En-face Optical Coherence Tomography Images Research Articles

Imaging the Area of Internal Limiting Membrane Peeling after Macular Hole Surgery.

Background: The aim of this study was to compare en-face optical coherence tomography (OCT) imaging and confocal scanning laser ophthalmoscopy (cSLO) imaging at different wavelengths to identify the internal limiting membrane (ILM) peeling area after primary surgery with vitrectomy and ILM peeling for macular hole (MH). Methods: In total, 50 eyes of 50 consecutive patients who underwent primary surgery with vitrectomy and ILM peeling for MH were studied. The true ILM rhexis based on intraoperative color fundus photography was compared to the presumed ILM rhexis identified by a blinded examiner using en-face OCT imaging and cSLO images at various wavelengths. To calculate the fraction of overlap (FoO), the common intersecting area and the total of both areas were measured. Results: The FoO for the measured areas was 0.93 ± 0.03 for en-face OCT, 0.76 ± 0.06 for blue reflectance (BR; 488 nm), 0.71 ± 0.09 for green reflectance (GR; 514 nm), 0.56 ± 0.07 for infrared reflectance (IR; 815 nm) and 0.73 ± 0.06 for multispectral (MS). The FoO in the en-face OCT group was significantly higher than in all other groups, whereas the FoO in the IR group was significantly lower compared to all other groups. No significant differences were observed in FoO among the MS, BR, and GR groups. In en-face OCT, there was no significant change in the ILM peeled area measured intraoperatively and postoperatively (8.37 ± 3.01 vs. 8.24 ± 2.81 mm2; p = 0.8145). Nasal-inferior foveal displacement was observed in 38 eyes (76%). Conclusions: En-face OCT imaging demonstrates reliable postoperative visualization of the ILM peeled area. Although the size of the ILM peeling remains stable after one month, our findings indicate a notable inferior-nasal shift of the overall ILM peeling area towards the optic disc.

Macular hole with epiretinal proliferation: diagnostic value of en-face optical coherence tomography and clinical characteristics.

To elucidate the clinical features and surgical outcomes of full-thickness macular hole (FTMH) with epiretinal proliferation (EP) diagnosed by both en-face and B-mode optical coherence tomography (OCT). This retrospective cohort study classified idiopathic FTMHs into two groups, based on B-scan and en-face OCT imaging: FTMH with EP (EP group) and without EP (non-EP group). The preoperative features, as well as postoperative outcomes up to 12months, were compared between the two groups. Among 318 eyes of idiopathic FTMH that met the inclusion criteria, 59 eyes (18.6%) were in the EP group, and others were in the non-EP group. In 9 eyes (15.3%) out of the EP group, EP was not detected in the preoperative B-mode OCT but was identified through the en-face OCT. Baseline features showed a higher male proportion (47.5% vs. 27.8%, P = 0.005) and a lower incidence of vitreofoveal traction (P < 0.001) in the EP group than in the non-EP group. The EP group showed worse visual recovery than the non-EP group (- 0.23 vs. - 0.41 logarithm of the minimum angle of the resolution at 12months, P = 0.001). The en-face OCT enhances diagnostic accuracy of EP in FTMH eyes, especially in the case with smaller extent of EP. Eyes with FTMH with EP showed a worse visual recovery than FTMH without EP.

Safety Results for Geographic Atrophy Associated with Age-Related Macular Degeneration Using Subretinal Cord Blood Platelet-Rich Plasma

PurposeTo evaluate the safety of subretinal injection of cord blood platelet-rich plasma (CB-PRP) and its possible effect in eyes affected by geographic atrophy (GA) associated with dry age-related macular degeneration (d-AMD). DesignInterventional, open-label study started in January 2021 with at 12 months of follow-up (the Si.Cord Study). This study was a single-center, nonrandomized, sequential-assigned clinical trial conducted in Rome, Italy, at Fondazione Policlinico Universitario Agostino Gemelli IRCCS (ClinicalTrials.gov_NCT04636853). Subjects, Participants, and ControlsThirteen patients (26 eyes) with bilateral d-AMD-related GA were enrolled. One eye from each patient (with more advanced GA) underwent CB-PRP treatment, and the fellow eye was considered the control. All patients participated in follow-up at 12 months. InterventionAll 13 eyes received 23-gauge (G) vitrectomy and subretinal injection of CB-PRP using a 41-G needle. Main Outcomes and MeasuresBest corrected visual acuity (BCVA) with Early Treatment Diabetic Retinopathy Study (ETDRS) letters, central macular thickness using optical coherence tomography (OCT) and atrophic area measured on en-face OCT images were assessed at baseline, 1, 3, 6 and 12 months. ResultsThe BCVA in the treated group was 34.46 ± 20.8 ETDRS at baseline; 40.84 ± 20.52 at 1 month; 40.07 ± 20.34 at 3 months; 39.38 ± 19.84 at 6 months and 35.84 ± 18.38 at 12 months. In the untreated group, the BCVA was 53 ± 21.1 ETDRS letters at baseline; 51.54 ± 20.99 at 1 month; 46.62 ± 19.47 at 3 months; 46.85 ± 18.58 at 6 months and 43.92 ± 17.97 at 12 months (two-way ANOVA: interaction of treatment by eye or time, p= -0.084). Central macular thickness (CMT) did not show a significant inter-eye difference at 12 months (p=0.97). The atrophic geographic areas tended to increase in both treated and fellow eyes at 12 months (p<0.0001). No inflammatory reaction, endophthalmitis, retinal detachment, uveitis, or other complications due to the subretinal injection of CB-PRP were observed during the follow-up. ConclusionsSubretinal injection of CB-PRP could be safely used for d-AMD in its GA form. Despite its safety, a larger cohort of patients, and probably a new way of administration, will be needed in order to understand whether the CB-PRP could have a role in the GA treatment.

Evaluation of epiretinal membrane formation after scleral buckling for treating rhegmatogenous retinal detachment: En face optical coherence tomography image-based study.

To assess epiretinal membrane (ERM) formation, severity, and the associated risk factors after scleral buckling using en face optical coherence tomography (OCT) images. Medical records of 61 consecutive patients (66 eyes) with rhegmatogenous retinal detachment who underwent scleral buckling were retrospectively reviewed. Posterior vitreous detachment (PVD) was determined based on B-scan OCT images. En face OCT images were used to visualize the ERM and retinal folds. ERM formation was identified by comparing en face images pre- and post-surgery. The maximum depth of the retinal folds (MDRF) was measured using en face imaging to objectively assess traction strength. ERM formation occurred in 15 (22.7%) eyes at the final visit; the foveal pit was preserved in all cases. Parafoveal retinal folds were present in 5 (7.6%) eyes, with a mean MDRF of 21.8 ± 12.6µm. No significant difference was observed in best-corrected visual acuity (logarithm of the minimal angle of resolution) between the ERM formation (-0.019 ± 0.128) and non-ERM formation (-0.001 ± 0.213) groups at the final visit (P = 0.593; Mann-Whitney U test). Multivariate logistic regression analysis revealed that older age and the presence of PVD were significant risk factors for ERM formation (odds ratio 1.07, 95% confidence interval 1.01-1.14, P = 0.032; odds ratio 5.26, 95% confidence interval 1.06-26.10, P = 0.042; respectively). ERM occurred in 22.7% of cases but was mild and did not affect visual acuity. Older age and the presence of PVD are risk factors for ERM formation.

Factors associated with intrachoroidal cavitation and sinkhole formation in eyes with glaucomatous visual-field defects

PurposeTo investigate factors associated with intrachoroidal cavitation (ICC) and sinkhole formation in eyes with glaucomatous visual-field defects.MethodsThis retrospective, cross-sectional study enrolled a total of 2808 eyes of 1482 patients who were diagnosed/treated for glaucoma and underwent swept-source optical coherence tomography (OCT). We first determined the prevalence of ICCs and sinkholes and their locations. Next, we selected one eye from each patient and compared the clinical characteristics of eyes with and without ICCs. Finally, in eyes with ICCs, we compared the clinical characteristics of eyes with and without sinkholes. Blood flow (BF), represented by laser speckle flowgraphy–measured tissue-area mean blur rate (MBR), was measured in the temporal optic nerve head (ONH), temporal peripapillary chorioretinal atrophy (PPA) zone, and in the ICC zone. ICC area and angle were analyzed in OCT en-face images. Mean deviation and total deviation in the central area (TD-central) were measured with Humphrey visual-field testing.ResultsA total of 86 eyes (3.1%) had ICCs and 52 eyes (1.9%) had sinkholes. ICC eyes had a lower spherical equivalent and longer axial length (AL) than non-ICC eyes (P < 0.05). Patients with eyes with sinkholes were more elderly and had worse best-corrected visual acuity, worse TD-central, a larger ICC, and lower tissue-area MBR in the temporal ONH, temporal PPA zone, and ICC zone (P < 0.05).ConclusionIn eyes with glaucoma, AL elongation might be linked to ICC formation. Sinkhole formation might be associated with ICC enlargement, impaired ocular BF, and impaired retinal structure and function involving the central area.

CHOROIDAL VASCULAR DENSITY IN DIABETIC RETINOPATHY ASSESSED WITH SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY.

We aimed to assess choroidal vascularity by diabetic retinopathy (DR) stage using the choroidal vascular density (CVD) obtained from swept-source optical coherence tomography en-face images. This prospective, cross-sectional, multicenter study included patients from Niigata City General Hospital and Saiseikai Niigata Hospital between October 2016 and October 2017. Choroidal vascular density was obtained by binarizing swept-source optical coherence tomography en-face images of patients with diabetes and those with DR, patients without DR, and healthy age-matched volunteers. Patients were allocated to the healthy control (n = 28), no DR (n = 23), nonproliferative DR (NPDR) without diabetic macular edema (DME) (n = 50), NPDR + DME (n = 38), and proliferative DR (PDR) or any previous treatment with panretinal photocoagulation (n = 26) groups. Investigation of the choriocapillaris slab level indicated that the no DR group had significantly high CVD values ( P < 0.05), and the PDR groups had significantly low CVD values ( P < 0.01). Investigation of the large choroidal vessel level indicated that the NPDR + DME and PDR groups had significantly lower CVD values than the control group ( P < 0.05 and P < 0.01, respectively). We found that at the choriocapillaris slab level, the no DR group had a higher CVD and the NPDR with DME and PDR groups had a lower CVD than the control group. At the level of the large choroidal vessels, the NPDR with DME and PDR groups had a lower CVD than the control group. There were significant differences in choroidal vasculature found using CVD obtained from swept-source optical coherence tomography en-face images of patients with diabetes and DR.

Structural-vascular-functional correlation in type 2 non-proliferative macular telangiectasia

PurposeTo correlate the structural-vascular-functional changes in type 2 non-proliferative macular telangiectasia (MacTel) using optical coherence tomography (OCT) angiography (OCTA).MethodsIn this retrospective study, OCTA and enface OCT image analysis of eyes with confirmed diagnosis of non-proliferative type 2 MacTel was performed. The ‘MacTel area’ was calculated by marking the outer boundary of an area affected by MacTel on superficial (SCP) and deep capillary plexus (DCP) on OCTA images and photoreceptor layer (PRL) on enface OCT scan. At every follow-up OCTA scan visit, best-corrected visual acuity, MacTel area and stage of disease was documented. Analyses between disease stage, MacTel area and logMAR visual acuity was carried out.ResultsIn total, 38 single-visit OCTA scans of 22 patients were included. The mean age was 58.9 ± 10.98 years. An increase in disease severity stage correlated positively with MacTel area in SCP segmentations slab (r = 0.334; p = 0.04) and logMAR visual acuity (r = 0.338; p = 0.038). No correlation in the DCP area or PRL area (p > 0.05) was noted with disease stage. A statistically significant positive correlation was noted between the structural changes in PRL layer with vascular changes in SCP (p = 0.021) but not in DCP (p = 0.199). No correlation of visual acuity with changes in SCP, DCP or PRL was noted (p > 0.05).ConclusionOCTA is a useful adjunct for determining disease severity in type 2 non-proliferative MacTel by assessing the structural-vascular changes. Further longitudinal studies need to be considered in future for understanding the pathomechanism of retinal damage in type 2 MacTel.

The effect of axial length to basement-membrane opening to fovea distance on optical coherence tomography.

Optical Coherence Tomography (OCT) lateral scaling is influenced by axial length (AL). There is a need to incorporate a method to correct this measurement bias for accurate lateral OCT measurement. To identify the correlation of optic-nerve-to-fovea distance measurement to AL by OCT) as an internal factor for lateral scaling. Using Heidelberg Spectralis OCT, distance from the basement membrane opening at the optic disc margin to the centre of the fovea (BMO-fovea distance) was measured in 135 eyes (77 subjects, ages 25-85). These measurements were correlated with AL measurements from Zeiss IOLMaster 700 using linear regression before and after correction for ocular magnification. Statistical analysis including Shapiro-Wilk test for normality, Pearson correlation, and multivariate analysis of the association between disc-fovea distance and AL was performed using Wizard statistical software for mac. After lateral scaling, the mean distance between the fovea and BMO was 3.60 ± 0.25 mm (median: 3.59; range 3.07-4.23 mm). There was a significant positive correlation between AL and Bennett's formula-corrected BMO-fovea distance (p <0.001, r = 0.354). While there is significant variability in BMO-fovea distances, it is positively correlated with AL. A standard method is needed to improve the lateral scaling measurements in order to unify the results for enface OCT imaging.

Dissociated optic nerve fiber layer-like appearance indicating an internal limiting membrane defect associated with an epiretinal membrane: two case reports

BackgroundWe report for the first time a way to predict the 2-dimensional extension of an internal limiting membrane (ILM) defect by detecting the area with dissociated optic nerve fiber layer (DONFL)-like spots in the preoperative optical coherence tomography (OCT) en-face images.Case presentationsCase 1 was a 67-year-old man with metamorphopsia and decreased vision in his right eye. His best-corrected visual acuity (BCVA) was 20/100, with a pterygium, a moderate nuclear cataract, and an epiretinal membrane (ERM). Case 2 was a 73-year-old man with metamorphopsia and decreased vision in his left eye. His BCVA was 20/25, with a moderate nuclear cataract and an ERM. Both patients underwent simultaneous cataract surgery and pars plana vitrectomy with ERM and ILM peeling. Brilliant Blue G staining, performed before ERM and ILM peeling, revealed an unstained area. A careful evaluation of the area showed that it was not covered by either the ERM or ILM. A postoperative evaluation of the preoperative OCT images obtained from these cases showed DONFL-like low-brightness spots in the ILM defect area on the OCT en-face images.ConclusionsOCT en-face images may indicate the area of the ILM defect. To avoid iatrogenic damage to the retinal nerve fiber layer by touching/pinching it with forceps, detecting areas with DONFL-like spots in the preoperative OCT en-face images may be useful to predict an ILM defect.

Comparison of choroidal hyperreflective spots on optical coherence tomography images between both eyes of normal subjects.

Advancement of optical coherence tomography (OCT) technology allows for better in vivo visualization of the choroidal architecture, which comprises vessels and stroma. However, most OCT studies using image binarization methods have focused only on choroidal vessels represented by dark pixels. This study aimed to compare the distribution of choroidal hyperreflective spots on swept-source OCT (SS-OCT) images between both eyes of normal subjects. In this observational comparative study, we included SS-OCT images of healthy subjects, which were prospectively obtained to compare images among the devices. SS-OCT images acquired using PLEX Elite 9000 and DRI-OCT Triton were analyzed. En-face OCT images were obtained at five different depth positions of the inner choroid at the macula. The mean reflectivity of the choroidal slabs, the number, total area, and circularity of hyperreflective spots were quantitatively compared between the devices and between both eyes of the same subjects. In 30 eyes of 15 healthy subjects, the mean reflectivity of the choroidal slabs varied with the scan depth on both devices (P<0.001 and P<0.001). Hyperreflective spots were similarly distributed in the images from both devices, but at different depths. The number and area of hyperreflective spots in the second and third layers of the DRI-OCT Triton were positively correlated with those in the fourth and fifth layers of the PLEX Elite 9000, respectively (all P<0.05). The intraclass correlation coefficients (ICC) for the area of hyperreflective spots were excellent for the third slab of the DRI-OCT and the fifth slab of the PLEX Elite (ICC =0.798; 95% CI, -0.576-0.904). The number and area of hyperreflective spots were correlated between both eyes in the third, fourth and fifth layers on DRI-OCT Triton (all P<0.05) and in the first, second, and fifth layers on PLEX Elite 9000 (all P<0.05). Hyperreflective spots in en-face images from two different SS-OCT devices were similarly observed between both eyes of the same person. The distributions of spots between the two eyes of the same person were correlated. These findings suggest that the distribution of hyperreflective spots on the choroid reflects the choroidal characteristics of the subject.

EN-FACE IMAGING OF ATYPICAL EPIRETINAL TISSUE IN LAMELLAR MACULAR HOLE.

To elucidate the significance of en-face optical coherence tomography imaging of atypical epiretinal tissue (AET) in the lamellar macular hole (LMH). This study involved 29 eyes of 29 patients who underwent surgical treatment for LMH with AET. Best-corrected visual acuity, metamorphopsia assessment (M-score), and optical coherence tomography were evaluated before and 6 months after surgery. The novel en-face optical coherence tomography parameters, such as the area of AET and hyperreflective fringe, were correlated with clinical factors before and after LMH surgery. Preoperatively, hyperreflective fringe was noted in 25 (86.2%) patients. The splitting of the inner retina, disruption of the ellipsoid zone, the extent of foveal cavitation, symptom duration, and change in best-corrected visual acuity were correlated with the area of AET (all P < 0.05). Multivariate regression analysis revealed that a larger area of AET was associated with longer symptom duration and less improvement in postoperative vision (all P < 0.05). The area of AET may represent the chronicity of LMH and is significantly associated with visual outcomes after LMH surgery. This novel en-face optical coherence tomography parameter can be used as a predictive factor for surgical outcomes in LMH with AET.

Analysis of microstructural changes in an X-linked juvenile retinoschisis patient harboring RS1 G668A mutation by en-face optical coherence tomography imaging

<br>Juvenile X-linked retinoschisis (JXLR) is an X-linked recessive retinal dystrophy caused by retinoschisin (<i>RS1</i>) gene mutations. The current study reports and describes the cumulative findings of en-face OCT for a 7-year-old JXLR patient harboring a hemizygous pathogenic <i>RS1</i> mutation (c.G668A; p.Cys223Tyr), where residue 223 is vital for cellular adhesion. Fundoscopy showed cart-wheel appearance at macula. Further, en-face OCT revealed characteristic schitic lesions in the ganglion cell layer, inner plexiform layer, inner nuclear layer, and outer plexiform layer. Our report adds to the Indian <i>RS1</i> mutation spectrum and casts insights into the schisis microstructure using en-face imaging.<br>

Perivenular fern-like paracentral acute middle maculopathy. En-face optical coherence tomography imaging

Perivenular fern-like paracentral acute middle maculopathy. En-face optical coherence tomography imaging

Preoperative imaging optimized for epiretinal membrane surgery

BackgroundTo compare imaging modalities for visualizing primary epiretinal membrane (ERM) with each other and with intraoperative digital images (IDI) after blue staining.MethodsThe records of consecutive patients operated for primary ERM over a 12-month period were retrospectively reviewed. Preoperative imaging included color fundus photography (CFP), En Face spectral-domain optical coherence tomography (OCT), 45° infrared- (IR) and blue-reflectance (BR) scanning laser ophthalmoscopy. All images were qualitatively analyzed and scored from 0–4 according to the ability to visualize ERM details (0 = no visible ERM or vessel contraction, 1 = vessel contraction, 2 = retinal folds, 3 = ERM limits, 4 = elevated ERM edge). The preoperative ERM morphology was then compared to that seen on the IDI acquired after 1-min blue dye staining when available.ResultsSeventy eyes were included. The highest score for ERM visualization was obtained on BR and En Face OCT. A score of 3 or 4 was obtained in 68.5%, 62.1%, 17.9% and 13.6% of cases on En Face OCT, BR, CFP and IR images, respectively. IDI were available for 20 eyes, and showed a similar ERM morphology compared to preoperative images in most cases: a negative staining pattern corresponded to a plaque on En face OCT in 91% of eyes. However, IDI failed to show the ERM edges in 37.5% of cases.ConclusionERM morphology was better visualized preoperatively by BR and En Face OCT, in a similar way to the IDI after staining. Future intraoperative visualization systems could integrate both imaging modalities overlaid with the IDI for guiding ERM removal instead of staining.

Recurrent Episodes with Serous Retinal Detachment and Anterior Uveitis in a Patient Using Nivolumab (Anti -PD-1 Antibody) Therapy: A case report and literature review

ABSTRACT Aim: Nivolumab is an immune checkpoint inhibitor that has recently been widely used for metastatic malignant melanoma. We report a case who developed multiple different ocular immune-related side effects (iRAEs) related to nivolumab. Case Presentation: A 60-year-old man on nivolumab treatment for metastatic malignant melanoma developed a decrease in vision in both eyes several days after the third infusion. The initial best-corrected visual acuity (BCVA) was counting fingers in both eyes. Slit-lamp examination revealed no abnormal findings in the anterior segment of both eyes. Posterior segment evaluation showed serous retinal detachment, including the whole macula and inferior retina in both eyes, and optical coherence tomography (OCT) confirmed the diagnosis. On en face OCT analysis, hyperautoflorescent dots were noticed on the whole macular region but more intense at the inferior quadrant corresponding to serous retinal detachment. On Fluorescein Angiography (FA), no abnormality was observed. Oral corticosteroid treatment was administered. Subretinal fluid resolved one week after treatment in the right eye and two weeks after treatment in the left eye. BCVA was 20/20 in both eyes at first month of treatment. After that, oral corticosteroid treatment was tapered and stopped at the end of the second month. The patient was followed monthly. Two months after the treatment patient presented with an anterior uveitis episode with mild vision loss. Slit-lamp examination revealed 3+ cells in the anterior chamber and posterior synechia in both eyes. Posterior segment examination was normal. The patient was treated with topical corticosteroid and cycloplegic for two months. Hyperautoflorescent dots formed with serous detachment disappeared six months after the onset of serous detachment, and they did not occur during anterior uveitis episodes. Conclusions: This is the first clinical report of nivolumab-associated ocular iRAEs presenting with recurrent episodes presenting with serous retinal detachment and anterior uveitis. En face OCT imaging may help diagnose and show the activity of the posterior segment manifestation. When managed properly and observed closely following general and ocular conditions, it is possible to held iRAEs and overcome them by oral and/or topical corticosteroid therapy without interrupting the nivolumab.

Quantification of Early and Intermediate Age-related Macular Degeneration Using OCT "en face" Presentation.

Early and intermediate age-related macular degeneration (AMD) results in drusen deposits under the retinal pigment epithelium (RPE). These early stages of AMD exhibit different risks of progressing to late AMD. To date, early AMD has been classified and quantified by fundus photography. This does not appear to be sensitive enough for clinical trials studying the impact on drusen. SD-OCT with two-dimensional rendering of the segmented slices analysed allows for en face imaging of the drusen. The present trial studied the potential of quantifying early and intermediate AMD by en-face optical coherence tomography (OCT). Thirty-one eyes of 29 patients in different stages of early and intermediate AMD were studied. To this end, fundus photographs (Kowa VX-10i, Kowa, Tokyo, Japan) and en-face OCT images (RTVue XR Avanti, Optovue, Inc., Fremont, CA, USA) were taken. First, different segmentation levels (6 µm underneath the RPE, on the RPE, 6 µm and 9 µm above the RPE) and different layer thicknesses (5 µm, 10 µm, 20 µm and 30 µm) were analysed to determine the best segmentation for visualising drusen. Drusen were marked manually and their number and surface area calculated. This analysis was then compared with the standardised drusen analyses on fundus photography. Additional changes in early and intermediate AMD such as pigment epithelial detachments (PEDs) and subretinal drusenoid deposits (SDD) as well as small atrophies were also documented and compared. The best segmentation for delineating the drusen on the en-face OCT images was found to be a segmentation 6 µm underneath the RPE with a slice thickness of 20 µm. Comparison of drusen quantification on en-face OCT images with the standardised drusen analysis on fundus photography revealed particularly good similarity. Other changes in early and intermediate AMD, such as PEDs, SDD and small atrophies, were easier to assess on the en-face OCT images. The analysis and quantification of drusen from en-face OCT images with 20 µm segmentation at 6 µm underneath the RPE allows differentiated quantification of various drusen characteristics. Moreover, other changes in early and intermediate AMD can also be analysed. In future observational and clinical trials, this could help quantify drusen.

The sensitivity and specificity of retinal and choroidal folds to distinguish between mild papilloedema and pseudopapilledema.

To determine if the presence or absence of retinal and choroidal folds on SD-OCT imaging can distinguish between mild papilloedema and pseudopapilledema. Cross-sectional cohort study METHODS: Subjects with optic disc elevation (Frisen grades 1 and 2 only) were eligible to be enrolled prospectively. Pseudopapilledema was defined as a lack of change in optic disc appearance between two visits <6 months apart, and papilloedema was defined as change in optic disc appearance between two visits <6 months apart determined by review of fundus photographs by a masked neuro-ophthalmologist. Three masked neuro-ophthalmologists independently reviewed en face and axial optical coherence tomography (OCT) images of the optic nerve of the study subjects for the presence or absence of retinal and choroidal folds. Concordance was determined when there was agreement between at least 2 of the 3 observers. Forty-five subjects (78 eyes) met inclusion criteria. There were 32 eyes with papilloedema and 46 eyes with pseudopapilledema. Choroidal and/or retinal folds were detected in 38% of eyes (12/32) with papilloedema and 19.6% of eyes (9/46) with pseudopapilledema. Post-hoc analyses eliminated six questionable cases of pseudopapilledema that had ancillary testing suggestive of elevated intracranial pressure and resulted in one remaining eye (2%) with more certain pseudopapilledema that was found to have folds. En face OCT imaging was more sensitive (71%) in detection of folds than axial OCT imaging (57%). Choroidal and/or retinal folds on OCT are commonly observed in patients with mild papilloedema and are uncommon in those with pseudopapilledema. The presence of folds on OCT in patients presenting with disc elevation suggests papilloedema.

Characteristics of secondary epiretinal membrane due to peripheral break

This study aimed to investigate morphological differences between idiopathic epiretinal membrane (ERM) and secondary ERM due to peripheral break (SEPB) and to identify clinical characteristics in eyes with SEPB to facilitate peripheral retinal examination. The retrospective cross-sectional study involved 93 consecutive eyes in 91 patients who underwent ERM removal surgery. Eyes were divided into two groups: the macular pucker group and the idiopathic ERM group. En-face Optical Coherence Tomography (OCT) images, fundus photographs, severity of metamorphopsia (M-score) and clinical characteristics of each group were compared. ERM extent and eccentricity (ratio of the shortest and longest distances from the foveal center to the boundary) were obtained through en-face OCT imaging. Fundus photographs were used to judge whether the membrane was turbid or not. Patients with SEPB were younger than patients with idiopathic ERM (61.3 ± 7.5 vs. 66.6 ± 8.3 years; p < 0.05). Preoperative M-score and myopic refractive error, axial length were also significantly higher in the macular pucker group than in the idiopathic ERM group (all p < 0.05). There was no difference in ERM extent between the two groups. The incidence of ERM eccentricity was 23 of the 34 eyes (67.6%) in the SEPB group and 26 of the 59 eyes (44.1%) in the idiopathic ERM group (p < 0.05). The incidence of turbid ERM was 18 of the 34 eyes (52.9%) in the SEPB group and 10 of the 59 eyes (16.9%) in the idiopathic ERM group (p < 0.01). The SEPB group, compared with the idiopathic ERM group, tended to have eccentric, turbid ERM at a younger age and with more severe metamorphopsia and myopic refractive error.

Depth-resolved variations in visibility of retinal nerve fibre bundles across the retina in enface OCT images of healthy eyes.

Recent developments in optical coherence tomography (OCT) technology enable direct enface visualisation of retinal nerve fibre bundle (RNFB) loss in glaucoma. However, the optimum depth at which to visualise RNFBs across the retina is unknown. We aimed to evaluate the range of depths and optimum depth at which RNFBs can be visualised across the retina in healthy eyes. The central±25° retina of 10 healthy eyes from 10 people aged 57-75years (median 68.5years) were imaged with spectral domain OCT. Slab images of maximum axial resolution (4μm) containing depth-resolved attenuation coefficients were extracted from 0 to 193.5μm below the inner limiting membrane (ILM). Bundle visibility within 10 regions of a superimposed grid was assessed subjectively by trained optometrists (n=8), according to written instructions. Anterior and posterior limits of RNFB visibility and depth of best visibility were identified for each grid sector. Effects of retinal location and individual eye on RNFB visibility were explored using linear mixed modelling with likelihood ratio tests. Intraclass correlation coefficient (ICC) was used to measure overall agreement and repeatability of grading. Spearman's correlation was used to measure correlation between depth range of visible RNFBs and retinal nerve fibre layer thickness (RNFLT). Retinal location and individual eye affected anterior limit of visibility (χ2(9) =58.6 and 60.5, both p<0.0001), but none of the differences exceeded instrument resolution, making anterior limit consistent across the retina and different eyes. Greater differences were observed in the posterior limit of visibility across retinal areas (χ2(9) =1671.1, p<0.0001) and different eyes (χ2(9) =88.7, p<0.0001). Optimal depth for visualisation of RNFBs was around 20µm below the ILM in most regions. It varied slightly with retinal location (χ2(9) =58.8, p<0.0001), but it was not affected by individual eye (χ2(9) =10.7, p=0.29). RNFB visibility showed good agreement between graders (ICC 0.89, 95%CI 0.87-0.91), and excellent repeatability (ICC 0.96-0.99). Depth range of visible RNFBs was highly correlated with RNFLT (ρ=0.9, 95%CI: 0.86-0.95). The range of depths with visible RNFBs varies markedly across the healthy retina, consistently with RNFLT. To extract all RNFB information consistently across the retina, slab properties should account for differences across retinal locations and between individual eyes.

Case report: the first case of unilateral retinal pigment epithelium dysgenesis in China

BackgroundUnilateral retinal pigment epithelium dysgenesis (URPED) is a rare condition and is characterized by a unilateral and solitary lesion in the peripapillary region. The lesion presents with central atrophy, peripheral fibrosis, and hyperplastic changes in the retinal pigment epithelium (RPE). Herein, we report the first case of URPED in a Chinese individual using multimodal imaging techniques such as en-face optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA).Case presentationA 10-year-old girl presented with 20/40 vision in her left eye. Presented as a solitary, unilateral, large and yellowish-white lesion, with fringe-like margins was observed in the posterior pole and lower middle periphery of the left eye continuous with the optic nerve, indicated URPED. Infrared fundal (IR) images showed that the fringe-like contour of the lesion was visible, with diffuse hyperreflective signals specifically in the fovea, while with peripheral dark spots, having a typical leopard-spot like appearance. Fundus autofluorescence (FAF) revealed a markedly scalloped lesion containing a hypoautofluorescence area mixed with an isoautofluorescence area. Spectral-domain optical coherence tomography (SD-OCT) revealed the outer segments of photoreceptors presented with an inhomogeneous signal in the fovea, with a weak local signal. The ellipsoid and interdigitation zones were thinner than normal, while the RPE/Bruch’s complex was not flat, with locally visible protrusions. En-face OCT image at the level of the RPE zone showed a mottled hyperreflective signal with peripheral hyporeflective spots, fringe-like margin lesions. OCTA of the avascular area of the fovea in the superficial, deep, and outer retinal layers appeared to be oval in shape, the choroid capillary layer revealed an increase in the density of the choroidal vasculature in the fovea.ConclusionsThis is the first report on URPED in China. Both en-face OCT and OCTA were essential in observing and studying the disease. Further investigation is required to better define the en-face OCT and OCTA features of URPED and clarify the disease characteristics and prognosis.