Fluorescein Leakage and Optical Coherence Tomography Angiography Features of Microaneurysms in Diabetic Retinopathy

Background and Objective. To correlate optical coherence tomography angiography (OCTA) characteristics of diabetic microaneurysms (MAs) with leakage status on fluorescein angiography (FA). Patients and Methods. 167 MAs from 39 diabetic eyes were analyzed using OCTA and FA simultaneously. The characteristics of MAs on OCTA en face, OCT en face, and OCT B-scan with flow overlay were evaluated and correlated with fluorescein leakage status. Results. Thirty-six, fifty-two, and seventy-nine MAs showed no, mild, and severe leakage on FA, respectively. Most MAs (61.7%) were centered in the inner nuclear layer. Cystoid spaces were observed adjacent to 60 (35.9%) MAs. MAs with severe leakage had a statistically higher flow proportion compared to MAs with no or mild leakage (both P < 0.001 ). Only 112 MAs (67.1%) were visualized in the OCTA en face images, while 165 MAs (98.8%) could be visualized in the OCT en face images. The location of MAs did not associate significantly with FA leakage status. The presence of nearby cystoid spaces and higher flow proportion by OCT B-scan with flow overlay correlated significantly with FA leakage status. Conclusion. The flow proportion of MAs observed on OCT B-scans with flow overlay might be a potential biomarker to identify leaking MAs. A combination of OCT B-scan, OCT en face, and OCTA en face images increased the detection rate of diabetic MAs in a noninvasive way.

Choroidal caverns in pachychoroid neovasculopathy

Background. Choroid plays an important role in the pathogenesis of retinal pathology. Choroidal cavern, a recently identifi ed fi nding of optical coherent tomography (OCT), has been described in some degenerative and atrophic forms of retinal pathology. In the literature, there are only a few studies of choroidal cavers in pachychoroid neovasculopathy, newly described form of age related macular degeneration.The aim: to perform a detailed analysis of choroidal structure on OCT scans of patients with pachychoroid neovasculopathy and to reveal the frequency of choroidal caverns identifi cation.Material and methods. The data of 30 patients (30 eyes) aged 64.4 ± 5.6 years with pachychoroid neovascularization were retrospectively analyzed. The patients underwent spectral OCT and OCT-angiography (OCTA) using a Spectralis device (Heidelberg Engineering, Germany). The protocol was “Posterior Pole”, consisting of 61 scans. To assess the structure of the choroid, an enhanced image depth (EDI) module was used. OCT angiography was performed with a scan area of 6 × 6 mm. These methods were compared to identify choroidal caverns.Results. On OCT subretinal type 1 neovascularization was revealed as a fl at detachment of the pigment epithelium and visualization of blood flow on OCTA in the lesion as angled vessels (21 eyes) or a seafan (9 eyes). On OCT-EDI scans, there was diffuse or local choroidal thickening of choroid with an increase in the vessels of the Haller’s layer and thinning of the choriocapillaries. Choroidal caverns appeared on OCT and en-face OCT as areas with low optical density, round or irregular, located in different layers of the chorioid, without hyperrefl ective boundaries. A typical sign of choroidal cavern is the tail of hypertransmission after the cavern toward the sclera. Choroidal caverns were found in 4 of 30 eyes (13.3 %) and were located both near the choroidal neovascularization lesion and beyond this area.Conclusion. The prevalence of choroidal cavities, a new choroidal biomarker, in pachychoroid neovasculopathy was 13.3 %. Identification of these changes is possible with the use of modern diagnostic techniques (OCT-EDI, OCTA and en-face OCT) that allow visualization the state of the choroid. The prognostic signifi cance of choroidal cavities requires further study.

Macular Dystrophy with Bilateral Macular Telangiectasia Related to the CYP2U1 Pathogenic Variant Assessed with Multimodal Imaging Including OCT-Angiography

Purpose: We report the case of a neurologically asymptomatic young boy presenting with an unusual phenotype of CYP2U1 related macular dystrophy associating bilateral macular telangiectasia (MacTel) and fibrotic choroidal neovascularization (CNV), assessed with complete multimodal imaging including optical coherence tomography angiography (OCT-A). Case presentation: A twelve-year-old boy from a non-consanguineous family complained of bilateral progressive visual loss and photophobia. The best-corrected visual acuity was 2/10 on the right eye and 3/10 on the left eye. Fundus examination showed central pigmented fibrotic macular scar and yellowish punctuate deposits in both eyes. En face OCT-A detected typical macular telangiectasia (MacTel) in both eyes with dilated telangiectatic capillaries in the deep capillary plexus associated with vascular anomalies in the superficial and deep capillary plexus. Typical hypo-reflective cavities were observed within the inner foveal layers on structural OCT. En face OCT-A also confirmed the presence of bilateral inactive CNV within the fibrotic scars, showing high-flow vascular network at the level of the subretinal hyperreflective lesions. Whole exome sequencing identified a known homozygous pathogenic variant in CYP2U1 gene (c.1168C > T, p.Arg390*), which is a disease-causing mutation in autosomal recessive spastic paraplegia type 56 (SPG56). The neurological examination was normal, and electromyography and brain magnetic resonance imaging were unremarkable as well. Conclusion: Macular dystrophy can be the first manifestation in SPG56. A particular phenotype with MacTel was observed, and neovascular complications are possible. CYP2U1 should be included in the panels of genes tested for macular dystrophies, especially in the presence of MacTel and/or neurological manifestations.

Vitamin A retinopathy secondary to Billroth II anastomosis triggered after the beginning of dialysis

Purpose: To report a case of vitamin A retinopathy secondary to Billroth II anastomosis triggered after the beginning of dialysis in a patient with a chronic renal failure. Case report: A 73-year-old male complained of nyctalopia that had started 9 months ago, coinciding with the beginning of dialysis. His medical history is remarkable for hepatic cirrhosis and Billroth II anastomosis 20 years ago. Best-corrected visual acuity (BCVA) was 60 letters in both eyes. Dilated fundus examination showed faint white-yellowish dots. Optical coherence tomography (OCT) illustrated hyperreflective dots and small hyporreflective cavities between the retinal pigment epithelium (RPE) and the ellipsoid zone (EZ). En face OCT showed multiple hyperreflective dots that coincide with white-yellowish dots of the fundus, and multiple hyporreflective defects which correspond to hyporreflective cavities seen in the OCT. Visual field examination showed concentric narrowing of the visual field. A diagnosis of vitamin A deficiency was confirmed and oral vitamin A supplementation was initiated. One month after treatment, the patient reported a subjective improvement of nyctalopia, and BCVA ameliorated up to 80 and 85 letters. Fundus examination, OCT, and en face OCT showed a diminution of the observed lesions. Moreover, visual field improved. Conclusion: Early diagnosis of vitamin A deficiency can prevent irreversible visual sequelae. This highlights the crucial role of ophthalmologists in the prompt detection of this condition. A lifelong monitoring should be needed in patients undergoing biliopancreatic diversion surgery. Furthermore, OCT and en face OCT becomes a main tool in the diagnosis and monitor response to treatment.

Preoperative imaging optimized for epiretinal membrane surgery

Background To compare imaging modalities for visualizing primary epiretinal membrane (ERM) with each other and with intraoperative digital images (IDI) after blue staining. Methods The 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. Results Seventy 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. Conclusion ERM 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.

Artifact Removed Quantitative Analysis Of Choriocapillaris Flow Voids

Purpose: To investigate choriocapillaris flow voids (FV) with a new optical coherence tomography angiography (OCTA) image processing strategy to exclude artifacts due to vitreous opacities, subretinal pigment epithelium (sub-RPE) fluid and deposits, and subretinal fluid (SRF) by thresholding the en-face OCT image of the outer retina.Methods: This retrospective study included 15 eyes with drusen and 15 eyes with SRF. Number (FVn), average area (FVav), and maximum area (FVmax) of FV and the percentage of the nonperfused choriocapillaris area (PNPCA) obtained using the proposed strategy were compared with those obtained by removing only artifacts due to superficial capillary plexus (SCP).Results: There were three eyes with autosomal dominant drusen and 12 eyes with drusen secondary to non-exudative AMD in the drusen group. SRF group included 15 eyes with active central serous chorioretinopathy. PNPCA, FVav, FVmax, and FVn obtained using the algorithm were significantly lower than those obtained by removing only SCP in both groups (all p< 0.05). The algorithm was able to remove 94.7% of artifacts secondary to vitreous opacities and all artifacts secondary to serous pigment epithelial detachments. Conclusion: Nonperfusion areas of choriocapillaris may be overestimated in eyes with RPE abnormalities and SRF. These areas can be removed using thresholded images of the outer retina en-face OCT scans.