MULTIMODAL IMAGING IN NONEXUDATIVE CHOROIDAL NEOVASCULARIZATION: A Pilot Study of Status of Retinal Pigment Epithelium.

PURPOSE: To study the status of retinal pigment epithelium in nonexudative and active choroidal neovascularization (CNV) in neovascular age-related macular degeneration. METHODS: Only treatment-naïve neovascular age-related macular degeneration patients were enrolled in this prospective case-control study, including 17 eyes with nonexudative CNV (6 males and 11 females, 74.9 ± 10.0 years) and 28 eyes with active CNV (8 males and 20 females, 69.3 ± 6.8 years). All patients received a comprehensive ophthalmic examination, optical coherence tomography, dark-field scanning laser ophthalmoscopy, and fundus autofluorescence. The status of the retinal pigment epithelium was assessed with ImageJ software as the brightness of the CNV region on transillumination optical coherence tomography, dark-field scanning laser ophthalmoscopy, and fundus autofluorescence images. Choroidal neovascularization vessel density was measured based on optical coherence tomography angiography. RESULTS: The brightness of CNV region in nonexudative CNV was statistically significantly lower than in active CNV with both optical coherence tomography transillumination ( P = 0.004) and dark-field scanning laser ophthalmoscopy ( P = 0.0015). No difference in brightness of the CNV region between nonexudative and active CNV was found based on fundus autofluorescence ( P = 0.44). The vessel density of nonexudative CNV was statistically significantly higher than that of active CNV with a median value of 64.5% (95% confidential interval [CI] 53.4-79.0%) and 55.3% (95% CI 52.2-60.0%), respectively ( P = 0.05). CONCLUSION: Multimodal imaging revealed substantial alteration of the retinal pigment epithelium in active CNV but not in nonexudative CNV which correlates with the higher vessel density of nonexudative CNV.

Interocular asymmetry in distribution of leaks in central serous chorioretinopathy.

PURPOSE: To study interocular asymmetry in distribution of leaks in central serous chorioretinopathy (CSC). MATERIAL AND METHODS: Patients with unilateral CSC were included in this retrospective multicenter study. All patients received multimodal imaging. The prevalence of leaks within 1 disk diameter (DD) peripapillary area and the mean shortest distance between a leak and the optic disk edge was analyzed for the right and left eyes separately based on FA images. Clinical and morphological characteristics were collected and compared between eyes with a peripapillary leak and eyes with a leak elsewhere. RESULTS: In total, 152 eyes (77 right eyes and 75 left eyes) of 152 patients (128 males and 24 females) with a mean age of 45.2 ± 9.8 years were included. The mean distance from the leak to the edge of the optic disk was statistically significantly lower (p = 0.0003), and the prevalence of the leaks within the 1 DD-peripapillary area was higher in the left eye than in the right eye (32.1% versus 10.7%, respectively, p = 0.0017). The eyes with a peripapillary leak had a longer duration of the disease (p < 0.05), a wider area of retinal pigment epithelium alteration (p < 0.001), and a higher prevalence of outer retinal atrophy (p < 0.001) compared to the eyes with a leak elsewhere. CONCLUSION: The left eye showed closer location of the leak to the optic disk edge and higher prevalence of leaks within the peripapillary area. The cases with peripapillary leak commonly demonstrated characteristics of chronic CSC despite relative preservation of visual acuity.

Retro-mode scanning laser ophthalmoscopy in evaluation of peripheral retinal lesions.

AIM: To study the diagnostic potential of retro-mode scanning laser ophthalmoscopy (RM-SLO) for evaluation of peripheral retinal lesions. METHODS: Based on the results of indirect ophthalmoscopy, in this study, we included asymptomatic subjects with lattice retinal degeneration, retinal break, or subclinical retinal detachment and subjects without any peripheral retinal lesions. All participants' fundus periphery was examined with RM-SLO over 360° for the presence of peripheral retinal lesions in a masked fashion. Detection rate for retinal breaks and detachments were compared between indirect ophthalmoscopy and RM-SLO. RESULTS: Twenty-six subjects (52 eyes, 15 males and 11 females, 34.8 ± 11.8 years) were included in the peripheral retinal lesion group and 25 individuals (50 eyes, 10 males and 15 females, 42.8 ± 14.5 years) were included in the group without peripheral retinal lesions. Among the patients with peripheral retinal lesions detected with indirect ophthalmoscopy in at least one eye, RM-SLO categorized 20.7% (p = 0.031) more eyes as having subclinical asymptomatic retinal detachment or at least one retinal break. Additionally, RM-SLO demonstrated 55.0% (p = 0.001) more subclinical retinal detachments and 31.5% (p = 0.002) more asymptomatic retinal breaks. CONCLUSIONS: RM-SLO showed high potential in diagnosing peripheral retinal lesions and may be a useful additional diagnostic tool for the patients who demonstrate peripheral retinal lesions with indirect ophthalmoscopy.

Structural en face optical coherence tomography imaging for identification of leaky microaneurysms in diabetic macular edema.

PURPOSE: To study the correspondence between fluorescein angiography (FA) and structural en face optical coherence tomography (OCT) in the identification of leaky microaneurysms in diabetic macular edema (DME). METHODS: Fourteen eyes of eight patients with DME (6 males and 2 females, mean age 67.3 ± 8.5) were included. For all eyes, a 6 × 6 mm structural en face image of the middle retina was obtained and superimposed on a FA image. The reflectivity, capsulation, and association with intraretinal cystic fluid (IRCF) of microaneurysms on en face were evaluated depending on their leaky status on FA. RESULTS: Out of the 320 leaky microaneurysms evaluated, 280 (89.0 ± 8.2%) coincided with those on en face OCT image. Twenty-nine (10.6 ± 6.9%) and 20 (6.5 ± 7.8%) out of all leaky microaneurysms were hyperreflective and demonstrated capsular appearance, respectively. A majority of leaky microaneurysms (97.9 ± 3.2%) were associated with IRCF. From 146 microaneurysms which were found only on en face images, 130 (88.2% ± 15.7%) were hyperreflective, 33 (23.9% ± 15.6%) demonstrated capsular structure, and 13 (9.2% ± 15.0%) demonstrated no associated IRCF. After exclusion of microaneurysms of the inner retina, 95.4 ± 5.4% of leaky microaneurysms were identified on en face image. En face imaging demonstrated 83.5% sensitivity and 89.4% specificity (the area under the curve 0.87) in the identification of leaky microaneurysms. CONCLUSIONS: Structural en face imaging is comparable to FA in identification of leaky microaneurysms in diabetic macular edema. Moderate reflectivity, the absence of capsular structure, and neighboring intraretinal cystic fluid indicate leaky microaneurysms.

Improved analysis of foveal avascular zone area with optical coherence tomography angiography.

PURPOSE: To investigate the relationship between the foveal avascular zone (FAZ) and the inner nuclear layer (INL)-free zone in the center of the fovea in order to provide an improved approach to evaluation of the FAZ area with optical coherence tomography angiography (OCTA). METHODS: Thirty-six healthy individuals (36 eyes) and 15 age-matched patients (15 eyes) with nonproliferative diabetic retinopathy (nPDR) were included in this study. The FAZ, as well as INL-free zone, was measured on OCTA images. The FAZ area, INL-free zone area, and the ratio of the INL-free zone area to the FAZ area were compared between healthy subjects and nPDR patients. RESULTS: The mean FAZ area in healthy subjects and nPDR patients was 0.33 ± 0.1 mm2 and 0.41 ± 0.19 mm2 (p < 0.05), respectively. The mean INL-free zone area in healthy subjects and nPDR patients was 0.33 ± 0.07 mm2 and 0.25 ± 0.09 mm2 (p > 0.05), respectively. The INL-free zone area to the FAZ area ratio in healthy subjects and nPDR patients was 1.08 ± 0.25 and 0.56 ± 0.18 (p < 0.001), respectively. Receiver operating characteristic analysis showed that the INL-free zone area to the FAZ area ratio had a higher area under curve (0.94; 80.0% sensitivity and 97.2% specificity) compared to the FAZ area (0.61; 40.0% sensitivity and 94.4% specificity) for differentiating nPDR from healthy eyes. CONCLUSION: This study showed that analysis of the FAZ based on the ratio of the INL-free zone area to the FAZ area has better accuracy compared to the conventional FAZ area measurement in differentiating eyes with mild to moderate nPDR without any structural abnormalities in the fovea from healthy eyes.

Involvement of Sclera in Lattice Retinal Degeneration: An Optical Coherence Tomography Study.

The aim of the study was to evaluate the local status of the sclera in lattice retinal degeneration. Patients with lattice degeneration, snail-track degeneration, or horseshoe retinal breaks were included. One lesion of a single eye in each patient was captured with cross-sectional optical coherence tomography (OCT) along and across the greatest lesion dimension. The maximum height of scleral indentation was measured and compared between different lesion types and between lattice lesions with and without retinal breakage or local detachment. The correlation between the maximum height of the scleral indentation of lattice lesions and the age of the patients was calculated. Seventy-five eyes of 75 patients (44.4 ± 14.7 years; 35 males and 30 females) were included. OCT showed variable local scleral indentation in 52 out of 55 (94.5%) lattice lesions, in five out of nine (55.5%) snail-tack lesions, and in three out of eleven (27.3%) horseshoe breaks. The maximum scleral indentation within lattice lesions, snail-tack lesions, and horseshoe breaks was 227.2 ± 111.3, 22.0 ± 49.2, and 88.5 ± 48.4 µm, respectively (p < 0.001 for snail-tack lesions and horseshoe breaks compared to lattice lesions). Lattice lesions with retinal breaks and/or local retinal detachment had statistically significantly lower scleral indentation than those without (p = 0.01). The height of the scleral indentation of lattice lesions was positively correlated with patient age (r = 0.51, p = 0.03). In conclusion, scleral indentation is one of the hallmarks of lattice retinal degeneration and may be associated with a reduced risk of rhegmatogenous retinal detachment.

Photoreceptor outer segment layer thinning as a biomarker in acute central serous chorioretinopathy.

Background: The photoreceptor outer segment (PROS) layer demonstrates focal thinning above the fluorescein leakage in acute central serous chorioretinopathy (CSC); however, the nature of this phenomenon is not known. Objectives: To study the relationship between the PROS layer and thickness of the outer retinal layers above the fluorescein leakage in newly diagnosed acute CSC. Design: Single-center retrospective study. Methods: All participants received multimodal imaging, including fluorescein angiography and optical coherence tomography. Thickness of PROS, outer nuclear layer (ONL), and ONL-outer plexiform layer (OPL) complex was measured above the leakage and outside the leakage within the area of neurosensory detachment. The number of intraretinal hyperreflective foci of the outer retina was counted. The correlation between PROS thickness and ONL, OPL-ONL complex thickness, and the number of intraretinal hyperreflective foci was calculated. Results: Fifty eyes of 48 patients (38 males and 10 females, 43.8 ± 10.6 years) with a mean symptom duration of 1.4 ± 1.3 months were included. PROS thickness above the fluorescein leakage showed a statistically significant correlation with ONL thickness, OPL-ONL complex thickness, and the number of hyperreflective foci in the outer retina, 0.57, 0.60, and -0.46, respectively (p < 0.001). Measuring the extent of PROS thinning above the leakage in newly diagnosed CSC allowed to predict self-resolution of subretinal fluid. The greatest linear dimension of PROS thinning showed an area under the receiver operating curve (ROC) curve of 0.98. The cases without PROS thinning had the fastest resolution of subretinal fluid. Conclusion: PROS thinning above the fluorescein leakage in acute CSC is associated with thinning of the outer retinal layers and reveals mild outer retinal atrophy. The absence of PROS thinning predicts faster resolution of CSC.

Efficacy and Safety of Cataract Surgery-Assisted Selective Laser Trabeculoplasty: A Pilot Study.

Purpose: To evaluate the intraocular pressure (IOP)-lowering effect and safety of selective laser trabeculoplasty (SLT) with same-day cataract surgery which we named cataract surgery-assisted selective laser trabeculoplasty (CAST) compared to conventional SLT and cataract surgery as standalone procedures. Methods: Patients with primary open-angle glaucoma and cataract were included in this prospective interventional study. All patients received either a CAST procedure, standard SLT, or standard cataract surgery. IOP was assessed at baseline and at months 1, 2, 3, and 6. Topical IOP-lowering medication was canceled during the follow-up if necessary. Results: Twenty-nine, twenty-seven, and thirty eyes received the CAST procedure, SLT, and standard cataract surgery, respectively. There was no statistically significant difference in age, male-to-female ratio, or baseline IOP between groups (P > 0.05). The mean IOP reduction at 6 months after the CAST procedure, SLT, and standard cataract surgery was -7.3 ± 3.8 mmHg, -3.8 ± 3.7 mmHg, and -0.7 ± 3.7 mmHg, respectively (P < 0.001). Eleven out of 29 (37.9%) and 5 out of 27 (18.5%) eyes achieved 30% reduction of IOP after the CAST procedure and SLT, respectively. No eyes achieved 30% reduction of IOP at the end of the follow-up in cataract surgery group. The median number of IOP-lowering medications cancelled after the CAST procedure was 1.0 (range, 0-3). No antiglaucoma medication was cancelled after SLT or cataract surgery. No adverse events were registered in patients who received the CAST procedure. Conclusion: At 6-month follow-up, the CAST procedure had a significantly greater IOP-lowering effect and reduction of topical antiglaucoma medication than SLT or cataract surgery alone.

Spotlight on Lattice Degeneration Imaging Techniques.

Lattice degeneration (LD), routinely diagnosed with indirect ophthalmoscopy, is one of the most common and clinically significant peripheral retinal findings. In this review, we have summarized the data on currently available imaging techniques which help to improve diagnosis and our understanding of LD pathogenesis. Ultra-wide field imaging provides reliable color fundus capturing for the primary diagnosis of LD and may also be used as a screening tool. Wide-field imaging can be used for targeted documentation of LD lesions using true colors and with minimal optical distortions. Information on the status of the vitreoretinal interface, including detection of retinal holes, detachments, and vitreous tractions, can be obtained with peripheral structural optical coherence tomography (OCT) or scanning laser ophthalmoscopy in retro-mode. These techniques clarify the associated risks of rhegmatogenous retinal detachment. Fundus autofluorescence can provide details on atrophic changes. However, the risk of retinal detachment by means of this technique requires further investigation. OCT angiography may be successfully performed for some lesions. Taken together, OCT and OCT angiography demonstrate thinning of the choroid, alteration of local choroidal microcirculation, and, in severe lesions, involvement of the sclera. OCT angiography confirms loss of retinal microcirculation within LD lesion, which was previously shown with fluorescein angiography. In conclusion, despite relatively simple primary diagnosis, imaging of LD lesions remains challenging due to their peripheral localization. However, several new strategies, including ultra-wide field imaging, peripheral OCT, and scanning laser ophthalmoscopy, make LD imaging possible on a routine basis, improving diagnosis and understanding of LD pathogenesis.

Pulsatile Ocular Blood Flow Registered with Optical Coherence Tomography Angiography in Patients with High Intraocular Pressure.

Purpose: To present a series of cases demonstrating pulsatile ocular blood flow registered with optical coherence tomography angiography (OCTA) and to describe the clinical characteristics of this phenomenon. Methods: Seven primary open-angle glaucoma patients (eight eyes) were included, with a median age of 67.0 years (range, 39-73 years), who demonstrated alternating hypointense bands of OCTA flow signal on the macular scan at increased intraocular pressure (IOP). All patients received comprehensive ophthalmic examination, OCTA examination with RTVue-XR, and infrared video scanning laser ophthalmoscopy. Changes in retinal microcirculation were assessed on the raw OCTA scans as well as the resultant vessel density maps before and after IOP reduction. Results: Median IOP in study eyes was 39.0 mmHg (range, 36-58 mmHg). Hypointense bands of OCTA flow signal were associated with arterial pulsation on video scanning laser ophthalmoscopy in all eyes and agreed with the heart rate and resulted in a spotted grid pattern of hypoperfusion on vessel density maps in seven eyes. Median vessel density in superficial capillary plexus and deep capillary plexus was 32.4% and 47.2%, respectively, at high IOP, and increased statistically significantly to 36.5% (P = 0.016) and 50.9% (P = 0.016), respectively, after IOP reduction. Conclusions: Alternating hypointense flow signal bands on OCTA scans are possibly caused by the pulsatile character of retinal blood flow during the cardiac cycle in eyes with high IOP and may reflect the imbalance between IOP and perfusion pressure. This phenomenon is responsible for the reversible decrease of vessel density at high IOP.

Association of Resolved Paracentral Acute Middle Maculopathy Lesions with Diabetic Retinopathy.

Purpose: To evaluate the association between paracentral acute middle maculopathy (PAMM) lesions and diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA). Methods: Thirteen diabetic patients without DR, 13 patients with mild nonproliferative DR (NPDR), 18 patients with moderate-to-severe NPDR, and 20 patients with proliferative DR (PDR) were included in this retrospective study. For each patient, 6 mm × 6 mm macular OCTA scans of both eyes were reviewed for the presence of acute and resolved PAMM lesions. Results: Among diabetic patients with and without DR, 49 (94.9%) and 7 (53.8%) patients demonstrated small resolved PAMM lesions, respectively. The odds ratio for the presence of resolved PAMM lesions in the eye with DR compared to the eye of diabetic patient without DR was 21.8 (P < 0.001, 95% confidence interval 7.0-67.8). In the mild NPDR group, moderate-to-severe NPDR group, and the PDR group, 11 (84.6%), 18 (100.0%), and 20 (100.0%) patients demonstrated resolved PAMM lesions, respectively. There was a statistically significant increasing prevalence of PAMM lesions as the severity of DR increased (P < 0.001). Conclusion: Small resolved PAMM lesions are a common form of ischemic retinal lesions in DR.

Lattice Degeneration Imaging with Optical Coherence Tomography Angiography.

Purpose: To describe a series of cases of lattice degeneration of the retina imaged with optical coherence tomography angiography (OCTA). Methods: Four eyes of four patients were included and evaluated with green reflectance using a confocal scanning laser ophthalmoscopy and OCTA. In each case, the microcirculation of the retina and choriocapillaris within the lesion, as well as choroidal thickness beneath the lesion, were assessed. Results: OCTA showed regional loss of retinal perfusion and rarefication of the choriocapillaris network within the lesion and the presence of venous collectors in the choroid beneath the lesion. The choroid was substantially thinner beneath the lesion compared to the adjacent normal region. Cross-sectional OCT scans showed retinal thinning, vitreal adhesion, atrophic holes, and subretinal fluid within the lesions. Conclusion: Lattice degeneration is characterized by significant local changes in retinal and choroidal microcirculation which may play an important role in the pathophysiology of lattice degeneration.

Choriocapillaris alteration in patients with paracentral acute middle maculopathy.

PURPOSE: To evaluate with optical coherence tomography angiography the status of the choriocapillaris in the eyes of patients with resolved paracentral acute middle maculopathy (PAMM). METHODS: Nine patients with unilateral resolved PAMM, 14 age-matched healthy individuals, and 16 age-matched patients with unilateral retinal vein occlusion (RVO) were included. The choriocapillaris flow area, and the number of choriocapillaris flow voids was compared between the eyes of healthy individuals, both eyes of the PAMM patients, and the fellow eyes of unilateral RVO patients. RESULTS: The number of choriocapillaris flow voids in the unaffected eyes of PAMM patients was statistically significantly higher than in the eyes of healthy individuals (p < 0.001) and in the fellow eyes of unilateral RVO patients (p = 0.022). The choriocapillaris flow area in the unaffected eyes of PAMM patients was statistically significantly lower than in the eyes of healthy individuals (p < 0.001) and in the fellow eyes of unilateral RVO patients (p = 0.019). There was no difference in the status of the choriocapillaris between two eyes of PAMM patients. CONCLUSION: Eyes of patients with resolved PAMM have a substantial decrease of choriocapillaris perfusion.

Retinal Macrophage-Like Cells as a Biomarker of Inflammation in Retinal Vein Occlusions.

Aim: To study the macrophage-like cells (MLC) of the inner retinal surface in eyes with retinal vein occlusions (RVO) and the association of MLC with clinical characteristics of RVO. Methods: In this retrospective cross-sectional study, the medical records and multimodal imaging data of treatment-naïve patients with unilateral RVO and no abnormalities of vitreoretinal interface electronic were reviewed and analyzed. To visualize MLC, structural projections of optical coherence tomography (OCT) angiography scans within a slab between two inner limiting membrane segmentation lines (with 0 and −9 µm offset) were evaluated. The density of MLC was calculated and compared between affected and fellow eyes of each patient with regards to OCT and clinical characteristics of RVO. Results: Thirty-six eyes (twenty-eight branch RVO and eight central RVO) of 36 patients (21 males and 15 females, mean age 48.9 ± 9.8 years) were included. The density of MLC in affected eye was statistically significantly higher than that of the fellow eye, 8.5 ± 5.5 and 4.0 ± 3.6 cells/mm2, respectively (p < 0.001). The MLC density in the affected eye had a statistically significantly correlation with that of the fellow eye (r = 0.76, p = 0.0001), but with none of the OCT and clinical characteristics of the affected eye apart from the presence of subfoveal fluid. Eyes with subfoveal fluid had a statistically significantly higher mean number of MLC than that of eyes without subfoveal fluid, 12.6 ± 6.3 and 6.9 ± 4.0 cells/mm2, respectively (p = 0.009). Conclusion: The number of MLC on the inner retinal surface increases in RVO eyes which may reflect the activation of inflammatory pathways.

Dark-Field Scanning Laser Ophthalmoscopy for Prediction of Central Serous Chorioretinopathy Responsiveness to Laser Therapy.

PURPOSE: To study the potential of dark-field scanning laser ophthalmoscopy (DF-SLO) for the prediction of central serous chorioretinopathy (CSC) responsiveness to laser therapy. METHODS: Fifty-two eyes of 52 patients (44 males and 8 females, mean age of 45.4 ± 8.8 years) newly diagnosed with CSC were included in this prospective cohort study. At baseline, all patients received multimodal imaging including DF-SLO and then were observed until resolution of subretinal fluid or, in nonresolving cases, treated with laser therapy. At the end of the follow-up, each case was categorized as either self-resolving, resolving after laser treatment, or nonresolving after laser treatment. Presence of granular retinal pigment epithelium (RPE) changes and lucency of RPE/choroid complex at the leak on DF-SLO images were used by two masked graders to identify cases nonresolving after laser treatment. RESULTS: Using DF-SLO images, the masked grader correctly classified 45 of 52 (86.5%) CSC cases. Kappa value for the classification by two graders was 0.95 (95% confidential interval [CI] 0.85-1.0). The area under the receiver operating curve, sensitivity, and specificity of DF-SLO in identifying nonresolving after laser treatment cases were 0.92 (95% CI: 0.79-0.98), 86.7% (95% CI: 59.5%-98.3%), and 96.6% (95% CI: 82.2%-99.2%), respectively. CONCLUSION: DF-SLO may be a useful technique in prognostication of response to laser treatment in newly diagnosed CSC.

Retinal Pigment Epithelium Reflectivity at Leakage Site on Spectral-Domain Optical Coherence Tomography in Acute Central Serous Chorioretinopathy.

PURPOSE: To study the reflectivity of the retinal pigment epithelium (RPE) at the leakage site in acute central serous chorioretinopathy (CSC). METHODS: Twenty-nine patients (24 males and 5 females, mean age 46.1 ± 11.0 years) were included. The mean relative RPE reflectivity and the difference between the maximum and minimum relative RPE reflectivity at the leakage site and control site were measured on cross-sectional optical coherence tomography (OCT) scans. In eyes with pinpoint leakage, cross-sectional OCT scans and corresponding reflectivity profile plots were reviewed by a masked grader for the presence of visible RPE defects and focal depression of relative RPE reflectivity at the leak. RESULTS: Twenty-one (61.7%) and 13 (38.2%) leaks showed pinpoint and diffuse leakage, respectively. The mean relative RPE reflectivity at the leakage site was statistically significantly higher than that of the control site (0.82 ± 0.09 and 0.79 ± 0.12, respectively, p=0.03) in eyes with pinpoint leakage as well as in eyes with diffuse leakage (0.81 ± 0.10 and 0.74 ± 0.13, respectively, p=0.01). The difference of relative RPE reflectivity was statistically significantly higher at the leakage site compared to control site (0.56 ± 0.20 and 0.41 ± 0.06, respectively, p=0.002) in eyes with pinpoint leakage, but not in eyes with diffuse leakage (0.46 ± 0.12 and 0.40 ± 0.07, respectively, p=0.16). On cross-sectional OCT scans visible RPE defects at pinpoint leakage were found in 10 out of 21 (47.6%) cases. Focal depressions of RPE reflectivity corresponding to presumed RPE defects were found in 18 out of 21 (85.7%) cases. CONCLUSION: Leakage in acute CSC is associated with significant local increase of RPE reflectivity.

Status of Choriocapillaris in Fellow Eyes of Patients With Unilateral Retinal Vein Occlusions.

BACKGROUND AND OBJECTIVE: To study the status of the choriocapillaris in fellow eyes of patients with unilateral retinal vein occlusions (RVOs). PATIENTS AND METHODS: Thirty-two healthy eyes of patients with unilateral RVO and 16 eyes of healthy age-matched controls were included. Choriocapillaris flow voids and device-specific choriocapillaris total flow areas were quantified based on 3-mm optical coherence tomography angiography (OCTA) scans and their correlation with the number of resolved para-central acute middle maculopathy (PAMM) lesions on 6-mm OCTA scans was calculated. RESULTS: In fellow eyes of unilateral RVOs and in eyes of healthy individuals, the number of choriocapillaris flow voids was 20.8 ± 5.5 and 13.4 ± 5.4, respectively (P < .001), and choriocapillaris total flow area was 6.0 ± 0.34 mm2 and 6.22 ± 0.13 mm2, respectively (P = .005). The number of resolved PAMM lesions correlates significantly with the number of choriocapillaris flow voids (r = 0.44; P = .002) and with choriocapillaris total flow area (r = -0.52; P < .001). CONCLUSION: Fellow eyes of patients with unilateral RVO demonstrate a substantial decrease of perfusion in choriocapillaris, which correlates with the prevalence of small resolved PAMM lesions. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:23-28.].

Vascular Microanatomy of Small Resolved Paracentral Acute Middle Maculopathy Lesions.

PURPOSE: To study microvascular characteristics of small resolved paracentral acute middle maculopathy (PAMM) lesions in fellow eyes of patients with unilateral retinal vein occlusion (RVO). DESIGN: Prospective cross-sectional study. PARTICIPANTS: Patients with prior unilateral branch or central RVO and OCT evidence of resolved PAMM in the fellow, otherwise normal, eye were recruited prospectively and imaged with OCT angiography (OCTA). METHODS: The resolved PAMM lesions were identified as focal areas of inner nuclear layer thinning over an anteriorly displaced outer plexiform layer (OPL). En face OCTA projections showing the location and size of the resolved PAMM lesions were created using 2 OPL segmentation lines with -9-µm and 0-µm offsets, and the cumulative distribution was evaluated. Anterior to the resolved PAMM lesions, vessels in the superficial vascular plexus were traced to identify small arterioles supplying the affected areas. MAIN OUTCOME MEASURES: Cumulative spatial distribution on small resolved PAMM lesions. RESULTS: From 24 fellow eyes of 24 patients with unilateral RVO (15 men and 9 women; mean age, 62.1 ± 13.6 years), 152 resolved PAMM lesions were identified. Of these lesions, 130 (85.5%) were found within the perifoveal region, and only 12 (7.9%) were found within the temporal quadrant. Of 28 lesions analyzed, the arteriole supplying the affected area was a single side branch of a larger vessel, with only 3 supplied by a terminal branch. CONCLUSIONS: Small resolved PAMM lesions in fellow eyes of patients with unilateral RVO are most prevalent in perifoveal regions supplied by side branches of low-order retinal arteries.

Artifact-Free Evaluation of Choriocapillaris Perfusion in Central Serous Chorioretinopathy.

In this study, using optical coherence tomography angiography (OCTA) we evaluated choriocapillaris perfusion in eyes with central serous chorioretinopathy (CSC) after excluding all possible artifacts caused by alterations of neurosensory retina or retinal pigment epithelium (RPE). We have included 22 unilateral acute CSC patients (18 males and four females, 41.8 ± 5.7 years) and 18 healthy subjects (13 males and five females, 40.9 ± 9.7 years). The number of flow voids per 1 mm2 of scan area and percentage of flow signal area was calculated based on choriocapillaris slab of 3 × 3 mm2 OCTA scans after excluding all possible artifacts caused by alterations of neurosensory retina or RPE. The percentage of flow signal area after the exclusion of neurosensory retina and RPE alterations in the eyes of healthy individuals was higher than in CSC eyes (p = 0.006) and fellow unaffected eyes of CSC patients (p = 0.02). The number of flow voids larger than 25,000 µm2 in eyes of healthy individuals was lower than in the CSC eyes (p = 0.0006). There were no statistically significant differences in study parameters between CSC eyes and fellow eyes of CSC patients (p > 0.05). The general decrease of choriocapillaris perfusion in both eyes of CSC patients exists independently of the presence of acute disease or asymptomatic structural RPE changes.

Anterior chamber particles are associated with reduction of intraocular pressure after selective laser trabeculoplasty.

PURPOSE: To study the correlation between intraocular pressure (IOP) reduction and the number of hyper-reflective particles appearing in the anterior chamber following selective laser trabeculoplasty (SLT). MATERIAL AND METHODS: In this prospective interventional study, we included primary open-angle glaucoma patients. All participants received a standardised SLT session, which consisted of 100 pulses of 0.9 mJ over 360°. Anterior segment optical coherence tomography (4×4 mm volume scan, 101 horizontal cross-sectional scans) and applanation tonometry were performed before SLT and 15 min, 1 day, 1 week, 1 month and 3 months after. Particles were counted on cross-sectional scans using a standardised algorithm. RESULTS: In this study, we included 25 patients (25 eyes), 14 males and 11 females, with a mean age of 68.9±10.5 and baseline IOP of 21.4±4.5 mm Hg. IOP at month 1 and month 3 after SLT was 18.0±4.0 and 17.4±3.3 mm Hg, respectively. The mean number of anterior chamber particles before and 15 min after SLT was 0.62±0.2 and 7.1±2.0 particles/mm2, respectively (p=0.036). There was a statistically significant correlation between the mean number of anterior chamber particles 15 min after SLT and IOP reduction at 1 month (r=0.62, p=0.03) and 3 months (r=0.71, p=0.01). CONCLUSION: The number of the anterior chamber particles graded using anterior segment optical coherence tomography after the procedure correlates with the IOP-lowering effect of SLT.