Changes In Retinal Nerve Fiber Layer Thickness Research Articles

Correlation of pre-operative and post-operative retinal nerve fibre layer thickness with visual outcome following decompression of pituitary macroadenoma

ObjectiveTo (i) correlate preoperative retinal nerve fibre layer (RNFL) thickness with visual parameters in patients with pituitary macroadenomas. (ii) study the predictive role of preoperative RNFL in visual outcome following surgery for pituitary macroadenomas (iii) correlate change in postoperative RNFL thickness (RNFLT) with visual outcome. MethodsPreoperative and post-operative RNFL thickness of thirty-three consecutive patients operated for pituitary macro adenoma between June 2022 and May 2023 were measured using Optical Coherence Tomography (OCT) and compared with standard visual examination findings and Magnetic Resonance Imaging (MRI) measurements. ResultsA total of 66 eyes of 33 patients who underwent surgical excision of pituitary macro adenoma between June 2022 and May 2023 were studied. The mean age in years of the study group was 44.36 ± 13.77 and both sexes were equally represented (Male: Female = 16:17). RNFL thinning predominantly involved the temporal (51.21+/-15.19 μm) followed by nasal quadrants (62.67+/- 17.03 μm) and correlated well with the visual field (VF) deficit (p <0.001). Patients with severe disc pallor had extremely thin RNFL (less than 67 +/- 8.68 μm). Patients with moderate to severe visual acuity (VA) deficits had significantly thinner RNFLs (65.08±7.09) compared to patients with normal to mild impairment in vision. (83.185±1.2) (p<0.05). RNFL values were significantly thinner for patients with Wilson Grade C, D and E tumours (66.13 ±12.19 μm) compared to those in Grade A and B (77.67±22.12 μm). The mean preop RNFL of patients who showed post-operative improvement in vision was 87.025± 15.02 μm, of patients in whom vision remained static was 74.58 ±18.31 μm. The mean VA (Decimal) increased from a minimum of 0.60 at the pre-operative timepoint to a maximum of 0.68 at the post-operative timepoint. (Wilcoxon Test: V = 42.5, p = <0.001). The mean RNFLT (µm) increased from 77.14 μm at the pre-operative timepoint to 83.77 μm at the post-operative timepoint. (Wilcoxon Test: V = 218.0, p = <0.001). The mean change of RNFL in patients in whom vision improved was 3.6 μm and the mean change of RNFL in patients in whom vision remained static was 9.51 μm. Absence of postoperative visual improvement was noted despite postoperative RNFL thickness improvement in eyes which showed significant preoperative thinning of the nasal (<65 μm) and temporal (<52μm) quadrants. ConclusionRNFL thinning corelates directly with visual acuity, visual field, and optic disc pallor. Patients with pituitary adenoma have preferential thinning of temporal and nasal quadrants. Visual outcome is better in patients with preserved RNFLT of values more than 82 +/- 5 μm. Reversal of RNFL thinning postoperatively need not necessarily correlate with visual improvement especially in patients who showed significant preoperative thinning of nasal and temporal quadrants.

Changes in Retinal Ganglion Cell (RGC) and Retinal Nerve Fiber Layer (RNFL) Thickness in Children with Type 1 Diabetes Mellitus at Dr. M. Djamil General Hospital, Padang, Indonesia

Background: Type 1 diabetes mellitus (DM) is a chronic metabolic disorder that causes hyperglycemia and increases the risk of morbidity and mortality. Diabetic retinopathy, a microvascular complication that often occurs in DM patients, can cause visual impairment and even blindness. Regular eye examinations are important for early detection of diabetic retinopathy. Optical coherence tomography (OCT) is a non-invasive method that can be used to measure the thickness of retinal layers, including RGC and RNFL. It is thought that thinning of the retinal layer can be a sensitive biomarker in detecting diabetic retinopathy in type 1 DM patients. This study aims to determine changes in RGC and RNFL thickness in children with type 1 DM. Methods: This cross-sectional design analytical observational study was conducted at the eye polyclinic of Dr. M. Djamil General Hospital Padang in November 2023-March 2024. A total of 46 eyes from 46 people, divided into two groups: the type 1 DM group and the control group, were recruited in this study. RGC thickness was measured using AS-OCT GC-IPL thickness analysis and RNFL with optic disc RNFL thickness analysis. Data analysis was carried out using the unpaired T-test. Results: The results showed RGC depletion in the type 1 DM group (RGC 83.48 ± 3.75) compared to the control group (RGC 86.70 ± 4.87) with a value of p = 0.016 (p &lt; 0.05). There was no statistical difference in RNFL thickness between the type 1 DM group (RNFL 102 ± 11.80) and the control group (RNFL 100.96 ± 10.97) with a value of p = 0.581 (p&gt; 0.05). Conclusion: This study found RGC thinning in type 1 DM patients, but did not find differences in RNFL thickness between the two groups. This RGC depletion is thought to be caused by apoptosis of retinal neuronal cells due to chronic hyperglycemia. Examination of RGC thickness with OCT can be developed as an early detection of diabetic retinopathy in children with type 1 DM.

Assessment of Time Lag Between Blood Flow, Retinal Nerve Fiber Layer Thickness and Visual Field Sensitivity Changes in Glaucoma.

This study investigates the temporal relationship between blood flow changes and alterations in retinal nerve fiber layer thickness (RNFLT) and mean deviation (MD) in individuals with glaucoma. Blood flow, measured by mean blur rate in optic nerve head vessels (MBRv) and tissues (MBRt) using laser speckle flowgraphy (LSFG)-NAVI, was analyzed using structural equation models (SEMs). SEMs assessed whether the previous rate of one parameter predicted the current rate of the other parameter, adjusted for its own rate in the previous time interval. Data from 345 eyes of 174 participants were gathered from visits every six months. Rates of change of both MBRv and MBRt were significantly predicted by their own rate in the previous time interval and by the rate of change of MD in the previous time interval (P < 0.001 and P = 0.043, respectively), but not by the rate of MD in the concurrent interval (P = 0.947 and P = 0.549), implying that changes in MD precede changes in blood flow. Rates of change of RNFLT were predicted by their own previous rate and the rate of change of MBRv and MBRt in either the previous interval (P = 0.002 and P = 0.008) or the concurrent interval (P = 0.001 and P = 0.018), suggesting that MBR may change before RNFLT. The evidence supports a temporal sequence where MD changes precede blood flow changes, which, in turn, may precede alterations in RNFLT.

Peran Citicoline Oral Sebagai Terapi Tambahan dalam Pengobatan Glaukoma

Glaucoma is the second-leading global cause of blindness. Lowering intraocular pressure can prevent the worsening of open-angle glaucoma, but alternative neuroprotective therapies are needed; citicoline is supposed to have neuroprotective potential. This evidence-based case report was to review the effectiveness of oral citicoline as an adjunct therapy for glaucoma. From 22 studies identified through PubMed, Scopus, Cochrane, EBSCO Host, and Google Scholar, three articles were selected for critical review. Lanza M. found the RNFL and GCC of the citicoline group 500 mg were significantly higher, 70.39 and 71.19 Pm, p&lt;0,01 compared to controls, after 12 months. Sahin A, et al, showed that the RNFL was significantly higher in the third month than baseline in the oral citicoline 250 mg group, p = 0.038. Putri VC, et al, found that after 60 days, based on sub-group analysis, there was a significant difference in RNFL and GCIPL thickness changes after citicoline 500 mg intervention in the mild glaucoma group and after citicoline 1,000 mg in the moderate-severe glaucoma group. Oral citicoline supplementation prevents significant worsening of glaucoma, it can be given as an adjunct therapy.

Longitudinal Changes in the Retinal Nerve Fiber Layer Thickness in Amyotrophic Lateral Sclerosis and Parkinson's Disease.

There is increasing evidence that the anterior visual pathways are involved in neurodegenerative diseases including amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD). This study investigated longitudinal changes in retinal nerve fiber layer (RNFL) thickness in patients with ALS and PD with the aim of better understanding their roles as biomarkers of disease progression. This study recruited 21 ALS patients, 19 age-matched PD patients, and 21 agematched healthy controls. Patient demographics and clinical scores relating to the respective diseases were documented. The RNFL thickness was measured using optical coherence tomography at baseline and after 6 months. At baseline, the RNFL in the superior quadrant was significantly thinner in the patients with ALS than in healthy controls (109.90±22.41 µm vs. 127.81±17.05 µm [mean±standard deviation], p=0.008). The RNFL thickness did not differ significantly between the ALS and PD patients or between the PD patients and healthy controls. At 6 months, there was further significant RNFL thinning in patients with ALS, for both the overall thickness (baseline: median=94.5 µm, range=83.0-106.0 µm; follow-up: median=93.5 µm, range=82.5-104.5 µm, p=0.043) and the thickness in the inferior quadrant (median=126 µm, range=109.5-142.5 µm; and median=117.5 µm, range=98.5-136.5 µm; respectively, p=0.032). However, these changes were not correlated with the ALS functional scores. In contrast, the patients with PD did not demonstrate a significant change in RNFL thickness between the two time points. The RNFL thickness is a promising biomarker of disease progression in patients with ALS but not in those with PD, which has a slower disease progression.

Short‐term intraocular pressure fluctuation in primary angle closure glaucoma

Purpose: To identify the most sensitive period for detecting significant circadian and ultra‐short‐term intraocular pressure (IOP) fluctuation associated with disease progression in primary angle closure glaucoma (PACG).Methods: PACG eyes, which had been followed up for over 2 years under the CUHK PACG Longitudinal (CUPAL) Study, were recruited. Eyes with or without functional or structural glaucomatous progression were classified into ‘progressive’ or ‘stable’ groups based on serial visual field (VF) and retinal nerve fibre layer (RNFL) thickness documentations, respectively. Circadian and ultra‐short‐term IOP fluctuations were recorded by Sensimed Triggerfish® sensors with 288 readings over 30 s, at 5‐min intervals, over a 24‐h period. The circadian IOP fluctuation was represented by smoothed sensor output signals using B‐spline smoothing transform and described by functional data analysis. In each of seven activity‐related 1‐h periods during the examining day, the mean value of the amplitude‐frequency profiles of the signal fluctuations in twelve 30‐s intervals, which represent the ultra‐short‐term IOP fluctuation, was calculated by semi‐variogram/semi‐variance. The signals were compared between ‘progressive’ and ‘stable’ groups by permutation tests on functional t‐statistics.Results: Among the 25 recruited PACG eyes, 16 eyes were classified as RNFL ‘progressive’ group (the mean rate of change in global RNFL thickness: −0.199 ± 0.128 μm/month). Statistically significant differences were found during the time periods from 22:00 to 23:00 and from 07: 00 to 08:00 in gradients that reflected by the first derivative of the IOP fluctuation curve, as well as from 23:00 to 24:00 and 08:00 to 09:00 in curvatures that reflected by the second derivative of the IOP fluctuation curve, between the VF progressive and the VF stable groups (p &lt; 0.05). Gradients differences were also found during the time periods from 24:00 to 01:00 and 02:00 to 03:00 between structural progressive and stable groups (p &lt; 0.05). Higher signal fluctuations, in terms of amplitude‐frequency, were found during the first 1‐h period of sleeping in the RNFL ‘progressive’ group, compared to the RNFL ‘stable’ group (p = 0.028).Conclusions: Between RNFL ‘progressive’ and ‘stable’ PACG eyes, significant differences in circadian IOP fluctuation and ultra‐short‐term IOP fluctuation at the 1‐h period after falling asleep were identified. Large circadian IOP fluctuations may be associated with disease progression in PACG eyes. The first hour of sleeping may be the most sensitive period for detecting significant short‐term IOP fluctuation in PACG eyes.

Analysis of macula structural changes in Moyamoya disease using AI-assisted OCT

ObjectiveTo investigate macula structure thickness and volume changes in patients with moyamoya disease (MMD). MethodIn this cross-sectional study, we used artificial intelligence (AI) -assisted optical coherence tomography (OCT) to analyze the thickness and volume of macula in Moyamoya patients. ETDRS zoning divides the macula into nine different regions. In 15 patients with radial scanning OCT, the average thickness and volume of retina, RNFL, GCL, and choroid in these regions were measured. In 30 patients with radial or horizontal scanning OCT, based on the anatomical structure, the macula is divided into seven segments. Mean Sattler layer–choriocapillaris complex thickness (SLCCT), Haller layer thickness, and total choroidal thickness were measured for each segment using AI-assisted OCT. ResultsWe recruited 30 patients (59 eyes) with MMD. In the 15 patients (29 eyes) who underwent radial scanning OCT, no significant change in retina, RNFL, GCL, and choroidal thickness was identified between the two groups (p > 0.05). There was no significant change in retina, RNFL, or choroidal volume between the two groups in different ETDRS macula regions (p > 0.05). The GCL volume in the macula's inner ring nasal portion (IN) was significantly lower. SLCCTs were considerably reduced in six macula regions in moyamoya groups (p < 0.05). There was no statistically significant change in Haller layer thickness. Only the nasal perifovea (PE_N) exhibited a significant variation in choroidal thickness. The Moyamoya group showed reduced choroidal thickness in PE_N segment. ConclusionIn patients with MMD, there is thinning of the Sattler layer–choriocapillaris complex in the choroid.

Factors Affecting Post-Cataract OCT Parameters in Open-Angle and Angle-Closure Glaucoma Eyes: Optic Disc Head Analysis

Purpose: The aim of this study was to investigate whether there are differences in the effects of cataract surgery based on the type of glaucoma and changes in the retinal nerve fiber layer (RNFL) thickness and Bruch's membrane opening-minimum rim width (BMO-MRW) thickness around the optic nerve and macula in patients with glaucoma. Furthermore, the factors influencing these effects were explored.Methods: 68 patients with glaucoma were enrolled, and changes in RNFL thickness and BMO-MRW before and after cataract surgery were measured using SD-OCT. The patients were divided into angle-closure and open-angle glaucoma groups and values before and after cataract surgery were analyzed.Results: The male-female ratio was 26:42, with an average age of 71.72 years at the time of surgery. There were 35 eyes with open-angle glaucoma and 33 eyes with angle-closure glaucoma. After cataract surgery, both RNFL and BMO-MRW values significantly increased. In the angle-closure glaucoma group, preoperative visual acuity was significantly better and RNFL image Q was significantly higher before cataract surgery. In a multivariate linear regression analysis, the factor influencing the increase in RNFL thickness was found to be the preoperative RNFL thickness in both the overall open angle glaucoma group and the angle closure glaucoma group. In other words, patients with thinner RNFL thickness before cataract surgery showed an increase in RNFL thickness after the surgery. In the angle closure glaucoma group, it was observed that worse preoperative visual acuity was associated with an increase in RNFL thickness after surgery. Conversely, no factors affecting BMO-MRW thickness were identified.Conclusions: The factors influencing the increase in RNFL thickness after cataract surgery were the preoperative RNFL thickness in open angle glaucoma group and the preoperative visual acuity in the angle closure glaucoma group.

Significant loss of retinal nerve fibre layer and contrast sensitivity in people with well controlled HIV disease: implications for aging with HIV.

Antiretroviral therapy has decreased the prevalence of retinal opportunistic infections in people living with HIV (PLWH). However, abnormalities in visual function are evident and may be associated with an early onset of aging in PLWH. In this study, we examined the Retinal Nerve Fibre Layer (RNFL) thickness and visual function in PLWH and HIV non-infected controls in Malaysia. Cross-sectional study. Two hundred and two (202) PLWH without retinal opportunistic infection and 182 age-matched, HIV seronegative individuals were enrolled. PLWH were recruited from the Infectious Disease clinic at the University Malaya Medical Centre. Controls were recruited among the hospital staff and community volunteers. RNFL thickness was measured with spectral domain optical coherence tomography (SDOCT). Visual functions include visual acuity using LogMAR chart and contrast sensitivity using Pelli- Robson Chart. All PLWH (mean age 46.1 years ± 9.9 years) in the study were on ART and 61.2% had a CD4+ T-cell count more than 500 cell/μl. The mean visual acuity was similar between the two groups (LogMAR 0.05 vs. 0.07, p = 0.115). Contrast sensitivity was lower in PLWH compared to HIV seronegative individuals (1.90 vs 1.93, p = 0.032). RNFL thickness was significantly thinner in the temporal quadrant for PLWH compared to controls (68.89 μm vs 74.08 μm, p = 0.001). Changes in RNFL thickness and contrast sensitivity were seen in PLWH despite their relatively young age and well controlled HIV disease. The changes reflect structural and functional deficits, and could have long-term implications on their health trajectory.

Effect of pan retinal photocoagulation on macular ganglion cell - inner plexiform layer and peripapillary retinal nerve fibre layer thickness

: To determine the effect of pan retinal photocoagulation (PRP) on spectral domain optical coherence tomography (SD OCT) morphologic parameters like macular ganglion cell-inner plexiform layer (GCIPL), peripapillary retinal nerve fibre layer (RNFL) thickness and central macular thickness (CMT) in diabetic retinopathy cases. This is a retrospective study including 52 eyes with severe non-proliferative to proliferative diabetic retinopathy without macular oedema who required PRP. Macular GCIPL, CMT and peripapillary RNFL thickness measured at baseline and at 1-, 6-, 12- and 18-months post PRP with SD OCT. CMT, Macular GCIPL and peripapillary RNFL thickness increased significantly at 1 month (p&amp;#60;0.05), thereafter a decreasing trend noted at 6, 12 and 18 months. At 18 month CMT, GCIPL and RNFL thickness are higher than baseline but not statistically significant except temporal RNFL and Average GCIPL (p&amp;#60;0.05). A significant correlation found between changes in temporal RNFL and average GCIPL thickness (Pearson Correlation coefficient r= 0.652, 0.557, 0.782, 0.624 at 1, 6, 12 and 18 months respectively. P&amp;#60;0.05 for all values) CMT, macular GCIPL and peripapillary RNFL thickness increase following PRP; peaking at month 1 and stabilizing through next 18 months. Macular GCIPL thickness could be a reproducible indicator of temporal RNFL.

Crocin supplementation in primary open angle glaucoma: A randomized, triple-blind, placebo-controlled clinical trial

PurposeGlaucoma is the leading cause of irreversible visual loss in the world. The present study was designed to evaluate the beneficial effects of crocin, as a supplement, in the management of primary open-angle glaucoma (POAG). MethodsIn total, 50 POAG patients within the age range of 30–71 years with intraocular pressure (IOP) between 12 and 21 mmHg were entered into the study, and ultimately, 40 patients (49 eyes) finished the clinical trial. The participants were randomly divided into crocin and placebo groups. Patients in the crocin group received a 15 mg crocin tablet per day for four months while others, in the placebo group, received a placebo tablet per day for four months besides the main medications during the study. After four months, all patients underwent a two-month washout period. The IOP level and optical coherence tomography of the retinal nerve fiber layer (RNFL), cup-to-disc ratio (CDR), and the best-corrected visual acuity (BCVA), as the secondary outcomes, were measured at baseline, as well as four and six months later. ResultsThe IOP value decreased significantly in the crocin group after four (P = 0.0001) and six months (P = 0.003). The difference in CDR changes after four and six months was significant between the two groups (P = 0.00009). The crocin and placebo groups did not have a statistically significant difference regarding the changes in BCVA values and RNFL thickness (P = 0.092); however, the optical coherence tomography results showed stable conditions in the retinal nerve fiber layer. ConclusionThis study indicated that administration of crocin, as a potent neuroprotective and antioxidant ingredient of saffron, could be useful as a supplement for the prevention of the POAG progression.

A prospective observation of influence of anti-VEGF on optic disc vasculature in nAMD patients

BackgroundThis study aims to investigate the short-term changes in relatively normal retinal vessels following anti-vascular endothelial growth factor (anti-VEGF) therapy in nAMD patients, an area that currently represents a research gap. MethodsIn this prospective study, we enrolled patients newly diagnosed with neovascular age-related macular degeneration (nAMD) and received standardized monthly anti-VEGF therapy for three months. Follow-ups were conducted at baseline and 1-week, 1-month, 2-months and 3-months post first injection. Assessment indicators included radial peripapillary capillary vascular density (RPC-VD) and retinal nerve fiber layer (RNFL) thickness in different optic disk regions using optical coherence tomography angiography, as well as intraocular pressure (IOP). Results68 nAMD patients (68 eyes) were included in this study. Significant reductions of RPC-VD and increases of RNFL thickness primarily in the nasal regions were observed 1-week post anti-VEGF (adjusted P < 0.05). Significant negative correlations were found between 1-week changes in RPC-VD and RNFL thickness in the nasal sectors (P < 0.05). From 1 to 3 months post-injection, RPC-VD and RNFL thickness essentially returned to baseline levels. Throughout the follow-up periods, IOP remained stable (P > 0.05). ConclusionAnti-VEGF treatments transiently influence the relatively normal retinal vessels, which might lead to nerve fiber edema, predominantly on the nasal side of the optic disk.

Association of long-term exposure to ambient air pollution with retinal neurodegeneration: the prospective Alienor study

Chronic exposure to air pollution may have adverse effects on neurodegenerative diseases. Glaucoma, the second leading cause of blindness worldwide, is a neurodegenerative disease of the optic nerve, characterized by progressive thinning of the retinal nerve fiber layer (RNFL). We investigated the relationship of air pollution exposure with longitudinal changes of RNFL thickness in the Alienor study, a population-based cohort of residents of Bordeaux, France, aged 75 years or more. Peripapillary RNFL thickness was measured using optical coherence tomography imaging every 2 years from 2009 to 2020. Measurements were acquired and reviewed by specially trained technicians to control quality. Air pollution exposure (particulate matter ≤2.5 μm (PM2.5), black carbon (BC), nitrogen dioxide (NO2)) was estimated at the participants’ geocoded residential address using land-use regression models. For each pollutant, the 10-year average of past exposure at first RNFL thickness measurement was estimated. Associations of air pollution exposure with RNFL thickness longitudinal changes were assessed using linear mixed models adjusted for potential confounders, allowing for intra-eye and intra-individual correlation (repeated measurements).The study included 683 participants with at least one RNFL thickness measurement (62% female, mean age 82 years). The average RNFL was 90 μm (SD:14.4) at baseline. Exposure to higher levels of PM2.5 and BC in the previous 10 years was significantly associated with a faster RNFL thinning during the 11-year follow-up (−0.28 μm/year (95% confidence interval (CI) [-0.44;-0.13]) and −0.26 μm/year (95% CI [-0.40;-0.12]) per interquartile range increment; p < 0.001 for both). The size of the effect was similar to one year of age in the fitted model (−0.36 μm/year). No statistically significant associations were found with NO2 in the main models.This study evidenced a strong association of chronic exposure to fine particulate matter with retinal neurodegeneration, at air pollution levels below the current recommended thresholds in Europe.

Short-term effect of macular edema on the peripapillary retinal nerve fiber layer in patients with wet age-related macular degeneration and diabetic macular edema: A comparative study

BackgroundThe combined presence of glaucoma and age-related macular degeneration (ARMD), or glaucoma and diabetes mellitus (DM), occur fairly frequently, especially in elderly patients. This study was intended to compare the effect of resolving macular edema due to DM and wet ARMD on peripapillary retinal nerve fiber layer (RNFL) thickness. MethodsThis cross-sectional study included 76 patients with macular edema secondary to DM (n = 40, 52.6%) or wet ARMD (n = 36, 47.4%). The control group was comprised of 34 age and sex-matched healthy subjects. All study participants underwent evaluation of central macular thickness (CMT) and the peripapillary RNFL using spectral domain-optical coherence tomography (SD-OCT). Data from eyes that received an anti-VEGF injection were obtained one month after the procedure and were compared with pre-injection data. ResultsThe average initial thickness of the global peripapillary RNFL was 98.9 ± 16.7 (61–163) µm in the macular edema group and 92.0 ± 16.0 (84–115) µm in the control group (p = 0.045). The post-injection global peripapillary RNFL thickness was 97.3 ± 19.0 (61–163) µm in the macular edema group and 92.2 ± 18.0 (81–126) µm in the control group (p = 0.187). In the DM group, the changes in global RNFL thickness, as well as central and temporal quadrant thicknesses, were found to correlate significantly with the change in CMT (r = 0.356, p = 0.024; r = 0.545, p < 0.001, respectively). ConclusionsMacular edema in wet ARMD appeared not to affect RNFL thickness. Differences in the etiology of macular edema can have varied effects on peripapillary RNFL. It is recommended that peripapillary RNFL thickness be evaluated cautiously in DM patients receiving intravitreal anti-VEGF therapy.

Retinal Nerve Fiber Layer Changes after Intraocular Silicone Oil Tamponade in Rhegmatogenous Retinal Detachment

Rhegmatogenous retinal detachment (RRD) is a serious and emergency condition that may cause visual disturbance. Treatment includes pars plana vitrectomy with a tamponade such as intraocular gas or silicone oil (SO). In many countries, silicone oil is still favorable compared to intraocular gases as tamponade for reattachment of retinal detachment surgery. The application provides a higher anatomical success rate, especially in cases of proliferative vitreoretinopathy (PVR) that were previously considered untreatable. Objective assessment of the retinal nerve fiber layer (RNFL) using optical coherence tomography (OCT) in the eye with silicone oil tamponade is a challenge because of the limitations and difficulties in taking images. This study aims to assess the RNFL thickness changes in rhegmatogenous retinal detachment patients using SO tamponade and its subsequent removal conducted on a total of 35 post-operative RRD patients. Central macular and RNFL thickness, as well as best-corrected visual acuity (BCVA), were recorded at the time of tamponade and after the removal of the SO at 1, 4, and 8 weeks, respectively. The results showed that the changes in RNFL thickness significantly decreased in the group of ≤6 months, especially in the superior and temporal quadrants, and BCVA increased after SO removal (p < 0.05). Central macular thickness was significant (p < 0.001) at the end of the visit. Improved visual acuity is associated with decreased RNFL and central macular thickness after SO removal.

Structural and vascular changes in glaucoma with single-hemifield defect: predictors of opposite hemifield visual field progression.

To investigate longitudinal changes in optic nerve head (ONH) superficial vessel density (VD), macular VD, circumpapillary retinal nerve fiber layer (RNFL) thickness, and macular ganglion cell-inner plexiform layer (GCIPL) thickness, and their associations with future VF defects in unaffected hemifields of primary open angle glaucoma (POAG) eyes with baseline VF defect confined to a single hemifield. This retrospective observational study included 61 POAG eyes with VF defect confined to a single hemifield monitored over a mean follow-up time of 2.7years. Development of VF defect in opposite hemifield was defined based the Early Manifest Glaucoma Trail criteria. Each eye was classified into either "conversion" or "no conversion" groups according to development of VF defect in the unaffected hemifield. The rates of longitudinal changes in VD and structure parameters in each hemiretina were compared between the two groups. A Cox proportional hazard model was used to identify potential risk factors for VF conversion in the unaffected hemifield. Among 61 eyes, 17 eyes (27.9%) were classified as "conversion" and 44 eyes (72.1%) were classified as "non-conversion" groups. The conversion group exhibited significantly greater rates of both VD and structural changes in both hemiretinas. In Cox proportional hazard model, greater rate of change in GCIPL thickness, ONH superficial VD, and macular VD of both hemiretinas and greater rate of change in RNFL thickness of the unaffected hemiretina were identified as risk factors for VF conversion in the unaffected hemifield. Monitoring progressive changes in VD and structural parameters effectively predict future VF defect in the opposite hemifields of POAG eyes with single-hemifield defects.

Effect of peripheral laser photocoagulation retinopexy on macular morphology and optic nerve fiber layer thickness; a prospective case series

PurposeThe goal of the research was to determine the incidence of microstructural alterations in the macula and optic nerve head (ONH) occurred in eyes treated with peripheral laser photocoagulation retinopexy.MethodsPatients with retinal breaks, retinal holes, retinal dialysis, and lattice degenerations who required peripheral laser photocoagulation retinopexy were recruited in this prospective case series investigation. We performed preoperative and postoperative evaluations, including best corrected visual acuity (BCVA), slit lamp examination, intraocular pressure (IOP) measurement, funduscopic examination, and macular and ONH optical coherence tomography (OCT).ResultsThirty-three eyes of the twenty-three patients enrolled in this study, 14 of which were female. The mean age of the sample was 45.12 ± 9.12 years. The mean refractive error was − 2.45 ± 1.12 Diopters (D). The most prevalent reason for peripheral laser photocoagulation retinopexy was retinal thinning with symptomatic lattice degeneration (90%), followed by retinal hole and break (7%) and retinal dialysis (3%). Between preoperative and postoperative (6-month) evaluation, there was no statistically significant difference in BCVA (P = 0.82), IOP (P = 0.54), central foveal thickness in macular OCT (P = 0.39), or global retinal nerve fiber layer (RNFL) thickness (P = 0.51). There was no association between changes in central foveal thickness and global RNFL thickness and total laser spot numbers (r = − 0.17 P = 0.21, r = 0.06 P = 0.60, respectively). None of patients developed cystoid macular edema (CME) or macular epiretinal membrane (ERM) .ConclusionWe found that OCT parameters were not significantly affected by laser retinopexy in patients with high-risk peripheral retinal lesions, also none of our patients had developed ERM, vitromacular traction or CME at 6 months follow up periods.

Effect of FFP2/N95 facemask wear on retinal and choroidal thickness profile in healthy subjects.

To investigate the influence of non-oil 95 (N95)/filtering facepiece 2 (FFP2) facemask wear on retinal thickness, choroidal thickness (CT), retinal nerve fiber layer thickness (RNFLT), and ganglion cell layer thickness (GCLT) in healthy subjects. In this prospective study, 53 healthy participants who used FFP2/N95 facemask were enrolled. Participants underwent optical coherence tomography imaging before and at 1 and 4h following FFP2/N95 facemask wear. The last imaging session was performed 1h after FFP2/N95 removal. Retinal thickness, CT, RNFLT, and GCLT were assessed at each session. Vital parameters were also assessed. The pulse rate of the subjects significantly decreased at 1 and 4h compared to baseline values (P<0.05). No significant changes in retinal thickness, RNFLT, and GCLT were observed in the study. CT profile showed a significant increase at all measured locations except 1-mm temporal, 1-mm inferior and 2-mm inferior points following FFP2/N95 wear which turned to baseline values after FFP2/N95 removal. Pulse rate and CT changes at 4h were significantly correlated (P<0.05). Parasympathetic activation during FFP2/N95 facemask wear might have a role on elevated CT measurements in healthy individuals by virtue of increased choroidal blood flow.

Comparison of changes in retinal nerve fiber layer thickness and intraocular pressure between glaucoma and non-glaucoma patients after phacoemulsification.

To compare the changes in Retinal Nerve Fiber Layer (RNFL) thickness and Intraocular Pressure (IOP) after phacoemulsification in patients with glaucoma versus without glaucoma. This was a quasi-experimental study, done at Lahore General Hospital, from January 2021 to December 2021. Patients with senile cataract were divided into two groups. One group included 40 patients, with ≥40 years of age and diagnosed with primary open angle glaucoma compared with a second group of 40 age-matched controls without glaucoma, undergoing phacoemulsification and Intraocular Lens Implantation (IOL). Goldman Applanation Tonometer (GAT) and Spectral Domain Optical Coherence Tomography (SD-OCT) were used to record IOP and RNFL thickness, before surgery, at one week and one month after surgery. The results were compared with baseline readings and also between the two groups. A total of 80 patients were included in the study. Mean age was 60.3±7.9 years with male to female ratio of 1:1. Mean change in RNFL thickness in glaucomatous eyes group and non-glaucomatous Eyes group from pre-operative baseline was 11.33±4.30μm and 4.08±2.59μm respectively after one month (p-value<0.001). Difference of mean change in RNFL thickness from baseline was statistically significant between both groups (p< 0.001). Difference of mean change in IOP from baseline at four weeks was statistically significant in the individual groups but between both groups was statistically insignificant (p= 0.234). Phacoemulsification results in increase in RNFL thickness and decrease in IOP, which are good prognostic factors in control of glaucoma. However, a mean change of IOP of 1mmHg in glaucoma patient does not affect management of glaucoma.

Quantitative Assessment Parameters of Peripapillary Regions with Branch Retinal Vein Occlusion by Using Optical Coherence Tomography Angiography.

To investigate the baseline parameters of peripapillary regions in both eyes of patients with unilateral branch retinal vein occlusion (BRVO) using optical coherence tomography angiography (OCTA) and their association with best-corrected visual acuity (BCVA). Forty-eight unilateral BRVO patients were enrolled. The 4.5 × 4.5 mm disc angiogram was acquired in the BRVO eyes and fellow eyes using the OCTA. Radial peripapillary capillary (RPC), whole vessel density, and retinal nerve fiber layer (RNFL) thickness in different regions and optic nerve head (ONH) analysis were automatically calculated. The partition includes the whole image, peripapillary, superior hemifield, inferior hemifield, eight equally divided sectors, and nine evenly divided square areas. All vessel density and capillary vessel density in the whole and peripapillary regions of BRVO eyes were significantly lower than those in fellow eyes. The RNFL peripapillary thickness in BRVO eyes was significantly higher than those in fellow eyes. In eyes with supertemporal vein occlusion, all vessel density both in the superior hemifield and in the G12 region was significantly reduced compared with that in the fellow eyes. The capillary vessel density was significantly lower in the superior hemifield, superior temporal (ST), superior nasal (SN), and temporal superior (TS) areas than in the fellow eyes. The RNFL thickness in the NI, IN, TI, and TS sectors was significantly higher than in fellow eyes (all P < 0.05). OCTA provided quantitative information on peripapillary vascular density and RNFL thickness changes in BRVO. Branch retinal vein occlusion not only affects the blood vessel density in the macular area but also decreases the radial peripapillary capillaries. The capillary density is mainly affected in the affected hemifield but not in the unaffected hemifield.