas GUCY2D and CEP290 mutations had a lower frequency than that found in other reports. This finding suggests that the genetic epidemiology of LCA in Italy is different from that reported in the United States and in northern European countries. Autofluorescence in patients with RPE65 mutations was more frequently associated with preserved retinal thickness, which suggests that these mutations are not associated with progression of retinal degeneration. Therefore, normal retinal thickness (identified with OCT) and fundus autofluorescence may be the means with which to identify patients with LCA who carry RPE65 mutations, which are expected to be a potential gene therapy target in the near future.     

The predictive value of ectopic inner retinal layer staging scheme for idiopathic epiretinal membrane: surgical results at 12 months

Background/objectivesTo assess the effect of ectopic inner foveal layers (EIFL) based staging scheme, foveal avascular zone (FAZ) alterations and other microstructural optical coherence tomography (OCT) findings on visual function for patients undergoing idiopathic epiretinal membrane (iERM) surgery.Subjects/methodsIn this retrospective study, patients who underwent 27 G pars plana vitrectomy (PPV) for idiopathic ERM with a minimum follow-up of 12 months were included. Preoperative and postoperative OCT scans, FAZ area measurements on en face OCT angiography images and mean retinal sensitivity (MRS) using microperimetry were recorded in all cases. The correlation of FAZ area, EIFL and other OCT parameters with preoperative and postoperative best-corrected visual acuity (BCVA) was analysed.ResultsIn all, 112 eyes of 112 patients were included. Visual acuity improvement was statistically significant in all four stages; however, differences between Stages 2, 3 and 4 ERMs remained significant (p < 0.05). The presence and thickness of the EIFL was associated with worse baseline (p = 0.013; p = 0.005, respectively) and final (p < 0.001 for both) BCVA. The presence of cystoid macular oedema was associated with worse BCVA at baseline (p = 0.027) and postoperative month-6 (p = 0.04). The mean FAZ area was significantly reduced in all stages of ERM compared with the fellow eyes (p < 0.05 for all). Postoperative retinal sensitivity improvement was statistically significant in Stage 1 and Stage 2.ConclusionThe presence of EIFL is an independent predictor of worse postoperative BCVA. Accordingly, despite significant BCVA improvements in all stages of ERM, visual acuity gain remains limited in eyes with Stage 3 and Stage 4 ERM.Subject terms: Retinal diseases, Fluorescence spectroscopy     

Retinal miRNAs variations in a large cohort of inherited retinal disease

Background: Although great efforts have been paid on identification of genetic predisposition in the inherited retinal disease (IRD), genetic causes of a large proportion of patients remain a mystery. This dilemma makes us attempt to speculate that genetic components other than coding genes might be an additional pool predisposing IRD. In this study, we aim to perform a mutational screening in a large cohort of IRD patients with a particular focus on retina-specific or abundant microRNAs (miRs).

Material and methods: A total of 324 unrelated patients with IRD were recruited. Targeted next-generation sequencing (tNGS) was performed to survey genetic mutations in 32 known miRs highly expressed in the retina, followed by validation with Sanger sequencing, co-segregation analysis in each family, and computational assessments.

Results: Novel genotype-phenotype associations have been uncovered. In total, six different variants in the miRs were identified, including four rare ones, miR-216a (n.56C>A), miR-216b (n.43_44insG), miR-7–2 (n.107C>T), and miR-7–3 (n.95G>A). The other two variants, miR-182 (n.106G>A) and miR-216a (n.105T>A), were considered as polymorphic.

Conclusions: We for the first time screened candidate retinal miRs in patients with IRD. Although there is no convincing evidence that these variants are responsible for the IRD, the results enhance the current knowledge of the associations between IRD and miRNAs variants.     

Identification of the genetic determinants responsible for retinal degeneration in families of Mexican descent

Purpose: To investigate the clinical characteristics and genetic basis of inherited retinal degeneration (IRD) in six unrelated pedigrees from Mexico.

Methods: A complete ophthalmic evaluation including measurement of visual acuities, Goldman kinetic or Humphrey dynamic perimetry, Amsler test, fundus photography, and color vision testing was performed. Family history and blood samples were collected from available family members. DNA from members of two pedigrees was examined for known mutations using the APEX ARRP genotyping microarray and one pedigree using the APEX LCA genotyping microarray. The remaining three pedigrees were analyzed using a custom-designed targeted capture array covering the exons of 233 known retinal degeneration genes. Sequencing was performed on Illumina HiSeq. Reads were mapped against hg19, and variants were annotated using GATK and filtered by exomeSuite. Segregation and ethnicity-matched control sample analyses were performed by dideoxy sequencing.

Results: Six pedigrees with IRD were analyzed. Nine rare or novel, potentially pathogenic variants segregating with the phenotype were detected in IMPDH1, USH2A, RPE65, ABCA4, and FAM161A genes. Among these, six were known mutations while the remaining three changes in USH2A, RPE65, and FAM161A genes have not been previously reported to be associated with IRD. Analysis of 100 ethnicity-matched controls did not detect the presence of these three novel variants indicating, these are rare variants in the Mexican population.

Conclusions: Screening patients diagnosed with IRD from Mexico identified six known mutations and three rare or novel potentially damaging variants in IMPDH1, USH2A, RPE65, ABCA4, and FAM161A genes that segregated with disease.     

Effect of Foveal Pit Restoration in Foveal Avascular Zone after Surgery for Idiopathic Epiretinal Membrane

PurposeTo investigate the relationship between ophthalmic parameters—including optical coherence tomography (OCT) and OCT angiography findings—and foveal pit restoration in eyes that had undergone vitrectomy for idiopathic epiretinal membrane (iERM) removal.MethodsThis study retrospectively analyzed data of patients who underwent pars planar vitrectomy for the removal of epirentinal membrane. Only eyes with iERM above stage 2 with a follow-up over 6 months were included. Baseline data and changes in ophthalmic parameters were analyzed from 3 months before to 12 months after surgery. Additionally, we stratified iERM patients into two groups (foveal pit restoration and no restoration group). Longitudinal comparison analyses between the two groups were done in best-corrected visual acuity (BCVA), central foveal thickness (CFT) and foveal avascular zone (FAZ) areas measurements using swept-source OCT and OCT angiography.ResultsForty-three patients with a mean age of 75 ± 5 years were enrolled. After surgery, BCVA, FAZ, and CFT showed improvements over time (all p < 0.002). Thirty-one patients were designated into the foveal pit restoration (R) group and 12 patients into the no restoration (NR) group. Differences in BCVA and FAZ area in both groups existed up to 6 months. However, BCVA improved and FAZ expanded (R, 0.20 ± 0.05 vs. NR, 0.18 ± 0.04) in both groups showing no statistical difference 12 months postsurgery. The CFT decreased in both groups, but the R group was thinner at every point compared to the NR group (all p < 0.05).ConclusionsThe removal of epirentinal membrane in pars planar vitrectomy significantly improves BCVA, decreases the CFT and expands the FAZ. Foveal pit restoration improves BCVA, CFT, and FAZ area possibly at a faster rate in the early months but long-term improvements could be achieved regardless of the status of foveal pit restoration.     

Postoperative microstructural re-modelling and functional outcomes in idiopathic full thickness macular hole

Purpose:To analyze the effect of various macular hole indices and postoperative microstructural changes of all retinal layers on postoperative functional outcomes in patients with idiopathic full-thickness macular hole (FTMH).Methods:In this prospective study, pre and post-operative optical coherence tomography (OCT) scans of 36 eyes with idiopathic FTMH were analyzed. Hole indices and microstructural changes of all retinal layers such as ellipsoid zone (EZ), external limiting membrane (ELM) integrity, outer and inner retinal defects, and cystoid resolution were studied on follow-up visits.Results:Out of 36 eyes, type-1 closure was achieved in 23 eyes (65.7%) and type-2 closure in 11 eyes (31.42%), one eye showed persistent hole, and one eye was lost to follow-up. The mean minimum diameter of hole (P = 0.026), mean MHI (P = 0.001), DHI (P = 0.158), THI (P = 0.001), and HFF (P < 0.001) showed statistical significance with the type of hole closure. Postoperatively, eyes with intact ELM and EZ had better BCVA at the final visit. The BCVA was better by logMAR 0.73 ± 0.38 (P < 0.001) in patients with absent outer retinal defects. There was a significant difference in BCVA of 0.52 ± 0.35 at 1 month and 0.64 ± 0.34 at 6 months in eyes without inner retinal defects (P < 0.001). At 6 months, cystoid resolution was observed in 28 (80%) eyes. BCVA was significantly better at 1 month (P < 0.001) and at 6 months (P = 0.001) in eyes with no DONFL.Conclusion:Macular hole indices determine the closure type. Postoperative regeneration of outer retinal layers and resolution of retinal defects significantly influence the final visual outcomes. ELM recovery is seen as a prerequisite for EZ regeneration with no new IRD after a period of 3 months.     

Optical coherence tomography study of foveal microstructure after successful retinal detachment surgery

PurposeTo evaluate foveal anatomical abnormalities after the successful repair of rhegmatogenous retinal detachments (RRDs) and to investigate the relationship between foveal microstructural changes and postoperative best-corrected visual acuity (BCVA).Materials and methodsThis study was a retrospective consecutive case series comprising all RRD patients with anatomical reattachment performed by a single surgeon from January 2009 to June 2010. Complete medical and ophthalmic histories, BCVA, duration of symptoms, number of breaks, extent of the retinal detachment (RD), lens status, and type of surgery were preoperatively recorded. The main outcome measurements for data analysis were postoperative BCVA and optical coherence tomography (OCT) imaging of the foveal microstructure.ResultsClinical data and OCT images were obtained from 83 eyes of 80 patients who underwent successful RRD surgeries. Anatomic foveal abnormalities were identified in 72% of eyes, including disruption of the junction between the inner and outer photoreceptor segments (IS/OS) in 59% of all cases with or without external limiting membrane (ELM) disruptions, residual subretinal fluid (7%), epiretinal membranes (22%), cystoid macular edema (7%), uneven surface (4%), retinal pigment epithelium (RPE) defects (1%), RPE folding (1%), and macular holes (2%). Multiple linear regression analysis showed that the significant factors associated with postoperative BCVA were ELM disruption and macular holes. Foveal photoreceptor layer integrity as determined by OCT imaging after a successful macula-off RD repair was used to classify each eye included in the study into one of three subgroups: intact IS/OS junction and ELM (11), disrupted IS/OS junction but intact ELM (11), and disruption of the IS/OS junction and ELM (37). Mean postoperative BCVA (0.18 ± 0.13 logMAR units, 0.43 ± 0.26 logMAR units, and 0.69 ± 0.42 logMAR units, respectively) was significantly different among these subgroups (p < 0.001).ConclusionOCT is a useful, noninvasive tool for evaluating foveal microstructural abnormalities and predicting visual outcomes after a successful RRD repair.     

Progressive Dysmorphia of Retinal Pigment Epithelium in Age-Related Macular Degeneration Investigated by Fluorescence Lifetime Imaging

PurposeThe purpose of this study was to observe changes of the retinal pigment epithelium (RPE) on the transition from dysmorphia to atrophy in age-related macular degeneration (AMD) by fluorescence lifetime imaging ophthalmoscopy (FLIO).MethodsMultimodal imaging including color fundus photography (CFP), optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, and FLIO was performed in 40 eyes of 37 patients with intermediate AMD and no evidence for geographic atrophy or macular neovascularization (mean age = 74.2 ± 7.0 years). Twenty-three eyes were followed for 28.3 ± 18.3 months. Seven eyes had a second follow-up after 46.6 ± 9.0 months. Thickened RPE on OCT, hyperpigmentation on CFP, hyper-reflective foci (HRF) on OCT, attributed to single or clustered intraretinal RPE, were identified. Fluorescence lifetimes in two spectral channels (short-wavelength spectral channel [SSC] = 500–560 nm, long-wavelength spectral channel [LSC] = 560–720 nm) as well as emission spectrum intensity ratio (ESIR) of the lesions were measured by FLIO.ResultsAs hyperpigmented areas form and RPE migrates into the retina, FAF lifetimes lengthen and ESRI of RPE cells increase. Thickened RPE showed lifetimes of 256 ± 49 ps (SSC) and 336 ± 35 ps (LSC) and an ESIR of 0.552 ± 0.079. For hyperpigmentation, these values were 317 ± 68 ps (p < 0.001), 377 ± 56 ps (P < 0.001), and 0.609 ± 0.081 (P = 0.001), respectively, and for HRF 337 ± 79 ps (P < 0.001), 414 ± 50 ps (P < 0.001), and 0.654 ± 0.075 (P < 0.001).ConclusionsIn the process of RPE degeneration, comprising different steps of dysmorphia, hyperpigmentation, and migration, lengthening of FAF lifetimes and a hypsochromic shift of emission spectra can be observed by FLIO. Thus, FLIO might provide early biomarkers for AMD progression and contribute to our understanding of RPE pathology.     

Subcellular Comparison of Visible-Light Optical Coherence Tomography and Electron Microscopy in the Mouse Outer Retina

PurposeWe employed in vivo, 1.0-µm axial resolution visible-light optical coherence tomography (OCT) and ex vivo electron microscopy (EM) to investigate three subcellular features in the mouse outer retina: reflectivity oscillations inner to band 1 (study 1); hyperreflective band 2, attributed to the ellipsoid zone or inner segment/outer segment (IS/OS) junction (study 2); and the hyperreflective retinal pigment epithelium (RPE) within band 4 (study 3).MethodsPigmented (C57BL/6J, n = 10) and albino (BALB/cJ, n = 3) mice were imaged in vivo. Enucleated eyes were processed for light and electron microscopy. Using well-accepted reference surfaces, we compared micrometer-scale axial reflectivity of visible-light OCT with subcellular organization, as revealed by 9449 annotated EM organelles and features across four pigmented eyes.ResultsIn study 1, outer nuclear layer reflectivity peaks coincided with valleys in heterochromatin clump density (−0.34 ± 2.27 µm limits of agreement [LoA]). In study 2, band 2 depth on OCT and IS/OS junction depth on EM agreed (−0.57 ± 0.76 µm LoA), with both having similar distributions. In study 3, RPE electron dense organelle distribution did not agree with reflectivity in C57BL/6J mice, with OCT measures of RPE thickness exceeding those of EM (2.09 ± 0.89 µm LoA). Finally, RPE thickness increased with age in pigmented mice (slope = 0.056 µm/mo; P = 6.8 × 10⁻⁷).ConclusionsVisible-light OCT bands arise from subcellular organization, enabling new measurements in mice. Quantitative OCT–EM comparisons may be confounded by hydration level, particularly in the OS and RPE. Caution is warranted in generalizing results to other species.     

Hyperreflective Foci,Optical Coherence Tomography Progression Indicators in Age-Related Macular Degeneration,Include Transdifferentiated Retinal Pigment Epithelium

PurposeBy optical coherence tomography (OCT) imaging, hyperreflective foci (HRF) indicate progression risk for advanced age-related macular degeneration (AMD) and are in part attributable to ectopic retinal pigment epithelium (RPE). We hypothesized that ectopic RPE are molecularly distinct from in-layer cells and that their cross-retinal course follows Müller glia.MethodsIn clinical OCT (61 eyes, 44 patients with AMD, 79.4 ± 7.7 years; 29 female; follow-up = 4.7 ± 0.9 years), one HRF type, RPE plume (n = 129 in 4 morphologies), was reviewed. Twenty eyes of 20 donors characterized by ex vivo OCT were analyzed by histology (normal, 4; early/intermediate AMD, 7; geographic atrophy, 6; neovascular AMD, 3). Cryosections were stained with antibodies to retinoid (RPE65, CRALPB) and immune (CD68, CD163) markers. In published RPE cellular phenotypes, red immunoreactivity was assessed semiquantitatively by one observer (none, some cells, all cells).ResultsPlume morphology evolved over time and many resolved (40%). Trajectories of RPE plume and cellular debris paralleled Müller glia, including near atrophy borders. RPE corresponding to HRF lost immunoreactivity for retinoid markers and gained immunoreactivity for immune markers. Aberrant immunoreactivity appeared in individual in-layer RPE cells and extended to all abnormal phenotypes. Müller glia remained CRALBP positive. Plume cells approached and contacted retinal capillaries.ConclusionsHRF are indicators not predictors of overall disease activity. Gain and loss of function starts with individual in-layer RPE cells and extends to all abnormal phenotypes. Evidence for RPE transdifferentiation, possibly due to ischemia, supports a proposed process of epithelial–mesenchyme transition. Data can propel new biomarkers and therapeutic strategies for AMD.     

Comparison of two protocols of subthreshold micropulse yellow laser treatment for non-resolving central serous chorioretinopathy

Purpose:To study the effect of subthreshold micropulse yellow laser treatment on central serous chorioretinopathy (CSC) and to compare two laser protocols. As per our knowledge, there are no studies comparing the two protocols of subthreshold laser.Methods:Twenty-three patients with non-resolving CSC of at least three months duration were treated with subthreshold laser (577 nm). Ten patients were treated with 5% duty cycle (group A) and 13 patients with 10% duty cycle (group B). At one month, best corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF), choroidal thickness (CT) and choroidal vascularity index (CVI) were evaluated.Results:In group A, BCVA improved from 0.508 ± 504 to 0.174 ± 0.171 (P = 0.0058), CMT improved from 349.8 ± 168.9 micrometers (µm) to 183.3 ± 70.312 µm (P = 0.0093) and SRF reduced from 202.4 ± 158.024 to 43.8 ± 46.599 µm (P = 0.0069). In group B, BCVA improved from 0.437 ± 0.426 to 0.289 ± 0.470 (P = 0.0026), CMT improved from 280.846 ± 72.668 to 196.769 ± 72.62 µm (P = 0.0002) and SRF reduced from 110.385 ± 57.687 µm to 52.538 ± 52.111 µm (P = 0.0064). No significant difference was found in BCVA and CMT between the groups (P = 0.8716 and P = 0.8523, respectively). CSC completely resolved in 50% of cases in group A and in 69.2% of cases in group B. This difference was not statistically significant (0.423); however, the odds ratio of resolution was 2.25 times more with 10% duty cycle. No change was observed on fundus autofluorescence (FAF) following laser.Conclusion:Subthreshold micropulse laser can lead to resolution of SRF in 60.87% of cases (groups A and B combined). Ten per cent duty cycle had higher odds of resolution without causing any RPE damage.     

Clinical and visual electrophysiological characteristics of vitelliform macular dystrophies in the first decade of life

Purpose:To evaluate patterns of pediatric vitelliform macular dystrophy (PVMD).Methods: This is a retrospective analysis of Indian children with vitelliform macular dystrophy (VMD) presenting within the first decade of life. Records were evaluated for clinical findings, family screening, and investigative findings including optical coherence tomography (OCT), fundus autofluorescence (FAF), full-field electroretinogram (ERG) and electrooculogram (EOG). Electrophysiology was scrutinized and audited for acquisition and interpretation errors. Findings on follow-up were also recorded.Results: 46 eyes of 24 patients were included. Mean age at presentation was 7.17 ± 2.17 years. Mean follow-up duration was 1.55 ± 1.69 years. Best disease was the commonest type of VMD detected (21 patients), while autosomal recessive bestrophinopathy was seen in three cases. Mean logMAR BCVA was 0.364 which decreased to 0.402 on follow-up. Hyperopia was noted in 29 out of 46 eyes (mean being +3.87 D, range ebing +0.75 to +8.75 D). Four eyes of four children had choroidal neovascular membrane at presentation, while another child developed while in follow-up. Solid type subretinal deposit was the commonest OCT finding (n = 29/38) and central hyper FAF was the commonest pattern (n = 18/32). EOG was available for review in 32 eyes, but was unreliable in 11 eyes. Seven eyes demonstrated complete absence of light rise on EOG.Conclusion: PVMD can present in advanced forms. Progression to complications with loss of visual acuity can happen within the first decade of life. EOG shows grossly suppressed waveforms in the light phase in a large number of such children.     

Clinical characteristics of central serous chorioretinopathy in patients by age

Purpose

To investigate the clinical characteristics of central serous chorioretinopathy (CSC) with age.

Study design

Retrospective, cross-sectional study.

Methods

One-hundred and forty-seven CSC patients were classified into three age groups (aged <50 years (younger group; n=53), 50–70 years (middle group; n=68), and >70 years (senior group; n=26)) and the characteristics were compared. Bilateral ophthalmic evaluation included the best corrected visual acuity (BCVA), spherical equivalents, fundus examination, fundus autofluorescence, optical coherence tomography (OCT), fluorescein angiography (FA), and indocyanine green angiography.

Results

The male/female ratio became lower at more advanced ages (P=0.011). Bilateral macular abnormalities were observed more frequently in the senior group than the other groups (p=0.018) and multiple drusen were characteristic in the senior group (p<0.0001). The more advanced age groups displayed a worse BCVA (P=0.002). The rate of eyes with flat retinal pigment epithelium (RPE) elevation on OCT was significantly higher in the middle group than the other groups (P=0.024). The mean subfoveal choroidal thickness (SCT) was thickest in the younger group (P<0.0001). Unifocal leakage on FA and choroidal vascular hyperpermeability were mostly found in eyes of the younger group (P<0.001,P=0.020).

Conclusion

CSC cases in those aged >70 years were associated with an increased proportion of women and having bilateral macular abnormalities, multiple drusen, and multifocal leakage sites. The BCVA and the SCT decreased with age. Patients with CSC aged 50–70 years had the highest rate of flat RPE elevation on OCT. These characteristics need to be considered to make an accurate diagnosis, particularly in elderly patients.