Retinal Nerve Fiber Layer Loss Research Articles

Rate of Initial Optic Nerve Head Capillary Density Loss and Risk of Visual Field Progression

Rapid initial optic nerve head capillary density loss may be used to assess the risk of glaucoma visual field progression. To investigate the association between the rate of initial optic nerve head capillary density loss from optical coherence tomography angiography (OCTA) and visual field progression. This was a retrospective study of a longitudinal cohort at a glaucoma referral center. A total of 167 eyes (96 with primary open-angle glaucoma and 71 with glaucoma suspect) of 109 patients were monitored for a mean (SD) of 5.7 (1.4) years from January 2015 to December 2022. Data analysis was undertaken in April 2023. The rates of initial capillary density and average retinal nerve fiber layer loss were calculated from the first 3 optic nerve head OCTA and OCT scans, respectively, during the initial follow-up (mean [SD], 2.0 [1.0] years). Based on the median rate, eyes were categorized into fast and slow progressor groups. The association between initial capillary density change or retinal nerve fiber layer thinning and visual field progression was evaluated using linear-mixed and time-varying Cox models. A total of 167 eyes of 109 patients (mean [SD] age, 69.0 [11.1] years; 56 [51.4%] female and 53 [48.6%] male) were assessed. Eighty-three eyes were slow OCTA progressors, while 84 eyes were fast with mean capillary density loss of -0.45% per year and -1.17% per year, respectively (mean difference, -0.72%/year; 95% CI,-0.84 to -0.60; P < .001). Similarly, 83 eyes were slow OCT progressors, while 84 eyes were fast with mean retinal nerve fiber layer thinning of -0.09 μm per year and -0.60 μm per year, respectively (mean difference, -0.51 μm/year; 95% CI,-0.59 to -0.43; P < .001). The fast OCTA and OCT progressors were associated with more rapid visual field loss (mean difference, -0.18 dB/year; 95% CI,-0.30 to -0.06; P = .004 and -0.17 dB/year; 95% CI,-0.29 to -0.06; P = .002, respectively). Fast OCTA progressing eyes were more likely to have visual field progression (hazard ratio, 1.96; 95% CI, 1.04-3.69; P = .04). Seventeen of 52 eyes (32.7%; 95% CI, 32.5-32.8) with fast OCTA and OCT progression developed subsequent visual field likely progression. Rapid initial optic nerve head capillary density loss from OCTA was associated with a faster rate of visual field progression and a doubling of the risk of developing event progression in this study. These findings may support clinical use of OCTA and OCT optic nerve head measurements for risk assessment of glaucoma progression.

Social history and glaucoma progression: the effect of body mass index, tobacco and alcohol consumption on the rates of structural change in patients with glaucoma

Background/aimsAlthough obesity, tobacco and alcohol consumption were linked to the progression of numerous chronic diseases, an association of these social history aspects with glaucoma progression is not yet determined. This...

The Impact of Social Vulnerability on Structural and Functional Glaucoma Severity, Worsening, and Variability

To determine the association between social vulnerability index (SVI) and baseline severity, worsening, and variability of glaucoma, as assessed by visual field (VF) and optical coherence tomography (OCT). Retrospective longitudinal cohort study. Adults with glaucoma or glaucoma suspect status in one or both eyes. VFs were derived from 7,897 eyes from 4,482 patients, while OCTs were derived from 6,271 eyes from 3,976 patients. All eyes had a minimum of 5 tests over follow-up using either the Humphrey Field Analyzer or the Cirrus HD-OCT. SVI, which measures neighborhood-level environmental factors, was linked to patient addresses at the census tract level. Rates of change in mean deviation (MD) and retinal nerve fiber layer (RNFL) thickness were computed using linear regression. The slope of the regression line was used to assess worsening, while the standard deviation (SD) of residuals was used as a measure of variability. Multivariable linear mixed-effects models were used to investigate the impact of SVI on baseline, worsening, and variability in both MD and RNFL. We further explored the interaction effect of mean IOP and SVI on worsening in MD and RNFL. Glaucoma severity defined based on baseline MD and RNFL thickness. Worsening defined as MD and RNFL slope. Variability defined as the SD of the residuals obtained from MD and RNFL slopes. Increased (worse) SVI was significantly associated with worse baseline MD (β = -1.07 dB, 95% CI: [-1.54, -0.60]), thicker baseline RNFL (β = 2.46 μm, 95% CI: [0.75, 4.17]), greater rates of RNFL loss (β = -0.12 μm, 95% CI: [-0.23, -0.02]), and greater VF variability (β = 0.16 dB, 95% CI: [0.07, 0.24]). Having worse SVI was associated with worse RNFL loss with increases in IOP (βinteraction = -0.07, [95% CI: -0.12, -0.02]). Increased social vulnerability index score is associated with worse functional (VF) loss at baseline, higher rates of structural (OCT) worsening over time, higher VF variability, and a greater effect of IOP on RNFL loss. Further studies are needed to enhance our understanding of these relationships and establish their cause.

Comparison of diagnostic capability of macular ganglion cell complex vs retinal fiber layer thickness in primary open angle glaucoma patients of Indian origin.

Comparison of diagnostic capability of macular ganglion cell complex thickness vs. retinal nerve fiber layer (RNFL) thickness in patients of primary open-angle glaucoma (POAG). This cross-sectional observational study was carried out between June 2021 and October 2022 at a tertiary care hospital in North India. A total of 118 eyes were included in the study with 30 control and the rest 88 eyes with POAG were divided into three groups based on visual field loss Group 1 (30 eyes): early field loss with mean deviation (MD) < -6 dB; Group 2 (30 eyes): moderate field loss with MD -6 to -12 dB; and Group 3 (28 eyes): severe field loss with MD > -12 dB. Optical coherence tomography (OCT) scans to measure RNFL loss and ganglion cell inferior plexiform layer (GCIPL) loss were taken for each patient. Categorical variables were analyzed using either the Chi-square test or Fisher's exact test. A receiver operating characteristics analysis was calculated to determine optimal cut-off values of superior, inferior, and average GCIPL and RNFL for determining the severity of field loss as compared to controls (30 normal eyes). In the mild field loss group the sensitivity of superior, inferior, and average GCIPL was 86.7, 96.7, and 96.7%, respectively. Similarly, the specificity was 96.7, 93.3, and 100%, respectively. In the same group, the sensitivity of superior, inferior, and average RNFL was 70, 93, and 66%, respectively. Similarly, the specificity was 46.7, 83.3, and 70%, respectively. In the moderate and severe groups, the results were comparable. The sensitivity and specificity of GCIPL loss are significantly better than that of RNFL parameters in the mild field loss group.

Efektivitas Tetes Mata Citicoline terhadap Perbaikan Lapang Pandang dan Ketebalan Lapisan Serabut Saraf Retina pada Glaukoma Primer Sudut Terbuka

Primary open-angle glaucoma (POAG) is the second leading cause of irreversible blindness worldwide with increasing prevalence. Oral citicoline has been shown to have a role in glaucoma; however, studies regarding citicoline eye drops for glaucoma are still limited. This is a critical appraisal of the literature on the effectiveness of citicoline in improving the mean deviation (MD) of the visual field and thickness of the retinal nerve fiber layer (RNFL) in POAG. A literature search was done on 4 databases: PubMed, Cochrane, Embase, and Scopus. From the 165 studies initially identified, 3 studies were qualified for critical review. Rossetti demonstrated significant MD (p=0.02) and RNFL (p=0.04) differences after 3 years of citicoline eye drops compared to placebo. Mirachtsis showed that after citicoline administration for 3 months there was a significant difference in RNFL (p=0.029), but no significant improvement in MD (p&gt;0.05). Parisi showed an improvement in MD after 4 months (+0.56 dB) and 6 months (+0.18 dB) of citicoline administration. Citicoline eye drops have the potential to inhibit glaucoma progression by inhibiting RNFL loss, but further research is needed on visual field improvement.

Optic Neuropathy Associated with POLG Mutations: A Case Series and Literature Review.

The clinical characteristics of patients with polymerase gamma (POLG) mutation-associated optic neuropathy remain incompletely characterized. We describe the clinical characteristics of 3 patients with POLG-associated optic neuropathy. We performed a literature review of optic neuropathy cases associated with POLG mutations and compared them with our cohort. Many published cases of POLG-associated optic neuropathy in our literature review lacked details regarding severity of vision loss, visual field defects, and optical coherence tomography analysis. The clinical presentation of POLG mutations remains widely variable in age (from pediatric cases to adults) and associated systemic findings. All patients in our literature review presented with systemic symptoms, most commonly muscle weakness, ptosis, and ophthalmoplegia, whereas many young patients had severe systemic symptoms. In our case series, all 3 cases had isolated optic neuropathy affecting the papillomacular bundle, with signs such as reduced visual acuity and color vision, central visual field defects, temporal retinal nerve fiber layer loss with temporal optic disc pallor, and retinal ganglion cell complex loss. In addition, 2 of the 3 cases had added mitochondrial stressors in addition to the POLG mutation. Clinicians should be aware that POLG mutations can present as isolated optic neuropathy primarily affecting the papillomacular bundle. With mitochondrial failure being the likely underlying pathogenic mechanism in POLG-associated optic neuropathy, helping affected patients eliminate mitochondrial stressors may be important in reducing the risk for progressive vision loss in this otherwise currently untreatable disorder.

Progression of Retinal Ganglion Cell and Nerve Fiber Layer Loss in Spinocerebellar Ataxia 3 Patients.

Spectral domain optical coherence tomography (SD-OCT) allows noninvasive measurements of retinal neuron layers. Here, we evaluate the relationship between clinical features and anatomical SD-OCT measurements in patients with spinocerebellar ataxia type 3 (SCA3) and how they change with time. A retrospective review was conducted on SCA3 patients. Clinical variables such as disease duration, number of CAG repeats, and the Scale for the Assessment and Rating of Ataxia (SARA) score were correlated with SD-OCT measurements, including retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC) thickness, macular volume (MV), and central macular thickness (CMT). Seventeen SCA3 patients with an average follow-up of 44.9months were recruited. Clinical features with significant baseline correlations with SD-OCT measurements included disease duration (CMT r = - 0.590; GCC r = - 0.585), SARA score (CMT r = - 0.560; RNFL r = - 0.390), and number of CAG repeats (MV r = - 0.552; RNFL r = - 0.503; GCC r = - 0.493). The annual rate of change of the SARA score during follow-up was associated with that of both the MV (r = - 0.494; p = 0.005) and GCC thickness (r = - 0.454; p = 0.012). High disability (stages 2 and 3) was independently inversely associated with the annual change in MV (ß coefficient - 17.09; p = 0.025). This study provides evidence of an association between clinical features and objective anatomical measurements obtained by SD-OCT in SCA3 patients. MV and GCC thickness could serve as potential biomarkers of disease severity, as their rates of decrease seem to be related to a worsening in the SARA score. These findings highlight the potential of SD-OCT as a noninvasive tool for assessing disease severity and progression in SCA3 patients.

Retinal nerve fibre layer thinning and corneal nerve loss in patients with Bardet-Biedl syndrome

BackgroundBardet-Biedl syndrome (BBS) is an autosomal recessive, genetically heterogeneous, pleiotropic disorder caused by variants in genes involved in the function of the primary cilium. We have harnessed genomics to identify BBS and ophthalmic technologies to describe novel features of BBS.Case presentationA patient with an unclear diagnosis of syndromic type 2 diabetes mellitus, another affected sibling and unaffected siblings and parents were sequenced using DNA extracted from saliva samples. Corneal confocal microscopy (CCM) and retinal spectral domain optical coherence tomography (SD-OCT) were used to identify novel ophthalmic features in these patients. The two affected individuals had a homozygous variant in C8orf37 (p.Trp185*). SD-OCT and CCM demonstrated a marked and patchy reduction in the retinal nerve fiber layer thickness and loss of corneal nerve fibers, respectively.ConclusionThis report highlights the use of ophthalmic imaging to identify novel retinal and corneal abnormalities that extend the phenotype of BBS in a patient with syndromic type 2 diabetes.

Focused analysis of RNFL decay in glaucomatous eyes using circular statistics on high-resolution OCT data.

We generated Optical Coherence Tomography (OCT) data of much higher resolution than usual on retinal nerve fiber layer (RNFL) thickness of a given eye. These consist of measurements made at hundreds of angular-points defined on a circular coordinate system. Traditional analysis of OCT RNFL data does not utilize insightful characteristics such as its circularity and granularity for common downstream applications. To address this, we present a new circular statistical framework that defines an Angular Decay function and thereby provides a directionally precise representation of an eye with attention to patterns of focused RNFL loss. By applying to a clinical cohort of Asian Indian eyes, the generated circular data were modeled with a finite mixture of von Mises distributions, which led to an unsupervised identification in different age-groups of recurrent clusters of glaucomatous eyes with distinct directional signatures of RNFL decay. New indices of global and local RNFL loss were computed for comparing the structural differences between these glaucoma clusters across the age-groups and improving classification. Further, we built a catalog of directionally precise statistical distributions of RNFL thickness for the said population of normal eyes as stratified by their age and optic disc size.

Genetic risk of glaucoma is associated with vascular and retinal nerve fibre wedge defects.

To evaluate the association between localised vascular and retinal nerve fibre layer (RNFL) loss and genetic risk for glaucoma and cardiovascular disease using polygenic risk scores (PRS). 858 eyes were included from 455 individuals with suspect and early manifest primary open angle glaucoma. Eyes were characterised as having localised vascular and/or RNFL wedge-shaped defects by scrutiny of optical coherence tomography angiography (OCTA) and OCT images, respectively. Investigations included associations with pre-established scores for genetic risk of glaucoma and cardiovascular disease in the context of glaucoma risk factors and systemic vascular disease outcomes. Higher genetic risk for glaucoma was associated with both vascular wedge defects and RNFL defects (p < 0.001 and p = 0.020, respectively). A greater genetic risk of glaucoma was associated with the presence of multiple vascular wedges per eye (p = 0.005). Glaucoma progression based on global RNFL loss was associated with vascular and RNFL wedge defects (p ≤ 0.001 and p = 0.008, respectively). The glaucoma PRS was significantly associated with vascular, but not RNFL, wedge defects after controlling for disc haemorrhage (p = 0.007 and p = 0.070, respectively). Vascular wedge defects were not related to the cardiovascular PRS. Individuals with a higher genetic risk of glaucoma based on the PRS were more likely to have retinal vascular defects, as well as structural glaucomatous loss, but this did not relate to systemic cardiovascular risk. This possibly implies a local pathophysiology for the vascular defects in some cases, which may have clinical relevance in the early stages of glaucoma and in individuals at high genetic risk.

An Artificial Intelligence Enabled System for Retinal Nerve Fiber Layer Thickness Damage Severity Staging

To develop an objective glaucoma damage severity classification system based on OCT-derived retinal nerve fiber layer (RNFL) thickness measurements. Algorithm development for RNFL damage severity classification based on multicenter OCT data. A total of 6561 circumpapillary RNFL profiles from 2269 eyes of 1171 subjects to develop models, and 2505 RNFL profiles from 1099 eyes of 900 subjects to validate models. We developed an unsupervised k-means model to identify clusters of eyes with similar RNFL thickness profiles. We annotated the clusters based on their respective global RNFL thickness. We computed the optimal global RNFL thickness thresholds that discriminated different severity levels based on Bayes' minimum error principle. We validated the proposed pipeline based on an independent validation dataset with 2505 RNFL profiles from 1099 eyes of 900 subjects. Accuracy, area under the receiver operating characteristic curve, and confusion matrix. The k-means clustering discovered 4 clusters with 1382, 1613, 1727, and 1839 samples with mean (standard deviation) global RNFL thickness of 58.3 (8.9) μm, 78.9 (6.7) μm, 87.7 (8.2) μm, and 101.5 (7.9) μm. The Bayes' minimum error classifier identified optimal global RNFL values of > 95 , 86 to 95 , 70 to 85 and < 70 for discriminating normal eyes and eyes at the early, moderate, and advanced stages of RNFL thickness loss, respectively. About 4% of normal eyes and 98% of eyes with advanced RNFL loss had either global, or ≥ 1 quadrant, RNFL thickness outside of normal limits provided by the OCT instrument. Unsupervised machine learning discovered that the optimal RNFL thresholds for separating normal eyes and eyes with early, moderate, and advanced RNFL loss were 95 , 85 μm, and 70 , respectively. This RNFL loss classification system is unbiased as there was no preassumption or human expert intervention in the development process. Additionally, it is objective, easy to use, and consistent, which may augment glaucoma research and day-to-day clinical practice. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Optic Nerve Head Morphology is Associated with the Initial Location of Structural Progression in Early Open-Angle Glaucoma.

To investigate the effects of clinical variables on the temporal relationship between macular ganglion cell-inner plexiform layer (mGCIPL) loss and peripapillary retinal nerve fiber layer (pRNFL) loss in glaucoma. Glaucoma eyes with a small cup-to-disc ratio tend to show retinal nerve fiber layer progression earlier than ganglion cell-inner plexiform layer progression. This retrospective observational study used medical records of patients diagnosed with open-angle glaucoma. Structural change was determined using guided progression analysis software of Cirrus optical coherence tomography. Based on the time of detection of pRNFL and mGCIPL changes, eyes showing progressive layer loss were categorized into the pRNFL-first and mGCIPL-first groups. The association between sites of layer thinning and clinical variables such as major retinal arterial angles and several optic disc measurements including disc area, average cup-to-disc ratio (CDR), and vertical CDR were analyzed. A total of 282 eyes were included in the study, of which 104 showed structural progression either in the mGCIPL or pRNFL. Out of these, 49 eyes showed first progression in pRNFL, while 37 eyes showed first progression in mGCIPL. The minimum mGCIPL thickness, pRNFL thickness, average CDR, vertical CDR, and location of progression were significantly different between the two groups (P=0.041, P=0.034, P=0.015, P<0.001, and P<0.001, respectively). In multivariate analysis, average CDR and vertical CDR were significantly associated with the progression site (P=0.033 and P=0.006, respectively). The structural changes in the inferoinferior area and the superior vulnerability zone were significantly associated with RNFL-first progression (P<0.001 for both). The location of layer loss and CDR are related to the layer where loss is first detected (either pRNFL or mGCIPL) in open-angle glaucoma.

Retinal hypoplasia and degeneration result in vision loss in Friedreich ataxia.

Friedreich ataxia (FRDA) is an inherited condition caused by a GAA triplet repeat (GAA-TR) expansion in the FXN gene. Clinical features of FRDA include ataxia, cardiomyopathy, and in some, vision loss. In this study, we characterize features of vision loss in a large cohort of adults and children with FRDA. Using optical coherence tomography (OCT), we measured peripapillary retinal nerve fiber layer (RNFL) thickness in 198 people with FRDA, and 77 controls. Sloan letter charts were used to determine visual acuity. RNFL thickness and visual acuity were compared to measures of disease severity obtained from the Friedreich Ataxia Clinical Outcomes Measures Study (FACOMS). The majority of patients, including children, had pathologically thin RNFLs (mean = 73 ± 13 μm in FRDA; 98 ± 9 μm in controls) and low-contrast vision deficits early in the disease course. Variability in RNFL thickness in FRDA (range: 36 to 107 μm) was best predicted by disease burden (GAA-TR length X disease duration). Significant deficits in high-contrast visual acuity were apparent in patients with an RNFL thickness of ≤68 μm. RNFL thickness decreased at a rate of -1.2 ± 1.4 μm/year and reached 68 μm at a disease burden of approximately 12,000 GAA years, equivalent to disease duration of 17 years for participants with 700 GAAs. These data suggest that both hypoplasia and subsequent degeneration of the RNFL may be responsible for the optic nerve dysfunction in FRDA and support the development of a vision-directed treatment for selected patients early in the disease to prevent RNFL loss from reaching the critical threshold.

Development of a deep learning system to detect glaucoma using macular vertical optical coherence tomography scans of myopic eyes

Myopia is one of the risk factors for glaucoma, making accurate diagnosis of glaucoma in myopic eyes particularly important. However, diagnosis of glaucoma in myopic eyes is challenging due to the frequent associations of distorted optic disc and distorted parapapillary and macular structures. Macular vertical scan has been suggested as a useful tool to detect glaucomatous retinal nerve fiber layer loss even in highly myopic eyes. The present study was performed to develop and validate a deep learning (DL) system to detect glaucoma in myopic eyes using macular vertical optical coherence tomography (OCT) scans and compare its diagnostic power with that of circumpapillary OCT scans. The study included a training set of 1416 eyes, a validation set of 471 eyes, a test set of 471 eyes, and an external test set of 249 eyes. The ability to diagnose glaucoma in eyes with large myopic parapapillary atrophy was greater with the vertical than the circumpapillary OCT scans, with areas under the receiver operating characteristic curves of 0.976 and 0.914, respectively. These findings suggest that DL artificial intelligence based on macular vertical scans may be a promising tool for diagnosis of glaucoma in myopic eyes.

Autosomal recessive Leber hereditary optic neuropathy, a new neuro-ophthalmo-genetic paradigm.

Leber Hereditary Optic Neuropathy (LHON) is a primary inherited neurodegenerative disorder of the optic nerve. It has been ascribed to variants in the mitochondrial genome, mainly the m.3460G > A, m.11778G > A and m.14484T > C mutations in ND1, ND4 and ND6 respectively. Nonetheless, inconclusive molecular diagnosis is not uncommon. Recently, biallelic mutations in the NDUFS2, DNAJC30, MCAT and NDUFA12 nuclear genes have been identified in unresolved LHON cases, identifying an autosomal recessive LHON (arLHON, OMIM:619382). The clinical presentation of arLHON copies that of typical mtLHON, with an acute phase of sudden and severe vision loss, telangiectatic and tortuous vessels around the optic nerve, and swelling of the retinal nerve fiber layer (RNFL). This is followed by a chronic phase of RNFL loss, but eventually, affected individuals recovered partial or full visual acuity. Idebenone treatment significantly improved vision recovery in DNAJC30-associated patients. As mtLHON, arLHON predominantly affected male as compared to female carriers. The discovery of arLHON cases breaks with the dogma of exclusive maternal inheritance. It defines a new neuro-ophthalmo-genetic paradigm which should be considered in individuals manifesting a LHON phenotype, but inconclusive molecular diagnosis. NDUFS2, DNAJC30, MCAT and NDUFA12 should be investigated in these individuals, knowing that other arLHON genes might exist.

Peripapillary nerve fiber layer in patients with iron deficiency anemia: A cross-sectional study in a tertiary eye care center in Central India.

The aim of this study is to evaluate the effect of iron-deficiency anemia (IDA) on peripapillary retinal nerve fiber layer (RNFL) thickness using spectral-domain optical coherence tomography (SD-OCT). The study was conducted at tertiary eye care center in Central India. This study was a prospective, cross-sectional, case-control, and observational study. In the present study, 58 eyes of patients with IDA were compared with 58 eyes of healthy individuals. All individuals underwent a thorough hematological, clinical, and ophthalmic examination, followed by peripapillary RNFL analysis using SD-OCT. A total of 116 eyes were included in the study. The average RNFL thickness (RNFLT) in the cases was 97.26 ± 5.96, and 102.32 ± 6.26 (P = 0.005) in controls. There was a significant RNFL loss in the temporal (66.76 ± 6.1, P = 0.02), superior (119.66 ± 10.47, P = 0.01), nasal (73.59 ± 9.52, P = 0.003), and inferior (129.05 ± 10.96, P = 0.001) quadrants in the cases and controls. Serum hemoglobin, iron, ferritin, total iron-binding capacity, and transferrin saturation were lower in the cases (P < 0.05). A positive correlation was observed between average RNFLT and hemoglobin (r = 0.321), iron (r = 0.122), ferritin (r = 0.152), and transferrin (r = 0.190) levels. In patients with IDA, RNFLT was decreased in all quadrants compared to normal healthy individuals. The inferior and nasal RNFL showed a significant decrease in thickness. The presence of myopia, glaucoma, and diabetic and hypertensive retinopathy can exert an additive effect in the thinning of RNFLs and cause significant visual loss; hence, the correction of anemia is essential. There is a pressing need to raise public and health professional awareness of these problems and their prevention, diagnosis, and management.

Long-term effect of panretinal photocoagulation on optic nerve head parameters in diabetic retinopathy using Heidelberg retinal tomography III.

The aim of this study was to evaluate the effect of panretinal photocoagulation (PRP) in diabetic retinopathy patients using Heidelberg retinal tomography III (HRT). A total of 90 eyes of 90 consecutive newly diagnosed patients with diabetic retinopathy (nonproliferative diabetic retinopathy, NPDR, Group I and proliferative, PDR, Group II) were recruited for the study. The eyes with PDR were subjected to PRP. The effect of PRP was measured on optic nerve head (ONH) parameters using HRT. Follow-up up to 4 years in both groups indicated that in Group II proliferative diabetic retinopathy (PDR) participants undergoing PRP, the ONH parameters showed a significant difference in cup area (P = 0.023), cup volume (P = 0.001), mean cup depth (P = 0.015), maximum cup depth (P < 0.001), mean retinal nerve fiber layer (RNFL) thickness (P < 0.001) at 1 year of follow-up, and remained significant in all at 4 years of follow-up, whereas there was no significant difference in any of the optic disc parameters in the participants of Group I belonging to NPDR group as compared to PDR group after 4 years. PRP affected the ONH morphology in the PDR group and the effect of this change should be interpreted with caution. This may require setting a new baseline for RNFL measurements using the HRT when documenting RNFL loss or glaucoma progression in patients who have undergone PRP.

Characteristics of macrophage-like cells in acute nonarteritic anterior ischemic optic neuropathy and the normal fellow eyes on en face optical coherence tomography.

To quantitatively analyze macrophage-like cells (MLCs) at the vitreoretinal interface (VRI) in acute nonarteritic anterior ischemic optic neuropathy (NAION) using en face swept-source optical coherence tomography (OCT). Twenty-five acute NAION eyes and 25 normal fellow eyes from 25 patients were included in the study. MLCs were visualized in a 3 μm 6 mm×6 mm en face OCT slab above the VRI centered on the optic nerve head (ONH). After semiautomatic binarization and quantification, we evaluated the MLC density between the two groups. We also investigated the relationship between MLC density and other OCT parameters, including the increase in peripapillary retinal nerve fiber layer (RNFL) thickness and loss of vessel density (VD) in radical peripapillary capillary (RPC). The MLC density in the affected eye of the ONH was highly correlated with that in the fellow eye (r=0.612, p=0.001). The MLC density significantly increased in acute NAION eyes (NAION vs. normal, 11.97 ± 6.66 vs. 9.31 ± 6.10 cell/mm2, p=0.028). In sectorial analysis, the increase in MLCs was mainly in the superior regions (4.13 ± 7.49 vs. 0.94 ± 5.21 cell/mm2, p=0.001). The VD of RPC decreased significantly in the affected eyes (NAION vs. normal, 37.54 ± 5.25 vs. 40.56 ± 4.25, p=0.016), and the loss of RPC was predominantly in the superior sectors and the temporal sectors when compared to the inferior sectors and the nasal sectors, respectively (superior vs. inferior, -3.54 ± 6.71 vs. -0.37 ± 8.07, p=0.004; temporal vs. nasal, -2.69 ± 8.72 vs. -1.22 ± 6.06, p=0.005). The loss of RPC and the increase in MLC density were greater in affected sector corresponding to the visual field (VF) defect. MLCs located above the VRI increased significantly in acute NAION eyes, especially in subregions corresponding to VF defect, which provides clinical evidence supporting that the inflammatory response participates in the pathological process of NAION. The magnitude of the increase in MLCs corresponds to the RPC loss in the quadrant analysis.

12‐month outcomes of trabecular microbypass iStent inject W implantation combined with cataract surgery in open‐angle glaucoma eyes

AbstractPurpose: To evaluate the effectiveness (lowering medication) of a single trabecular microbypass stent (iStent Inject® W, Glaukos) implantation in combination with phacoemulsification in open‐angle glaucoma eyes over a 12‐month period.Methods: Non‐randomized, single‐centre, retrospective case series of glaucoma eyes undergoing iStent implantation with phacoemulsification. Patients with no prior glaucoma surgery and intolerant or non‐compliant with medications were eligible for inclusion. Primary outcome effectiveness measures include reduction number of glaucoma medications and stabilization of intraocular pressure (IOP).Results: 30 eyes of 24 patients (mean age 74.9 ± 8.4) were included in this study. Mean baseline IOP was 17.7 ± 3.5 mmHg and was reduced to 16.1 ± 2.6 and 15.7 ± 2.5 at 6‐ and 12 months respectively (p = 0.002). Mean number of medications was 2.3 ± 1 at baseline and was significantly reduced to 0.7 ± 0.9 at 12 months (p &lt; 0.001; −68%). No eye was medication free at baseline versus 50% (n = 15) at 12 months. In controlled glaucoma eyes (≤18 mmHG), mean IOP was stable (15.5 ± 2.1 at baseline; 15.3 ± 2.4 at 12‐month) while medications were reduced from 1.9 ± 0.7 at baseline to 0.5 ± 0.6, whereas in uncontrolled glaucoma eyes (&gt;18mmHG at baseline) both IOP and medications were reduced from 20.7 ± 2.5 and 2.7 ± 1.2 at baseline to 16.2 ± 2.6 and 1.1 ± 1.1 at 12‐month respectively. There was no statistically significant change in retinal nerve fibre layer (RNFL) thickness at 12 months (p = 0.32). No eyes have experienced adverse events such as postoperatively IOP spikes or hyphema.Conclusions: iStent Inject W implantation with phacoemulsification results in a significant reduction in mean glaucoma medications in glaucoma eyes. IOP was also reduced and there was no loss of visual acuity or RNFL. In uncontrolled IOP eyes, the stent implantation has brought IOP under control and reduced the number of medications, while in controlled IOP eyes, it has lowered the number of medications.

Two Year Functional and Structural Changes-A Comparison between Trabeculectomy and XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography.

The aim of this study was to analyze retinal nerve fiber layer (RNFL) thickness after trabeculectomy (TE) versus XEN microstent implantation (XEN) in primary open-angle glaucoma (POAG) cases naïve to prior incisional glaucoma surgery. We examined 119 consecutive glaucoma patients retrospectively, who received a TE or XEN for medically uncontrolled POAG. Intraocular pressure (IOP), amount of IOP-lowering medication, mean deviation of standard automated perimetry and peripapillary RNFL thickness were evaluated during the first 24 months after surgery. Fifty eyes were treated with TE and 69 eyes with XEN. Mean IOP decreased from 25.1 ± 0.8 to 13.3 ± 0.6 mm Hg (p < 0.01) and mean number of IOP-lowering eye drops from 3.2 ± 0.2 to 0.4 ± 0.1 (p < 0.01) 24 months after TE. In 69 eyes undergoing XEN, mean IOP dropped from 24.8 ± 0.6 to 15.0 ± 0.4 mm Hg (p < 0.01) and medication from 3.0 ± 0.1 to 0.6 ± 0.1 (p < 0.01) during the 24 months follow-up. Mean deviation of standard automated perimetry remained stable in TE (8.5 ± 0.7 to 8.1 ± 0.8 dB; p = 0.54) and XEN group (11,0 ± 0.5 to 11.5 ± 0.5 dB; p = 0.12) after 24 months, while mean RNFL thickness further deteriorated in the TE (−2.28 ± 0.65 µm/year) and XEN (−0.68 ± 0.34 µm/year) group. Postoperative RNFL loss develops after TE and XEN despite effective and significant lowering of IOP and amount of IOP-lowering medication. RNFL loss was more pronounced in the first year after glaucoma surgery.