Optical Coherence Tomography Parameters Research Articles

Hemodialysis-induced positional changes in lamina cribrosa

This study is aimed to investigate the effect of hemodialysis (HD) on the lamina cribrosa (LC) of the optic nerve head (ONH) using swept-source optical coherence tomography (SS-OCT) and other ophthalmological parameters in patients with end-stage kidney disease (ESKD). This prospective observational study included 29 patients who underwent HD for ESKD. ONH parameters including neural canal diameter (NCD), peripapillary vertical height (PVH), and anterior LC depth (LCD), were assessed using SS-OCT. Changes in the ONH parameters before and after HD were statistically analysed. Correlations between changes in the LCD and other ocular and systemic measurements were identified using Pearson’s correlation analyses. The mean anterior LCD significantly decreased from 441.6 ± 139.8 μm before HD to 413.5 ± 141.7 μm after HD (P = 0.001). Mean NCD and PVH did not show significant changes after HD (P = 0.841 and P = 0.574, respectively). A significant correlation was found between changes in the anterior LCD and the mean ocular perfusion pressure (r = 0.397, P = 0.036). We observed a significant decrease in anterior LCD after HD. Our study suggests that HD can influence the ONH, especially in the LC.

Could the thick of retinal nerve fiber layer be a potential measure of axonal loss in hearing loss?

The objective of the study is to compare the optic coherence tomography (OCT) parameters of the healthy and affected sides of patients with idiopathic sudden sensorineural hearing loss (ISSNHL) and to investigate the relationships between these and the improvement in hearing levels. A bilateral eye evaluation of patients diagnosed with ISSNHL was performed with OCT. The ganglion cell complex (GCC) and retina nerve fiber layer (RNFL) thickness values were recorded and the differences between the two eyes were examined. An evaluation was made of 39 patients with a mean age of 44.82 ± 14.90 years. The RNFL thickness of the eyes was determined to be mean 89.87 ± 3.65 µm on the affected side and 103.87 ± 3.98 µm on the healthy control side (p = 0.0001). The mean GCC was determined to be mean 90.46 ± 3.49 µm on the affected side and 103.77 ± 3.96 µm on the healthy control side (p = 0.0001). A statistically significant difference was observed between the healthy and affected eyes of patients with ISSNHL with respect to mean GCC and mean RNFL thickness. OCT could be a useful technique for measuring this neural degeneration.

Exploring the utility of retinal optical coherence tomography as a biomarker for idiopathic intracranial hypertension: a systematic review

AbstractThis study aimed to examine the existing literature that investigated the effectiveness of optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A) as a biomarker for idiopathic intracranial hypertension (IIH). Our search was conducted on January 17th, 2024, and included the databases, Medline, Scopus, Embase, Cochrane, Latin American and Caribbean Health Sciences Literature (LILACS), International Standard Randomized Controlled Trial Number (ISRCTN) registry, and the International Clinical Trials Registry Platform (ICTRP). Our final review included 84 articles. In 74 studies, OCT was utilized as the primary ocular imaging method, while OCT-A was employed in two studies including eight studies that utilized both modalities. Overall, the results indicated that IIH patients exhibited significant increases in retinal nerve fiber layer (RNFL) thickness, total retinal and macular thickness, optic nerve head volume, and height, optic disc diameter and area, rim area, and thickness compared to controls. A significant correlation was observed between cerebrospinal fluid (CSF) pressure and OCT parameters including RNFL thickness, total retinal thickness, macular thickness, optic nerve head volume, and optic nerve head height. Interventions aimed at lowering CSF pressure were associated with a substantial improvement in these parameters. Nevertheless, studies comparing peripapillary vessel density using OCT-A between IIH patients and controls yielded conflicting results. Our systematic review supports OCT as a powerful tool to accurately monitor retinal axonal and optic nerve head changes in patients with IIH. Future research is required to determine the utility of OCT-A in IIH.

Variability of relationship between inner-retinal structural changes and visual dysfunction in optic neuropathy

Optical coherence tomography (OCT) displays the retinal nerve fiber layer (RNFL) or macular ganglion cell and inner plexiform layer (GCIPL) thickness below 1st percentile in red color. This finding generally indicates severe inner-retinal structural changes and suggests poor visual function. Nevertheless, some individuals show preserved visual function despite these circumstances. This study aimed to identify the correlation between best-corrected visual acuity (BCVA) and inner-retinal thickness based on OCT parameters in various optic neuropathy patients with extremely low RNFL/GCIPL thickness, and determine the limitation of OCT for predicting visual function in these patients. 131 patients were included in the study. The mean BCVA in logMAR was 0.55 ± 0.70 with a broad range from − 0.18 to 3.00. Among the OCT parameters, temporal GCIPL (r = − 0.412) and average GCIPL (r = − 0.366) exhibited the higher correlations with BCVA. Etiological comparisons of optic neuropathies revealed significantly lower BCVA in LHON (all p < 0.05). Idiopathic optic neuritis (ON) and MOGAD exhibited better and narrower BCVA distributions compared to the other optic neuropathies. OCT had limited utility in reflecting BCVA, notwithstanding significant inner-retinal thinning after optic nerve injuries. Caution is needed in interpreting OCT findings, especially as they relate to the etiology of optic neuropathy.

Prediction of long-term visual outcome of idiopathic full-thickness macular hole surgery using optical coherence tomography parameters that estimate potential preoperative photoreceptor damage.

To identify optical coherence tomography (OCT) parameters that predict postoperative best corrected visual acuity (BCVA) and are based on recent understanding of the pathomechanism of idiopathic full thickness macular hole (iFTMH) formation and closure. A retrospective consecutive case series of patients who had macular hole (MH) surgery at our institution between 2016 and 2022 was performed. 32 eyes of 30 patients were selected with at least 12months of follow-up, closed MH and good quality OCT at each visit. Univariate correlation analysis, multiple logistic regression with forward stepwise selection, and Akaike's Information Criterion (AIC) were used to identify the best predictors for postoperative BCVA at 6 and 12months (M), and final (≥ 12M) visits, and a new OCT index was created. Abilities of best models/indices to predict < 0.30 logMAR (> 20/40) BCVA were compared to macular hole index (MHI) using the area under the receiver operating curve (AU-ROC) analysis. Statistical analysis revealed base diameter (B) (6M), preoperative BCVA and B (12M) and smaller ELM-GCL distance (A), and B (final visit) as predictors for postoperative BCVA. AU-ROC analysis indicated greatest AUC at 6M for MHI and B (0.797, p = 0.004 and 0.836 p = 0.001, respectively) and for the new A/B index at 12M and final visit (0.844, p = 0.002 and 0.913, p = 0.003, respectively). Our study suggests that MHI and B can be useful predictors of short term BCVA while the new A/B index that incorporates OCT parameters indicating potential preoperative photoreceptor damage may be a good predictor for long term postoperative BCVA. Our findings support the theory that initial hole formation mechanisms and photoreceptor damage define visual prognosis.

Racial-ethnic disparities in concurrent rates of peripapillary & macular OCT parameters among a large glaucomatous clinical population.

To compare rates of change in peripapillary retinal nerve fibre layer (pRNFL) and macular ganglion cell-inner plexiform layer (mGCIPL) parameters among different race-ethnicities from a large electronic health record database of subjects with or suspected of glaucoma. In this retrospective cohort study, rates of change were obtained using joint longitudinal linear mixed models for eyes with ≥3 visits and ≥1 year of follow-up, adjusting for age, sex, intraocular pressure, central corneal thickness, and baseline pRNFL and mGCIPL thickness. Best linear unbiased predictor estimates of various parameters were stratified by baseline glaucoma severity and analysed by racial-ethnic group. A total of 21,472 spectral domain optical coherence tomography (OCT) pRNFL scans and 14,431 mGCIPL scans from 2002 eyes were evaluated. A total of 200 (15.6%) and 601 (46.8%) subjects identified as non-Hispanic Black (NHB) and Hispanic, respectively. NHB eyes exhibited faster rates of change in pRNFL among glaucoma suspect (global pRNFL -0.57 ± 0.55 µm/year vs. -0.37 ± 0.62 µm/year among Hispanics, p < 0.001), mild glaucoma (superior pRNFL quadrant -1.20 ± 1.06 µm/year vs. -0.75 ± 1.51 µm/year among non-Hispanic Whites (NHW), p = 0.043), and moderate glaucoma eyes (superior pRNFL quadrant -1.31 ± 1.49 µm/year vs. -0.52 ± 1.26 µm/year among Hispanics, p = 0.003). NHB eyes exhibited faster rates of mGCIPL loss corresponding to pRNFL rates. Global pRNFL and mGCIPL rates were strongly correlated (R2 = 0.70). Adjusted rates of pRNFL and mGCIPL loss significantly differed between racial-ethnic groups when stratified by glaucoma severity, with faster rates among NHB patients. These differences highlight key racial-ethnic disparities in adjusted rates of glaucoma OCT parameters.

Evaluation of the standard test methods for optical coherence tomograph for the posterior segment of the human eye

Optical Coherence Tomography (OCT) has revolutionized retinal imaging by offering non-invasive high-resolution three-dimensional visualization capabilities. OCT has become the standard of care in routine ophthalmological practice, especially for the posterior segment. Given its widespread clinical applications, establishing standardized test devices and methods for key OCT parameters is imperative to ensure both optimal imaging performance and diagnostic accuracy and treatment effectiveness. As a widely applied standard, ISO 16971:2015 published by the International Organization for Standardization specifies the minimum requirements, test device, and methods for OCT for the posterior segment of the human eye. Notably, these standards lacked experimental validation. In the present study, we implement the test device according to ISO 16971:2015, and assess a commercially available ophthalmic OCT instrument with the suggested test device and methods. Results show that the test device and methods could facilitate a rudimentary evaluation of OCT key parameters. Nevertheless, refinements of the test device and methods are requisite to enhance measurement accuracy, reliability, traceability, and practicability, catering to the diverse needs of manufacturers, end-users, and regulatory entities.

Subretinal transient hyporeflectivity in neovascular age-related macular degeneration and its response to a loading phase of aflibercept: PRECISE report 4.

To describe the prevalence of subretinal transient hyporeflectivity (STHR) in exudative neovascular age-related macular degeneration (nAMD) and its response to a loading phase of aflibercept. Optical coherence tomography (OCT) scans of treatment-naïve nAMD patients captured at baseline and after a loading phase of aflibercept were graded for presence of STHR, defined as a small, well-defined, round, subretinal, hyporeflective area, delimited between the ellipsoid zone (EZ) and the retinal pigmented epithelium/Bruch membrane complex. OCT parameters recorded were macular neovascularisation (MNV) subtypes, location of retinal fluids (subretinal fluid, SRF and intraretinal fluid, IRF), central retinal and choroidal thickness. Response was defined as absence of IRF and SRF. Factors associated with completely resolved STHR versus persistent STHR post-loading phase were compared. 2039 eyes of 1901 patients were analysed. STHR was observed in 79 eyes of 78 patients, with an estimated prevalence of 3.87% (95% CI 3.08-4.81%). STHR were seen in 44 type 1 MNV (56%), 27 with type 2 (34%), and 8 with type 3 (10%). At baseline, a total of 303 STHR were present, ranging between 1-22 per eye. The total number of STHR reduced significantly after the loading phase to 173 (p = 0.002). Complete disappearance of STHR was seen in 44 eyes (56%) and persistent STHR in the rest (44%). STHR may represent a marker of low-grade exudation in nAMD eyes with good response to a loading phase of aflibercept. However, its potential role as an independent nAMD activity biomarker is limited as most resolve after the loading phase.

Hemoglobin levels are associated with retinal vascular caliber in a middle-aged birth cohort

Vascular and neural structures of the retina can be visualized non-invasively and used to predict ocular and systemic pathologies. We set out to evaluate the association of hemoglobin (Hb) levels within the national reference interval with retinal vascular caliber, optical coherence tomography (OCT) and visual field (VF) parameters in the Northern Finland 1966 Birth Cohort (n = 2319, 42.1% male, average age 47 years). The studied parameters were evaluated in Hb quintiles and multivariable linear regression models. The lowest Hb quintile of both sexes presented the narrowest central retinal vein equivalent (CRVE) and the healthiest cardiometabolic profile compared to the other Hb quintiles. In the regression models, CRVE associated positively with Hb levels in both sexes, (Bmales = 0.068 [0.001; 0.135], Bfemales = 0.087 [0.033; 0.140]), after being adjusted for key cardiometabolic and inflammatory parameters, smoking status, and fellow vessel caliber. No statistically significant associations of Hb levels with central retinal artery equivalent, OCT or VF parameters were detected. In conclusion, Hb levels were positively and specifically associated with CRVE, indicating that Hb levels are an independent factor affecting CRVE and the effect is in parallel with established risk factors for cardiometabolic diseases.

Reverse pupillary block, in contemporary scleral intraocular lens procedures.

To evaluate the frequency and anterior segment optical coherence tomography parameters of patients with scleral fixated intraocular lenses (IOL) and reverse pupillary block (RPB). Retrospective analysis at a tertiary care centre (Department for Ophthalmology and Optometry, Medical University of Vienna, Austria). We researched our records for patients who underwent scleral fixated IOL implantation from January 2018 till February 2023. Patients were included only if there was at least one adequate post-operative scan of anterior segment optical coherence tomography (AS-OCT) available. Initially, AS-OCT scans were assessed for IOL tilt and decentration employing a 3D scan and then later for anterior chamber angle (ACA), aqueous anterior chamber depth (AQD), pupil diameter and iris-IOL distance using the 2D scan at a 0° angle. Both an iris-IOL distance of 0 or less and an ACA of more than 70° were required to define an RPB. A total of 110 patients met the inclusion criteria, 41 were treated using the Carlevale, 33 the four flanged, 24 the Yamane and 12 the Scharioth technique, respectively. RPB was found in 32 patients (29%). Twenty patients with RPB were treated using YAG peripheral iridotomy, mean ACA decreased from 91.91° ± 13.77 to 61.02° ± 8.52, (p < 0.001), mean AQD decreased from 4.67 mm ± 0.47 to 4.31 ± 0.36 mm (p < 0.001) and mean iris-IOL distance increased from -0.09 ± 0.04 to 0.33 ± 0.30 (p < 0.001). RPB is found in a third of eyes who have undergone scleral fixated IOL implantation without iridectomy. YAG peripheral iridotomy is a potent option to treat RPB, and subsequently reduce the risk of iris chafing and secondary inflammation or glaucoma.

Optical coherence tomography (OCT) and OCT-angiography in syndromic versus non-syndromic USH2A-associated retinopathy.

To compare non-syndromic and syndromic forms of USH2A-related retinitis pigmentosa (RP) by means of structural optical coherence tomography (OCT) and OCT-angiography (OCTA). Observational, cross-sectional, multicenter study. All patients underwent best corrected visual acuity (BCVA) measurement, OCT (Spectralis HRA + OCT, Heidelberg Engineering) and OCTA (OCT DRI Topcon Triton, Topcon Corporation). We compared subfoveal choroidal thickness (SCT), choroidal vascularity index (CVI), presence of cystroid macular edema (CME), macular vessel density (VD) at the superficial and deep capillary plexa, as well as VD of the radial peripapillary capillary (RPC) network, between syndromic and non-syndromic patients with USH2A-associated retinopathy. Thirty-four eyes from 18 patients (7 females) were included. Thirteen patients (72.2%) were affected by Usher syndrome type 2, whereas the remaining 5 subjects (27.8%) had non-syndromic retinitis pigmentosa (nsRP). Syndromic patients were younger than nsRP (p = 0.01) and had a worse visual acuity than those with the exclusively retinal phenotype. Patients with Usher syndrome type 2 had a higher prevalence of CME and a thicker choroid compared to nsRP, although these results were not statistically significant (p = 0.775 and p = 0.122, respectively). Similarly, none of the other quantitative OCT and OCTA parameters was statistically different between the two groups. Despite their younger age, patients with Usher syndrome type 2 displayed similar choroidal and microvascular changes compared to those with nsRP.

Anatomical Features can Affect OCT Measures Used for Clinical Decisions and Clinical Trial Endpoints.

To understand the association between anatomical parameters of healthy eyes and optical coherence tomography (OCT) circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements. OCT cpRNFL thickness was obtained from 396 healthy eyes in a commercial reference database (RDB). The temporal quadrant (TQ), superior quadrant (SQ), inferior quadrant (IQ), and global (G) cpRNFL thicknesses were analyzed. The commercial OCT devices code these values based on percentiles (red, <1%; yellow, ≥1% and <5%), after taking age and disc area into consideration. Four anatomical parameters were assessed: fovea-to-disc distance, an estimate of axial length, and the locations of the superior and the inferior peaks of the cpRNFL thickness curve. Pearson correlation values were obtained for the parameters and the thickness measures of each of the four cpRNFL regions, and t-tests were performed between the cpRNFL thicknesses coded as abnormal (red or yellow, <5%) versus normal (≥5%). For each of the four anatomical parameters, the correlation with the thickness of one or more of the TQ, SQ, IQ, and G regions exceeded the correlation with age or disc area. All four parameters were significantly (P < 0.001) associated with the abnormal cpRNFL values. The significant parameters were not the same for the different regions; for example, a parameter could be negatively correlated for the TQ but positively correlated with the SQ or IQ. In addition to age and disc area, which are used for inferences in normative databases, four anatomical parameters are associated with cpRNFL thickness. Taking these additional anatomical parameters into consideration should aid diagnostic accuracy.

Deep learning assisted fluid volume calculation for assessing anti-vascular endothelial growth factor effect in diabetic macular edema

ObjectiveTo develop an algorithm using deep learning methods to calculate the volume of intraretinal and subretinal fluid in optical coherence tomography (OCT) images for assessing diabetic macular edema (DME) patients’ condition changes. DesignCross-sectional study. ParticipantsTreatment-naive patients diagnosed with DME recruited from April 2020 to November 2021. MethodsThe deep learning network, which was built for autonomous segmentation utilizing an encoder-decoder network based on the U-Net architecture, was used to calculate the volume of intraretinal fluid (IRF) and subretinal fluid (SRF). The alterations of retinal vessel density and thickness, and the correlation between best-corrected visual acuity (BCVA) and OCT parameters were analyzed. Results2,955 OCT images of fourteen eyes from DME patients with IRF and SRF who received anti-vascular endothelial growth factor (VEGF) agents were obtained. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve of the algorithm was 0.993 for IRF and 0.998 for SRF. The volumes of IRF and SRF were significantly decreased from 1.93 ± 0.58 /1.14 ± 0.25 mm3 (baseline) to 0.26 ± 0.13 /0.26 ± 0.18 mm3 (post-injection), respectively (p = 0.0170 for IRF, and p = 0.0004 for SRF). The Spearman correlation demonstrated that the reduction of IRF volume was negatively correlated with age (coefficient = −0.698, p = 0.006). ConclusionWe developed a deep learning assisted fluid volume calculation algorithm with high sensitivity and specificity for assessing the volume of IRF and SRF in DME patients. Key words: deep learning; diabetic macular edema; optical coherence tomography.

Visual Field and Optical Coherence Tomography Parameters With and Without Positive Family History of Glaucoma.

To evaluate the Retinal Nerve Fiber Layer and Ganglion Cell Complex thickness using Spectral Domain Optical Coherence Tomography with and without positive family history of Primary Open Angle Glaucoma and its relation to visual field. Total 120 eyes with each subjects with positive family history of Primary Open Angle Glaucoma (Group I, n=30) and healthy subjects without positive family history of Primary Open Angle Glaucoma (Group II, n=30) undergone complete ophthalmic evaluation with Retinal Nerve Fiber Layer, Ganglion Cell Complex and VF obtained from Spectral Domain Optical Coherence Tomography RTVue-100 and Humphrey visual field respectively .The measurements were analyzed and compared among two groups using independent-t test by using SPSS version 23.The relationship of Retinal Nerve Fiber Layer with visual field were evaluated with correlation analysis. There were 75 patients included in the study.nasal, temporal RNFL and average Ganglion Cell Complex was significantly lower and thinner in Group I with mean difference of -8.53±2.30 µm (p<0.001), -7.35±3.34 µm (p<0.001), -8.52±3.58µm (p<0.001),-11.87±2.24µm (p<0.001), -5.31±1.95µm (p<0.001) and -8.05±1.52µm (p<0.001) respectively. Correlation plot with Retinal Nerve Fiber Layer thickness as predictor of Mean Deviation and Pattern Standard Deviation indicated statistically significant degree of determination in Group I (r=0.455 and r=0.623, p<0.001 and p<0.001). The Optical Coherence Tomography and visual field Parameters are lower in group I and used as an early predictor, diagnosis, monitoring and management.

Short Wavelength Automated Perimetry, Standard Automated Perimetry, and Optical Coherence Tomography in Dominant Optic Atrophy.

Background: Blue-yellow axis dyschromatopsia is well-known in Autosomal Dominant Optic Atrophy (ADOA) patients, but there were no data on the correlation between retinal structure and short-wavelength automated perimetry (SWAP) values in this pathology. Methods: In this cross-sectional case-control study, we assessed the correlation between best corrected visual acuity (BCVA), standard automated perimetry (SAP), SWAP, and optical coherence tomography (OCT) parameters of 9 ADOA patients compared with healthy controls. Correlation analysis was performed between BCVA, mean deviation, pattern standard deviation (PSD), and fovea sensitivity (FS) values and the OCT thickness of each retinal layer and the peripapillary retinal nerve fiber layer (pRNFL). Results: The following significant and strong correlations were found: between BCVA and ganglion cell layer (GCL) and the global (G) pRNFL thicknesses; between SAP FS and GCL and the G-pRNFL thicknesses; between SWAP PSD and total retina, GCL, inner plexiform layer, inner nuclear layer, inner retinal layer and the temporal pRNFL thicknesses. We found a constant shorter duration of the SITA-SWAP compared with the SITA-STANDARD strategy. Conclusions: SWAP, SAP, and BCVA values provided relevant clinical information about retinal involvement in our ADOA patients. The perimetric functional parameters that seemed to correlate better with structure involvement were FS on SAP and PSD on SWAP.

Estimation of angle parameters by ASOCT and biometric parameters by optical biometer in eyes with occludable angles and open angles.

To compare anterior chamber angle (ACA) parameters measured by Anterior Segment Optical Coherence Tomography (ASOCT) and biometric parameters measured by Swept-Source (SS) OCT-based biometry among patients with suspected occludable angles and open angles. An analytical, cross-sectional study was performed on subjects attending our ophthalmology outpatient department with suspected occludable angles (van Herick grades 0, 1, and 2) in group 1, and with open angles (van Herick grades 3 and 4) in group 2. Each subject underwent a complete ophthalmic examination to exclude any intraocular pathology like cataract. We recruited 128 eyes of 64 subjects, 34 in group 1 and 30 in group 2. Each eye was henceforth subjected to ASOCT (Spectralis, Heidelberg Engineering, Heidelberg) and SS-OCT-based optical biometry (IOL Master 700, Carl Zeiss Meditec AG). Anatomical parameters were recorded and compared between the two groups. The main outcome measures of the study included nine ASOCT parameters (central corneal thickness [CCT], lens vault, AOD750, ACA, TISA750 [nasal and temporal], and ACW) and five optical biometric parameters (CCT, ACD, WTW, LT, and axial length). We found a significant difference (p < 0.05) among all the anatomical parameters between the two groups, except CCT which was not significantly different (p = 0.297). ASOCT and SSOCT biometry overcome the challenges of gonioscopy and allow screening for angle closure disease in otherwise normal subjects. ASOCT may serve as an alternative to gonioscopy as it clearly separates occludable angles from open angles in a non-invasive and objective manner.

Choroidal hypertransmission width on optical coherence tomography: a prognostic biomarker in idiopathic macular hole surgery.

To test the hypothesis that optical coherence tomography (OCT) choroidal hypertransmission width (CHW) is a prognostic biomarker in idiopathic macular hole (MH) surgery METHODS: Retrospective cohort study of consecutive patients undergoing successful pars plana vitrectomy for idiopathic MH. We collected demographic, clinical, and OCT variables at the preoperative and last available visits. Two investigators assessed the following OCT parameters: MH minimum diameter, base diameter, CHW, ellipsoid zone, and external limiting membrane status (absent vs. present). Delta CHW was calculated as the difference between CHW and MH minimum diameter. Linear models were used to investigate factors associated with postoperative best-corrected visual acuity (BCVA) and BCVA change. Thirty-six eyes (36 patients) with a median (interquartile range (IQR)) follow-up of 9 (8-11) months were included. The median BCVA (IQR) improved from 0.75 (1-0.6) logMAR preoperatively to 0.2 (0.6-0.1) logMAR at the last visit (p < 0.001). Preoperative MH minimum diameter (for a 10-μm increase, estimate (standard error (SE)): 0.009 (0.003) logMAR, p = 0.003), base diameter (for a 10-μm increase, 0.003 (0.001) logMAR, p = 0.032), CHW (for a 10-μm increase, 0.008 (0.002) logMAR, p < 0.001), and delta CHW (for a 10-μm increase, 0.013 (0.005) logMAR, p = 0.009) were significantly associated with postoperative BCVA. The proportion of variance explained was the highest for MH CHW (R2 0.35), followed by minimum MH diameter (R2 0.24), delta CHW (R2 0.19), and MH base diameter (R2 0.14). None of the study variables was associated with delta BCVA. Preoperative CHW is associated with postoperative visual acuity in patients undergoing successful idiopathic MH surgery and may be a useful OCT prognostic biomarker.

Comparison of focal loss volume, global loss volume, retinal nerve fiber layer thickness, and corneal epithelial thickness in eyes with glaucoma and suspicious optic discs

Abstract: PURPOSE: The purpose of this study was to study the role of the focal loss volume (FLV), global loss volume (GLV), and other spectral-domain optical coherence tomography (SD-OCT) parameters in early diagnosis of glaucomatous damage. METHODS: A retrospective study included records of 34 eyes with early glaucoma (Group A) and 17 eyes with suspicious optic discs (Group B). Retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and corneal thickness parameters were assessed by the SD OCT (RTVue SD-OCT). These included the FLV, GLV, in addition to RNFL thickness, cup/disc ratio, GCC thickness, and anterior segment OCT for assessment of central corneal thickness and central corneal epithelial thickness. Data from both groups were subjected to statistical analysis. RESULTS: The FLV and GLV had the highest areas under the receiver operating characteristic curve in Group A eyes. FLV had higher (97.2%) specificity and was the earliest parameter to be affected by glaucomatous damage, followed by GLV. Moreover, Group A eyes had significant thinning of the RNFL (91.59 μm) compared to Group B (118.18 μm), and GCC thickness was also significantly thinner in Group A (92.07 μm) than in Group B (110.54 μm). Interestingly, Group A eyes had thinner corneal epithelium (nonsignificant) than Group B. CONCLUSION: FLV and GLV were of the greatest value in the assessment of early glaucomatous GCC degeneration.

Myelin Oligodendrocyte Glycoprotein Antibody Disease Optic Neuritis: A Structure-Function Paradox?

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a demyelinating disorder that most commonly presents with optic neuritis (ON) and affects children more often than adults. We report 8 pediatric patients with MOG-associated ON and characterize focal optical coherence tomography (OCT) abnormalities over time that help distinguish this condition from the trajectories of other demyelinating disorders. These OCT findings are examined in the context of longitudinal visual function testing. This is a retrospective case series of 8 pediatric patients with MOG-associated ON who were referred for neuro-ophthalmic evaluation. Longitudinal data for demographics, clinical history, physical examination, and OCT obtained in the course of clinical evaluations were collected through retrospective medical record review. Patients demonstrated acute peripapillary retinal nerve fiber layer (RNFL) thickening in one or both eyes, consistent with optic disc swelling. This was followed by steady patterns of average RNFL thinning, with 9 of 16 eyes reaching significantly low RNFL thickness using OCT platform reference databases ( P < 0.01), accompanied by paradoxical recovery of high-contrast visual acuity (HCVA) in every patient. There was no correlation between HCVA and any OCT measures, although contrast sensitivity (CS) was associated with global thickness, PMB thickness, and nasal/temporal (N/T) ratio, and color vision was associated with PMB thickness. There was a lower global and papillomacular bundle (PMB) thickness ( P < 0.01) in clinically affected eyes compared with unaffected eyes. There was also a significantly higher N:T ratio in clinically affected eyes compared with unaffected eyes in the acute MOG-ON setting ( P = 0.03), but not in the long-term setting. MOG shows a pattern of prominent retinal atrophy, as demonstrated by global RNFL thinning, with remarkable preservation of HCVA but remaining deficits in CS and color vision. These tests may be better clinical markers of vision changes secondary to MOG-ON. Of the OCT parameters measured, PMB thickness demonstrated the most consistent correlation between structural and functional measures. Thus, it may be a more sensitive marker of clinically significant retinal atrophy in MOG-ON. The N:T ratio in acute clinically affected MOG-ON eyes in our study was higher than the N:T ratio of neuromyelitis optica (NMO)-ON eyes and similar to the N:T ratio in multiple sclerosis (MS)-ON eyes as presented in the prior literature. Therefore, MOG may share a more similar pathophysiology to MS compared with NMO.

Optical coherence tomography parameters as prognostic factors for stereopsis after vitrectomy for unilateral epiretinal membrane: a cohort study

This retrospective cohort study explored the relationship between monocular and interocular optical coherence tomography (OCT) parameters and stereopsis in 56 patients undergoing pars plana vitrectomy (PPV) for unilateral idiopathic epiretinal membrane (IERM). IERM impairs visual functions, with symptoms ranging from asymptomatic to severe impairment. Despite established surgical interventions, including PPV with membrane peeling, the impact on advanced three-dimensional visual functions such as stereopsis remains inadequately investigated. All subjects were assessed for stereopsis, visual acuity, and metamorphopsia, alongside spectral domain OCT parameters. These visual functions significantly improved 3-month postoperatively. Central retinal thickness at the fovea, parafovea, and perifovea (CFT, CRT-3 mm, and CRT-6 mm), ectopic inner foveal layer thickness, and retinal layer thickness notably decreased 1 week to 3 months after surgery. The interocular difference in OCT parameters between bilateral eyes was included as a parameter. Baseline CRT-3 mm difference and inner nuclear layer (INL) thickness were independently correlated with postoperative stereopsis on the Titmus Stereo Test, while baseline CRT-6 mm difference and INL thickness were independently related to stereopsis on the TNO stereotest. This study highlights the substantial enhancement in stereopsis post-IERM surgery, with both interocular and monocular OCT parameters independently influencing postoperative stereopsis. These findings underscore the importance of retinal microstructures in assessing and predicting stereopsis in IERM patients after vitrectomy.