Comparison between Spectral-Domain and Swept-Source OCT Angiography for the Measurement of Persistent Hypertransmission Defects in Age-Related Macular Degeneration.

Purpose: Spectral-domain OCT angiography (SD-OCTA) scans were tested in an algorithm developed for use with swept-source OCT angiography (SS-OCTA) scans to determine if SD-OCTA scans yielded similar results for the detection and measurement of persistent choroidal hypertransmission defects (hyperTDs). Design: Retrospective study. Participants: Forty pairs of scans from 32 patients with late-stage nonexudative age-related macular degeneration (AMD). Methods: Patients underwent both SD-OCTA and SS-OCTA imaging at the same visit using the 6 × 6 mm OCTA scan patterns. Using a semiautomatic algorithm that helped with outlining the hyperTDs, 2 graders independently validated persistent hyperTDs, which are defined as having a greatest linear dimension ≥250 µm on the en face images generated using a slab extending from 64 to 400 µm beneath Bruch's membrane. The number of lesions and square root (sqrt) total area of the hyperTDs were obtained from the algorithm using each imaging method. Main Outcome Measures: The mean sqrt area measurements and the number of hyperTDs were compared. Results: The number of lesions and sqrt total area of the hyperTDs were highly concordant between the 2 instruments (rc = 0.969 and rc = 0.999, respectively). The mean number of hyperTDs was 4.3 ± 3.1 for SD-OCTA scans and 4.5 ± 3.3 for SS-OCTA scans (P = 0.06). The mean sqrt total area measurements were 1.16 ± 0.64 mm for the SD-OCTA scans and 1.17 ± 0.65 mm for the SS-OCTA scans (P < 0.001). Because of the small standard error of the differences, the mean difference between the scans was statistically significant but not clinically significant. Conclusions: Spectral-domain OCTA scans provide similar results to SS-OCTA scans when used to obtain the number and area measurements of persistent hyperTDs through a semiautomated algorithm previously developed for SS-OCTA. This facilitates the detection of atrophy with a more widely available scan pattern and the longitudinal study of early to late-stage AMD. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Hyperreflective ganglion cell layer band in a large cohort of non-syndromic retinitis pigmentosa: Frequency and clinical correlations.

PURPOSE: Recently, an 'hyperreflective ganglion cell layer band' (HGB) has been described on spectral-domain optical coherence tomography (SD-OCT) in a subset of patients with retinitis pigmentosa (RP). This study aims to validate and describe the frequency of HGB in a large cohort of Portuguese patients with RP. METHODS: This single-centre, cross-sectional cohort study included consecutive patients with a genetic diagnosis of RP. SD-OCT images were reviewed to identify the presence of the HGB and other retinal comorbidities. The HGB was defined as a continuous hyperreflective band within the thickness of the ganglion cell layer (GCL). We built mixed-effects regression models, accounting for inter-eye correlations, to investigate features predictive of visual acuity. Subsequently, a reduced model was fitted. RESULTS: A total of 398 eyes from 201 patients were included. HGB was identified in 69 (17.3%) eyes from 39 (19.4%) patients. Patients presenting with the HGB were significantly younger at diagnosis and at symptom onset. Median BCVA [ETDRS (IQR)] was 65 (29) letters in eyes with the HGB and 70 (21) letters in eyes without HGB (p < 0.001). In both the full and reduced mixed-effects models, the presence of HGB and macular hole (MH) was significantly associated with worse BCVA. CONCLUSIONS: This study validates the recent description of HGB within the GCL in a subset of patients with RP. Eyes with HGB demonstrated significantly worse BCVA compared to those without HGB, suggesting that the presence of HGB may serve as an SD-OCT biomarker of worse visual prognosis in these patients.

Application of the full-width-at-half-maximum image segmentation method to analyse retinal vascular changes in patients with internal carotid artery stenosis.

Background: To investigate the correlation between retinal vascular changes and ICA stenosis by measuring retinal vessels using full-width-at-half-maximum (FWHM) and intelligent image recognition. Methods: This research selected patients who were admitted to the Vascular Surgery Department of Quzhou People's Hospital from January 2018 to December 2020 and were preparing for Carotid Artery Stenting (CAS). Participants were divided into two groups: without ICA stenosis (Group 0) and with ICA stenosis (Group 1). A total of 109 cases were included in the study, with 50 cases in Group 1 and 59 cases in Group 0. Vascular images of superior temporal zone B of the retina were obtained by spectral domain optical coherence tomography (SD-OCT). The edges of retinal vessels were identified by FWHM. Each vessel of all subjects was measured three times with the FWHM, and the average value was taken to obtain the retinal arteriolar lumen diameter (RALD), retinal arteriolar outer diameter (RAOD), retinal venular lumen diameter (RVLD), and retinal venular outer diameter (RVOD),Arterial Wall Thickness (AWT),Venular Wall Thickness (VWT)=(RVOD-RVLD)/2,Arteriovenous Ratio (AVR) = RAOD/RVOD. Results: We found that compared to Group 0, Group 1 had smaller RALD (P < 0.001) and RAOD (P < 0.001), and wider RVOD (P < 0.001), with thicker VWT (P < 0.001). When compared with the contralateral eye in Group 1, the ipsilateral eye exhibited even smaller RALD,RAOD and AVR (P < 0.001, P < 0.001, P < 0.001). After CAS, the RALD,RAOD and AVR in Group 1 increased (P < 0.001, P < 0.001, P < 0.001),while the RVLD and RVOD decreased (P < 0.05, P < 0.001). Our research reveals a significant correlation between retinal vascular changes and internal ICA stenosis. Conclusion: Utilizing SD-OCT in conjunction with the FWHM,we achieved a non-invasive, intelligent, stable, and precise acquisition of data pertaining to retinal vessels. These findings underscore a significant correlation between alterations in retinal vascular structure and the presence of ICA stenosis, as demonstrated by our research.

Comparison of ocular changes in multiple sclerosis and neuromyelitis optica spectrum disorder patients.

Purpose: To explore ocular changes in patients with MS and NMOSD via SD-OCT and PVEP analysis. Methods: From August 2020 to July 2021, 82 patients (164 eyes) diagnosed with MS, 59 patients (118 eyes) diagnosed with NMOSD and 50 healthy controls (100 eyes) were retrospectively selected. SD-OCT and PVEP were performed to compare retinal nerve fibre layer (RNFL) thickness around the optic disc, ganglion cell inner plexiform layer (GCIPL) thickness in the macula and P100 latency and amplitude between the disease groups and the control group. Results: In the NMOSD and MS groups, the thickness of the GCIPL quadrants in eyes with optic neuritis was thinner than that in eyes without optic neuritis, and the amplitude of the P100 wave decreased. In addition, in eyes with optic neuritis, patients with NMOSD have thinner RNFL thicknesses in the temporal and superior quadrants than patients with MS, and the thickness of the GCIPL is thinner in each region. In eyes without optic neuritis, patients with MS have thinner nasal RNFL than do those with NMOSD. Conclusion: SD-OCT and VEP may be useful for monitoring and distinguishing pathological changes in MS and NMOSD patients.

Impact of vitreomacular interface on intravitreal Brolucizumab efficacy in age-related macular neovascularization.

BACKGROUND: This study aimed to assess the influence of vitreoretinal interface (VRI) on the outcome of Brolucizumab intravitreal injections (IVBr) in patients with age-related macular neovascularization (MNV). METHODS: 40 eyes of 40 patients with active-naive MNV candidates to IVBr were enrolled at the Ophthalmology Clinic of the University "G. d'Annunzio," Chieti-Pescara, Italy. Based on the VRI condition, 20 patients were included in the G0 group (without evidence of VRI alterations), whereas 20 patients were enrolled in the G1 group (with VRI abnormalities). The primary outcome measures were changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (SCT), pigment epithelial detachment presence and maximum height (PEDMH), intraretinal fluid (IRF) presence, subfoveal subretinal fluid (SSRF) presence and thickness (SSRFT), subretinal pigment epithelium fluid (SRPEF) presence and SRPEF thickness (SRPEFT). RESULTS: There were no significant differences in BCVA and SCT between the two groups, although both parameters significantly changed over time (BCVA p 0.005; SCT p < 0.001). No differences in CMT and PEDMH were found between the two groups. SSRF presence showed differences between the two groups at T4 (p 0.044), and IRF presence showed significant differences over time (p 0.008) in favor of MNV eyes without VRI alterations. CONCLUSIONS: Concomitant vitreomacular interface disease alterations in eyes treated with IVBr for MNV influenced fluid presence with greater persistence of SSRF and IRF compared to MNV eyes without VRI. Nevertheless, the overall macular thickness and visual function were not significantly different between the two groups.

Interpretation of SD-OCT imaging data in real-life conditions versus standardized reading centre analysis in eyes with diabetic macular oedema or macular oedema secondary to retinal vein occlusion: 24-month follow-up of the ORCA study.

PURPOSE: As part of the prospective, non-interventional OCEAN study, the ORCA module evaluated physicians' spectral domain optical coherence tomography (SD-OCT) image interpretations in the treatment of diabetic macular oedema (DME) or macular oedema (ME) secondary to retinal vein occlusion (RVO). METHODS: Presence of intraretinal fluid (IRF) and/or subretinal fluid (SRF) was evaluated independently by physicians and reading centres (RCs) on 1612 SD-OCT scans of 133 patients diagnosed with either DME or ME secondary to RVO. Agreement between physicians and RCs was calculated for both cohorts individually and as a combined ME cohort. Physicians' treatment decisions were analysed related to the results of the OCT-evaluations. RESULTS: For the combined ME cohort, presence of IRF/SRF was recorded by RCs in 792/1612 (49.1%) visits and by physicians in 852/1612 (52.9%) visits, with an agreement regarding presence or absence of foveal fluid in 70.4% of cases. In 64.4% (510/792) of visits with RC-detected foveal IRF and/or SRF no injection was given. In 30.3% of these visits with foveal fluid no reason was identified for a 'watch and wait' approach indicating possible undertreatment. BCVA deterioration was seen in a quarter of these eyes at the following visit. CONCLUSION: Despite good agreement between physicians and RCs to recognize SRF and IRF, our data indicate that omitting injections despite foveal involvement of fluid is frequent in routine clinical practice. This may put patients at risk of undertreatment, which may negatively impact real-life BCVA outcomes. TRIAL REGISTRATION: www. CLINICALTRIALS: gov , identifier NCT02194803.

Prevalence of Fovea Plana in patients with rhegmatogenous retinal detachment.

PURPOSE: To assess the prevalence of fovea plana in patients with rhegmatogenous retinal detachment and compare characteristics of the detachment between patients with and without fovea plana. METHODS: This retrospective, cross-sectional, case-control study included individuals with rhegmatogenous retinal detachment. We collected demographics and data on the operated eye, spherical equivalent, best-corrected visual acuity, lens status, macula status, number of retinal holes or tears, and presence of intravitreal hemorrhage, macular hole, epiretinal membrane, posterior vitreous detachment and proliferative vitreoretinopathy. The type of surgery, the tamponade, and cataract surgery following retinal surgery were also recorded. Spectral-domain optical coherence tomography macular cubes were used to evaluate the fovea by using the Spectralis HRA-OCT device (Heidelberg Engineering, Germany). Images were graded by two different investigators and a third investigator in case of disagreement. RESULTS: We included 204 individuals; 35 (17.2%) had fovea plana, a proportion significantly higher than in the general population (p = 0.041). Individuals with and without fovea plana did not differ in any of the characteristics mentioned above apart from posterior vitreous detachment, which was more frequent in those with than without fovea plana (p = 0.038). CONCLUSION: The prevalence of fovea plana is higher in patients with rhegmatogenous retinal detachment, which suggests an association between fovea plana and potential vitreoretinal interface changes.

Tracking Macular Sensitivity and Inner Retinal Thickness in Long-Term Type 1 Diabetes: A Five-Year Prospective Examination in Patients without Diabetic Retinopathy.

The aim of the study is to compare macular sensitivity and retinal thickness in patients with long-term type 1 diabetes mellitus (DM1) without diabetic retinopathy (DR) after 5 years of follow-up. Thirty-two eyes from 32 long-term DM1 patients without DR were included. All participants underwent a complete ophthalmological examination, including microperimetry and spectral domain optical coherence tomography (SD-OCT). The data were compared with results from 5 years prior. The mean age of the DM1 patients was 43.19 ± 10.17 years, with a mean disease duration of 29.84 ± 8.98 years and good glycemic control. In 2023, patients exhibited a significantly worse best corrected visual acuity (BCVA) compared to 2018 (p < 0.001). DM1 patients did not show statistically significant changes in macular sensitivity over the 5-year follow-up period. Macular integrity showed significant differences between the two time points (p = 0.045). Retinal thickness showed significant differences, particularly in inner retinal layers (IRL) across most of the ETDRS areas. Long-term DM1 patients without DR lesions showed worsened macular integrity and a lower BCVA in 2023. Additionally, they displayed significant alterations in retinal thicknesses, especially in the IRL, between 2018 and 2023. These findings suggest that even in the absence of visible DR, long-term DM1 patients may experience subclinical retinal changes and functional deterioration over time, highlighting the importance of regular monitoring for the early detection and management of potential complications.

A spectral domain optical coherence tomography (SD-OCT) study of intraretinal hyperreflective foci and its relationship with visual acuity and grades of retinopathy among patients of diabetes mellitus in Indian population.

Background: Hyperreflective foci (HRF) are biomarkers in detection of diabetic retinopathy (DR). Presence of HRF on spectral domain optical coherence tomography (SD-OCT) can give a correlation with visual acuity change and grades of DR. Purpose of this study is to determine the presence, location, and role of HRF in the retina of DM patients with and without retinopathy. Methods: A total of 192 eyes of patients suffering from type II DM were evaluated. Patients were divided into 2 groups, with Group A having diabetes without retinopathy (20 patients) and group B (76 patients) having diabetes and various grades of retinopathy. SD-OCT was performed in all patients, passing through the center of fovea. On OCT, presence and absence of HRF were noted. Characteristics of the hyper-reflective spots were evaluated: location, shape, size, back shadowing and association with central macular thickness (CMT), visual acuity, and grades of retinopathy. Results: HRF were present in 169 eyes (88%) out of 192 eyes. The shape and location of HRF tend to change with disease progression. HRF were significantly associated with increasing grades of retinopathy (χ2 = 57.586, p < 0.01) Association of macular edema was significant with both retinopathy (χ2 = 8.895, p < 0.05) and HRF (χ2 = 34.720, p < 0.01). Association of best-corrected visual acuity with HRF (χ2 = 21.232, p < 0.01), macular edema (χ2 = 86.960, p < 0.01), and CMT (χ2 = 47.959, p< 0 .01) was significant. Conclusion: HRF is a great indicator for early diagnosis of subclinical retinopathy and can be used to monitor the progression of disease and development of macular edema. Significant difference is present in HRF distribution and morphology.

Combination of optical coherence tomography-derived shape and texture features are associated with development of sub-foveal geographic atrophy in dry AMD.

Geographic atrophy (GA) is an advanced form of dry age-related macular degeneration (AMD) that leads to progressive and irreversible vision loss. Identifying patients with greatest risk of GA progression is important for targeted utilization of emerging therapies. This study aimed to comprehensively evaluate the role of shape-based fractal dimension features ( F fd ) of sub-retinal pigment epithelium (sub-RPE) compartment and texture-based radiomics features ( F t ) of Ellipsoid Zone (EZ)-RPE and sub-RPE compartments for risk stratification for subfoveal GA (sfGA) progression. This was a retrospective study of 137 dry AMD subjects with a 5-year follow-up. Based on sfGA status at year 5, eyes were categorized as Progressors and Non-progressors. A total of 15 shape-based F fd of sub-RPE surface and 494 F t from each of sub-RPE and EZ-RPE compartments were extracted from baseline spectral domain-optical coherence tomography scans. The top nine features were identified from F fd and F t feature pool separately using minimum Redundancy maximum Relevance feature selection and used to train a Random Forest (RF) classifier independently using three-fold cross validation on the training set ( S t , N = 90) to distinguish between sfGA Progressors and Non-progressors. Combined F fd and F t was also evaluated in predicting risk of sfGA progression. The RF classifier yielded AUC of 0.85, 0.79 and 0.89 on independent test set ( S v , N = 47) using F fd , F t , and their combination, respectively. Using combined F fd and F t , the improvement in AUC was statistically significant on S v with p-values of 0.032 and 0.04 compared to using only F fd and only F t , respectively. Combined F fd and F t appears to identify high-risk patients. Our results show that FD and texture features could be potentially used for predicting risk of sfGA progression and future therapeutic response.

Choroidal Thickness Measurement in Systemic Lupus Erythematosus Patients with or Without Ocular Manifestation.

BACKGROUND: Systemic Lupus Erythematosus is a multi-systemic disease that has a high morbidity rate. Choroids usually have a distinct structural makeup in different systemic disorders which makes it easier to be used as a potential tool for the study of disease activity. METHODS: This study was an observational cross-sectional prospective study with a total of 51 Systemic Lupus Erythematosus patients and 51 normal controls were included. The choroidal thickness values were determined using the Spectralis Spectral Domain Optical Coherence Tomography instrument (Heidelberg Engineering). RESULTS: The results showed that the mean subfoveal, nasal, and temporal choroidal thickness in Systemic Lupus Erythematosus patients with ocular manifestations had thinner choroidal thickness compared to normal controls with p<0.001, p=0.008, and p<0.001, respectively. On the other hand, Systemic Lupus Erythematosus patients without ocular manifestations had relatively thicker subfoveal choroidal thickness compared to normal controls (p<0.001) but nasal and temporal choroidal thickness were not statistically significant (p=0.264 and p=0.347 respectively). CONCLUSIONS: The findings suggested that choroidal thickness measurement may serve as an indicator of disease activity and prognosis in Systemic Lupus Erythematosus patients, as well as a potential tool to predict the occurrence of ocular manifestations. Thinning of the choroid may be associated with factors such as decreased blood flow leading to atrophy or chronic inflammation, while thickening of the choroid may indicate active stage of the disease and the possibility of severe ocular manifestations in the future.

The Usefulness of 55° Wide-Field Spectral-Domain Optical Coherence Tomography in Monitoring the Features of Peripheral Subretinal Fluid Remnants after Rhegmatogenous Retinal Detachment Surgery.

BACKGROUND: This study aimed to assess the effectiveness of 55° wide-field (WF) spectral-domain (SD) optical coherence tomography (OCT) for detecting peripheral subretinal fluid (SRF) after surgery for rhegmatogenous retinal detachment (RRD). METHODS: In this retrospective observational study, the retinal periphery was examined to evaluate the possible presence of persistent SRF after surgery. OCT scans were acquired in infrared mode to use any peripheral vessel as a landmark for better repeatability in monitoring fluid remnants. RESULTS: A total of 80 patients (10% with high myopia) were examined using 55° WF SD OCT after successful pars plana vitrectomy (83.8%) or scleral buckling (16.3%) for RRD. A total of 18 patients (22.5%), 16 of whom underwent pars plana vitrectomy and 2 who underwent scleral buckling, showed SRF at the OCT examination during the follow-up. Potential risk factors associated with SRF persistence were analyzed, revealing a significative association with young age (p = 0.009). After a follow-up period of 7.05 ± 2.44 months (ranging from 3 to 12 months), a complete resorption in all patients (100%) within 12 months was observed. Best-corrected visual acuity significantly improved in both groups over time. CONCLUSION: Using 55° WF SD-OCT successfully assessed the course of SRF reabsorption, offering a viable alternative for all those realities where technologies such as ultra-wide-field (UWF) OCT are not available.

Combined Rotating Ultra-High-Resolution Spectral Domain OCT and Scheimpflug Imaging for In Vivo Corneal Optical Biopsy.

PURPOSE: This article introduces the Pentacam® Cornea OCT (optical coherence tomography). This advanced corneal imaging system combines rotating ultra-high-resolution spectral domain OCT with sub- 2-micron axial resolution and Scheimpflug photography. The purpose of this study is to present the first experience with the instrument and its potential for corneal diagnostics, including optical biopsy. METHODS: In this prospective study, the Pentacam® Cornea OCT was used to image the corneas of seven patients. The novel wide-angle pericentric scan system enables optimal OCT imaging performance for the corneal layer structure over the entire width of the cornea, including the limbal regions. A detailed analysis of the resulting images assessed the synergism between the OCT and Scheimpflug photography. RESULTS: The Pentacam® Cornea OCT demonstrated significantly improved image resolution and ability to individualize corneal layers with high quality. There is a synergism between the OCT high-definition signal to individualize details on the cornea and Scheimpflug photography to detect and quantify corneal scattering. The noncontact exam was proven safe, user-friendly, and effective for enabling optical biopsy. CONCLUSIONS: Pentacam® Cornea OCT is an advancement in corneal imaging technology. The ultra-high-resolution spectral domain OCT and Scheimpflug photography provide unprecedented detail and resolution, enabling optical biopsy and improving the understanding of corneal pathology. Further studies are necessary to compare and analyze the tomographic reconstructions of the cornea with the different wavelengths, which may provide helpful information for diagnosing and managing corneal diseases.

Clinical characteristics of peripapillary hyperreflective ovoid mass-like structures in myopic children.

AIM: To describe the characteristics of peripapillary hyperreflective ovoid mass-like structure (PHOMS) in myopic children and to investigate factors associated with PHOMS. METHODS: This retrospective observational study included 101 eyes of 101 children (age ≤17y) with myopia. All included patients underwent comprehensive clinical examination. Optic nerve canal parameters, including disc diameter, optic nerve head (ONH) tilt angle, and border tissue angle were measured using serial enhanced-depth imaging spectral-domain optical coherence tomography (EDI-OCT). Based on the optic disc drusen consortium's definition of PHOMS, eyes were classified as PHOMS group and non-PHOMS group. PHOMS was categorized according to height. RESULTS: Sixty-seven (66.3%) eyes were found with PHOMS. Small PHOMS could only be detected by optical coherence tomography (OCT). Medium PHOMS could be seen with blurred optic disc borders corresponding to OCT. The most frequent location of PHOMS was at the nasosuperior (91%, 61 of 67 eyes) to ONH disc. The axial length and spherical equivalent were more myopic in the PHOMS group than in the non-PHOMS group (both P<0.001). ONH tilt angle was also significantly greater in PHOMS group than in non-PHOMS group [8.90 (7.16-10.54) vs 3.93 (3.09-5.25), P<0.001]. Border tissue angle was significantly smaller in PHOMS group than in non-PHOMS group [29.70 (20.90-43.81) vs 45.62 (35.18-60.45), P<0.001]. In the multivariable analysis, spherical equivalent (OR=3.246, 95%CI=1.209-8.718, P=0.019) and ONH tilt angle (OR=3.275, 95%CI=1.422-7.542, P=0.005) were significantly correlated with PHOMS. There was no disc diameter associated with PHOMS. In the linear regression analysis, border tissue angle was negatively associated with PHOMS height (ß=-2.227, P<0.001). CONCLUSION: PHOMS is associated with optic disc tilt and optic disc nasal shift in myopia. Disc diameter is not a risk factor for PHOMS. The changes in ONH caused by axial elongation facilitated an understanding of the mechanism of PHOMS.

Evaluation of the lamina cribrosa after topical latanoprost therapy in primary open-angle glaucoma or ocular hypertension.

PURPOSE: To investigate that the changes of lamina cribrosa (LC) thickness and depth after latanoprost therapy in primary open-angle glaucoma (POAG) and ocular hypertension (OHT) patients. METHODS: In this single-center prospective cross-sectional study, 35 eyes from 35 patients with POAG or OHT (study group) and 26 age- and gender- matched healthy individuals (control group) were included. All participants were examined by spectral domain optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI) mode for LC thickness and depth measurements at the first visit before latanoprost therapy and at visits after 1 (second visit) and 3 (third visit) months of latanoprost therapy. RESULTS: The mean LC thickness in both horizontal and vertical scans of the study group were thinner than the control group (p < 0.001, for both). During latanoprost therapy in the study group, the LC thickness values in horizontal scans significantly differed over the three visits, gradually increased (p < 0.05). There was significantly decrease in LC depth in horizontal scans between the first and third visits, and the second and third visits (p = 0.003 and p = 0.008, respectively). The gradual decrease in LC depth in vertical scans was observed at all visits, but the statistically significant difference was between the first and third visits only (p = 0.048). CONCLUSION: POAG/OHT patients showed more LC thinning compared with healthy individuals. The significant increase in LC thickness and the significant decrease in LC depth were detected after IOP reduction therapy with latanoprost in ocular hypertensive/ glaucomatous eyes.

Assessment of retinal atrophy in mixed breed dogs using spectral domain optical coherence tomography (SD-OCT) and electroretinography.

The aim of the study was to characterize retinal atrophy (RA) with progressive retinal atrophy symptoms in mixed breed dogs using ophthalmoscopy, spectral domain optical coherence tomography (SD-OCT) and electroretinography (ERG).The study was performed on 13 mixed breed dogs affected by retinal atrophy (11 males and 2 females that were 1.5-14 years old). Depending on the advancement of RA, SD-OCT examinations identified retinal abnormalities ranging from layer disorganisation to advanced atrophy. The most advanced RA occurred ventral to the optic disc. Total retinal thickness in both eyes (mean ± SD) was lower in dogs with RA compared to controls dorsally (77.7 ± 39.5 µm vs 173.5 ± 13.3 µm), ventrally (33.4 ± 29.9 µm vs 139.5 ± 10.8 µm), nasally (65.0 ± 34.5 µm vs 163.9 ± 11.0 µm) and temporally (61.8 ± 41.7 µm vs 171.9 ± 11.1 µm) to the optic disc. In dogs with locally normal architecture of inner retina, loss of definition of outer retinal layers occurred in many regions. Dark and light-adapted ERGs were reduced in 2 dogs with RA and were unrecordable in 11 dogs. Lesions evident in SD-OCT scans of mixed breed dogs affected with retinal atrophy initially appear ventrally to the optic disc and ventro-dorsally in advanced RA. In all mixed breed dogs with retinal atrophy, clinical signs and SD-OCT results correlate with ERG findings.

Evaluation of changes in lacrimal canaliculi width depending on temperature and viscosity of eye drops using spectral-domain optical coherence tomography in dogs.

OBJECTIVE: To evaluate the changes in the width of the lower lacrimal canaliculi (LC) upon instillation of artificial tears (AT) at different temperatures and viscosities using spectral-domain optical coherence tomography (SD-OCT). ANIMAL STUDIED: Eight eyes of four client-owned adult dogs. PROCEDURES: Imaging of lower LC was performed under general anesthesia. AT at temperatures of 2°C, 20°C, and 38°C, and a high-viscosity tear gel of 20°C, were topically instilled in 100 µL volumes. SD-OCT tracked LC width changes following each instillation. RESULTS: The average baseline width of the LC was 96.38 ± 30.18 µm. The 2°C AT expanded LC width to 183.50 ± 44.11 µm, returning to baseline in 5.00 ± 1.31 min. The 20°C AT resulted in a width of 155.25 ± 35.79 µm, with a 3.88 ± 1.25 min return. The 38°C AT expanded LC width to 131.75 ± 29.49 µm, with a 2.25 ± 0.89 min return. The high-viscosity tear gel expanded LC width to 208.57 ± 56.31 µm, with remained expanded for 10 or more minutes. In temperature comparisons, the 2°C and 20°C AT significantly expanded the LC width more and had longer return times than the 38°C AT (p < .05). Viscosity comparisons showed higher viscosity eye drops significantly expanded LC width more than lower viscosity eye drops (p < .05). CONCLUSIONS: This study found that lower temperature and higher viscosity of eye drops had tendency to result in a wider expansion of the LC width. Additionally, the return time to baseline for LC width tended to be longer with eye drops of lower temperature and higher viscosity. This finding could be helpful in advancing future research on tear dynamics.

Intraoperative quantitative crystalline lens nuclear opacities analysis based on crystalline lenSx platform.

PURPOSE: The main objective is to quantify the lens nuclear opacity using spectral-domain optical coherence tomography (SD-OCT) and to evaluate its association with Lens Opacities Classification System III (LOCS-III) system, lens thickness (LT), and surgical parameters. The secondary objective is to assess the diagnostic model performance for hard nuclear cataract. METHODS: This study included 70 eyes of 57 adults with cataract, with 49 (70%) and 21 (30%) in training and validation cohort, respectively. Correlations of the average nuclear density (AND) /maximum nuclear density (MND) with LOCS-III scores, LT, and surgical parameters were analyzed. Univariate and multivariate logistic regression analysis, receiver operating characteristic curves and calibration curves were performed for the diagnostic of hard nuclear cataract. RESULTS: The pre-operative uncorrected distance visual acuity (UDVA), intraocular pressure (IOP), mean axial length (AL), and LT were 1.20 ± 0.47 log MAR, 15.50 ± 2.87 mmHg, 27.34 ± 3.77 mm and 4.32 ± 0.45 mm, respectively. The average nuclear opalescence (NO) and nuclear colour (NC) scores were 3.61 ± 0.94 and 3.50 ± 0.91 (ranging from 1.00 to 6.90), respectively. The average AND and MND were 137.94 ± 17.01 and 230.01 ± 8.91, respectively. NC and NO scores both significantly correlated with the AND (rNC = 0.733, p = 0.000; rNO = 0.755, p = 0.000) and MND (rNC = 0.643, p = 0.000; rNO = 0.634, p = 0.000). In the training cohort, the area under the curve (AUC) of the model was 0.769 (P < 0.001, 95%CI 0.620-0.919), which had a good degree of differentiation (Fig. 2a). The calibration curve showed good agreement between predicted and actual probability. CONCLUSION: The nuclear density measurement on SD-OCT images can serve as an objective and reliable indicator for quantifying nuclear density.

The role of multimodal imaging in characterization and monitoring of choroidal neovascularization secondary to angioid streaks.

BACKGROUND: To characterize and monitor choroidal neovascularisation (CNV) secondary to angioid streaks (AS) using multimodal imaging and to compare the results with conventional fluorescein angiography (FA). METHODS: A total of 11 eyes with CNV secondary to AS were included in this retrospective study. Multimodal morphological and functional assessment, including spectral-domain optical coherence tomography (SD-OCT), spectral-domain optical coherence tomography angiography (SD-OCTA), and fundus autofluorescence (FAF), were used to assess for evidence of CNV activity and compared with conventional FA. Morphological features of CNV were analyzed and treatment was continuously monitored using SD-OCT and SD-OCTA. RESULTS: Our results showed that SD-OCTA provided reliable results for the detection of secondary CNV in AS that were comparable to conventional FA. With SD-OCTA, a total of 13 CNVs were detected in 11 eyes and analyzed by means of outer retinal choriocapillaris depth (ORCC) segmentation and the corresponding B-scans. Twelve of the 13 CNVs were classified as active and therefore required treatment. For treatment monitoring during intravitreal therapy (IVT), SD-OCTA was found to be a valuable diagnostic tool over a mean follow-up of 76 weeks. CONCLUSIONS: Our study demonstrates that SD-OCTA can be routinely used to identify ill-defined CNV without dye-based angiography, especially in cases of CNV secondary to AS, where Bruch's membrane (BM) defects limit the diagnostic value of FA. Our results showed that non-invasive multimodal imaging facilitates sufficient CNV monitoring and treatment guidance. Further studies are warranted to provide more evidence in this rare retinal disease.

Diagnostic Utility of Swept-Source OCT-Based Biometry and Fundus Photographs Compared to Spectral Domain OCT in Center-Involving Diabetic Macular Edema.

PURPOSE: This study was aimed to evaluate the agreement between the swept-source optical coherence tomography (SS-OCT)-based biometry, fundus photographs, and their combination, in comparison to the gold standard spectral-domain optical coherence tomography (SD-OCT) for the detection of center-involving diabetic macular edema (CI-DME). METHODS: We conducted a retrospective cross-sectional study involving 55 subjects (78 eyes) diagnosed with diabetic macular edema (DME) detected clinically and on SD-OCT (Carl Zeiss Meditec AG). Post-mydriatic 45-degree color fundus photograph (Crystal-Vue NFC-700), 1 mm macular scan obtained from SS-OCT-based biometry (IOL-Master 700), and macula cube scan obtained from SD-OCT was used to detect and grade DME into CI-DME and NCI-DME. RESULTS: Our findings revealed that SS-OCT-based biometry was noted to have a high sensitivity of 1 (0.94-1.00) and a specificity of 0.63 (0.31-0.89) in detecting CI-DME compared to the gold standard (SD-OCT). When combined with data from fundus photographs, specificity decreased to 0.32 (0.15-0.53). Fundus photographs alone exhibited a low sensitivity of 0.52 (0.38-0.64) and a specificity of 0.45 (0.16-0.76) in CI-DME detection. CONCLUSION: In conclusion, SS-OCT-based biometry can be used as an effective tool for the detection of CI-DME in diabetic patients undergoing cataract surgery and can serve as a screening tool in centers without SD-OCT facilities.

Diabetic Macular Edema (DME); Center Involving Diabetic Macular Edema (CI-DME); Non-Center Involving Diabetic Macular Edema (NCI-DME); Swept-Source Optical Coherence Tomography (SS-OCT); Spectral-Domain Optical Coherence Tomography (SD-OCT); Anti-Vascular Endothelial Growth Factor (Anti-VEGF); Central Retinal Thickness (CRT); Intra Retinal Fluid (IRF); Sub Retinal Fluid (SRF); Diabetic Retinopathy (DR); Non Proliferative Diabetic Retinopathy (NPDR); Proliferative Diabetic Retinopathy (PDR); Best Corrected Visual Acuity (BCVA); Glycosylated hemoglobin (HbA1c); Mean Spherical Error (MSE); Standard Deviation (SD); Positive Predictive value (PPV); Predictive value (PPV); Negative predictive value (NPV); Area under the Curve (AUC).