Atypical case of choroidal osteoma associated to polypoidal choroidal vasculopathy and preretinal neovascular membrane.

PURPOSE: To report a very rare and atypical case of an elderly Caucasian female patient who developed perilesional multiple polypoidal choroidal vasculopathy (PCV) as a probable complication of choroidal osteoma (CO), associated to preretinal neovascular membrane overlying the lesion. METHODS: Observational case report. CASE OBSERVATION: A 60-year-old Caucasian woman presented with blurred vision in her right eye (RE). Fundus examination revealed a round white-yellowish calcified deep lesion in the juxta-papillary superior area, measuring 4 disc-diameters, with well-defined scalloped margins and an irregular surface. B-scan ultrasonography and orbital tomography confirmed the diagnosis of choroidal osteoma (CO). Further investigation with multimodal imaging including infracyanine green angiography, fluorescein angiography, swept source optical coherence tomography and angiography highlighted the presence of multiple aneurysmal choroidal dilations around the CO, corresponding to PCV. We also noted the presence of a preretinal neovascular membrane overlying the CO. The patient was monitored with regular follow-up since no signs of activity were detected on multimodal imaging. CONCLUSION: Our case report represents an exceptional and atypical association between pre-retinal neovascularization, PCV and choroidal osteoma. While the mechanisms underlying the development of PCV and pre-retinal neovascularization in the setting of CO are not well understood, it is imperative for ophthalmologists to recognize this association as a potential cause of sudden vision loss in patients with CO, and to consider appropriate diagnostic and management strategies.

Choroidal features in non-neovascular and neovascular pachychoroid diseases.

PURPOSE: To evaluate choroidal findings on multimodal imaging in eyes within pachychoroid spectrum diseases and to compare quantitative and qualitative choroidal features between non-neovascular (NNV-PDS) and neovascular (NV-PDS) pachychoroid diseases. METHODS: Retrospective cross-sectional study comparing between NV-PDS and NNV-PDS. All patients underwent multimodal imaging including infracyanine green angiography (IFCGA) and swept source optical coherence tomography (OCT) and angiography (OCT-A). The following parameters were analyzed: subfoveal choroidal thickness (SFCT), choroidal vascular index (CVI), presence of pachyvessels and choroidal vascular interconnections (CVIC), presence of choroidal neovascularization and choriocapillaris density. RESULTS: Of the 87 eyes included in the study, 63 eyes (73%) had NNV-PDS and 24 eyes (27%) had NV-PDS. Mean SFCT and CVI were significantly higher in NNV-PDS group (p = 0.01; p = 0.022). Pachyvessels were more diffusely distributed in NNV-PD group and more focally distributed in NV-PDS group (p = 0.029). CVIC were more frequently noted in NV-PDS group (p = 0.024). A higher CVI was associated to a thicker choroid (p < 0.001), with significant negative correlations between the presence of CVIC and both SFCT (p = 0.015) and CVI (p = 0.002). We also observed a lower choriocapillaris vascular density and higher number of choriocapillaris flow voids in eyes with NNV-PDS (p = 0.24; p = 0.61). CONCLUSION: NNV-PDS eyes had a significantly thicker SFCT, higher CVI and a lower rate of detected CVIC than eyes with NV-PDS. These highlighted choroidal vascular changes might lead to a better understanding of pachychoroid disease pathophysiology. More frequently observed in NV-PDS group, CVIC are believed to assess the development of vortex vein anastomoses as a remodelling process for vascular decongestion.

Optical coherence tomography and angiography in Alzheimer's disease and other cognitive disorders.

AIMS: The aims of this study were to analyze retinal and choroidal changes on optical coherence tomography (OCT) and OCT-Angiography (OCT-A) in Alzheimer's disease (AD) patients and compare them to other forms of major dementia. We also aimed to analyze the correlation between clinical severity of global cognitive deficiency assessed by the mini-mental state exam (MMSE) score and OCT/OCT-A parameters. METHODS: Retrospective cross-sectional evaluative study of AD, and age-and gender-matched patients with other dementias. Fundus examination, OCT and OCT-A were compared. RESULTS: Ninety-one eyes of AD patients and 53 eyes of patients with other dementias were included. Retinal deposits were found in 6.59% of AD cases. OCT highlighted the presence of hyperreflective deposits and localized areas of outer retina and ellipsoid zone disruption, respectively in 20.87% and 15.38% of AD cases. Hyperreflective foci were noted within inner retinal layers in 4.39% of AD cases. Quantitative analysis revealed a thicker nasal retinal nerve fiber layer (p = 0.001) and ganglion cell complex in superior (p = 0.011) and temporal quadrants (p = 0.009) in eyes of AD patients, compared to other dementias. OCT-A showed a significantly higher fractal dimension of both superficial and deep capillary plexus (p = 0.005), with lower choriocapillaris density (p = 0.003) in AD patients. CONCLUSIONS: Structural OCT could highlight the presence of hyperreflective deposits in AD, probably reflecting beta-amyloid deposits, associated to outer retinal disruptions. Quantitative OCT analysis showed structural differences between AD patients and other dementias, and combined OCT-A could identify microvascular changes in AD patients representing new potential differential diagnosis criteria.

Multimodal imaging of bilateral immunogammopathy maculopathy associated to Waldenström's macroglobulinemia.

AIM: Our aim is to report a case with bilateral Waldenström's macroglobulinemia (WM) associated maculopathy, assessed with multimodal imaging including swept source optical coherence tomography (SS-OCT) and OCT-Angiography (OCT-A). METHODS: Observational case report. CASE PRESENTATION: A 61-year-old diabetic woman with history of treated WM currently in remission, presented with progressive bilateral visual loss. Best-corrected visual acuity was 20/100 in the right eye (RE) and 20/200 in the left eye (LE). Fundus examination showed bilateral microaneurysms and retinal punctuate hemorrhages and a large macular serous detachment in the LE. There was no retinal ischemia on FA nor macular dye leakage. SS-OCT showed a significant schisis-like intraretinal fluid accumulation in the RE and a large prominent macular detachment with significant subretinal fluid accumulation in the LE. Retinal and choriocapillaris vascular densities were normal on OCT-A. CONCLUSION: Our case illustrated characteristic multimodal imaging findings in WM associated maculopathy such as schisis-like intraretinal fluid accumulation and angiographically silent serous macular detachment. OCT-A could non-invasively analyze macular vascular densities layer-by-layer, without noticing any vascular anomaly.

FOCAL CHOROIDAL THICKNESS HEMODYNAMICS AS a SIGN OF MACULAR NEOVASCULARIZATION ACTIVITY IN PATHOLOGIC MYOPIA.

PURPOSE: To analyze the relationship between a focal increase of choroidal thickness (ChT) and exudative activity of macular neovascularization (MNV) secondary to pathologic myopia. METHODS: Retrospective analysis including eyes with pathologic myopia presenting with a focally increased ChT underneath active MNV. All patients included were treated, and ChT was measured before and after each intravitreal injection by two experienced ophthalmologists. RESULTS: Fifty-two eyes of 52 patients with myopic MNV (19 men and 33 women) were included in this analysis. ChT at T-1 averaged 51.09 ± 33.56 µ m, whereas at the time of MNV activation (T0), ChT was significantly thicker: 85.11 ± 43.99 µ m ( P < 0.001). After a single intravitreal injection, the ChT significantly decreased to 53.23 ± 34.15 µ m ( P < 0.001). CONCLUSION: This study showed that focal ChT variations may be considered an interesting corollary sign of MNV in high myopic patients, indicating the activity of myopic neovascularization.

Management of a Bilateral Post-Uveitic Complex Glaucoma with Pupillary Block, Rupture of the Anterior Lens Capsule, and Malignant Glaucoma following Laser Peripheral Iridotomies: Case Report and Literature Review.

Purpose: To report a case of a bilateral complex uveitic glaucoma (UG) with pupillary block, rupture of the anterior lens capsule, and malignant glaucoma in a young high-myopic patient and to report anterior segment optical coherence tomography (AS-OCT) findings initially and following surgery. Methods: A 21-year-old high-myopic woman who had a history of anterior uveitis with extensive posterior synechiae, presented with acute bilateral ocular pain, redness, and blurred vision following bilateral Nd: YAG laser peripheral iridotomy (LPI). Results: Visual acuity was limited to light perception in both eyes (OU), with a flat anterior chamber (AC) and anterior luxation of lens fragments. Intraocular pressure (IOP) was over 60 mmHg OU. AS-OCT showed closed angles and hyperreflective heterogeneous material within the flat AC. The iris and lens fragments were plated against the corneal endothelium OU. We performed an urgent pars plana vitrectomy associated with lensectomy. It was uneventful in OU. Repeated AS-OCT revealed a deep AC, widely open angles, and aphakia. IOP was lowered to 9 mmHg and visual acuity improved to 5/10 in OU. Conclusion: Performing LPI might be harmful in the presence of UG with extensive posterior synechia, resulting in complex mechanism glaucoma with aqueous misdirection syndrome associated with a pupillary block due to anterior lens luxation, even in high-myopic eyes. Nd: YAG LPI should not be performed simultaneously in OU, especially in pathologic eyes, to prevent bilateral vision-threatening complications. AS-OCT was of great help, allowing easy and detailed ultrastructural assessment of the ACs, and iridocorneal angles before and after surgery.

Swept source OCT-Angiography assessing a case of aneurysmal type 1 neovascularization secondary to high-myopic posterior staphyloma.

AIM: To report an uncommon case of aneurysmal type 1 neovascularization (polypoidal choroidal vasculopathy) secondary to high-myopic staphyloma in a Caucasian patient, assessed with multimodal imaging including swept source OCT-Angiography. METHODS: Observational case report. RESULTS: About 73-year-old Caucasian male patient with high myopia (axial length = 27.24 mm). Fundus examination showed a myopic conus and a deep orange-brownish nodular lesion at the edge of a deep haemorrhage and connected to a large choroidal vessel. ICGA showed a circular hyperfluorescent lesion in mid-phase, without any branching vascular network. OCT-Angiography could detect the aneurysmal lesion non-invasively as a small circular high-flow lesion in the outer retina slab, with a shadowing in the choriocapillaris slab. At the level of the aneurysmal lesion, structural OCT showed a high bilobed PED, without any subretinal fluid. A vascular flow was noted within the PED on cross-sectional OCT-A, confirming the vascular aneurysmal nature of this lesion. Additionally, swept source OCT highlighted the presence of an abrupt change in choroidal thickness, from 62 µm in the peripapillary area to 120 µm underneath the polypoidal lesion, with dilated choroidal vessels. CONCLUSION: To our knowledge, this is the first report of OCT-A findings in aneurysmal (polypoidal) dilation secondary to high-myopic staphyloma. We could demonstrate the usefulness of OCT-A detecting non-invasively the aneurysmal dilation and the usefulness of swept source OCT assessing the choroidal structure to better understand the pathophysiology of this uncommon finding.

Irregular vascular network identified with OCT-A in angioid streaks: A probable predictor of active choroidal neovascularization (case series).

PURPOSE: To evaluate the risk of active choroidal neovascularization (CNV) in presence of deep irregular vascular network (IVN) in eyes with angioid streaks (AS). METHODS: Observational case series including three treatment-naive eyes with angioid streaks and IVN, without CNV. Patients were followed-up during 18 months with multimodal imaging including structural optical coherence tomography (OCT) and OCT Angiography (OCT-A) to detect possible neovascular complication. RESULTS: On OCT-A, IVN was detected as a peripapillary and/or macular high-flow lesion, filling the spaces between the angioid streaks in the outer retina slab. Repeated OCT-A could detect an active CNV emerging from the IVN, as a high-flow rich anastomotic vascular network with a perilesional dark halo. Patient was treated with intravitreal injections of Bevacizumab on a Pro Re Nata regimen, with a decreased CNV area and lower vascular density on control OCT-A. CONCLUSION: OCT-A shown to be helpful in detecting the presence of IVN in asymptomatic eyes with AS during a routine examination. In our series, the IVN seems to be predictor of active CNV, needing a close surveillance and frequent follow-up to allow early treatment upon CNV activation.

OCT-angiography assessing quiescent and active choroidal neovascularization in retinitis pigmentosa associated with PRPH2 pathogenic variant.

PURPOSE: To report multimodal imaging findings including optical coherence tomography angiography (OCT-A) of a patient presenting with a quiescent choroidal neovascularization (CNV) in one eye and an active CNV in the fellow eye, complicating retinitis pigmentosa (RP) linked to PRPH2 pathogenic variant, with follow-up and management of both eyes. METHODS: Observational case report. RESULTS: A 40-year-old female with history of autosomal dominant RP consulted for acute visual loss in her right eye (RE). Multimodal imaging including OCT-A confirmed the diagnosis of active type 2 CNV in the RE and highlighted an incidental asymptomatic non-exudative "quiescent" CNV in the left eye (LE). This complication was managed by intra-vitreal Bevacizumab injections in the RE and regular monitoring of the LE. Frequent follow-up could detect early CNV activation signs in LE allowing early treatment. Mutation analysis of PRPH2 exons identified a known heterozygous pathogenic missense variation c.646C>T, p.P216S in exon 2. CONCLUSION: Multimodal imaging and especially OCT-A can be of a great help in the diagnosis and the management of CNV complicating RP, even at the stage of quiescent CNV. In presence of neovascular complication, PRPH2 gene should be investigated because of its frequent macular involvement despite high phenotypic variability.

Case Report: Swept-source Optical Coherence Tomography and Angiography Findings in Lipemia Retinalis.

SIGNIFICANCE: Lipemia retinalis is a very rare ocular manifestation of severe hypertriglyceridemia. It is usually symptomatic and regresses after normalization of triglycerides levels. Early recognition is important to prevent ocular and life-threatening complications. PURPOSE: This study aimed to report a case of marked lipemia retinalis secondary to type V hypertriglyceridemia assessed with swept-source optical coherence tomography (OCT) and OCT angiography (OCT-A), with follow-up after dietary lipid restriction. METHODS: Observational case report of lipemia retinal findings on color fundus photography, swept-source OCT and OCT-A, initially and after triglycerides lowering. CASE REPORT: A 32-year-old pregnant patient with gestational diabetes and a history of hypertriglyceridemia was referred for diabetic retinopathy screening. Fundus examination revealed bilateral milky-white discoloration of retinal vessels with a "salmon-colored" retina. Swept-source OCT and OCT-A revealed extremely hyperreflective and dilated retinal vessels and multiple high-flow retinal hyperreflective dots, corresponding to dilated retinal capillaries. Choroidal vessels were enlarged and engorged, and choriocapillaris layer appeared thickened and hyperreflective with dilated and tortuous capillaries. Serum triglycerides were very high (70.02 mmol/L). After 21 days of very-low-fat diet, it was lowered to 15 mmol/L. We noted a normalization of the clinical, structural, and vascular findings. However, peripheral retinal vessels remained hyperreflective, despite their clinical normalization. CONCLUSIONS: Swept-source OCT and OCT-A were beneficial in assessing lipemia retinalis noninvasively and monitoring choroidal and retinal vascular changes. Lipemia retinalis signs regressed initially in the posterior pole, choroidal anomalies were first to resolve, and clinical normalization preceded tomographic resolution.

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.

Subthreshold micropulse laser adjuvant to bevacizumab versus bevacizumab monotherapy in treating diabetic macular edema: one- year- follow-up.

PURPOSE: To compare the therapeutic impact of combining intravitreal injections of bevacizumab (IVB) with micropulse laser (MPL) in central diffuse diabetic macular edema (DME) versus IVB monotherapy during 12 months follow-up. METHODS: We conducted a retrospective comparative study of 98 treatment-naive eyes (63 patients) with central diffuse DME. The first group of patients (IVB + MPL group, n = 49) was treated with 3 monthly IVB followed by MPL within 1 week after the third injection. Patients were then followed and treated on a pro re nata (PRN) basis, with MPL retreatment if necessary. The changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), number of IVB injections and MPL sessions were evaluated at 4, 8, and 12 months. A control group of diabetic patients with treatment-naive DME was treated with standard protocol of 3 monthly IVB as monotherapy then followed on a PRN basis (IVB group, n = 49). Statistic comparaison of BCVA, CMT, and IVB number variation was interpreted at 12 months between both groups. RESULTS: In IVB + MPL group, baseline BCVA improvement was not significant at 4 and 8 months (p = 0.90, p = 0.08), and was statistically significant (p = 0.01) at 12 months. Mean CMT significantly decreased at 4, 8, and 12 months (p < 0.01) in IVB + MPL group. The difference in BCVA (p = 0.091) and CMT (p = 0.082) variation at 12 months between both groups was not significant but the number of injections was significantly lower in IVB + MPL group (4.1 ± 1.5 injections) compared to IVB group (7.2 ± 1.3 injections) (p < 0.005). CONCLUSION: Combining intravitreal injections of bevacizumab and MPL in the treatment of DME is effective and safe. This protocol may decrease the number of IVB and its frequency. It offers the advantage of lasting therapeutic response with fewer recurrences.

E-learning for Ophthalmology Training Continuity During COVID-19 Pandemic: Satisfaction of residents of Hédi Raies Institut of Ophthalmology of Tunis.

INTRODUCTION: COVID-19 pandemic created great challenges for the continuity of medical education. At the Hédi Raies Institut of Ophthalmology of Tunis (HRIO), the need to ensure continuity in the teaching of ophthalmology has stimulated the development of a new e-learning resource based on clinical case studies. AIM:   To evaluate level of satisfaction of HRIO residents in regard to clinical case-study-based e-learning of ophthalmology. METHODS: Cross-sectional survey including 40 ophthalmology residents doing their internship at the ROHI during the first half of 2020. Learners were tutored in e-learning via the Moodle online learning platform and using a problem-solving format based on clinical case studies describing various ophthalmologic conditions. Data collection was carried out through an online survey after four months of training, designed to assess learners' satisfaction with the e-learning. RESULTS: Mean age of participants was 29.95 ± 1.73 years. The majority had found the navigation easy, the content relevant to their training objectives, and were satisfied with the discussion forums as a method of communication. All respondents were satisfied with clinical cases presented through the platform and felt that they helped them to better understand the content. Among them, 97.5% considered that this teaching method corresponded to their training needs. There was a statically significant difference in the level of knowledge before and after e-learning teaching, taking into account the residents' appreciation (p<0.001). CONCLUSIONS: This study highlights the importance of virtual learning in ophthalmology in the era of the COVID-19 pandemic. E-learning is well appreciated by ophthalmology residents, relatively easy to integrate to their training program, and reduces issues of time, patient availability and case exposure.

Central corneal thickness in a healthy Tunisian population.

AIM: To study the central corneal thickness of a Tunisian population and determine the influence of age, gender, axial length and refractive error on central corneal thickness (CCT) values. METHODS: An observational, cross-sectional study was conducted on 608 eyes of consecutive Tunisian patients without ophthalmic disease. Corneal tomography (Oculus Pentacam, USA) and a complete eye examination were performed on all patients. The relationship between the central corneal thickness values and variables of age, refractive error, axial length and gender was assessed. RESULTS: The mean central corneal thickness was 522±37.17µm (range 461 to 655 µm). No statistical association was found between central corneal thickness values and variables of age, refractive error, axial length and gender. CONCLUSIONS: The normal CCT value in the Tunisian population was of 522±37.17 µm. We have analyzed, for the first time, normal central corneal thickness values of a healthy Tunisian population.

Homozygous mutation in ABCA4 associated with cone rod dystrophy in a patient with Turner syndrome.

PURPOSE: We report a special case of a patient who presented with two rare genetic diseases, Turner syndrome and cone-rod dystrophy (CRD), caused by mutation in the ABCA4 gene. METHODS: We present a case of a 12-year-old female with a progressive visual loss, poor night vision and short stature. We performed a clinical, karyotype of peripheral blood and molecular genetic study. DNA sample from the index patient was subjected to whole exome sequencing. Variants localized in homozygous regions were validated by Sanger sequencing. RESULTS: Fundus examination presented CRD phenotype and the general examination revealed short stature, aortic coarctation and infantile uterus, without visible ovaries on pelvic ultrasound. The karyotype of peripheral blood showed monosomy 45,X. We identified a known homozygous deletion c.[885delC];[885delC] in ABCA4, resulting in a frameshift at the position p.[L296Cfs*4];[ L296Cfs*4] . In addition, mutations in RPGR and ORF15 were excluded. CONCLUSIONS: Several ocular disorders are known to be associated with Turner syndrome, however, in this case, we hypothesize that CRD is not related to Turner syndrome but may be a manifestation of the lack of a normal X chromosome with ABCA4 mutation.

Different Phenotypes in Pseudodominant Inherited Retinal Dystrophies.

Retinal dystrophies (RD) are a group of Mendelian disorders caused by rare genetic variations leading to blindness. A pathogenic variant may manifest in both dominant or recessive mode and clinical and genetic heterogeneity makes it difficult to establish a precise diagnosis. In this study, families with autosomal dominant RD in successive generations were identified, and we aimed to determine the disease's molecular origin in these consanguineous families. Whole exome sequencing was performed in the index patient of each family. The aim was to determine whether these cases truly represented examples of dominantly inherited RD, or whether another mode of inheritance might be applicable. Six potentially pathogenic variants in four genes were identified in four families. In index patient with enhanced S-cone syndrome in F1, we identified a new digenetic combination: a heterozygous variant p.[G51A];[=] in RHO and a homozygous pathogenic variant p.[R311Q];[R311Q] in NR2E3. Helicoid subretinal fibrosis associated with recessive NR2E3 variant p.[R311Q];[R311Q] was identified in F2. A new frameshift variant c.[105delG];[105delG] in RDH12 was found in F3 with cone-rod dystrophy. In F4, the compound heterozygous variants p.[R964*];[W758*] were observed in IMPG2 with a retinitis pigmentosa (RP) phenotype. We showed that both affected parents and the offspring, were homozygous for the same variants in all four families. Our results provide evidence that in consanguineous families, autosomal recessive can be transmitted as pseudodominant inheritance in RD patients, and further extend our knowledge of pathogenic variants in RD genes.

Swept Source Optical Coherence Tomography Angiography: Characteristic Findings in Type 3 Macular Neovascularization.

We report a typical illustration of Swept source OCT-Angiography (SS-OCT-A) findings in type 3 macular neovascularization(MNV) or retinal angiomatous proliferation (RAP). This is a case of a 70-year-old Caucasian male patient presenting with an exudative type 3 neovascular age-related macular degeneration. En face SS-OCT-A could non-invasively detect a tiny perifoveal circular "clew-like" high-flow neovascular lesion, visible in the deep capillary plexus, the outer retina and communicating with the choriocapillaris, with a perilesional dark halo and associated to no-flow macular cysts in the deep capillary plexus slab. En face SS-OCT-A could also highlight the presence of a telangiectatic capillary dilation in the superficial capillary plexus appearing to be at the origin of the retinal neovascularization. Cross-sectional SS-OCT-A showed an intra-retinal vertical high vascular flow within the hyper-reflective neovascular lesion, with a typical hyperreflective "kissing sign" and associated to subretinal and intraretinal fluid. In conclusion, en face OCT-A is useful tool to diagnose type 3 MNV or RAP non-invasively and associated cross-sectional OCT-A scan is very helpful highlighting the linear vascular high-flow within the retinal neovascularization.

Contribution of ultra-wide field fluorescein angiography in diabetic retinopathy in a Tunisian population.

AIM: To assess the contribution of ultra-wide field (UWF) fluorescein angiography (FA) in clinically non proliferative diabetic retinopathy (DR) and to study the relationship between peripheral vascular lesions and the presence of diabetic macular edema (DME). METHODS: Retrospective study of consecutive UWF-FA obtained using a wide-field contact lens system. DME was detected on both FA and spectral-domain optical coherence tomography (SD-OCT). RESULTS: A total of 71 eyes of 39 diabetic patients with clinically non proliferative DR (NPDR) was included. DR was clinically graded as severe NPDR in 52 eyes (73%), moderate NPDR in 15 eyes (21%) and mild NPDR in 4 eyes (6%). On UWF-FA, DR was predominantly anterior in 14% of cases (10/71), predominantly posterior in 48% of cases (34/71) and diffuse in 38% of cases (27/71). Retinal non perfusion was present in 87% of eyes (62/71), predominating in superior-temporal areas. Peripheral vessel leakage was present in 85% of cases (60/71) and retinal neovascularization was noted in 14% of cases (10/71), unpgrading DR severity from NPDR to proliferative DR in 10 eyes. DME was present on SD-OCT in 53% of cases. Central macular thickness was significantly higher in eyes with retinal non-perfusion (353 µm vs. 254 µm, p=0,006) and retinal non-perfusion was associated with macular edema (97% vs. 76%, p=0,01) and poor visual acuity (p<0.001). Peripheral vessel leakage was associated with retinal non-perfusion (p<0.001) and retinal neovascularization (53% vs. 35%, p=0.01), but it was not associated with the presence of DME (p=0.449). CONCLUSION: UWF-FA was of great help assessing DR and evaluating peripheral retinal lesions in order to refine DR staging and to guide laser treatment. Besides, it allows better understanding of DME pathophysiology.

Multimodal Imaging in Retinitis Pigmentosa: Correlations among Microvascular Changes, Macular Function and Retinal Structure.

PURPOSE: To analyze microvascular changes in patients with retinitis pigmentosa (RP) with relatively preserved visual acuity (VA), using swept source optical coherence tomography (SS-OCT) angiography to correlate results to macular function and structure. METHODS: This was a case-control study conducted over 70 eyes of 35 RP patients with relatively preserved VA. All patients underwent a complete ophthalmic examination, including SS-OCT, OCT angiography (OCT-A), fundus autofluorescence (FAF), and multifocal electroretinogram (mfERG). Thirty-four eyes of 34 healthy controls of age-, sex-, and axial length-matched (control group), were also analyzed. The main outcome measures were foveal and parafoveal vascular densities (FVDs and PFVDs) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular zone (FAZ) and its enlargement coefficient and their correlation with macular function (by means of VA and mfERG), and structure (by means of FAF and SS-OCT). RESULTS: In the RP group, PFVD was 25.99 ± 5.2% in the SCP and 34.47 ± 2.37% in the DCP and were significantly lower as compared to control group (P < 0.0001; P = 0.0026, respectively). Enlargement coefficient of FAZ was 1.78 ± 0.79. We found a statistically significant correlation between VA and PFVD in the DCP (P < 0.0001), FAZ disruption in the SCP (P = 0.006) and enlargement coefficient of FAZ (P = 0.01). The parafoveal DCP density was significantly correlated with P1 amplitude (P = 0.005) in rings 2, 3, 4, and 5 of the mfERG. We found a statistically significant correlation between parafoveal density in the DCP, thickness of ganglion cell complex (GCC) (P = 0.001), and the width of ellipsoid band (P = 0.041). Parafoveal SCP density was also correlated to GCC (P = 0.033). CONCLUSIONS: We showed that vascular alteration in RP begins at the level of the DCP, which affects the outer retina and leads to a narrowing of the ellipsoid. The alteration of the SCP would occur later in the evolution of the disease. Vascular changes occur early during RP and were highly correlated to retinal function and structure. OCT-A seems to be a good tool to quantify vascular network loss and could play a central role in staging, prognosis, and monitoring disease progression.

Genetic spectrum of retinal dystrophies in Tunisia.

We report the molecular basis of the largest Tunisian cohort with inherited retinal dystrophies (IRD) reported to date, identify disease-causing pathogenic variants and describe genotype-phenotype correlations. A subset of 26 families from a cohort of 73 families with clinical diagnosis of autosomal recessive IRD (AR-IRD) excluding Usher syndrome was analyzed by whole exome sequencing and autozygosity mapping. Causative pathogenic variants were identified in 50 families (68.4%), 42% of which were novel. The most prevalent pathogenic variants were observed in ABCA4 (14%) and RPE65, CRB1 and CERKL (8% each). 26 variants (8 novel and 18 known) in 19 genes were identified in 26 families (14 missense substitutions, 5 deletions, 4 nonsense pathogenic variants and 3 splice site variants), with further allelic heterogeneity arising from different pathogenic variants in the same gene. The most common phenotype in our cohort is retinitis pigmentosa (23%) and cone rod dystrophy (23%) followed by Leber congenital amaurosis (19.2%). We report the association of new disease phenotypes. This research was carried out in Tunisian patients with IRD in order to delineate the genetic population architecture.