Head-Tilt Perfluorocarbon-Air Exchange Technique With Heads-Up Surgery for Giant Retinal Tear-Associated Retinal Detachments to Prevent Retinal Slippage Without Using Silicone Oil.

PURPOSE: To report the efficacy of the perfluorocarbon liquid-air exchange with a head tilt toward the area of the giant retinal tear (GRT) using the heads-up surgery system to prevent retinal slippage during vitrectomy for GRT-associated retinal detachments. METHODS: Eyes with GRT-associated retinal detachments underwent vitrectomy using the heads-up surgery system and perfluorocarbon liquid-air exchange with a head tilt 45° toward the GRT to put the area of the tear in the most dependent position to drain fluid. This technique was evaluated to prevent retinal slippage. RESULTS: Five consecutive cases were evaluated. The mean GRT size was 174° (range, 90-240°) and the GRT was located temporally in two eyes, nasally in two eyes, and superiorly in one eye. The tamponade types were air (1 eye), sulfur hexafluoride (3 eyes), and perfluoropropane (1 eye). Our technique was feasible and the slippage did not occur in any eyes. Although the microscope needed to be tilted for optimal fundus visualization, heads-up surgery allowed surgeons to maintain ergonomic postures. Retinal reattachment was achieved with a single surgery in all eyes. CONCLUSION: The head-tilt perfluorocarbon liquid-air exchange with heads-up surgery is useful in preventing retinal slippage in eyes with GRT.

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

BACKGROUND: We 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 PRESENTATIONS: Case 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. CONCLUSIONS: OCT 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.

Anterior segment Scheimpflug imaging for detecting primary angle closure disease.

PURPOSE: To evaluate the capability of anterior segment Scheimpflug imaging for detecting primary angle closure disease (PACD): primary angle closure suspect, primary angle closure, and primary angle closure glaucoma, using cutoff points derived from reference databases of healthy subjects. METHODS: Eighty-seven patients with PACD and 49 age-matched control subjects were included. We evaluated the sensitivity and specificity of anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA) to differentiate patients with PACD from controls. Additionally, the study's raw data was analyzed via receiver operating characteristic curves for comparison. RESULTS: One standard deviation from the normative data's mean values was used as the cutoff point and yielded a sensitivity and specificity of 96.2% and 92.6% for ACD, 97.1% and 75.9% for ACV, and 93.3% and 72.2% for ACA, respectively. Receiver operating characteristic analysis of the raw data showed the area under the curve to be 0.984, 0.975, and 0.931 for ACD, ACV, and ACA, respectively. CONCLUSIONS: Our study demonstrated that the parameters of anterior segment Scheimpflug imaging, particularly ACD, accurately discriminate PACD. This was the first study to validate the device's normative data in a separate population. With its high reproducibility, ease of use, non-invasiveness, and speed, anterior segment Scheimpflug imaging is a potentially powerful screening tool for PACD.

Steatocystoma simplex of the lacrimal caruncle: a case report.

BACKGROUND: This is the third reported case of a steatocystoma simplex in the lacrimal caruncle. CASE PRESENTATION: A 60-year-old male presented with a history of a slowly progressing mass in the right lacrimal caruncle since several years before his initial visit. At the first examination, a yellowish, relatively smooth surface mass was observed in the right lacrimal caruncle. The caruncular mass was completely removed under local anesthesia. The pathological findings of this mass were consistent with a steatocystoma. At the 6-month follow-up, there was no sign of recurrence or development of the steatocystoma or any other masses. CONCLUSION: Although steatocystoma simplex rarely occurs in the lacrimal caruncle, it needs to be considered as a possible diagnosis for patients with a mass lesion in the caruncle.

Orbital Floor Thickness in Adult Patients With Isolated Orbital Floor Fracture Lateral to the Infraorbital Nerve.

Orbital floor fractures commonly occur just medial to the junction of the infraorbital nerve and the inferior orbital fissure because the bone is thinner posteromedial to the infraorbital nerve than that lateral to the nerve. The authors previously reported 2 pediatric patients with an isolated orbital floor fracture lateral to the infraorbital nerve. The authors showed that, on the unaffected side of these patients, the lateral portion of the orbital floor was thinner than the medial portion. In the present study of 5 adult patients with an isolated orbital floor fracture lateral to the infraorbital nerve, the authors compared the thickness of the medial and lateral portions of the orbital floor with that of the infraorbital nerve on the unaffected side. Computed tomographic images showed that the bone lateral to the infraorbital nerve was somewhat thinner than bone in the medial portion. Because the orbital structures are generally symmetrical, our findings suggest that these 5 patients had partial anatomical weakness in the lateral portion of the infraorbital nerve on the affected side, resulting in an isolated orbital floor fracture lateral to the infraorbital nerve.

Fundus examination using a wide-angle viewing system and intraocular illumination through the corneal incision during cataract surgery: a case series.

PURPOSE: To report a new technique for fundus examination using a wide-angle viewing system combined with intraocular illumination without accessing the vitreous cavity. STUDY DESIGN: Retrospective case series METHODS: Consecutive patients with atopic dermatitis-related cataracts who underwent standard cataract surgery and the novel fundus examination technique were included. After phacoemulsification, the anterior and posterior chambers were filled with ocular viscoelastic devices. A 27-gauge endo-illumination probe was inserted into the anterior chamber through a corneal incision made for cataract surgery. The fundus examination was performed with a wide-angle viewing system and scleral indentation. If any retinal breaks/detachments were detected, they were treated simultaneously. Finally, an intraocular lens was implanted. RESULTS: Ten patients (13 eyes) were included (mean age 26.8 years; 9 men). Retinal breaks were detected in 5 eyes (38%); 2 of the 5 had rhegmatogenous retinal detachment (RRD) (15%). Intraoperative cryopexy was performed for 3 eyes with retinal breaks, while 2 eyes with RRD underwent a scleral buckling procedure (SBP) during the same surgery. There were no intra- or postoperative complications, including posterior capsule damage. The average surgical time was 22 minutes for cases requiring only fundus examination and about 28 and for eyes with cryopexy and 80 minutes for SBP. CONCLUSION: The described technique may reduce the disadvantages of creating scleral incisions and provide comparable visibility to inserting the illuminator into the vitreous cavity.

En Face OCT Detects Preretinal Abnormal Tissues Before and After Internal Limiting Membrane Peeling in Eyes with Macular Hole.

PURPOSE: To assess preretinal abnormal tissue (PAT) using en face OCT in eyes with idiopathic macular holes (MHs). DESIGN: Retrospective, observational study. PARTICIPANTS: Patients with MH who received 6 × 6-mm spectral-domain-OCT scans. METHODS: Preretinal abnormal tissue was detected by en face OCT images with a custom slab, defined with an anterior boundary of 6 µm anterior to the internal limiting membrane (ILM) and a posterior boundary at 3 µm posterior to the ILM. The PAT was defined as any abnormal tissues observed in en face OCT. MAIN OUTCOME MEASURES: Characteristics of preoperative and postoperative PAT. RESULTS: Sixty eyes with MH from 60 patients were included. Fifty-one eyes underwent preoperative analysis, and 46 eyes underwent postoperative examination. Before surgery, 48 (94%) eyes had a mean (standard deviation [SD]) PAT of 6.6 (9.8) mm2. The corresponding cross-sectional OCT showed PAT consisting of epiretinal proliferation, epivascular glia, and a preretinal hyperreflective band. Preretinal abnormal tissue was contiguous to the hole (peri-MH PAT) in 12 eyes (24%), whereas others (36 eyes, 76%) had a scattered distribution (extrafoveal PAT). The area of PAT was greater in eyes with a peri-MH PAT than in eyes with an extrafoveal PAT (P < 0.0001). Compared to the eyes with the extrafoveal PAT, the eyes with the peri-MH PAT were associated with men (P = 0.0059) and worse baseline visual acuity (VA) (P = 0.0002). In eyes with ILM peeling (42 eyes), postoperative PAT proliferation was observed from the edge of the ILM peeling toward the periphery over a 1-year follow-up. The mean (SD) area of PAT at 2 weeks after surgery was 3.4 (3.6) mm2 and increased to 12.1 (6.4) mm2 at 12 months (P < 0.0001). However, no PAT increase was observed in 4 eyes that underwent vitrectomy without ILM peeling. The postoperative PAT size was not associated with the postoperative VA. CONCLUSIONS: En face OCT revealed PAT in most eyes with MHs. Peri-MH PAT was associated with worse VA and was seen more frequently in male patients. Postoperative PAT proliferation may be triggered by ILM peeling, but it is not associated with worse VA.

Practical Utility of Widefield OCT Angiography to Detect Retinal Neovascularization in Eyes with Proliferative Diabetic Retinopathy.

PURPOSE: To assess the real clinical utility of widefield OCT angiography (WF-OCTA) for detecting retinal neovascularization (RNV) in eyes with proliferative diabetic retinopathy (PDR). DESIGN: A retrospective cross sectional study. PARTICIPANTS: Consecutive eyes clinically suspected of PDR by physicians at a tertiary eye center between March 2021 and November 2022. METHODS: All eyes underwent ultrawidefield fluorescein angiography (UWF-FA) (California, Optos) and WF-OCTA (S1, Canon) with a 23 × 20 mm scan area. Two independent graders detected individual RNV lesions using UWF-FA and used them as the ground truth. Widefield OCT angiography images were first evaluated to determine whether the images successfully illustrated retinal vasculature, regardless of the image quality index or the presence of vitreous hemorrhage. The graders then identified the RNV lesions with WF-OCTA. We detected RNV by utilizing both the entire retinal slab, including flow signals in the retina, and the custom vitreoretinal interface slab, defined as flow signals from 20 µm below the internal limiting membrane (ILM) to 2000 µm above the ILM. We evaluated the applicability to real clinical practice by not correcting segmentation errors. MAIN OUTCOME MEASURES: The success rate of imaging and the detection rate of RNV using WF-OCTA. RESULTS: Initially, 69 consecutive patients who underwent UWF-FA were identified. Of these, 114 eyes from 57 (83%) patients underwent both UWF-FA and WF-OCTA. Of the 114 eyes, 108 (95%) produced gradable WF-OCTA images. Using UWF-FA, the graders identified 175 RNV lesions in 40 eyes. Widefield OCT angiography achieved a sensitivity of 95% and specificity of 88% for detecting eyes with RNV. At the level of individual RNV lesions, graders detected 156 RNV lesions with WF-OCTA, with 118 of these confirmed by UWF-FA (true positive). Among the 57 false-negative lesions, the primary causes were being out of the scan range (26 lesions) and segmentation errors (21 lesions). CONCLUSIONS: Widefield OCT angiography imaging had a high success rate, achieving a sensitivity of 95% and a specificity of 88% for detecting eyes with RNV in a real clinical setting. Despite a 67% detection rate for individual RNV lesions, WF-OCTA may serve as a valuable noninvasive method for RNV detection in eyes with diabetic retinopathy. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Efficacy of Vitrectomy With Tamponade Versus No Tamponade for Myopic Traction Maculopathy: A Multicenter Study (SCHISIS Report No.1).

PURPOSE: To evaluate the influence of tamponade on the visual and anatomic outcomes of pars plana vitrectomy for myopic traction maculopathy (MTM). DESIGN: Multicenter, retrospective clinical cohort study. METHODS: Consecutive eyes that underwent vitrectomy for advanced MTM with tamponade of air, sulfur hexafluoride (SF6), or perfluoropropane (C3F8) or without tamponade with a minimum follow-up of 12 months were included. Main outcome measures included postoperative visual acuity (VA) at 12 months in eyes with vs without tamponade. RESULTS: We included a total of 193 eyes (193 patients) in this study; 136 eyes (70%) treated with tamponade were compared with 57 eyes (30%) treated without tamponade. Baseline characteristics did not differ significantly between the groups. Both groups showed significant visual improvement at 12 months (both P < .001). However, postoperative visual acuity and visual improvement at 12 months were significantly better (P = .003 and P = .028, respectively) in eyes without tamponade, although the MTM in these eyes without tamponade took longer to resolve (P = .039). Retinal thickness and the ellipsoid zone were more preserved in eyes without tamponade (P < .001 and P = .001, respectively). Complications such as macular holes did not differ between the groups. A novel imaging finding of "schisis bending (accordioning)" was identified during MTM resolution. CONCLUSIONS: Vitrectomy either with or without tamponade for MTM was effective in improving vision in this study. However, eyes without tamponade experienced even better visual improvement and preserved retinal anatomy, despite a longer schisis resolution time. Surgery without tamponade may achieve better visual outcomes.

Risk Factors and Outcomes of Postoperative Macular Hole Formation after Vitrectomy for Myopic Traction Maculopathy: SCHISIS Report No. 2.

PURPOSE: To evaluate the incidence, pathogenesis, risk factors, and treatment outcomes of postoperative macular hole (MH) after pars plana vitrectomy (PPV) for myopic traction maculopathy (MTM). DESIGN: Multicenter, interventional, retrospective case series. SUBJECTS: Consecutive eyes that underwent PPV for MTM with a minimum 6-month follow-up. METHODS: We investigated the characteristics and treatment outcomes of postoperative MH after MTM surgery. MAIN OUTCOME MEASURES: Incidence, risk factors, and anatomic and visual outcomes of postoperative MH. RESULTS: We included 207 eyes (207 patients) with a mean follow-up of 25.9 months. During follow-up, 24 (11.6%) eyes developed MH (10 with concurrent MH retinal detachment); 15 eyes within 30 days (early), 4 eyes between 31 and 180 days (intermediate), and 5 eyes after 180 days (late). Logistic regression analysis revealed male gender (odds ratio [OR], 2.917; 95% confidence interval [CI], 1.198-7.100; P = 0.018), thinner preoperative choroidal thickness (OR, 0.988; 95% CI, 0.976-1.000; P = 0.048), and use of indocyanine green for internal limiting membrane peeling (OR, 2.960; 95% CI, 1.172-7.476; P = 0.022) as significant risk factors for postoperative MH. Internal limiting membrane peeling with a fovea-sparing technique tended to protect against postoperative MH, but it was not statistically significant (P = 0.096), because 1 eye still developed MH. Postoperative MHs were treated by observation (6 eyes), in-office octafluoropropane (C3F8) gas injection (7 eyes), or PPV (11 eyes). Macular hole closure was achieved in 20 eyes (83%). The hole closure rate was 67% (4/6 eyes) after observation, 71% (5/7 eyes) after C3F8 gas injection, and 91% (10/11 eyes) after PPV. However, visual outcomes were significantly worse for eyes with postoperative MH than those without (0.38 ± 0.43 vs. 0.68 ± 0.46; P = 0.002). CONCLUSIONS: Postoperative MH may occur in 11.6% of patients with MTM at any time after surgery. Retreatment resulted in relatively favorable anatomic closure but unfavorable visual outcomes. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Alterations of retinal thickness measured by optical coherence tomography correlate with neurophysiological measures in diabetic polyneuropathy.

AIMS/INTRODUCTION: Diabetic polyneuropathy (DPN) and diabetic retinopathy (DR) are traditionally regarded as microvascular complications. However, these complications may share similar neurodegenerative pathologies. Here we evaluate the correlations in the severity of DPN and changes in the thickness of neuroretinal layers to elucidate whether these complications exist at similar stages of progression. MATERIALS AND METHODS: A total of 43 patients with type 2 diabetes underwent a nerve conduction study (NCS), a macular optical coherence tomography, and a carotid artery ultrasound scan. Diabetic polyneuropathy was classified according to Baba's classification using NCS. The retina was automatically segmented into four layers; ganglion cell complex (GCC), inner nuclear layer/outer plexiform layer (INL/OPL), outer nuclear layer/photoreceptor inner and outer segments, and retinal pigment epithelium (RPE). The thickness of each retinal layer was separately analyzed for the fovea and the parafovea. RESULTS: Fourteen patients were classified as having moderate to severe diabetic polyneuropathy. The thicknesses of the foveal and parafoveal INL/OPL increased in patients with diabetic polyneuropathy compared with patients without. The thickness of the parafoveal retinal pigment epithelium decreased in patients with diabetic polyneuropathy. The thinning of parafoveal ganglion cell complex and foveal and parafoveal retinal pigment epithelium were positively correlated with deterioration of nerve functions in the nerve conduction study, but the thickening of INL/OPL was positively correlated with the nerve function deterioration. The thinning of parafoveal ganglion cell complex and foveal retinal pigment epithelium were positively correlated with the thickening of the carotid intima-media. CONCLUSIONS: Depending on the progression of diabetic polyneuropathy, the ganglion cell complex and retinal pigment epithelium became thinner and the INL/OPL became thicker. These retinal changes might be noteworthy for pathological investigations and for the assessment of diabetic polyneuropathy and diabetic retinopathy.

Optimal Display Positions for Heads-Up Surgery to Minimize Crosstalk.

Purpose: To determine optimal display positions during heads-up surgery (HUS) to minimize crosstalk. Methods: Three three-dimensional (3D) displays were analyzed to evaluate the relationship between display position and amount of crosstalk. First, the 3D displays were calibrated to show a completely white image in the right eye and completely black image in the left eye. Images were captured through the polarized filter, which corresponded to the left-eye image. The amount of crosstalk in the left eye was measured as white areas on the black background that originated from the right-eye image. The amount of crosstalk was measured at different display distances and heights to estimate the non-crosstalk display positions for each display. Results: Varying amounts of crosstalk (0%-70.3%) were observed for different display distances and heights. The crosstalk almost always started from the corner of the display, although the starting area varied according to the type of display. The minimum distance of non-crosstalk position was 1.26 meters away from display 1, 1.24 meters away from display 2, and 1.8 meters away from display 3. With regard to display height, the optimal center-of-display heights for displays 1, 2, and 3 were 72 mm below, 18 mm above, and 101 mm above eye level, respectively. Conclusions: The amount of crosstalk differed according to display positions and displays. Translational Relevance: The optimal HUS display settings differ among displays; therefore, each surgeon should carefully evaluate individual display characteristics before using HUS in practice.

Risk Factors, Onset, and Progression of Epiretinal Membrane after 25-Gauge Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment.

PURPOSE: To investigate the risk factors, onset timing, and progression of epiretinal membrane (ERM) after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD). DESIGN: Retrospective, comparative case series. PARTICIPANTS: The study included 322 eyes of 322 patients who underwent primary PPV for RRD from January 2014 through December 2016. METHODS: Patients underwent OCT before and 1, 3, 6, and 12 months after surgery. Patients showing hyperreflective lines above the inner retinal surface and deformation of the foveal pit were defined as ERM cases. Those with loss of the foveal pit were defined as advanced ERM cases. A multivariate logistic regression model was used to evaluate the risk factors of postoperative ERM. The onset timing of ERM and progression to advanced ERM after PPV for RRD were also investigated based on the OCT findings. MAIN OUTCOME MEASURES: Risk factors, onset timing, and progression of ERM after PPV for RRD. RESULTS: In the multivariate analysis, the incidence of postoperative ERM was significantly higher in eyes with preoperative vitreous hemorrhage (VH; P = 0.011) and without internal limiting membrane (ILM) peeling (P < 0.001). Among the patients who underwent ILM peeling, none demonstrated postoperative ERM. Postoperative ERM was observed in 39 of the 322 eyes (12.1%) within 1 year after surgery; in 30 of these eyes (76.9%), ERM occurred within 3 months after surgery. Advanced ERM was observed in 12 eyes (12/39 eyes [30.8%]). Among these, 9 eyes (9/12 eyes [75%]) showed progression within 3 months after surgery. CONCLUSIONS: Preoperative VH can increase the occurrence of postoperative ERM. In most patients with ERM, the occurrence and progression were detected relatively early after surgery; therefore, in high-risk patients, careful follow-up is encouraged until 3 months after surgery.

Visual Acuity Recovery After Macular Hole Closure Associated With Foveal Avascular Zone Change.

Purpose: To evaluate changes in the foveal avascular zone (FAZ) area during the postoperative period of macular hole (MH) surgery using the optical coherence tomography angiography (OCTA) and to investigate its relationship to visual acuity (VA). Methods: Consecutive unilateral MH patients who underwent successful MH closure with at least a six-month observation period were studied retrospectively. To evaluate the FAZ area, OCTA images were obtained at the preoperative visit, the first postoperative visit, and the six-month visit. Main outcome measures were postoperative FAZ change and its relationship to VA change after MH closure. Results: Fifty-one cases were studied. The FAZ area was 0.42 ± 0.11 mm2 at the preoperative visit, 0.25 ± 0.091 mm2 at the first postoperative visit and 0.31 ± 0.11 mm2 at the six-month visit. FAZ area at the first postoperative visit was significantly smaller (P < 0.0001) than at the preoperative visit. FAZ area at the six-month visit was significantly greater (P < 0.0001) than at the first postoperative visit, but still significantly smaller (P = 0.0002) compared to the normal fellow eye. The postoperative FAZ area enlargement from the first postoperative visit to the six-month visit was significantly correlated with the postoperative VA recovery (P = 0.0322) and the postoperative photoreceptor reconstruction (P = 0.0213). Conclusions: The FAZ area once decreases along with MH closure; it thereafter increases toward the normal value over time. The postoperative FAZ change was correlated with the VA recovery. Translational Relevance: This study suggests that the postoperative FAZ area enlargement might be a potential biomarker indicating foveal reconstruction after MH closure.

A Rare Form of Corneal Opacity Associated with Spondyloepiphyseal Dysplasia Congenita.

A 13-year-old Japanese female diagnosed with spondyloepiphyseal dysplasia congenita (SEDC) was referred for ophthalmologic evaluation. Examination with slit-lamp and optical coherence tomography revealed bilateral thin cornea with diffuse corneal opacity which was localised at the posterior stromal depth in the central cornea. Unlike the two previously reported cases of diffuse and nodular patterns of corneal opacity in SEDC, the current case exhibited a rare form of corneal opacity. SEDC is one of the type II collagenopathies, characterised by dwarfism because the mutations in COL2A1 prevent bone growth. Although the existence of type II collagen has not been reported in the human corneal stroma, the aetiology of the opacity in the corneal stroma in SEDC type II collagenopathy is of interest.

Sequential Observations of Conversion from Nonischemic to Ischemic Central Retinal Vein Occlusion Using Optical Coherence Tomography Angiography.

We report the sequential changes of retinal vessels observed by optical coherence tomography angiography (OCTA) in a case of nonischemic central retinal vein occlusion (CRVO) that converted to ischemic CRVO. An 81-year-old woman visited our Retina Clinic because of visual acuity loss in the left eye. Funduscopic examination showed venous tortuosity and intraretinal hemorrhage in all four quadrants of the fundus. OCT showed macular edema. Fluorescein angiography (FA) and OCTA showed loss of small capillaries. Nonischemic CRVO was diagnosed. Antivascular endothelial growth factor (VEGF) treatment resolved the edema and improved visual acuity. However, during follow-up, capillary dropout was observed on OCTA, which gradually enlarged. Eventually, FA confirmed the conversion to ischemic CRVO. In this case, sequential observations using OCTA showed that nonischemic CRVO did not convert to ischemic CRVO abruptly but occurred stepwise. Additionally, vascular changes began around the veins and blood flow changes were observed more clearly in deep capillary plexus than in superficial capillary plexus.

Gap in Capillary Perfusion on Optical Coherence Tomography Angiography Associated With Persistent Macular Edema in Branch Retinal Vein Occlusion.

Purpose: To evaluate correlations between persistent macular edema associated with branch retinal vein occlusion (BRVO) and the macular perfusion status in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) using optical coherence tomography angiography (OCTA). Methods: Retrospective, case-control study. Twenty patients with BRVO followed for 12 months or more were enrolled. Persistent macular edema was defined as central retinal thickness exceeding 300 µm that persisted or recurred less than 3 months after the final treatment. We compared two groups (i.e., seven eyes with persistent macular edema and 13 eyes without macular edema). The macular perfusion status was evaluated using OCTA. We defined a gap vessel as a residual vessel in the SCP that existed simultaneously with capillary loss in the DCP. The gap vessels were determined by subtracting the vessel images of the DCP from the images of the SCP using an image processing technique. Results: In eyes with persistent macular edema, the area with gap vessels was significantly (P = 0.0013) larger than in eyes without macular edema (14.34% vs. 8.02%). Other factors evaluated (i.e., the area of the foveal avascular zone, superficial vessel density, and deep vessel density) did not differ significantly (P = 0.66, P = 0.23, P = 0.34, respectively) between the groups. Conclusions: The difference in capillary loss between the SCP and DCP can facilitate development of persistent macular edema in BRVO.