Pigment Epithelium Layer Research Articles

Clinical classification, visual outcomes, and optical coherence tomographic features of 48 patients with posterior sympathetic ophthalmia

BackgroundTo investigate the clinical manifestations, visual outcomes and optical coherence tomographic (OCT) features of patients with posterior sympathetic ophthalmia (PSO).MethodsWe performed a retrospective review of 48 patients diagnosed with PSO between January 2013 and December 2019. We compared the clinical and OCT features among different clinical types of PSO.ResultsPSO could be classified into two types according to whether the fundus exhibited serous retinal detachment (SRD) or multifocal choroiditis (MFC). There were 41 patients (85.4%) with SRD and 7 patients (14.6%) with MFC. The latent period of patients with MFC was significantly longer than that of patients with SRD (P = 0.002). The final visual acuity of patients with MFC was significantly worse than that of patients with SRD (P = 0.0001). In patients with acute SRD, OCT revealed that the mean height of retinal detachment in the fovea was 528.8 ± 437.5 μm. After treatment, the retina reattached in all patients and the band structures of the outer retina were restored in most patients (92.7%). In patients with acute MFC, the OCT images revealed inflammatory lesions on the retinal pigment epithelium layer. After treatment, the OCT images showed hyperreflective fibrosis of the lesions and loss of the outer retinal band structures in all patients.ConclusionsWe found that PSO could be classified according to the presence of SRD or MFC. The visual prognosis differed significantly between these types of PSO. OCT imaging is useful for clinical classification and monitoring of retinal changes after treatment.

MORPHOLOGIC AND ANATOMICAL FEATURES OF TYPE 1 MACULAR NEOVASCULARIZATION TRUNKS IN AGE-RELATED MACULAR DEGENERATION USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

To evaluate the morphologic features of macular neovascularization (MNV) trunks at different layers using optical coherence tomography angiography. Type 1 MNV trunks in age-related macular degeneration were retrospectively evaluated at the subretinal pigment epithelium and sub-Bruch membrane (subBM) layers. The detectability and location of the trunks were compared. MNV trunks at the subBM layer on optical coherence tomography angiography B-scans were evaluated using a flow overlay. The correlations of the MNV trunk with optical coherence tomography angiography and optical coherence tomography parameters were evaluated. Among the 63 included eyes, 27 showed core vessels at the subretinal pigment epithelium layer and 52 showed MNV trunks at the subBM layer, which were connected with the MNV at the subretinal pigment epithelium layer. The locations of the MNV trunks in each layer were different. MNV trunk types at the subBM layer were related to disease duration, distance from the large choroidal vessels, and MNV vessel density. The large choroidal vessel diameter was correlated with the MNV trunk diameter at the subBM layer. Macular neovascularization trunks at the subBM layer were detected more frequently than distal MNV trunks at the subretinal pigment epithelium layer. Macular neovascularization trunk features at the subBM layer may be related to disease duration and a large choroidal vessel.

Dark Adaptation and Its Role in Age-Related Macular Degeneration.

Dark adaptation (DA) refers to the slow recovery of visual sensitivity in darkness following exposure to intense or prolonged illumination, which bleaches a significant amount of the rhodopsin. This natural process also offers an opportunity to understand cellular function in the outer retina and evaluate for presence of disease. How our eyes adapt to darkness can be a key indicator of retinal health, which can be altered in the presence of certain diseases, such as age-related macular degeneration (AMD). A specific focus on clinical aspects of DA measurement and its significance to furthering our understanding of AMD has revealed essential findings underlying the pathobiology of the disease. The process of dark adaptation involves phototransduction taking place mainly between the photoreceptor outer segments and the retinal pigment epithelial (RPE) layer. DA occurs over a large range of luminance and is modulated by both cone and rod photoreceptors. In the photopic ranges, rods are saturated and cone cells adapt to the high luminance levels. However, under scotopic ranges, cones are unable to respond to the dim luminance and rods modulate the responses to lower levels of light as they can respond to even a single photon. Since the cone visual cycle is also based on the Muller cells, measuring the impairment in rod-based dark adaptation is thought to be particularly relevant to diseases such as AMD, which involves both photoreceptors and RPE. Dark adaptation parameters are metrics derived from curve-fitting dark adaptation sensitivities over time and can represent specific cellular function. Parameters such as the cone-rod break (CRB) and rod intercept time (RIT) are particularly sensitive to changes in the outer retina. There is some structural and functional continuum between normal aging and the AMD pathology. Many studies have shown an increase of the rod intercept time (RIT), i.e., delays in rod-mediated DA in AMD patients with increasing disease severity determined by increased drusen grade, pigment changes and the presence of subretinal drusenoid deposits (SDD) and association with certain morphological features in the peripheral retina. Specifications of spatial testing location, repeatability of the testing, ease and availability of the testing device in clinical settings, and test duration in elderly population are also important. We provide a detailed overview in light of all these factors.

Leopard spot chorioretinopathy revealing late onset sympathetic ophthalmia

AbstractPurposeTo report a case of a very late onset atypical sympathetic ophthalmia presented as a leopard spot retinopathy.MethodsAn observational case report of a 64‐year‐old patient with a history of penetrating ocular trauma of the right eye (RE) at the age of 3‐year‐old who presented with visual blurring of the left eye (LE). The patient underwent complete ophthalmic examination, autofluorescence imaging, fluorescein angiography, Indocyanine Green (ICG) angiography, swept‐source optical coherence tomography (SS‐OCT).ResultsExamination of the RE showed a phthisis bulbi. Visual acuity of the LE was limited to hand motion. Slit lamp examination revealed +1 cells anterior chamber inflammation, granulomatous keratic precipitates, posterior synechiae, with a mild cataract and +2 vitreous cells. Fundoscopy showed multiple yellowish patchy subretinal lesions. Fluorescein angiography revealed hyperfluorescent nummular areas at early frames without late leakage surrounded by zones of hypofluorescences. Fundus autofluorescence imaging showed a leopard spot pattern with areas of hypoautofluorescence surrounded by hyperautofluorescence. ICG angiography showed no hypofluorescent dark dots. SS‐OCT demonstrated retinal thickening, multiple areas of flat subretinal fluid, irregular hyperreflective spots at the photoreceptor outer segment layer and irregularities of the retinal pigment epithelium. The diagnosis of unilateral diffuse uveal melanocytic proliferation (DUMP) was first made. The patient underwent a systemic workup with full‐body computed tomography scans, cerebral and ocular magnetic resonance imaging and blood tests including tumor markers. All tests were normal. The patient was put on oral prednisone (1 mg/kg/day) during 6 months with a gradual tapering and good initial outcome. Visual acuity increased to 40/200.Two weeks after stopping steroids, he presented with acute granulomatous anterior uveitis and the diagnosis of very late onset sympathetic ophthalmia was made.ConclusionsLeopard retinopathy can be an uncommon clinical presentation of a variety of disorders especially sympathetic ophthalmia. The diagnosis could be challenging in case of atypical presentation and very late onset. Treatment outcome and close follow‐up should be considered for a correct diagnosis.

Opportunities for agent based modeling of retinal stem cell transplantation.

Opportunities for agent based modeling of retinal stem cell transplantation.

A Device-Independent, Shape Preserving Retinal Optical Coherence Tomography Image Alignment Method Applying TV-Unet for RPE Layer Detection

Retinal optical coherence tomography (OCT) images are widely used in diagnosis of ocular conditions. However, random shift and orientation changes of the retinal layers in OCT B-scans yield to appearance variations across the scans. These variations reduce the accuracy of the algorithms applied in the analysis of OCT images. In this study, we propose a preprocessing step to compensate these variations and align B-scans. At first, by incorporating total variation (TV) loss in the well-known Unet model, we propose a TV-Unet model to accurately detect the retinal pigment epithelium (RPE) layer in each B-scan. Then we use the detected RPE layer in the alignment method to form a curvature curve and a reference line. A novel window transferring-based alignment approach is applied to force the curve points to form a straight line, while preserving the shape and size of the pathological lesions. Since detection of RPE layer is a crucial step in the proposed alignment method, we utilized various datasets to train and test the TV-Unet and provided a multimodal, device-independent OCT image alignment method. The TV-Unet localizes the RPE layer in OCT images with low boundary error (maximum of 1.94pixels) and high Dice coefficient (minimum of 0.98). Quantitative and qualitative results indicated that the proposed method can efficiently detects the RPE layer and align OCT images while preserving the structure and size of the retinal lesions (biomarkers) in the OCT scans.

Mechanism of Hypoxia Inducible Factor-1α (HIF-1α) in Choroidal Neovascularization in Macular Lutea of High Myopia

To explore the changes in the expression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in the process of choroidal neovascularization (CNV) in the macular area of cases with form deprivation myopia (FDM), in this study, 36 healthy mice were selected as research subjects for analysis. Specifically, they were randomly divided into test group (n = 18) and control group (n = 18). The right eye of the test group mice underwent form deprivation for 6 weeks to induce FDM, also known as FDM group. Five mice were randomly selected from FDM group and control group at 6 time points (before photocoagulation, at 7 d, 14 d, 21 d, 28 d, and 35 d after photocoagulation), respectively, for fluorescein angiography and hematoxylin-eosin staining (HE) staining to observe differences in the retina. It was found that the retina of Control group mice was well-structured with clear stratification, while that of the test group mice was severely damaged with a disordered structure, manifested as edema and swelling and damaged Bruch membrane and retinal pigment epithelium (RPE) layer. Furthermore, macrophages and RPE cells were observed in the photocoagulation area, and there was a high-fluorescence area with a blurred margin in the fundus, indicating the formation of new blood vessels. The immunohistochemical experiment revealed that within three weeks after the surgery, HIF-1α was highly expressed in the test group, and the expression level was obviously higher than the Control group. The real-time quantitative polymerase chain reaction (PCR) results showed that the expression level of VEGF and HIF-α in the test group was obviously higher than the Control group within three weeks after the surgery. The Western blot experiment was performed 1 week after the surgery, and it was noted that the expression level of VEGF and HIF-1α were higher in the test group versus the Control group. In summary, HIF-1α is instrumental in ocular CNV, which is also associated with VEGF.

Adaptive optics two-photon excited fluorescence lifetime imaging ophthalmoscopy of photoreceptors and retinal pigment epithelium in the living non-human primate eye.

Fluorescence lifetime imaging has demonstrated promise as a quantitative measure of cell health. Adaptive optics two-photon excited fluorescence (TPEF) ophthalmoscopy enables excitation of intrinsic retinal fluorophores involved in cellular metabolism and the visual cycle, providing in vivo visualization of retinal structure and function at the cellular scale. Combining these technologies revealed that macaque cones had a significantly longer mean TPEF lifetime than rods at 730 nm excitation. At 900 nm excitation, macaque photoreceptors had a significantly longer mean TPEF lifetime than the retinal pigment epithelium layer. AOFLIO can measure the fluorescence lifetime of intrinsic retinal fluorophores on a cellular scale, revealing differences in lifetime between retinal cell classes.

Analysis of Optical Coherence Tomography in Acute versus Chronic Central Serous Chorioretinopathy.

Central serous chorioretinopathy (CSC) is a common retinal disease that causes vision loss worldwide. Studying the imaging characteristics of CSC is helpful for the differential diagnosis of diseases. This study analyzed the differences between acute and chronic CSC and provide related information. The aim of this study was to describe the optical coherence tomography features in patients with acute and chronic CSC. Sixty-two eyes of 56 patients with CSC were included in the study. Optical coherence tomography was performed to observe the image features. The photoreceptor outer-segment (PROS) thickness above the pigment epithelium detachment (PED) coinciding with the leakage point in fundus fluorescein angiography was measured and compared with the mean PROS thickness outside the PED in acute cases. The SPSS 23.0 software (IBM Co., Chicago, IL) was used for statistical analysis. Of our 56 patients (62 eyes), 41 (73.21%) were male and 15 (26.79%) were female. There were 53 eyes (85.48%) with acute CSC and 9 eyes (14.52%) with chronic CSC. Besides other common features, the new feature of a high-reflection band in the outer nuclear layer was found to be limited to the macular detachment area. In acute cases, the mean PROS thickness above the retinal pigment epithelium layer protuberance coinciding with the leakage point was 22.7 ± 8.8 μm, which was less than the mean PROS thickness outside the PED at 64.3 ± 21.3 μm (P ≤ .001). The high-reflection band in the outer nuclear layer within the serous neurosensory detachment limited to the macular area was a new finding in CSC patients. This finding can be used as an imaging feature to aid in the diagnosis of CSC.

Decreasing myopic lacquer crack and widening parapapillary gamma zone: case report

BackgroundMyopic axial elongation may be due to an equatorial enlargement of Bruch’s membrane (BM), leading to a prolate eye shape and increasing strain with BM and the retinal pigment epithelium (RPE) layer at the posterior pole. The increased BM strain may cause an enlargement of Bruch’s membrane opening (BMO) of the optic nerve head, with the subsequent development and enlargement of parapapillary gamma zone as BM-free parapapillary zone. The increased strain within BM and RPE may also cause lacquer cracks (LCs) as linear breaks in the RPE and / or BM. Studies suggested that a more marked gamma zone enlargement is associated with lower prevalence of LCs or macular BM defects. Here report on the disappearance of a LC during a 10-year follow-up of a highly myopic eye, concurrent with a marked increase in gamma zone.Case presentationA 56-year-old woman showed in her right eye (axial length measured 30.69 mm) a LC, vertically oval optic disc, and parapapillary gamma zone in 2001. When re-examined in 2006, gamma zone had enlarged, while the LC was no longer detectable. In 2011, the LC was not visible neither upon ophthalmoscopy and or upon optical coherence tomography (OCT), while gamma zone had further enlarged. The gamma zone enlargement occurred in a direction perpendicular to the direction of the former LC.ConclusionsThe observation suggest that a LC can decrease in width, in temporal association with an enlargement of gamma zone. It fits with the notion that an enlargement of the BMO (i.e., enlarging gamma zone) may lead to a relaxation of the BM strain and subsequently to a decrease in the width of the LC.

Complex Rearrangement of the Entire Retinal Posterior Pole in Patients with Relapsing Remitting Multiple Sclerosis.

There are consolidated data about multiple sclerosis (MS)–dependent retinal neurodegeneration occurring in the optic disk and the macula, although it is unclear whether other retinal regions are affected. Our objective is to evaluate, for the first time, the involvement of the entire retinal posterior pole in patients diagnosed with relapsing remitting multiple sclerosis (RRMS) unaffected by optic neuritis using Spectral Domain–Optical Coherence Tomography (SD–OCT). The study protocol was approved by Tor Vergata Hospital Institutional Ethics Committee (Approval number 107/16), and conforms to the tenets of the Declaration of Helsinki. After a comprehensive neurological and ophthalmological examination, 53 untreated RRMS patients (aged 37.4 ± 10) and 53 matched controls (aged 36.11 ± 12.94) were enrolled. In addition, each patient underwent an examination of the posterior pole using the SD-OCT built-in Spectralis posterior pole scanning protocol. After segmentation, the mean thickness, as well as the thickness of the 64 single regions of interest, were calculated for each retinal layer. No statistically significant difference in terms of average retinal thickness was found between the groups. However, MS patients showed both a significantly thinner ganglion cell layer (p < 0.001), and, although not statistically significant, a thinner inner nuclear layer (p = 0.072) and retinal nerve fiber layer (p = 0.074). In contrast, the retinal pigment epithelium (p = 0.014) and photoreceptor layers p < 0.001) resulted significantly thicker in these patients. Interestingly, the analysis of the region of interest showed that neurodegeneration was non-homogeneously distributed across each layer. This is the first report that suggests a complex rearrangement that affects, layer by layer, the entire retinal posterior pole of RRMS retinas in response to the underlying neurotoxic insult.

Electrophysiological signs of retinal cone remodeling in geographic atrophy of the pigment epithelium in patients with non-exudative age-related macular degeneration

Testing patients with primary geographic atrophy (GA) requires a multimodal approach and identification of functional biomarkers characterizing retinal structural remodeling.Purpose: to identify the changes in the functional activity of the retinal cone system, which may serve as biomarkers of primary GA in non-exudative age-related macular degeneration (AMD).Material and methods. We tested 22 patients (30 eyes) aged 45–83 (ave. 72.1 ± 10.8 years) with non-exudative AMD and 18 age matched controls (60.2 ± 7.6 years) all of which underwent standard ophthalmological examinations, optical coherence tomography, autofluorescence study, and fundus photography. Standard photopic ERGs, photopic flicker ERGs to stimuli with frequencies of 8.3, 10, 12, and 24 Hz, multifocal ERG (mfERG), and electrooculogram (EOG) were recorded.Results. Electroretinographic signs for GA of retinal pigment epithelium and choriocapillary layer atrophy were described. The results confirm early impairment of the activity of cones in GA and weakening of the functional interaction of M ller cells with the cone bipolar cells. The delayed P1 peak latency of mfERG indicates a decrease in the entire central retina function in non-exudative AMD. A selective reduction in the fovea's mfERG magnitude can serve as a biomarker of primary GA. The spread of the P1 anomaly to adjacent rings may indicate a possible risk of disease progression. A decrease in the dark trough on the EOG and an increase in the Arden ratio can serve as a biomarker of primary GA.Conclusion. We determined electrophysiological signs which can serve as markers of early retinal dysfunction in eyes with primary GA and non-exudative AMD.

Detection of Choroidal Neovascularization (CNV) in Retina OCT Images Using VGG16 and DenseNet CNN

In this study, we intend to diagnose Choroidal Neovascularization in retinal Optical Coherence Tomography (OCT) images using Deep Learning Architectures. OCT images can be used to differentiate between a healthy eye and an eye with CNV disease. In CNV the Retinal Pigment Epithelial layer experiences changes in various properties which can be related to the assistance of OCT Images. This paper proposes a technique for finding CNV in OCTA pictures. Among the few attributes of CNV, the bigger turning point of veins is a moderately clear element, so we will utilize this property to see if there is CNV in an OCTA picture. DenseNet and Vgg16 Architectures of Deep Learning were used in the study and the hyper parameters of both of the architectures were changed to diagnose the disease properly. After the detection of the disease, the diseased OCT images are segmented from the background for the Region of Interest detection using Python OpenCV library that is used for the processing of images. The results of implementation of the Architectures showed that Vgg16 showed better results in detecting the images rather than Dense Net Architecture with an accuracy percentage of 97.53% approximately a percent greater than Dense Net.

Contrast sensitivity and quality of life following intravitreal ranibizumab injection for central retinal vein occlusion

Synopsis/precisWe investigated the relationship between contrast sensitivity (CS) and vision-related quality of life (VR-QOL) in patients with central retinal vein occlusion following ranibizumab intravitreal injection; CS showed a stronger association...

Decreased iris thickness on swept-source optical coherence tomography in patients with primary open-angle glaucoma.

To investigate the iris thickness (IT) of patients with primary open-angle glaucoma (POAG) and older adults using anterior segment swept-source optical coherence tomography (SS-OCT). In this comparative cross-sectional study, 154 participants were enrolled, including 40 patients with POAG and 114 healthy individuals. Nasal-angle SS-OCT images were analysed using callipers to measure the thickness of the iris, including the anterior border layer, stromal, and pigmented epithelial layer, at 1 and 2 mm from the pupil edge. The relationship between IT and glaucoma severity was analysed, and receiver operating characteristic curves were constructed to assess the ability of each IT parameter to distinguish patients with glaucoma from healthy controls. The IT parameters and iris area were lower in the POAG group than in the age-matched control group (p< 0.05). In the POAG group, the thickness of the pigmented epithelial layer at 1 and 2 mm was significantly correlated with the severity of glaucoma (p< 0.05). Iris area, with a cut-off of 1.43 mm2, exhibited the highest sensitivity (85%) and specificity (64.81%; area under the curve=0.783) for distinguishing patients with POAG from healthy controls. Older adults tended to have the thinnest IT, children had the smallest iris area (p< 0.05). In patients with POAG, the severity of iris atrophy was associated with glaucoma severity. The results of IT measurements by SS-OCT may help in the clinical evaluation of POAG.

Multimodal imaging of Hypotrichosis with juvenile macular dystrophy: a case report

BackgroundTo report the first Italian case of hypotrichosis with juvenile macular dystrophy complicated by macular neovascularization diagnosed through multimodal imaging.Case presentationAn 11-year-old boy was referred to our Institution for bilateral maculopathy of unknown origin. Multimodal imaging helps the diagnosis of Juvenile Macular Dystrophy with Hypotrichosis (HJMD). Fundus examination showed several alterations of the retinal pigment epithelium and circular pigmented area of chorioretinal atrophy. Structural spectral domain optical coherence tomography (OCT) showed some backscattering phenomenon with several alterations of retinal pigment epithelium and photoreceptor layer in both eyes. Moreover, OCT showed hyperreflective lesion beneath the neuroepithelium in left eye. OCT angiography (OCT-A) revealed a pathologic neovascular network in choriocapillaris plexus, probably the result of a fibrovascular membrane. Multifocal electroretinograms (MfERGs) showed functional alterations in 12.22° of the central retina. In order to confirm the suspicion of HJMD, the child and both parents underwent genetic testing. Both parents resulted to be heterozygous healthy carriers of a single variation.ConclusionMultimodal imaging, in particular OCT-A, is a useful aid, along to clinical findings and genetics, for the diagnosis of inherited retinal dystrophies.

AUY922 induces retinal toxicity through attenuating TRPM1

BackgroundOcular adverse events are common dose-limiting toxicities in cancer patients treated with HSP90 inhibitors, such as AUY922; however, the pathology and molecular mechanisms that mediate AUY922-induced retinal toxicity remain undescribed.MethodsThe impact of AUY922 on mouse retinas and cell lines was comprehensively investigated using isobaric tags for relative and absolute quantitation (iTRAQ)‑based proteomic profiling and pathway enrichment analysis, immunohistochemistry and immunofluorescence staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, MTT assay, colony formation assay, and western blot analysis. The effect of AUY922 on the Transient Receptor Potential cation channel subfamily M member 1 (TRPM1)-HSP90 chaperone complex was characterized by coimmunoprecipitation. TRPM1-regulated gene expression was analyzed by RNAseq analysis and gene set enrichment analysis (GSEA). The role of TRPM1 was assessed using both loss-of-function and gain-of-function approaches.ResultsHere, we show that the treatment with AUY922 induced retinal damage and cell apoptosis, dysregulated the photoreceptor and retinal pigment epithelium (RPE) layers, and reduced TRPM1 expression. Proteomic profiling and functional annotation of differentially expressed proteins reveals that those related to stress responses, protein folding processes, regulation of apoptosis, cell cycle and growth, reactive oxygen species (ROS) response, cell junction assembly and adhesion regulation, and proton transmembrane transport were significantly enriched in AUY922-treated cells. We found that AUY922 triggered caspase-3-dependent cell apoptosis, increased ROS production and inhibited cell growth. We determined that TRPM1 is a bona fide HSP90 client and characterized that AUY922 may reduce TRPM1 expression by disrupting the CDC37-HSP90 chaperone complex. Additionally, GSEA revealed that TRPM1-regulated genes were associated with retinal morphogenesis in camera-type eyes and the JAK-STAT cascade. Finally, gain-of-function and loss-of-function analyses validated the finding that TRPM1 mediated the cell apoptosis, ROS production and growth inhibition induced by AUY922.ConclusionsOur study demonstrates the pathology of AUY922-induced retinal toxicity in vivo. TRPM1 is an HSP90 client, regulates photoreceptor morphology and function, and mediates AUY922-induced cytotoxicity.

Repeatability and reproducibility of manual choroidal thickness measurement using Lenstar images in children before and after orthokeratology treatment

PurposeTo investigate the repeatability and reproducibility of choroidal thickness measurements using Lenstar images in young myopic children before and after one-month orthokeratology (ortho-k) treatment. MethodOcular biometry of 39 subjects were performed using the Lenstar 900. The first five measurements with maximum differences of 0.02 mm in axial length in the right eyes were saved and used for measurement of choroidal thickness. Subfoveal choroidal thickness were manually measured by identifying the signals from the retinal pigmented epithelium layer and chorioscleral interface. Repeatability was determined by comparing measurements of the same images made by the same observer on two separate occasions (four weeks apart), while reproducibility was calculated by comparing measurements of the same images made by two independent observers. Data was analysed using intra-class correlation coefficients (ICC) and non-parametric Bland and Altman plots. ResultsThe choroidal peaks could not be identified in all five measurements in all subjects. On average, only 71% subjects had at least four definable images. Compared with the use of fewer than four images, reliability using an average of four definable images improved statistically, but remained clinically unacceptable (>10 µm), although pre- and post-ortho-k ICC values were good to excellent for repeatability (0.867 and 0.975, respectively) and excellent and good for reproducibility (0.959 and 0.868, respectively). Non-parametric pre- and post-ortho-k limits of agreement (2.5% and 97.5% percentiles) obtained were −45.8 to 79.3 µm and −30.3 to 9.5 µm, respectively for repeatability, and −29.0 to 33.5 µm and −21.8 to 70.0 µm, respectively for reproducibility. ConclusionChoroidal thickness measurements using the Lenstar did not show good reliability, despite the high ICC values, non-parametric Bland and Altman plots demonstrated a wide variability of measurement errors. Any changes in subfoveal choroidal thickness, measured by Lenstar, of <80 µm may not represent real changes.

Safety of accelerated corneal collagen cross-linking in keratoconus patients on the basis of macular segmentation.

To investigate the safety of accelerated corneal collagen cross-linking (A-CXL) in patients with keratoconus on the basis of thickness analysis measurements of retinal layers and retinal morphology. This was a retrospective and comparative study. The study included 64 eyes of 32 patients with keratoconus disease. One eye of the patients underwent A-CXL for progressive keratoconus (CXL group) and the fellow eye was followed due to the absence of progression. Patients with at least 1-year follow-up after A-CXL were included. Keratometry, pachymetry and corrected-distance visual acuity (CDVA) levels of the patients were compared. The segmentation analysis of the individual retinal layers of the eyes with (CXL group) and without CXL (no CXL group) was compared with spectral domain-optical coherence tomography automatic segmentation program at baseline and at the last follow-up. The thickness of the retinal nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer and retina pigment epithelium layer in the central 1-mm subfield defined by the ETDRS was analyzed. The mean age of keratoconus patients was 23.9 ± 5.4years, patients were more likely to be male (21/11, 65.6%), and the mean follow-up duration was 13.9 ± 1.5months. When keratometry, pachymetry and CDVA levels were compared, only a significant difference was found between CDVA at the last follow-up (0.21 vs. 0.11 LogMAR). No significant difference was observed in neither retinal morphology nor segmentation of individual retinal layers at baseline and at the final evaluation (P > 0.05). It has been observed that the A-CXL protocol did not cause a significant change in both retinal layer thickness and macular morphology.

A Rare Case of Stargardt’s Disease

Abstract Objective To describe a clinical case of rare eye diseases – Stargardt’s disease. Material and methods: A detailed clinical examination, fundus autofluorescence, optical coherence tomography and electrophysiological studies were performed. The clinical diagnosis was also genetically confirmed. Results A classic Stargardt’s disease phenotype was found in a 10-year old boy with decreased visual acuity, atrophy of the photoreceptors and retinal pigment epithelium layers in the macula, plus hypoautofluorescence in the fovea. In full-field ERG there was no diffuse cone involvement. Multifocal ERG demonstrated a lower cone activity in the area of the central macula in both eyes, which is characteristic for hereditary maculopathies and differentiates them from cone-rod dystrophies, in which generalized damage of the photoreceptors in the retina may be observed. The genetic studies identified two missense mutations: c.3113C&gt; T (p.Ala1038Val) and c.1622T&gt; C (p.Leu541Pro) in a cis-position and a missense mutation c.2588G&gt; C (p.Gly863Ala) in the other allele of ABCA4 gene. The two pathogenic variants c.3113C&gt; T and c.1622T&gt; C formed a complex allele p. [A1038V; L541P], which was found in the genome of the asymptomatic mother. The other mutation c.2588G&gt; C affects a highly conserved amino acid from the ABCA4 protein (p.Gly863Ala) and was inherited from the patient’s clinically healthy father, who was a heterozygous carrier. Conclusion The comprehensive clinical, electrophysiological and genetic testing of patients with rare hereditary retinal dystrophies is essential for the correct diagnosis and the choice of therapeutic behavior.