Control Eyes Research Articles

Effect of intravitreal injection of anti-interleukin (IL)-6 antibody in experimental autoimmune uveitis in mice

PurposeThe aim of this study was to assess the functional and clinical impact of intravitreal administration of a neutralizing anti-IL-6 antibody in the treatment of experimental autoimmune uveitis (EAU) in mice.MethodsEAU was induced in 17 female B10.RIII mice by administering Inter-Photoreceptor-Binding-Protein (IRBP) in complete Freund’s adjuvant, followed by a boost with Pertussis toxin. Intravitreal injections of anti-Interleukin (IL)-6 antibody were administered on days 10, 13, and 16 after EAU induction (day 0) into the randomized treatment eye, with an isotype antibody similarly injected into the fellow control eye. Visual acuity was assessed using the optomotor reflex via OptoDrum, and clinical scoring was performed via fundus imaging (utilizing 6 EAU grades) in a single-blinded manner on days 0, 10, 13, 16, and 18.ResultsUveitis developed in all 17 mice. Significantly higher visual acuity was observed in treated eyes compared to control eyes on days 13, 16, and 18. The most pronounced effect was noted on days 16 and 18 (p < 0.001). On days 13, 16, and 18 the number of eyes with lower EAU-score was significantly higher in the treatment group, with the most notable effect observed on day 18 (p < 0.003).ConclusionIntravitreal administration of anti-IL-6 treatment notably mitigates experimental autoimmune uveitis in mice, both functionally and clinically. Further investigations are warranted to assess the potential of intravitreal anti-IL-6 therapy as a treatment option for non-infectious uveitis in humans.

Comparison of the quantitative contrast sensitivity function between early keratoconus and normal eyes

PurposeTo compare the characteristics of the quantitative contrast sensitivity function (qCSF) in eyes with early keratoconus (Early-KC) and normal control (NC) eyes and investigate the associated factors.DesignA cross-sectional study.MethodsThis study included 43 eyes of 43 patients with Early-KC (including subclinical keratoconus [SKC] and forme fruste keratoconus [FFKC]) and 77 NC eyes of 77 participants with corrected distance visual acuity (CDVA) all ≥ 20/20. Contrast sensitivity (CS) was assessed using the qCSF tests. Subgroup analysis was performed according to keratoconus type(SKC and FFKC) and astigmatism(cylindrical refraction >-1.0D or ≤-1.0D).ResultsSex ratio, spherical refraction, and spherical equivalent (SE) varied significantly between the two groups (all P < 0.01). The area under log CSF (AULCSF), CSF Acuity, and CS at low (1.0 and 1.5 cycles per degree [cpd]) and high (12.0 and 18.0 cpd) spatial frequencies decreased significantly in the Early-KC group than that in the NC group (all P < 0.05). The subgroup analysis revealed a similar decrease in the SKC group (all P < 0.05). AULCSF, CSF Acuity, and CS at high spatial frequencies of patients with cylindrical refraction ≤-1.0D in the Early-KC group decreased significantly (all P < 0.05) than those in the NC group. The index of vertical asymmetry and index of height decentration correlated negatively with CS at 1.5 cpd (r= -0.321 and -0.306; both P < 0.05).ConclusionsCS decreased significantly at low and high spatial frequencies in Early-KC, though with normal CDVA. The qCSF test can sensitively reflect visual performance in early keratoconus.

Association between axial length and uveitis.

Multiple studies have examined the association between myopia and various ocular diseases, but there is no clinical report of the relationship between myopia and uveitis. This study aimed to elucidate the relationship between myopia and uveitis by comparing axial lengths (AL) of uveitis patients with control individuals. This study included 1052 eyes (663 patients; 288 males, 375 females; median age 56.0years) with uveitis referred to Tokyo Medical University Hospital. Controls were 738 eyes with cataract but no other ocular diseases. AL was measured by IOLMaster or conventional A-mode ultrasound system. Uveitis eyes were grouped into various types of non-infectious uveitis, infectious uveitis, and unidentified uveitis. Median AL of each uveitis group was compared with control group using Mann-Whitney U-test, and also compared with adjustment for age and sex using multiple regression analysis. Binary logistic analysis was performed to examine whether AL plays a role in the risk of developing uveitis. Of 1052 eyes, 808 eyes (76.8%) were diagnosed with non-infectious uveitis [sarcoidosis (176 eyes, 16.7%), Vogt-Koyanagi-Harada disease (122 eyes, 11.6%), Behçet's disease (130 eyes, 12.4%), and others (380 eyes, 36.1%)], 146 eyes (13.9%) with infectious uveitis, and 98 eyes (9.3%) with unidentified uveitis. Median AL in all uveitis eyes was significantly shorter than in control eyes (23.73 vs 24.31mm, p < 0.001 unadjusted), and AL remained significantly shorter in uveitis than in control after age- and sex-adjustment (p < 0.001). Median AL was significantly shorter in non-infectious uveitis (23.72mm) and in infectious uveitis (23.99mm) compared to controls (p < 0.001 and < 0.05, respectively), and was significantly shorter in non-infectious uveitis than in infectious uveitis (p < 0.05). Each millimeter decrease in AL was associated with 1.266-fold increase in unadjusted risk [odds ratio (OR), 1.266; 95% confidence interval (CI), 1.196-1.341; p < 0.001) and 1.446-fold in age- and sex-adjusted risk (OR, 1.446; 95% CI, 1.349-1.549; p < 0.001) of developing uveitis. Median AL of uveitis eyes with infectious or non-infectious etiologies was significantly shorter than that in control eyes, suggesting an increased risk of developing uveitis in eyes with shorter AL. This feature should be considered when exploring new pathogenetic mechanisms of uveitis. What is known Shorter axial length may be associated with the pathogenesis of central serous chorioretinopathy and increased risk of early age-related macular degeneration. What is new Here we assessed the relationship between myopia and uveitis by comparing axial lengths of uveitis patients. Median axial length in all uveitis eyes was significantly shorter than in control eyes, and axial length remained significantly shorter in uveitis than in control after age- and sex-adjustment. Each millimeter decrease in axial length was associated with 1.266-fold increase in unadjusted risk and 1.446-fold in age- and sex-adjusted risk of developing uveitis.

Prevalence of Glaucoma Among US Adults in 2022

Glaucoma is the leading cause of irreversible blindness worldwide and, in the US, disproportionately affects people from racial and ethnic minority groups. Glaucoma prevalence has not been estimated for the US in more than a decade, and state- and county-level estimates are not available. To estimate glaucoma and vision-affecting glaucoma prevalence by demographic factors and US state and county for the Centers for Disease Control and Prevention's Vision and Eye Health Surveillance System (VEHSS). This meta-analysis used data from the National Health and Nutrition Examination Survey (2005-2008), Medicare fee-for-service claims (2019), IBM MarketScan commercial insurance claims (2016), population-based studies of eye disease (1985-2003), and 2022 population estimates from the US Census Bureau. PubMed was searched for population-based studies of glaucoma prevalence published between 1991 and 2016. Bayesian meta-regression methods were used to estimate the prevalence of glaucoma and vision-affecting glaucoma stratified by age, undifferentiated sex/gender (a measure that captures an unclear mix of aspects of sex and or gender), race and ethnicity, and US county and state. Prevalence of any type of glaucoma (open or closed angle) among people 18 years or older and vision-affecting glaucoma, defined as glaucoma and a visual field abnormality. For 2022, an estimated 4.22 million people (95% uncertainty interval [UI], 3.46 million to 5.23 million) in the US were living with glaucoma, with a prevalence of 1.62% (UI, 1.33%-2.00%) among people 18 years or older and 2.56% (UI, 2.10%-3.16%) among people 40 years or older. An estimated 1.49 million people (UI, 1.17 million to 1.90 million) were living with vision-affecting glaucoma, with a prevalence of 0.57% (UI, 0.45%-0.73%) among people 18 years or older and 0.91% (UI, 0.71%-1.16%) among people 40 years or older. Prevalence of glaucoma among people 18 years or older ranged from 1.11% (UI, 0.89%-1.40%) in Utah to 1.95% (UI, 1.57%-2.39%) in Mississippi. Black adults had a prevalence of 3.15% (UI, 2.32%-4.09%) compared with 1.42% (UI, 1.10%-1.85%) among White adults; adults in the Hispanic and all other racial and ethnic categories combined had a prevalence of 1.56% (UI, 1.13%-2.06%). This meta-analysis found that an estimated 2.56% of people 40 years or older have glaucoma, slightly more than estimated by previous studies. Black individuals are disproportionately affected. Prevalence estimates at the state and county level can help guide public health planning.

Corneal Endothelial Changes in Chinese Patients with Fuchs’ Uveitis Syndrome

ABSTRACT Purpose To analyze the changes of corneal endothelial cells in Chinese patients with unilateral Fuchs’ uveitis syndrome (FUS) and investigate the factors relevant to these changes. Methods Bilateral specular microscopic examination was performed in 459 Chinese patients with unilateral FUS from April 2008 to April 2023. The affected eyes constituted the study group, while the contralateral eyes served as controls. Results The median values of endothelial cell density (ECD), cell count, total cell size, and hexagonality were significantly lower in the FUS eyes compared to the control eyes (p < 0.001). The median values of average cell size, maximum cell size, SD of cell size, and CV were significantly higher in the FUS eyes compared to the control eyes (p < 0.001). Central ECD showed a negative correlation with age (r = −0.339; p < 0.001), maximum IOP (r = −0.127; p = 0.006), and the interval since symptom onset (r = −0.172; p < 0.001). The ECD was lower in eyes with ocular hypertension compared to those without ocular hypertension (p < 0.001). Eyes with KPs distributed on the central corneal endothelium had a significantly lower ECD than those with KPs distributed diffusely or KPs distributed triangularly on the inferior corneal endothelium (p = 0.006). Conclusion Our findings suggest decreased ECD, increased cell size, and morphological alterations in the affected eyes of Chinese patients with FUS. The reduction in ECD is correlated with age, elevated IOP, the interval since symptom onset, and the distribution of KPs.

Retinal oxygen metabolic function in choroideremia and retinitis pigmentosa.

To measure the retinal oxygen metabolic function with retinal oximetry (RO) in patients with choroideremia (CHM) and compare these findings with retinitis pigmentosa (RP) patients and controls. Prospective observational study including 18 eyes of 9 molecularly confirmed CHM patients (9♂; 40.2 ± 21.2years (mean ± SD), 77 eyes from 39 patients with RP (15♀ 24♂; 45.6 ± 14.7years) and 100 eyes from 53 controls (31♀ 22♂; 40.2 ± 13.4years). Main outcome parameters were the mean arterial (A-SO2; %), venular (V-SO2; %) oxygen saturation, and their difference (A-V SO2; %) recorded with the oxygen saturation tool of the Retinal Vessel Analyzer (IMEDOS Systems UG, Germany). Statistical analyses were performed with linear mixed-effects models. Eyes suffering from CHM differed significantly from both RP and control eyes, when the retinal oxygen metabolic parameters were taken into account. While RP showed significantly higher A-SO2 and V-SO2 values when compared to controls, CHM showed opposite findings with significantly lower values when compared to both RP and controls (P < 0.001). The A-V SO2, which represents the retinal oxygen metabolic consumption, showed significantly lower values in CHM compared to controls. The retina in CHM is a relatively hypoxic environment. The decrease in oxygen levels may be due to the profound choroidal degeneration, leading to decreased oxygen flux to the retina. RO measurements may help understand the pathogenesis of CHM and RP. These findings may provide useful details to inform the planning of clinical trials of emerging therapies for CHM. What was known before? Retinal oxygen metabolic function measured with retinal oximetry (RO) shows significant alterations in patients with retinitis pigmentosa. RO function in choroideremia is significantly altered when compared to controls. Furthermore, RO in choroideremia shows opposing findings within different oxygen metabolic parameters to those that were so far known for retinitis pigmentosa. By providing insights into the retinal oxygen metabolic mechanisms, RO can help understand the underlying pathophysiology in choroideremia.

Glial Cell Responses and Gene Expression Dynamics in Retinas of Treated and Untreated RPE65 Mutant Dogs.

The long-term evaluation of RPE65 gene augmentation initiated in middle-aged RPE65 mutant dogs previously uncovered notable inter-animal and intra-retinal variations in treatment efficacy. The study aims to gain deeper insights into the status of mutant retinas and assess the treatment impact. Immunohistochemistry utilizing cell-specific markers and reverse transcription-quantitative PCR (RT-qPCR) analysis were conducted on archival retinal sections from normal and RPE65 mutant dogs. Untreated middle-aged mutant retinas exhibited marked downregulation in the majority of 20 examined genes associated with key retinal pathways. These changes were accompanied by a moderate increase in microglia numbers, altered expression patterns of glial-neuronal transmitter recycling proteins, and gliotic responses in Müller glia. Analysis of advanced-aged mutant dogs revealed mild outer nuclear layer loss in the treated eye compared to moderate loss in the corresponding retinal regions of the untreated control eye. However, persistent Müller glial stress response along with photoreceptor synapse loss were evident in both treated and untreated eyes. Photoreceptor synaptic remodeling, infrequent in treated regions, was observed in all untreated advanced-aged retinas, accompanied by a progressive increase in microglial cells indicative of ongoing inflammation. Interestingly, about half of the examined genes showed similar expression levels between treated and untreated advanced-aged mutant retinas, with some reaching normal levels. Gene expression data suggest a shift from pro-degenerative mechanisms in middle-aged mutant retinas to more compensatory mechanisms in preserved retinal regions at advanced stages, despite ongoing degeneration. Such shift, potentially attributed to a number of surviving resilient cells, may influence disease patterns and treatment outcomes.

Dynamic BMP gene expression regulation in chick RPE during recovery from short term optical defocus and form-deprivation.

This study investigated the differential gene expression of BMPs in chick retinal pigment epithelium (RPE) during recovery from short term exposure to optical defocus and form-deprivation (FD) treatments. 14-day old White-Leghorn chicks wore either monocular +10 or -10 D lenses, or diffusers for 2 or 48 h, after which eyes were allowed unobstructed vision for up to 96 h. Over this recovery period, refractive errors and choroidal thickness (ChT) were tracked using retinoscopy and high-frequency A-scan ultrasonography. Real-time PCR was used to examine the expression of BMP2, 4, and 7 genes in RPE samples collected 0, 15 min, 2, 24, 48, and 96 h after the termination of treatments. Expression levels in treated eyes and their contralateral control eyes were compared. After the termination of the lens and diffuser treatments, eyes gradually recovered from induced shifts in refractive error. With all three treatments, ChT changes reached statistical significance after 48 h of treatment, be it thinning with the -10 D lens and diffuser treatments (-0.06 ± 0.03mm, p < 0.05; -0.11 ± 0.04 mm, p < 0.05, resp.), or thickening with the +10 D lens (0.31 ± 0.04 mm, p < 0.001). BMP2 gene expression was rapidly upregulated in eyes wearing the +10 D lens, being statistical significance after 2 h, as well as 48 h of treatment. With the 2 h treatment, the latter gene expression pattern persisted for 15 min into the recovery period, before decreasing to the same level as that of contralateral control eyes, with a short-lived rebound, i.e., upregulation, 24 h into the recovery period. With the longer, 48 h treatment, BMP2 gene expression decreased more gradually, from 739 ± 121% at the end of the treatment period, to 72 ± 14% after 48 h of recovery. Two and 48 h of both -10 D and FD treatments resulted in BMP2 gene expression downregulation, with the time taken for gene expression levels to fully recover varying with the duration of initial treatments. In both cases, BMP2 gene expression downregulation persisted for 15 min into the recovery period, but reversed to upregulation by 2 h. Similar gene expression patterns were also observed for BMP4, although the changes were smaller. The observed changes in BMP gene expression in chick RPE imply dynamic, albeit complex regulation, with the duration of exposure and recovery being critical variables for all three types of visual manipulations. This study provides further evidence for a role of the RPE as an important signal relay linking the retina to the choroid and sclera in eye growth regulation.

Diagnostic Performance for Detection of Glaucomatous Structural Damage Using Pixelwise Analysis of Retinal Thickness Measurements.

To compare the diagnostic accuracy of thickness measurements of individual and combined macular retinal layers to discriminate 188 glaucomatous and 148 glaucoma suspect eyes from 362 healthy control (HC) eyes on a pixel-by-pixel basis. For this retrospective study, we manually corrected the segmentations of posterior pole optical coherence tomography (OCT) scans to determine the thickness of the nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), the ganglion cell complex (GCC), and the total neural retina (TR). For each eye, the total number of pixels with thickness values less than the fifth percentile of the HC distribution was used to create a receiver operating characteristic (ROC) curve for each layer and for layer combinations. Using total abnormal pixel count criteria to discriminate glaucoma from HC eyes, the individual layers with the highest area under the ROC curve (AUC) were the NFL and GCL; IPL performance was significantly lower (P < 0.05). GCC had a significant higher AUC (94.3%) than individual the AUC of the NFL (92.3%) (P = 0.0231) but not higher than AUC of the GCL (93.4%) (P = 0.3487). The highest AUC (95.4%) and sensitivity (85.1%) at 95% specificity was found for the Boolean combination of NFL or GCL. The highest AUC is not significantly higher (P = 0.0882) than the AUC of the GCC but the highest sensitivity is significantly higher than the sensitivity of the GCC. This pattern was similar for discriminating between suspect and HC eyes (P = 0.0356). Using pixel-based methods, the diagnostic accuracy of NFL and GCL exceeded that of IPL and TR. GCC had equivalent performance as NFL and GCL. The specific spatial locations within the posterior pole that exhibit best performance vary depending on which layer is being assessed. Recognizing this dependency highlights the importance of considering multiple layers independently, as they offer complementary information for effective and comprehensive diagnosis.

IOP Reduction in Nonhuman Primates by Microneedle Injection of Drug-Free Hydrogel to Expand the Suprachoroidal Space.

Expansion of the suprachoroidal space (SCS) by a hydrogel injection has been shown to reduce intraocular pressure (IOP) in rabbits as a potential treatment for ocular hypertension in glaucoma. Here, we evaluate the safety and efficacy of this approach in hypertensive and normotensive eyes in nonhuman primates. A microneedle was used to inject a hyaluronic acid-based hydrogel or saline solution (control) into the SCS of cynomolgus monkey eyes that were either normotensive (n = 7 experimental; n = 2 control eyes) or had induced ocular hypertension (n = 6 experimental; n = 3 control eyes). IOP and the degree of SCS expansion were monitored over time by tonometry and ultrasound biomicroscopy, respectively. Safety was evaluated through slit lamp, fundus, and histology examinations. In hypertensive eyes, SCS injection with hydrogel initially reduced IOP by 47.5 ± 16.7%, and IOP returned to baseline in 38 days. In normotensive eyes, hydrogel injection initially reduced IOP by 38.8 ± 8.1% and IOP gradually returned to baseline also in 39 days. Sham injections resulted in mild IOP reduction in hypertensive eyes and normotensive eyes. The hydrogel injections were well tolerated by clinical assessments. IOP was reduced in nonhuman primates for over one month by sustained SCS expansion. This procedure was safe and simple to perform. These data confirm the translational potential of this treatment method. Further optimization of the hydrogel may provide longer durations of IOP reduction. A microneedle injection of hydrogel into the suprachoroidal space may provide a non-surgical, non-pharmacologic treatment for ocular hypertension in glaucoma patients.

Low Intraocular Pressure Induces Fibrotic Changes in the Trabecular Meshwork and Schlemm's Canal of Sprague Dawley Rats.

Continuous artificial aqueous humor drainage in the eyes of patients with glaucoma undergoing trabeculectomy likely exerts abnormal shear stress. However, it remains unknown how changes in intraocular pressure (IOP) can affect aqueous humor outflow (AHO). Here, we induced and maintained low intraocular pressure (L-IOP) in healthy Sprague Dawley (SD) rats by puncturing their eyes using a tube (200-µm diameter) for 2 weeks. After the rats were euthanized, their eyes were removed, fixed, embedded, stained, and scanned to analyze the physiological and pathological changes in the trabecular meshwork (TM) and Schlemm's canal (SC). We measured SC parameters using ImageJ software and assessed the expression of various markers related to flow shear stress (KLF4), fibrosis (TGF-β1, TGF-β2, α-SMA, pSmad1/5, pSmad2/3, and fibronectin), cytoskeleton (integrin β1 and F-actin), diastolic function (nitric oxide synthase and endothelial nitric oxide synthase [eNOS]), apoptosis (cleaved caspase-3), and proliferation (Ki-67) using immunofluorescence or immunohistochemistry. L-IOP eyes showed a larger SC area, higher eNOS expression, and lower KLF4 and F-actin expression in the TM and SC (both P < 0.05) than control eyes. The aqueous humor of L-IOP eyes had a higher abundance of fibrotic proteins and apoptotic cells than that of control eyes, with significantly higher TGF-β1, α-SMA, fibronectin, and cleaved caspase-3 expression (all P < 0.05). In conclusion, a persistence of L-IOP for 2 weeks may contribute to fibrosis in the TM and SC and might be detrimental to conventional AHO in SD rat eyes. Clinicians should consider that aberrant shear force induced by aqueous humor fluctuation may damage AHO outflow channel when treating patients.

A Modified Intravitreal Methotrexate Protocol for the Prevention of Proliferative Vitreoretinopathy after Silicone Oil Removal

ObjectiveTo utilize a modified intravitreal (IVT) methotrexate (MTX) protocol for the prevention of proliferative vitreoretinopathy (PVR) after silicone oil (SO) removal (SOR). DesignSingle-center nonrandomized retrospective comparative case series. SubjectsEyes with grade C PVR who underwent retinal detachment repair and SO placement between 2019-2022 with at least 6 months of follow-up after SOR. A control group of age- and sex-matched eyes was included. MethodsEyes were treated with one of two MTX protocols. Eyes in Group 1 received 6 IVT MTX injections following SO placement, and another 6 IVT MTX injections following SOR. Eyes in Group 2 received 6 IVT MTX following SO placement only. Each series of 6 IVT MTX injections (400 μg/0.1 mL) consisted of 3 injections every 2 weeks followed by 3 injections every 4 weeks. Main Outcome MeasuresThe primary outcome was the retinal attachment rate at 6 months post-SOR without re-detachment or re-operation. Secondary outcomes included change in visual acuity (VA) and rates of complications after SOR. ResultsFifty-two eyes of 52 patients (13 Group 1, 13 Group 2, 26 control) (mean age 59.8 years, 80.8% male) were included with a mean follow-up of 31.0 months. In aggregate, Group 1 and Group 2 eyes received a median (IQR) of 6 (5.25, 7) IVT MTX injections pre-SOR; eyes in Group 1 received a median (IQR) of 5 (3, 6) IVT MTX injections post-SOR. Twelve (92.3%) Group 1 eyes, 11 (84.6%) Group 2 eyes, and 21 (80.8%) control eyes had primary retinal attachment at 6 months post-SOR (P > 0.05). VA outcomes did not significantly differ between groups (P > 0.05). Rates of epiretinal membrane (ERM) and cystoid macular edema (CME) were significantly lower in Group 1 eyes (7.7% and 15.4%) compared to Group 2 (53.8% and 92.3%) and control (44.3% and 65.4%) eyes, respectively (P < 0.05). ConclusionsThe use of IVT MTX injections in eyes with PVR undergoing RD repair was associated with a high rate of primary retinal attachment after SOR. Eyes that received IVT MTX injections after SOR had significantly lower rates of ERM and CME than eyes that did not.

RETICULAR PSEUDODRUSEN DISAPPEARANCE AFTER DEVELOPMENT OF MACULAR NEOVASCULARIZATION.

To explore changes in reticular pseudodrusen (RPD) number and location after the development of macular neovascularization (MNV) in eyes with prior intermediate age-related macular degeneration, focusing on different retinal regions differently affected by MNV. This retrospective longitudinal study included intermediate age-related macular degeneration eyes with RPD that developed MNV. Reticular pseudodrusen were assessed at baseline when MNV was diagnosed (MNV stage) and after anti-vascular endothelial growth factor treatment. Three regions of interest were considered: MNV area, subretinal fluid (SRF) area, and a marginal area of 1,000 µm around SRF (marginal zone). Reticular pseudodrusen counts were compared with age- and sex-matched control eyes with RPD that did not develop MNV. Reticular pseudodrusen number exhibited a significant decrease after MNV development in the MNV area (P = 0.048) and in the area with SRF (P = 0.078). A statistically significant decrease was also disclosed in the marginal area around SRF (P = 0.002), associated with larger SRF areas. Control eyes did not show any significant change in the RPD count. Reticular pseudodrusen reduction after MNV development suggests a complex interplay involving the MNV itself, the presence of SRF, and trophic changes. The results of this study highlight the role of MNV in retinal nutritional balance and provide intriguing results in the RPD life cycle.

Comparison of Retinal Thickness betweenDiabetic Patients without Diabetic Retinopathy and Non-Diabetic Controls Using SD-OCT

Purpose: To determine retinal thickness in diabetic patients without diabetic retinopathy and non-diabetic controls using Spectral Domain Optical Coherence Tomography (SD-OCT). Study Design: Cross-sectional observational study. Place and Duration of Study: Diabetic Eye Clinic and General Eye OPD of Al-Ibrahim Eye Hospital, Karachi from July 2018 to August 2018. Methods: Patients with type 2 diabetes and non-diabetic healthy control eyes of either genderand age between 20 and 60 years were recruited. Patients with any other systemic and ocular disease affecting retinal thickness were excluded. After initial examination and informed written consent, patients were referred to ocular investigation department for detailed retinal examination and SD-OCT for measuring central retinal thickness. Data were analyzed for continuous and categorical variable using SPSS. Results: Average Central Retinal thickness was 297±21 and 315±13µmand Central Foveal Thickness was 246±16 and 249±19µmin diabetic and non-Diabetic patients respectively. Quadrant-wise evaluation revealed retinal thickness as follows; nasal 310 and 324µm), temporal (291and 304µm), superior (297and 316µm) and inferior (292and 314µm) in diabetics and non-diabetics respectively. Retinal thickness was greater at nasal and lesser at temporal regions. Conclusion: Diabetic patients without DR had thinner central retinal thickness compared to non-diabetic controls, as measured by Spectral Domain Optical Coherence Tomography (SD-OCT). Specifically, the average central retinal thickness and central foveal thickness were slightly reduced in diabetic patients. Quadrant-wise analysis revealed that the retinal thickness was consistently greater in the nasal region and lesser in the temporal region in both diabetic and non-diabetic patients.

Optical coherence tomography angiography analysis of the fellow eye in unilateral pseudoexfoliation syndrome

PurposeTo compare the macular and optic disc vascular parameters in the unaffected fellow eyes of subjects with unilateral pseudoexfoliation syndrome (PXS) and controls using optical coherence tomography angiography (OCTA).MethodsThe medical records of 61 eyes of 61 patients were analyzed in a retrospective study. Of these, 30 eyes were unaffected fellow eyes and 31 eyes were control eyes. The vessel density (VD), perfusion density (PD) and foveal avascular zone (FAZ)-related parameters of the superficial capillary plexus (SCP) in the circumpapillary and macular area and the VD and PD of the deep capillary plexus (DCP) in the macular area were measured using OCTA after dilatation and were compared between two groups after adjustment for age, sex and axial length.ResultsThere were no statistically significant differences in sex ratio or mean age, central corneal thickness measurements, refractive errors, intraocular pressures and axial length between both groups (all P > 0.05). In the circumpapillary area, inferior VD and PD in the inner zone, as well as average, temporal, inferior, and nasal VD and PD in the outer zone were significantly reduced in the unaffected fellow eyes with unilateral PXS, while the circumpapillary retinal nerve fiber layer (RNFL) thicknesses were similar between groups. In the macular SCP, VDs were significantly lower in all sectors in the inner area and in the outer zones (p < 0.05 for all), PDs were significantly lower in all sectors (p < 0.05 for all) except the nasal sector of the outer zone (p = 0.003 for average, p = 0.029 for superior sector, p = 0.004 for temporal sector, p < 0.001 for inferior sector), and the FAZ circularity (p = 0.037) were significantly lower in the unaffected fellow eyes with unilateral PXS, whereas macular ganglion cell inner plexiform layer (GCIPL) thickness was similar between the two groups.ConclusionsAlthough circumpapillary RNFL and GCIPL thicknesses were similar between the two groups, VDs and PDs in the circumpapillary and macular SCP and FAZ circularity were significantly lower in the fellow eye of subjects with unilateral PXS.

Rates of Visual Field Progression Before and After the Onset of Atrial Fibrillation.

This case-control study investigated the effect of atrial fibrillation (AF) on the progression of glaucoma. The presence of AF and related microvascular damage were associated with a slightly faster visual field loss in glaucoma patients. To investigate the effect of atrial fibrillation (AF) on glaucoma progression. In this longitudinal case-control study, a total of 144 eyes from 105 patients with primary open angle glaucoma were included. 48 eyes of case developed AF during the follow-up followed for 15.6 years. 96 eyes of control that did not have AF at baseline or during follow-up matched for age, baseline glaucoma severity and follow-up period were followed for an average of 14.7 years. Mixed-effects linear models were used to calculate the difference in the VF MD slopes before and after the AF. CHADS2 and CHA2DS2-VASc scores were used to evaluate the risk of thrombosis event, and related microvascular damage was assessed based on these scores. The rate of VF MD change was -0.20 (-0.42 to 0.02) dB/y before AF and -0.28 (-0.47 to -0.09) dB/y after AF for the patients with AF, and -0.21 (-0.25 to -0.17) dB/y for the control. In the multivariable models, the VF slope difference before and after the onset of AF (-0.10 (-0.14 to -0.05) dB/y, P<0.001), higher CHADS2 score (-0.07 (-0.13 to 0.00) dB/y per 1 unit, P=0.040), and higher CHA2DS2-VASc score (-0.05 (-0.10 to 0.00) dB/y per 1 unit, P=0.039) were associated with faster VF MD loss. The presence of atrial fibrillation and related microvascular damage might accelerate visual field loss. This underscores the need for a comprehensive medical history and management of cardiovascular risk factors to mitigate increase VF loss in glaucoma.

Progressive Thickening of Retinal Nerve Fiber and Ganglion Cell Complex Layers Following SDM Laser Vision Protection Therapy in Open-Angle Glaucoma.

This work aims to determine the effect on nerve fiber layer (NFL) and ganglion cell complex (GCC) thickness trends in eyes with open-angle glaucoma (OAG) treated with Vision Protection Therapy™ (VPT). A retrospective analysis of spectral-domain optical coherence tomography (OCT) measured NFL and GCC thickness trends was performed, excluding eyes with poor-quality scans and principal diagnoses other than OAG. This study compares eyes with OAG managed conventionally with IOP control alone (controls) to eyes managed with the addition of VPT (VPT eyes). The direction (+ or -) and magnitude (microns/year) of the OCT trends were the study endpoints. Seventy-eight control eyes of 40 patients and 61 VPT-treated eyes of 39 patients were included in the study. Positive NFL trends were noted in 5% of control eyes vs. 71% of VPT eyes (p < 0.0001). Positive GCC trends were noted in 8% of control eyes vs. 43% of VPT eyes (p < 0.0001). Mean NFL trends (µm/year) were - 0.692 for controls vs. 0.347 for VPT (p < 0.0001). Mean GCC trends (µm/year) were - 0.554 for controls vs. - 0.148 for VPT (p = 0.0175). The addition of VPT to the conventional management of OAG resulted in highly significant improvements in NFL and GCC trends, indicating a reversal of key indicators of glaucoma severity and progression.

Corneal Layer Thickness Mapping With Optical Coherence Tomography in Different Stages Reveals Pathologic Processes of Keratoconus

Purpose: The aim of this study was to characterize the corneal layer thickness profile in different stages of keratoconus (KC). Methods: Patients with clinical or subclinical KC without a history of contact lens use were retrospectively enrolled. We evaluated 164 eyes, including 69 clinical KC, 32 topographic KC (no clinical signs), 22 very asymmetric ectasia with normal topography and no clinical signs of ectasia (VAE-NT), and 41 control eyes. The corneal epithelial, stromal, and total thicknesses in a 10-mm diameter were evaluated using swept-source anterior segment optical coherence tomography. Results: The epithelial thickness in the control and VAE-NT groups was thicker inferiorly than superiorly. While epithelial thickness parameters between the VAE-NT and control groups did not differ, significant stromal thinning was observed in the paracentral inferior and midperipheral temporal areas. The epithelium in the topographic and clinical KC groups was thinner than that in the control and VAE-NT groups, with focal thinning of the epithelium in the inferior-temporal area. In clinical KC, stromal thinning increased mainly in the central and paracentral inferior/temporal areas. With KC progression, the thinnest epithelial points tended to be placed temporally and inferiorly. Conclusions: Corneal layer thickness mapping using swept-source optical coherence tomography in a 10-mm diameter cornea across various severities of KC, from very mild to advanced, revealed that epithelial and stromal thicknesses changed with KC severity and was involved in the pathogenesis of KC progression. Pathological changes in the stroma may precede those in the epithelium. Epithelial compensatory mechanisms in clinical and topographic KC may not have fully emerged in VAE-NT.

Retinal thickness and macular microvascular changes seen on optical coherence tomography angiography (OCTA) in patients with sickle cell retinopathy in a tertiary care eye hospital

PurposeTo report retinal thickness values and macular vascular flow characteristics identified by optical coherence tomography angiography (OCT-A) in patients with various sickle cell genotypes in a population from sub-Saharan Africa. DesignRetrospective, observational study. MethodsThis is a single-institution case series of adult patients with various sickle cell genotypes who presented to the Eye Foundation Hospital Lagos between January 2022 and December 2023. Case files of patients were reviewed, and macular OCT and OCT-A images analyzed quantitatively for macular thickness, areas of flow loss, size of foveal avascular area, parafoveal flow, as well as vascular density in both the superficial and deep vascular plexi. The findings were compared by sickle cell genotype and comparisons made with age matched normal patients. ResultsA total of 38 eyes of 19 patients’ records were reviewed, and 35 eyes met the inclusion criteria; 16 eyes of 9 age and gender matched controls were included. The mean central foveal thickness (CFT) was 242.4 μm ± 33.3 μm among patients’ eyes, while a mean CFT of 236.1 μm ± 10.1 μm was measured among controls (p = 0.312). A smaller mean FAZ area of 0.270 mm2 ± 0.116 mm2 was seen among the control eyes compared to a mean of 0.314 mm2 ± 0.206 mm2 among patients’ eyes (p = 0.439). The mean flow area was larger among control eyes with 0.849 mm2 ± 0.647 mm2 compared to a mean flow of 0.822 mm2 ± 0.471 mm2 among patients’ eyes (0.868). The mean superficial foveal vessel density was greater among control eyes (19.30 ± 4.58) compared to patient eyes (18.77 ± 7.78) (p = 0.765). The mean deep foveal vessel density was greater among controls (35.30 ± 8.36) than among patients (34.06 ± 9.30) (p = 0.650). The difference between eyes of SC (53.37 ± 5.13) patients and SS (47.94 ± 8.44) patients in the deep temporal perifoveal VD was statistically significant (p = 0.035). ConclusionThe retina in eyes with sickle retinopathy and that of controls tends to be thickest in the nasal quadrant, then the superior, then inferior, and then thinnest in the temporal quadrant. Macular vessel density in both the superficial and deep capillary plexi was thicker among controls compared to eyes with sickle cell retinopathy. Among patients’ eyes, the deep capillary vessel density in the temporal perifoveal quadrant was greater among SC patients compared to SS (p = 0.035).

Morphologic features of iris in highly myopic eyes based on a novel swept-source optical coherence tomography.

To investigate the morphologic features of iris in the highly myopic (HM) eyes using a novel swept-source optical coherence tomography (SS-OCT). In this retrospective case-control study, 100 eyes of 100 patients scheduled to have cataract surgery were included, categorized into the control (22 mm< AL < 24.5 mm) and HM (AL ≥ 26 mm) groups. Iris volume (IV), area of anterior iris surface (IS), area of posterior IS, and average iris thickness (IT), as well as anterior chamber volume (ACV) and trabecular-iris space at 500 µm (TISA 500) were evaluated using SS-OCT. The associated factors with morphologic features of iris were also investigated. The HM group showed significantly larger IV and area of anterior and posterior IS than the control group (all P < 0.001), while no difference was identified in IT between the groups. Similar trend in IV was seen in the superior and nasal segments, and area of anterior and posterior IS showed similar trends in all segments except the temporal segment. The IV, area of anterior and posterior IS were all positively correlated with AL (all P < 0.001). Multivariate linear regression revealed that a larger IV was associated with greater ACV. Both larger areas of anterior IS and posterior IS were associated with male, longer AL, greater ACV, and smaller TISA 500. The HM eyes showed larger IV and area of IS than the control eyes, indicating a coronal expansion of the iris with AL. Iris morphology correlated with anterior chamber angle configuration.