Genetic inhibition of collapsin response mediator protein-2 phosphorylation ameliorates retinal ganglion cell death in normal-tension glaucoma models.

Glaucoma is a neurodegenerative disorder caused by the death of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) is a cause of glaucoma. However, glaucoma often develops with normal IOP and is known as normal-tension glaucoma (NTG). Glutamate neurotoxicity is considered as one of the significant causes of NTG, resulting in excessive stimulation of retinal neurons via the N-methyl-D-aspartate (NMDA) receptors. The present study examined the phosphorylation of collapsin response mediator protein-2 (CRMP2), a protein that is abundantly expressed in neurons and involved in their development. In two mouse models, NMDA-injection and glutamate/aspartate transporter (GLAST) mutant, CRMP2 phosphorylation at the cyclin-dependent kinase-5 (Cdk5) site was elevated in RGCs. We confirmed that the decrease in the number of RGCs and thickness of the inner retinal layer (IRL) could be suppressed after NMDA administration in CRMP2KI/KI mice with genetically inhibited CRMP2 phosphorylation. Next, we investigated GLAST heterozygotes (GLAST+/-) with CRMP2KI/KI (GLAST+/-;CRMP2KI/KI) and GLAST knockout (GLAST-/-) mice with CRMP2KI/KI (GLAST-/-;CRMP2KI/KI) mice and compared them with GLAST+/- and GLAST-/- mice. pCRMP2 (S522) inhibition significantly reduced RGC loss and IRL thinning. These results suggest that the inhibition of CRMP2 phosphorylation could be a novel strategy for treating NTG.

Tight adherent feature on optical coherence tomography predict postoperative visual outcome in epiretinal membrane eyes.

BACKGROUND: To identify the predictive parameter among preoperative measurements that best predicts postoperative visual outcome in the epiretinal membrane (ERM). METHODS: Thirty-three consecutive patients with idiopathic unilateral ERM patients between 2015 and 2018 were enrolled. Nineteen healthy normal eyes were selected as an independent age-matched group. Based on preoperative optical coherence tomography (OCT), we further divided the patients with ERM into two groups: type 1, loosely attached ERM, and type 2, tight adherent ERM. We documented the vision and thickness of various retinal layers: nerve fiber layer, ganglion cell layer, inner plexiform layer (GCL + IPL), inner nuclear layer (INL), outer retinal layer (ORL), and retinal pigment epithelium/Bruch complex layer before and after the surgery. The association between postoperative visual acuity and these variables was analyzed using multiple linear regression analysis. RESULTS: All retinal layers of ERM eyes were thicker than the normal eyes (P < 0.05). Among ERMs, we identified 11 eyes with type 1 adhesions and 22 eyes with type 2 adhesions. The preoperative GCL + IPL layers were significantly thicker in type 2 patients than in type 1 patients (93.67 ± 33.03 um vs 167.71 ± 13.77 um; P = 0.023). Greater GCL + IPL thickness was correlated with a worse postoperative visual acuity and multiple linear regression analysis showed that GCL + IPL thickness was an independent predictor of postoperative visual acuity (VA) (beta value = 0.689; P = 0.012). A greater thickness of GCL + IPL layers of type 2 patients had worse postoperative best-corrected visual acuity (BCVA) (P = 0.028). Ectopic inner foveal layers with disappearance of fovea pit were persistently presented in OCT profiles of both groups. CONCLUSION: Idiopathic ERM demonstrated significantly thicker inner retinal layers (GCL + IPL and INL). However, the ORL thickness was similar between the normal eyes and ERM eyes. The preoperative GCL + IPL layers were significantly thicker in patients with type 2 ERM than that in patients with type 1 ERM. The increase in GCL + IPL thickness was significantly correlated with worse postoperative visual outcomes.

Inner retinal layers' alterations and microvasculature changes after vitrectomy for rhegmatogenous retinal detachment.

PURPOSE: To examine the retinal layers' changes and alterations in retinal microvasculature in patients with rhegmatogenous retinal detachment (RRD) treated with pars plana vitrectomy (PPV). METHODS: Participants in this study were 103 patients with RRD, 85 macula off and 18 macula on, who were treated with PPV and gas tamponade without internal limiting membrane peeling, in two centers. All participants underwent best corrected visual acuity measurement, slit-lamp examination, fundoscopy, spectral domain-optical coherence tomography and optical coherence tomography angiography at week 5 and at month 6 postoperatively. The fellow untreated eyes were also examined and served as control data. RESULTS: A statistically significant enlargement in foveal avascular zone (FAZ) in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) was noticed 5 weeks postoperatively in patients with RRD treated with PPV compared to the fellow eyes and remained 6 months after surgery. The FAZ enlargement in the operated eyes was accompanied with a statistically significant thinning of the inner retinal layer. In addition, there was a significant decrease in foveal and parafoveal vessel density (VD) in both SCP and DCP in the operated eyes compared to control eyes at week 5 postoperatively, which also remained at postoperative month 6. CONCLUSIONS: The study demonstrated that patients with RRD treated with PPV presented changes in the retinal microvasculature in both SCP and DCP, including enlargement of FAZ and decrease in VD. These changes seemed to be associated with inner retinal layer thinning.

Cognitive impairment in patients with multiple sclerosis is associated with atrophy of the inner retinal layers.

BACKGROUND: Inner retinal layer (IRL) atrophy is a potential biomarker for neurodegeneration in multiple sclerosis (MS). OBJECTIVE: To investigate the relationship between cognitive impairment and IRL atrophy in MS. METHODS: Cross-sectional study design, including 217 patients and 59 healthy controls. Subjects were investigated clinically, underwent retinal optical coherence tomography (OCT) and comprehensive cognitive assessments. The association between these modalities was evaluated by regression analyses. RESULTS: Of the patients, 44.2% were cognitively impaired. In the absence of multiple sclerosis-associated optic neuritis (MSON), cognitively impaired patients had a significantly lower mean peripapillary retinal nerve fiber layer (pRNFL, Δ: 8.13 µm, p < 0.001) and mean macular ganglion cell-inner plexiform layer (mGCIPL, Δ: 11.50 µm, p < 0.001) thickness compared to cognitively preserved patients. There was a significant association between the presence of cognitive impairment and pRNFL (odds ratio (OR): 1.11, 95% confidence interval (CI): 1.04-1.18, p = 0.001) and mGCIPL (OR = 1.11, 95% CI = 1.05-1.18, p < 0.001) atrophy. This association was masked by the severe IRL atrophy seen following MSON. CONCLUSION: The strong relationship between cognitive impairment across multiple cognitive domains and atrophy of the pRNFL and mGCIPL in patients who never suffered from MSON suggests that OCT is useful in assessing central nervous system neurodegeneration in MS.

Reproducibility of each retinal layer thickness measurement in epiretinal membrane patients with ectopic inner foveal layers.

BACKGROUND: To identify the reliability of each retinal layer thickness measurement in epiretinal membrane (ERM) patients with ectopic inner foveal layers (EIFLs). METHODS: Subjects were divided into two groups: ERM patients with EIFLs (Group 1) and without EIFLs (Group 2). The retinal layer thickness was measured twice, and intraclass correlation coefficient (ICC) and coefficient of variation (CV) values were calculated. RESULTS: In Group 1, the CVs of the nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL) were 22.39%, 13.12%, 13.37%, 13.21%, 15.09%, and 11.94%, while the ICCs were 0.431, 0.550, 0.440, 0.286, 0.279, and 0.503, respectively. In Group 2, the CVs were 18.20%, 10.59%, 10.65%, 13.27%, 14.75%, and 10.37%, while the ICCs were 0.788, 0.834, 0.830, 0.715, 0.226, and 0.439, respectively. The average central macular thickness (CMT) was significantly correlated with the CVs of NFL (coefficient = 0.317; P < 0.001), GCL (coefficient = 0.328; P < 0.001), and IPL (coefficient = 0.186; P = 0.042) in Group 1. CONCLUSIONS: The reproducibility of the inner retinal layer thickness measurements in ERM patients with EIFLs was low compared to those without EIFLs. The reproducibility of the outer retinal layer thickness measurements, including OPL and ONL, was poor regardless of the presence of EIFLs in ERM patients. Additionally, the thicker the CMT in patients with EIFLs, the lower the reproducibility of the inner retinal layer thickness measurements.

The Characteristic of Optical Coherence Tomography Angiography and Retinal Arteries Angle in Familial Exudative Vitreoretinopathy with Inner Retinal Layer Persistence.

PURPOSE: To compare the angle of retinal arteries and macular vessel density and foveal avascular zone (FAZ) in early stage familial exudative vitreoretinopathy (FEVR) patients with inner retinal layer (IRL) persistence with FEVR patients without IRL persistence and normal people. METHODS: This study enrolled 113 early stage FEVR patients and 55 age-matched normal subjects. FEVR patients were divided into IRL group and non-IRL group based on the presence or absence of IRL in fovea. The angle of superior temporal and inferior temporal branch retinal arteries on ultra-wide-field fundus images were measured. Superficial and deep vessel density of whole image, fovea and parafovea, the area and perimeter of FAZ, A-circularity index (AI, perimeter/standard circle perimeter with equal area) and vessel density around the 300-µm width of the FAZ (FD), central macular thickness (CMT) on 3 mm × 3mm OCTA were measured. RESULTS: 30 FEVR patients in IRL group, 83 FEVR patients in non-IRL group, 55 normal people in control group were evaluated. BCVA were worst in IRL group (p < .001). The angle of retinal arteries was smaller in FEVR groups (p < .001) and were smallest in IRL group (p < .001). Superficial and deep vessel density of whole and parafovea area in FEVR patients were significantly lower than that in normal people (p < .05), AI were biggest (p = .01) and FD were smallest in IRL group (p < .001). CMT in IRL group were thicker than non-IRL group and control group (p < .05). CONCLUSION: Worse BCVA, smaller angle of retinal arteries (more vessels traction), lower macular vessel density, smaller and more irregular FAZ and thicker CMT were observed in FEVR patients with IRL persistence even in early stage.

Evaluation of the optical coherence tomography findings of patients with idiopathic epiretinal membrane.

BACKGROUND: This study aimed to determine the relationship between basal visual acuity (VA) and basal optical coherence tomography (OCT) parameters of patients with idiopathic epiretinal membrane (iERM). METHODS: The study included 200 eyes of 200 patients with iERM. In the evaluation of basal VAs, logMAR 0.3 (0.5 on Snellen chart) was accepted as the limit, and the patients were divided into two groups as Group 1 with VA values below logMAR 0.3 and Group 2 with those above logMAR 0.3. Using OCT, the ellipsoid zone (EZ), interdigitation zone (IZ), external limiting membrane (ELM) integrity, peaked appearance of EZ in the fovea, disorganization of the inner retinal layers (DRIL), central foveal thickness (CFT), maximum retinal thickness (MRT), total photoreceptor length (TPL), photoreceptor outer segment length (PROSL), photoreceptor deformity index (PDI), and inner retinal layer irregularity index (IRLII) were evaluated and compared between the groups. RESULTS: There were an equal number of patients in Group 1 and Group 2. The preservation of ELM, EZ, and IZ integrity and the peaked appearance of EZ in the fovea were observed at higher rates in Group 1, whereas the rate of DRIL was higher in Group 2 (p < 0.05 for all). In the multiple regression analysis performed to evaluate categorical OCT parameters, only the presence of DRIL was found to be significantly associated with VA (p < 0.003). CFT*, MRT*, and IRLII** were significantly lower in Group 1 (*p < 0.001, **p = 0.001). TPU, PROSL, and FDI were similar between the two groups (p > 0.05 for all). CONCLUSION: According to the multiple regression analysis, only the presence of DRIL was correlated with lower VA values. Among the OCT parameters, an increase in CFT and MRT, as well as the IRLII value moving away from 1 were related to lower VA values.

Speckle Contrast as Retinal Tissue Integrity Biomarker in Patients with Type 1 Diabetes Mellitus with No Retinopathy.

PURPOSE: To study the retinal and choroidal layers in type 1 diabetes mellitus (DM1) without diabetic retinopathy (DR), using speckle contrast of optical coherence tomography (OCT) images as a tissue biomarker in comparison with healthy subjects. METHODS: OCT Spectralis images of 148 eyes, 84 from DM1 patients without DR signs, and 64 belonging to the control group, were collected. The speckle contrast and thickness of the inner retinal layer (IRL), the outer retinal layer (ORL), and the choroidal layer in the nasal parafoveal area (N3), were prospectively analyzed. RESULTS: A statistically significant difference (p = 0.001) in the IRL thickness between groups was observed, being thicker in the DM1 group. There were no differences in the ORL and choroidal thicknesses between groups. A statistically significant difference (p = 0.02) in the IRL speckle contrast was obtained, being lower in the DM1 group. The maximum speckle contrast was reached in the ORL for both groups, although in the DM1 group, it occurs closer to the choroid, at 64 ± 8 µm (p = 0.008). CONCLUSIONS: Statistically significant differences were found in speckle contrast and thickness between the control and the DM1 group, suggesting an IRL alteration of DM1 patients, supporting the retinal neurodegeneration before DR signs are observed.

Effects of lighting environment on the degeneration of retinal ganglion cells in glutamate/aspartate transporter deficient mice, a mouse model of normal tension glaucoma.

Lighting conditions may affect the development of retinal degenerative diseases such as macular degeneration. In this study, to determine whether the lighting environment affects the progression of degeneration of retinal ganglion cells (RGCs), we examined glutamate/aspartate transporter (GLAST) heterozygous (GLAST+/-) mice, a mouse model of normal tension glaucoma. GLAST+/- mice were reared under a 12-h light-dark cycle (Light/Dark) or complete darkness (Dark/Dark) condition after birth. The total RGC number in the Dark/Dark group was significantly decreased compared with the Light/Dark group at 3 weeks old, while the number of osteopontin-positive αRGCs were similar in both groups. At 6 and 12 weeks old, the total RGC number were not significantly different in both conditions. In addition, the retinal function examined by multifocal electroretinogram were similar at 12 weeks old. These results suggest that lighting conditions may regulate the progression of RGC degeneration in some types of glaucoma.

Microperimetry and Optical Coherence Tomography Changes in Type-1 Diabetes Mellitus without Retinopathy.

BACKGROUND: We aimed to measure and correlate inner retinal layer (IRL) thickness and macular sensitivity by optical coherence tomography (OCT) and by microperimetry, respectively, in type 1 diabetes mellitus patients (DM1) without diabetic retinopathy (DR). METHODS: Fifty-one DM1 patients and 81 age-matched healthy subjects underwent measurement of the axial length (AL), retinal thickness in the macular ETDRS areas by swept source (SS)-OCT and macular sensitivity by microperimeter. RESULTS: The total retinal and IRL thicknesses were thicker in the DM1 group (p < 0.05) in practically all ETDRS areas, and they had a generalized decrease in sensitivity (p < 0.05) in 9 areas between both groups. There was a significant negative correlation between retinal sensitivity and age in all areas and in visual acuity (VA) in 5 out of the 9 areas for DM1 patients. Only a mild negative correlation was observed between retinal sensitivity in the 5° nasal inner (5NI) area and in IRL thickness in the temporal inner (TI) area (-0.309 with p = 0.029) in the DM1 group. CONCLUSION: Aging and disease evolution in DM1 patients without DR signs generate a decrease in retinal sensitivity. There was a direct relationship between retinal sensitivity and macular thickness in the DM1 group.

Reduced macular thickness and macular vessel density in early-treated adult patients with PKU.

PURPOSE: Macular structure is poorly evaluated in early-treated phenylketonuria (ETPKU). To evaluate potential changes, we aimed to examine retinas of PKU patients using optical coherence tomography (OCT) with additional OCT angiography (OCTA) and compare the results to healthy controls. METHODS: A total of 100 adults were recruited in this monocentric, case-control study: 50 patients with ETPKU (mean age: 30.66 ± 8.00 years) and 50 healthy controls (mean age: 30.45 ± 7.18 years). Macular thickness, vessel density and flow area of the right eye was assessed with spectral domain OCT angiography SD-OCT(A). Macular microstructural data between the ETPKU and control group was compared. In the ETPKU group, the relationship between visual functional parameters (best corrected visual acuity [VA], spherical equivalent [SE], contrast sensitivity [CS] and near stereoacuity) and microstructural alterations was examined. The dependency of OCT(A) values on serum phenylalanine (Phe) level was analysed. RESULTS: There was significant average parafoveal and perifoveal total retinal layer thinning in ETPKU patients compared to healthy controls (p < 0.016 and p < 0.001, respectively), while the foveal region remained unchanged in the ETPKU group. Whole macular and parafoveal superficial capillary plexus density was significantly decreased in ETPKU compared to controls (p < 0.001). There were no significant differences in the foveal avascular zone, nonflow area, macular superficial and deep capillary plexus between the groups. The temporal parafoveal inner retinal layer thickness was found to negatively correlate with individual Phe levels (r = -0.35, p = 0.042). There was no difference in vascular density and retinal thickness in the subgroup analysis of patients with good therapy adherence compared to patients on a relaxed diet. CONCLUSIONS: Durable elevation in Phe levels are only partially associated with macular retinal structural changes. However, therapy adherence might not influence these ophthalmological complications.

Normative Data and Minimally Detectable Change for Inner Retinal Layer Thicknesses Using a Semi-automated OCT Image Segmentation Pipeline.

Neurodegenerative and neuroinflammatory diseases regularly cause optic nerve and retinal damage. Evaluating retinal changes using optical coherence tomography (OCT) in diseases like multiple sclerosis has thus become increasingly relevant. However, intraretinal segmentation, a necessary step for interpreting retinal changes in the context of these diseases, is not standardized and often requires manual correction. Here we present a semi-automatic intraretinal layer segmentation pipeline and establish normative values for retinal layer thicknesses at the macula, including dependencies on age, sex, and refractive error. Spectral domain OCT macular 3D volume scans were obtained from healthy participants using a Heidelberg Engineering Spectralis OCT. A semi-automated segmentation tool (SAMIRIX) based on an interchangeable third-party segmentation algorithm was developed and employed for segmentation, correction, and thickness computation of intraretinal layers. Normative data is reported from a 6 mm Early Treatment Diabetic Retinopathy Study (ETDRS) circle around the fovea. An interactive toolbox for the normative database allows surveying for additional normative data. We cross-sectionally evaluated data from 218 healthy volunteers (144 females/74 males, age 36.5 ± 12.3 years, range 18-69 years). Average macular thickness (MT) was 313.70 ± 12.02 µm, macular retinal nerve fiber layer thickness (mRNFL) 39.53 ± 3.57 µm, ganglion cell and inner plexiform layer thickness (GCIPL) 70.81 ± 4.87 µm, and inner nuclear layer thickness (INL) 35.93 ± 2.34 µm. All retinal layer thicknesses decreased with age. MT and GCIPL were associated with sex, with males showing higher thicknesses. Layer thicknesses were also positively associated with each other. Repeated-measurement reliability for the manual correction of automatic intraretinal segmentation results was excellent, with an intra-class correlation coefficient >0.99 for all layers. The SAMIRIX toolbox can simplify intraretinal segmentation in research applications, and the normative data application may serve as an expandable reference for studies, in which normative data cannot be otherwise obtained.

Effect of optic disc-fovea distance on the normative classifications of macular inner retinal layers as assessed with OCT in healthy subjects.

PURPOSE: To determine the influence of the optic disc-fovea distance (DFD) on the normative classifications based on thickness measurements of macular inner retinal layers with spectral-domain optical coherence tomography (OCT) in healthy subjects. METHODS: A total of 182 eyes from 182 healthy subjects were included (mean (SD) spherical equivalent -0.8 (1.9) dioptres). We performed macula and optic disc imaging with the Topcon 3D OCT 2000. The thickness of the macular inner retinal layers (macular retinal nerve fibre layer (mRNFL), ganglion cell-inner plexiform layer (GCIPL) and both combined (ganglion cell complex; GCC)) and the corresponding classifications based on the built-in normative database were recorded. The occurrence of an abnormal normative classification (occurrence of any thickness variable below the fifth percentile) was related to the DFD and other factors (axial length/refraction, optic disc area, fovea-disc angle, age, gender, image quality, visual field mean deviation and peripapillary retinal nerve fibre layer thickness), using logistic regression. RESULTS: The mean (SD) DFD was 4.90 (0.29) mm. A greater DFD was associated with a higher percentage of abnormal normative classification in the OCT parameters describing the thickness of the mRNFL (OR (95%CI) per 0.1 mm increase in DFD: 1.30 (1.13 to 1.50), p<0.001), GCIPL (1.18 (1.02 to 1.38), p=0.023) and GCC measurement (1.29 (1.08 to 1.55), p=0.006). CONCLUSIONS: Eyes with a greater DFD are prone to false-positive classifications in the thickness assessment of the macular inner retinal layers. The thicknesses should always be interpreted in the context of DFD.

Disorganization of retinal inner layers correlates with ellipsoid zone disruption and retinal nerve fiber layer thinning in diabetic retinopathy.

PURPOSE: To study the correlation between disorganization of inner retinal layer (DRIL) and macular thickness parameters, ellipsoid zone (EZ) disruption and retinal nerve fiber layer (RNFL) thickness on spectral domain optical coherence tomography (SD-OCT) in diabetic retinopathy (DR), for the first time. METHODS: A tertiary care center-based cross-sectional study was undertaken. One hundred and four consecutive study subjects of type 2 diabetes mellitus were included: diabetes mellitus with no retinopathy (No DR) (n = 26); non-proliferative DR (NPDR) (n = 26); proliferative DR (PDR) (n = 26) and healthy controls (n = 26). Best Corrected Visual Acuity (BCVA) was measured on the logarithm of the minimum angle of resolution (logMAR) scale. Clinician-friendly, SD-OCT based, grading systems were created for DRIL and EZ disruption, within the macular cube. DRIL was graded as: grade 0, DRIL absent; and grade 1, DRIL present. EZ disruption was graded as; Grade 0: Intact EZ; Grade 1: Focal disruption and Grade 2: Global disruption. Every study subject underwent RNFL thickness analysis. RESULTS: DRIL was significantly associated with increase in severity of DR.Pearson correlation analysis showed significant positive correlation between DRIL and CST CAT and grades of EZ disruption . However, a significant negative correlation was found between DRIL and RNFL thickness . CONCLUSION: Presence of DRIL correlates with severity of DR, EZ disruption and RNFL thinning.

Macular Inner Retinal Layer Thinning in Diabetic Patients without Retinopathy Measured by Spectral Domain Optical Coherence Tomography.

The aim of this study was to use Spectral Domain-Optical Coherence Tomography (SD-OCT) to measure the thickness of the Macular Inner Retinal Layer (MIRL) and compare the results between diabetic patients with no signs of retinopathy and healthy subjects. Overall, 47 type 2 diabetic patients without clinical signs of retinopathy were prospectively analyzed along with 36 healthy subjects. This study excluded patients with other systemic or ocular diseases. All patients had their MIRL thickness measured by RTVue-100 SD-OCT (7x7 mm macular grid). The MIRL thickness is provided by the ganglion cell complex scan (comprised of the retinal nerve fiber, ganglion cell, and inner plexiform layers). Only one eye was randomly selected if both were eligible for analysis. Mean age was similar between the two groups (diabetic patients: 57.3 ± 10.6 and control subjects: 60.2 ± 12.2 years) (P = 0.19). No significant differences regarding optic disc area and cup-to-disc ratio was observed in the comparison of the two groups (P ≥ 0.38 for both comparisons). In patients with diabetes, the average MIRL was significantly thinner when compared to controls (91.6 versus 96.2 micrometer (µm); P = 0.02). Regional analysis revealed superior and inferior MIRL to be significantly thinner in patients with diabetes than the controls (P ≤ 0.04). The juxtafoveal area was compromised (thinned) in 70% of diabetic eyes, classified as abnormal (P < 1%; compared to the device's normative database). In conclusion, patients with type 2 diabetes without clinical evidence of retinopathy had lower MIRL average values when compared to the control group. This can be explained by the ischemia and retinal tissue injury caused by diabetes even in early stages of diabetic retinopathy, which can affect MIRL thickness. Possible implications of these findings on diagnosis and treatment of diabetic retinopathy requires further investigation.

Outcome of vitreoretinal surgery for rhegmatogenous retinal detachment in X-linked juvenile retinoschisis.

PURPOSE: Rhegmatogenous retinal detachment (RRD) is a vision-threatening complication of X-linked juvenile retinoschisis (XLRS). The aim of this study is to report the anatomical and functional outcomes of vitreoretinal surgery for the treatment of RRD in X-linked juvenile retinoschisis (XLRS). METHODS: This is a retrospective, interventional, consecutive case series in which case records of 34 eyes of 28 XLRS patients, who underwent surgery for RRD, were reviewed. Statistical analysis used is as follows: visual outcomes were categorized into three groups: improved, remained stable or deteriorated. Wilcoxon signed-rank test was used to determine the difference in visual acuity at baseline and at final visit. Univariate binary logistic regression analysis was used to determine the risk factors for retinal detachment. Any P value < 0.05 was considered as statistical significant. RESULTS: Mean age of the boys at presentation was 9.2 ± 3.5 years. Indication for surgery was RRD in all eyes. Concurrent vitreous haemorrhage was present in four eyes (11.8%). The primary surgical intervention was scleral buckle in 12 eyes and pars plana vitrectomy in 22 eyes. Persistence of subretinal fluid/redetachment was seen in 15 eyes of which 11 eyes underwent additional surgeries. At final follow up, 27 eyes (79.4%) were noted to have an attached retina. Of the total eyes, in 20, 6 and 8 eyes the visual acuity improved, stabilized and deteriorated, respectively. CONCLUSION: Favourable outcomes are seen in a majority of eyes after vitreoretinal surgery for RRD in XLRS; however, multiple surgical interventions may be necessary.

Multiple evanescent white dot syndrome associated with retinal vasculitis.

PURPOSE: A recent study revealed thickening of the inner retinal layers in acute stage of multiple evanescent white dot syndrome (MEWDS); however, the pathogenesis is still unknown. We report two cases with MEWDS whose funduscopy showed obvious retinal vasculitis. METHODS: Case reports. RESULTS: Healthy myopic 16- and 27-year-old women were the cases under study. In both cases, funduscopic examination revealed multiple, faint, small, subretinal white dots at the posterior pole to the midperiphery and macular granularity oculus dexter. Retinal vascular sheathing was also observed at midperiphery. Late-phase fluorescein angiography revealed leakages corresponding to the vascular sheathing. Enhanced depth imaging optical coherence tomography revealed the discontinuity of the ellipsoid zone corresponding to the white dots and increased macular choroidal thickness. One month later, these white dots and retinal sheathing spontaneously resolved in both cases. Three months later, impairments of the outer retinal morphology and the visual acuity were restored. CONCLUSION: These results suggest that retinal vasculitis possibly plays a role in the pathogenesis of thickened inner retinal layers in acute stage of MEWDS.

Changes of the Individual Retinal Layer Thickness in Non-proliferative Diabetic Retinopathy in Type 2 Diabetes

PURPOSE: To compare retinal layer thickness in non-proliferative diabetic retinopathy in type 2 diabetic patients as measured by optical coherence tomography. METHODS: A total of 108 eyes from 71 patients, between January 2015 and July 2016, were included in this study. Of these, 39 eyes were included in the control group, 38 eyes in the diabetic group without non-proliferative diabetic retinopathy, and 31 eyes in the non-proliferative diabetic retinopathy group (NPDR). We measured the thickness of each retinal layer by optical coherence tomography (OCT). A total of ten layers were evaluated including the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), retinal pigment epithelium (RPE), inner retinal layer (IRL), outer retinal layer (ORL), and the total retinal layer (TRL). We compared the superior, inferior, nasal, and temporal regions at 1–3mm from the central fovea. RESULTS: RNFL was thinner in the superior region of the NPDR, as compared with that of the control group, showing statistical significance (p = 0.016). The thickness of all regions in the GCL, IPL, and IRL were decreased in NPDR, as compared to the control group with statistical significance. In addition, the thickness of the superior region in the GCL, IPL, and IRL showed statistically significant differences between controls and the no diabetic retinopathy (DR) group (p = 0.026, 0.003, 0.003). The thickness of the INL, OPL plus ONL, RPE, and ORL in all three groups showed no significant difference. The differences in the decreased thickness in the IRL were similar to that of TRL. CONCLUSIONS: Retinal neurodegeneration was observed in the IRL, which included changes to the RNFL, GCL, and IPL in early type 2 diabetes before microvascular injury was apparent. Thorough control of blood glucose is required in early diabetes, and further studies to delay retinal neurodegeneration are required. OCT might have an important role in early diagnosis and follow up of diabetic retinopathy.

Detection of retinal changes in Parkinson's disease with spectral-domain optical coherence tomography.

PURPOSE: This pilot study investigated whether high-resolution spectral-domain optical coherence tomography (SD-OCT) could detect differences in inner retinal layer (IRL), peripapillary retinal nerve fiber layer (RNFL), and macular thickness between patients with Parkinson's disease (PD) and controls. METHODS: Both eyes of patients with PD and age-matched controls were imaged with the Heidelberg Spectralis(®) HRA + OCT. RNFL, IRL, and macular thickness were measured for each eye using Heidelberg software. These measurements were compared with validated, published normal values for macular and RNFL thickness, and compared with matched controls for IRL thickness. RESULTS: Eighteen eyes from nine subjects with PD and 19 eyes of 16 control subjects were evaluated using SD-OCT. The average age of PD patients was 64 years with a range of 52-75 years. The average age of controls was 67 years with a range of 50-81 years. No significant reduction in IRL thickness was detected between PD patients and age-matched controls at 13 points along a 6 mm horizontal section through the fovea. No significant difference in RNFL thickness was detected between PD patients and published normal values. Overall average RNFL thickness was 97 µm for PD patients, which exactly matched the normative database value. However, significant differences in macular thickness were detected in three of nine subfields between PD subjects and published normal values. In PD subjects, the outer superior subfield was 2.8% thinner (P = 0.026), while the outer nasal and inner inferior subfields were 2.8% (P = 0.016) and 2.7% (P = 0.001) thicker compared to published normal values. CONCLUSION: In this pilot study, significant differences in macular thickness were detected in three of nine subfields by SD-OCT. However, SD-OCT did not detect significant reductions in peripapillary RNFL and IRL thickness between PD patients and controls. This suggests that macular thickness measurements by SD-OCT may potentially be used as an objective, noninvasive, and easily quantifiable in vivo biomarker in PD. Larger, longitudinal studies are needed to explore these relationships further.