Analysis of retinal microvasculature in Fuchs' uveitis syndrome. Retinal microvasculature in Fuchs' uveitis

Evaluation of Optical Coherence Tomography Angiography Findings in Pars Planitis and Multiple Sclerosis Associated Intermediate Uveitis in Remission

PURPOSE

To evaluate the microvasculature during remission in patients with pars planitis (PP-IU) and multiple sclerosis-associated intermediate uveitis (MS-IU) using optical coherence tomography angiography (OCT-A).

METHODS

Single-center, descriptive, case-control study was conducted. Adult patients (≥16 years) with IU in remission (PP-IU and MS-IU) and healthy age-sex matched healthy controls (HC) were enrolled to the study. Demographic/clinical features, best-corrected visual acuity (BCVA), ocular findings, neurological symptoms and preferred treatments were recorded. The presence of cystoid macular edema (CME) during follow-up was recorded. All IU patients in remission and HC subjects were scanned with OCT-A. Foveal avascular zone (FAZ) areas of superficial and deep capillary plexus (SCP/DCP) and vascular densities of SCP, DCP and choriocapillaris were obtained from OCT-A and compared between the groups.

RESULTS

Sixty-nine eyes of 37 IU patients in remission and 20 HC were included (44 eyes/23 patients in PP-IU, 25/14 in MS-IU, 40/20 in HC). No statistically significant differences were observed in terms of demographic or clinical characteristics of the patients. The vascular density in the SCP was significantly reduced in the PP-IU and MS-IU groups compared to the HC group (p < .05). Nevertheless, there were no significant changes in any of the OCTA parameters between the IU groups. Uveitis duration was found to be correlated with enlargement of the FAZ area in PP-IU (p = .039).

CONCLUSION

OCTA may not be useful in differentiating between PP-IU and MS-IU. Nevertheless, the primary implication in SCP potentially elucidates the pathogenesis of these two subtypes of IU, which are characterized by a shared pathogenesis. The monitoring of the FAZ area in the PP-IU group is valuable in terms of chronicity.

Optical coherence tomography angiography analysis methods: a systematic review and meta-analysis

Optical coherence tomography angiography (OCTA) is widely used for non-invasive retinal vascular imaging, but the OCTA methods used to assess retinal perfusion vary. We evaluated the different methods used to assess retinal perfusion between OCTA studies. MEDLINE and Embase were searched from 2014 to August 2021. We included prospective studies including ≥ 50 participants using OCTA to assess retinal perfusion in either global retinal or systemic disorders. Risk of bias was assessed using the National Institute of Health quality assessment tool for observational cohort and cross-sectional studies. Heterogeneity of data was assessed by Q statistics, Chi-square test, and I2 index. Of the 5974 studies identified, 191 studies were included in this evaluation. The selected studies employed seven OCTA devices, six macula volume dimensions, four macula subregions, nine perfusion analyses, and five vessel layer definitions, totalling 197 distinct methods of assessing macula perfusion and over 7000 possible combinations. Meta-analysis was performed on 88 studies reporting vessel density and foveal avascular zone area, showing lower retinal perfusion in patients with diabetes mellitus than in healthy controls, but with high heterogeneity. Heterogeneity was lowest and reported vascular effects strongest in superficial capillary plexus assessments. Systematic review of OCTA studies revealed massive heterogeneity in the methods employed to assess retinal perfusion, supporting calls for standardisation of methodology.

Optic coherence tomography angiography findings in fuchs heterochromic iridocyclitis

PURPOSE

To evaluate macular capillary perfusion in patients with fuchs heterochromic iridocyclitis (FHI) by using optical coherence tomography angiography (OCTA).

MATERIAL AND METHOD

A total of 19 eyes of 19 patients with unilateral FHI underwent detailed eye examination. OCTA (RTVue-XR Avanti) images were obtained from both eyes. OCTA parameters, including foveal avascular zone, superficial capillary plexus and deep capillary plexus vessel densities, were compared between the involved and fellow control eyes.

RESULTS

The median age of the patients (11 females, 8 males) was 42.0 ± 9.63 (range 24-57) years. DCP and SCP densities at the parafoveal and perifoveal area were significantly lower in the FHI eyes compared to the control eyes (44.80 ± 5.24% vs. 54.70 ± 3.76% and 43.30 ± 5.10% vs. 53.70 ± 2.73%, respectively; p < 0.05). The median FAZ was 0.29 ± 0.12 (0.11-0.42) mm² in the FHI eyes and 0.26 ± 0.09 (0.10-0.40) mm² in the control eyes. This difference did not reach statistical significance (p = 0.199).

CONCLUSION

Macular capillary perfusion was significantly reduced in both SCP and DCP in the eyes with FHI. FHI, which is known to affect the choroid layer, could also compromise macular capillary perfusion of the retina.

Contrast Sensitivity Deficits and Its Structural Correlates in Fuchs Uveitis Syndrome

Purpose

To investigate the deficits in contrast sensitivity in patients with Fuchs uveitis syndrome (FUS) and to explore the potential relationship between contrast sensitivity and ocular structure.

Methods

In this prospective study, 25 patients with FUS and 30 healthy volunteers were recruited. Eyes were divided into three groups: FUS-affected eyes (AE), fellow eyes (FE), and healthy eyes. The contrast sensitivity function (CSF) of all participants was evaluated using the quick CSF (qCSF) method. Fundus photographs were collected for the analysis of refractive media, and vascular density (VD) was assessed using optical coherence tomography angiography (OCTA). Data were analyzed and compared using the generalized estimating equation (GEE).

Results

The CSF of AE was significantly lower than that of FE and controls, while no significant difference was observed between FE and controls. Contrast sensitivity was negatively correlated with the grade of haze. No significant correlation was found between visual function and VDs in FUS eyes.

Conclusions

We found that the CSF of FUS-affected eyes was significantly reduced, and the visual impairment was predominantly caused by the refractive media turbidity.