Optical coherence tomography angiography vessel density parameters in primary open-angle glaucoma.

BACKGROUND: Many studies suggest the existence of an alteration of the retinal hemoperfusion in primary open-angle glaucoma. The OCT-A is a novel technique that allows to provide information on retinal microcirculation in a non-invasive way, thus it represents a possible imaging target for the early diagnosis and follow-up of glaucoma. The aim of our work is to evaluate the contribution of vascular parameters provided by OCT-A and their diagnostic abilities in the different stages of primary open-angle glaucoma. METHOD: This is a prospective cross-sectional study involving 200 eyes of control subjects and 250 eyes of glaucomatous subjects divided into early glaucoma, moderate glaucoma and advanced glaucoma subgroups. They were assessed for MD, LV by visual field, RNFL and GCC thickness by SS-OCT papillary and macular vascular densities by SS-OCT A. RESULTS: OCT-A vessel densities determined in the optic nerve head, in the peripapillary and in the macular regions were significantly lower in glaucomatous eyes. Among the vascular parameters studied the whole image vascular density showed the best diagnostic ability in the discrimination between glaucomatous eyes and healthy eyes with an AUC of 0.949. Nevertheless, the diagnostic ability of vascular parameters remains lower than of the structural parameters RNFL (AUC: 0.981). A significant correlation was found between structural, functional and vascular parameters with r < 0.05. The quadratic non-linear model defines better the relationship between structural, vascular and functional damage in glaucoma. CONCLUSION: The OCT-A plays an important role in the early diagnosis and follow-up of PAOG. It also contributes to the understanding of some aspects of the vascular role in glaucoma.

Contribution of optical coherence tomography angiography OCT-A in diabetic maculopathy.

INTRODUCTION: Diabetic retinopathy (DR) increases the risk of blindness by 25 times. Advanced researchs are justified for better management, leading to the role of Optical Coherence Tomography-Angiography (OCT-A), a new non-invasive imaging technique exploring retinal vascularization.Our purpose is to identify microvascular macular anomalies of DR on OCT-A with qualitative and quantitative evaluation of their impact on retinal vascularization. PATIENTS AND METHODS: This is a descriptive cross-sectional study where 120 eyes of 66 diabetic patients were enrolled. All patients were diabetic and went through OCT-A imaging. RESULTS: Microanevrysms were identified in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) where they were more frequently visualized. Macular edema was present in 16,7% of cases in the SCP, and in 30% in DCP. Edema spaces were more frequently present in DCP (p < 0,05). Capillary nonperfusion areas were identified in 82,5% of cases in SCP and in 60% of cases in DCP. The main peri-foveal vascular density was 18,95 ± 5,37%. The main surface of foveal avascular zone (FAZ) in the SCP was 462,52 µm2 and was 555,04 ± 329,11 µm2 in the DCP where it was larger. CONCLUSION: OCT-A is a modern imaging tool that could be used for the diagnosis and monitoring of DR as well as the understanding of its pathophysiology.

Spectral optical coherence tomography findings in patients with ocular toxoplasmosis: A case series study.

PURPOSE: Ocular toxoplasmosis is the most common cause of infectious uveitis worldwide. The diagnosis of ocular toxoplasmosis is primarily clinical when it is a typical presentation.With an atypical presentation in the fundus, parasitological diagnosis is a decisive contribution, as well as multimodal imaging. The aim of this study was to investigate vitreal, retinal, and choroidal morphologic changes in active and scarred toxoplasmosis lesions using swept source optical coherence tomography. To our knowledge, it is the first study in Tunisia which describes with precision the retinochoroidal lesions caused by Toxoplasma Gondi by means of the optical coherence tomography (OCT). METHODS: A retrospective analysis of fifteen patients diagnosed with ocular toxoplasmosis was conducted. The patients were examined at ophthalmology service of Farhat Hached Hospital in Sousse Tunisia between January 2002 and December 2019. Complete ophthalmologic examination including best-corrected visual acuity, slit lamp biomicroscopy, dilated biomicroscopic and fundus examinations, colour fundus photography as well as fluorescein angiography and OCT were done at the initial visit and during follow-up. RESULT: In the acute phase, thickening, hyper-reflectivity of the neurosensory retina, posterior shading, bumping of the RPE, hyporeflectivity and thickening of choroid were found in 86,6% of patients. During follow-up, neurosensory retinal layers thinning and disorganization, interrupting ofthe ellipsoid zone (EZ), and RPE hyper reflective were noticed in 73% of patients. The choroid became thin and more hyperreflective in 73% of patients. Multiple hyperreflective dots in the vitreous cavity and posterior hyaloid thickening were demonstrated in the acute phase in 60% of patients, with complete resolution and detachment of the posterior hyaloid in the scarred lesions. CONCLUSION: The SS-OCT is an important adjunctive imaging modality in the diagnosis and follow-up of patients with ocular toxoplasmosis.

Retinal vasoproliferative tumor in intermediate uveitis: A case report.

INTRODUCTION: Retinal vasoproliférative tumors (VPTs) have been reported as uncommon complications of intermediate Uveitis. CASE DESCRIPTION: A patient consulted for a gradually decreased vision in the right eye (RE). The examination of the RE found a corrected visual acuity at 20/100 with normal eye pressure measured. The anterior segment was deep and quiet and 2+ vitreous haze was found. Funduscopy showed a VPT. Retinal fluorescein angiography of the RE revealed macular cystoid edema also objectified by the Optical Coherence Tomography (OCT). Intermediate Uveitis was considered idiopathic. The patient received a cryoapplication and was put on oral corticosteroid therapy with improvement of visual acuity and a regress of both vitreous inflammation and cystoid macular edema. CONCLUSION: The association of a VPT with intermediate uveitis represents a real diagnostic and therapeutic challenge and imposes rigorous care and monitoring strategy combining internist and ophthalmologist.