Evaluation of the retina, choroid and optic disc vascular structures in individuals with a history of COVID-19.

INTRODUCTION: In this study, we aimed to detect changes in posterior segment structures and vascular density caused by COVID-19 using an optical coherence tomography angiography (OCTA) device. MATERIALS AND METHODS: The study included 20 eyes of 20 patients no systemic or ocular disease who were followed at the Ophthalmology Clinic of Health Sciences University Antalya Training and Research Hospital. The OCTA images of these individuals taken prior to contracting COVID-19 and six months after recovery were examined. RESULTS: The mean choriocapillaris blood flow was 2.00±0.13mm2 before COVID-19 and 2.08±0.23mm2 after the disease, and the mean subfoveal choroidal thickness was 247.33±7.65µm before the disease and 273.08±4.92µm after the disease, indicating a statistically significant difference (P=0.003, P=0.001, respectively). The mean retinal nerve fiber layer thickness before and after COVID-19 were 119.33±3.88 and 117.50±3.92µm, respectively, representing a statistically significant decrease (P<0.001). CONCLUSION: This is the first study in the literature to evaluate the post-COVID-19 changes in the vascular structures of the eye compared to the pre-disease values. In this study, we found statistically significant changes in choriocapillaris blood flow, subfoveal chroidal thickness and retinal nerve fiber layer thickness after COVID-19 infection. Further research with a greater sample size is needed to explore the effect of COVID-19 on these parameters.

Alteration in choroidal microvasculature determined by optical coherence tomography angiography in patients with acromegaly.

AIM: We aimed to investigate the retinal layers and macular capillary structure using optical coherence tomography angiography (OCTA) with acromegaly patients and determine the relationship between OCTA parameters and disease duration, Growth hormone (GH) and Insuline growth factor (IGF - 1) levels. PATIENTS AND METHOD: Twenty-two patients with acromegaly who were followed up in the endocrinology outpatient clinic of Sisli Hamidiye Etfal Health Training and Research Hospital, were recruited into the study. Healthy control group was consisted of 22 age and gender matched subjects. Complete opthalmological examination including best visual acuity (BCVA), axial lenght, intraocular pressure (IOP) measurement, anterior segment and fundus examination, central corneal thickness with pachymetry and OCTA measurement were performed in the patients and healthy control group. Foveal avascular zone (FAZ), foveal vascular density (FVD), parafoveal vascular density (PFVD), choroidal flow (CF), foveal thickness (FT) and choroidal thickness (CT) were compared beetwen groups. Correlation between disease duration, GH and IGF-1 levels and OCTA parameters were evaluated. RESULTS: There was no statistically significant difference between the groups in terms of BCVA, axial length, IOP, FT, FAZ, FD and PFVD. Choroidal thickness and CF was significantly high in the patients group compared to healthy controls (respectively, p = 0.003, p = 0.022). The mean follow-up period in patients with acromegaly was 90±50.2 months. There was a significant correlation between GH and subfoveal choroidal thickness in the patient group (p < 0.001, r = 0.52), a significant correlation was determined between disease duration and corneal thickness (p = 0.01, r = 0.41). In addition, an inverse correlation was detected between the IGF-1 level and the FAZ domain (p = 0.022, r= -0.34). CONCLUSION: In patients with acromegaly, choroidal vasculature seems to be more affected than the retinal vasculature.

Macular microvascular changes in resolved central serous chorioretinopaty using spectral-domain optical coherence tomography angiography.

PURPOSE: The purpose of this study was to evaluate microvascular changes in the retina and choriocapillaris in central serous chorioretinopathy (CSCR) patients with resolved serous detachment using optical coherence tomography angiography (OCTA). METHOD: 49 eyes of 46 patients with CSCR were included in the study. 32 eyes of 16 age-matched controls were included in the control group. Fundus photography, fluorescein angiography, spectral-domain optical coherence tomography and OCTA were used. Choriocapillaris (CC) flow area, foveal avascular zone (FAZ), parafoveal vascular density of superficial and deep capillary plexus of the acute and chronic CSCR groups were compared with the values of the control group. Contrary to previous studies, OCTA data were obtained at a time when there was no serous detachment. This was because we aimed at minimizing erroneous measurements that might arise due to serous detachment. RESULTS: 1- The acute CSCR patients (1.705±0.292mm2) were found to have lower choriocapillaris (CC) flow area compared to the control group (2.155±0.069mm2). (P<0.001). Lower CC flow area was found in the chronic CSCR patients (1.774±0.216mm2) compared to the control group (2.155±0.069mm2) (P<0.001). 2- Chronic CSCR patients (49.27%±3.84) had a lower parafoveal density in the superficial capillary plexus compared to the control group (52.25%±2.85) (P<0.05). 3- No statistically significant difference was found between the acute CSCR group (55.07%±6.29) and chronic CSCR group (52.65%±5.18) in terms of parafoveal density in the deep capillary plexus when individually compared to the control group (53.34%±2.7). 4-A positive correlation was found between the parafoveal density in the deep capillary plexus and central foveal thickness (CFT) in the chronic CSCR group (r=0.382) (P˂0.05) 5- No statistically significant difference was found in the FAZ of the acute CSCR group (0.258±0.054mm2) and chronic CSCR group (0.342±0.124mm2) when individually compared to the control group (0.311±0.1mm2). The largest mean FAZ area was found in the chronic CSCR group. CONCLUSION: Our study showed that the pathogenesis of CSCR is characterized by choriocapillaris and retinal microvascular changes.

The retinal nerve fiber layer, choroidal thickness, and central macular thickness in morbid obesity: an evaluation using spectral-domain optical coherence tomography.

OBJECTIVE: To assess the effect of morbid obesity on retinal nerve fiber layer (RNFL) thickness, central macular thickness (CMT), retinal ganglion cell (RGC), choroidal thickness (CT), central corneal thickness (CCT), and intraocular pressure (IOP). PATIENTS AND METHODS: Sixty-seven patients defined as having morbid or class III obesity (BMI ≥ 40; Group 1) scheduled to undergo sleeve gastrectomy surgery and 29 nonobese patients (BMI 18.50-24.99; Group 2) underwent complete ophthalmic examination for measurement of IOP, CT, RNFL thickness, CMT, RGC, and CCT. RNFL thickness, CMT, and RGC were measured using spectral-domain optical coherence tomography (SD-OCT). CT measurement was performed using the enhanced depth imaging technique of the SD-OCT. The group data were analyzed and compared using the Mann-Whitney U test and Student's t-test. The relationship between the clinical ocular variables and obesity was analyzed using the Spearman's rank correlation test. RESULTS: The mean IOP and CCT of Group 1 were found to be significantly higher (p < 0.001) and the mean RNFL, RGC, and CT significantly lower (p < 0.05) than those of Group 2. While Group 2 was found to have a slightly larger cup-to-disc ratio and Group 1 to have a thinner CMT, the differences between Groups 1 and 2 regarding these variables were not found to be statistically significant (p = 0.322 and p = 0.072, respectively). The results of Spearmen correlation analysis indicated the existence of a moderately positive correlation between IOP and BMI (p < 0.001; r = 0.5-0.6). CONCLUSIONS: We have demonstrated by SD-OCT that morbid obesity may have a significant influence on RNFL, RGC, and CT. Morbid obesity may induce inflammatory, hormonal, and metabolic changes.