An investigation on optic nerve head involvement in Fuchs uveitis syndrome using optical coherence tomography and fluorescein angiography

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.

Measuring Inflammation in the Vitreous and Retina: A Narrative Review

Uveitis consists of a group of syndromes characterised by intraocular inflammation, accounting for up to 15% of visual loss in the western world and 10% worldwide. Assessment of intraocular inflammation has been limited to clinician-dependent, subjective grading. Developments in imaging technology, such as optical coherence tomography (OCT), have enabled the development of objective, quantitative measures of inflammatory activity. Important quantitative metrics including central macular thickness and vitreous signal intensity allow longitudinal monitoring of disease activity and can be used in conjunction with other imaging modalities enabling holistic assessment of ocular inflammation. Ongoing work into the validation of instrument-based measures alongside development of core outcome sets is crucial for standardisation of clinical trial endpoints and developing guidance for quantitative multi-modal imaging approaches. This review outlines methods of grading inflammation in the vitreous and retina, with a focus on the use of OCT as an objective measure of disease activity.

Peripapillary optical coherence tomography as an alternative to fluorescein angiography for monitoring Behcet's retinal vasculitis

To study the correlation of OCT parameters including central subfield macular thickness (CSMT), peripapillary retinal thickness (PRT), and peripapillary retinal nerve fiber layer thickness (PNFLT) with fluorescein angiography (FA) in evaluation of inflammatory activity in Behcet’s retinal vasculitis. In this case-series, concurrent FA and OCT were performed. A scoring system was devised for FA. PNFLT in 3.4-mm-diameter circle as well as PRT in doughnut shaped regions between the 1-mm- and 2.2-mm-diameter and between the 2.2-mm- and 3.45-mm-diameter circles was measured. The correlation of FA and OCT parameters was analyzed. A total of 105 sets of FA from 28 eyes (15 patients) were reviewed. Four (26.6%) were female and mean age was 31.6 ± 8.49 years. Each micron increase in CSMT, PRT2.2, PRT3.45, and PNFLT, caused a rise of 0.018 (95% CI 0.008–0.027, P < 0.001, r = 0.413), 0.053 (95% CI 0.035–0.070, P < 0.001, r = 0.443), 0.086 (95% CI 0.065–0.108, P < 0.001, r = 0.707), and 0.185 (95% CI 0.152–to 0.218, P < 0.001, r = 0.850) unit in FA score, respectively. Parameters having significant correlation with angiographic inflammatory activity, were CSMT, PRT2.2, PRT3.45 and RNFLT. Those with the strongest correlation, PRT3.45 and PNFLT, may be considered as quantitative non-invasive alternatives to FA for monitoring Behcet’s retinal vasculitis.

Analysis of Corneal Densitometry and Endothelial Cell Function in Fuchs Uveitis Syndrome

OBJECTIVES

To evaluate corneal densitometry and endothelial cell properties in patients with unilateral Fuchs uveitis syndrome (FUS), and to compare results with unaffected contralateral eyes and healthy control subjects.

METHODS

A total of 90 participants were included in this prospective cross-sectional study. Forty-five affected eyes of patients with FUS were regarded as group 1 (FUSa), 45 fellow eyes were regarded as group 2 (FUSf), and 45 healthy-control eyes were regarded as group 3. Corneal densitometry was measured with densitometry software of Scheimpflug Corneal Topography (Pentacam HR, Oculus GmbH, Wetzlar, Germany), whereas endothelial cell measurement was evaluated with specular microscopy (Tomey, EM4000, GmbH, Germany).

RESULTS

The mean corneal densitometry values were higher in the midstromal (zones; 2-6, 6-10 mm), posterior (all zones), and total thickness (zones; 2-6, 6-10 mm) layers in the FUSa compared with FUSf and control eyes (P<0.05 for all comparisons). The mean values of average cell area and cell size characteristics (minimum, maximum, SD, and coefficient of variation) were higher; endothelial cell density and percentage of hexagonal cells were lower in the FUSa than in the other two groups (P<0.05 for all comparisons). There was a significantly strong correlation between specular microscopy parameters and posterior corneal densitometry values in the FUSa group.

CONCLUSIONS

Impairment of endothelial cell function in affected eyes of patients with FUS resulted in increased values of corneal densitometry, especially posterior layer.

[Application of high-resolution optical coherence tomography for visualization of eye structures in uveitis of different localization]

The article presents an analysis of publications in main Russian and foreign journals devoted to the use of optical coherence tomography in intravital visualization of the structures of the eye for diagnosis, assessment of the changes during relapses, recovery and remission stages, as well as the effectiveness of treatment for uveitis of different localization. It describes in detail the results of studies conducted using spectral optical coherence tomography, changes in the anterior chamber and cornea in uveitis of the anterior localization, morphological changes in the vitreous body, vitreomacular interface, retina, choroid and optic disc in the anterior and posterior localization of inflammation, and presents the features of OCT diagnosis in a number of nosological forms of uveitis based on the literature data.

Evaluation of radial peripapillary capillary density in patients with Fuchs uveitis syndrome

PURPOSE

To quantitatively analyze the microcirculation in the peripapillary sectors in the affected eyes and fellow unaffected eyes of individuals with unilateral Fuchs uveitis syndrome (FUS) using optical coherence tomography angiography (OCTA), and to compare the radial peripapillary capillary vessel density (RPCvd) with normal and age-matched individuals.

METHODS

Eyes were divided into three groups based on the involvement of the FUS: FUS-positive eye of patients (study eye), fellow eye of FUS-positive patients (fellow eye), and the control eye for the control group (control eye). RPCvd (%) and peripapillary retinal nerve fiber layer (RNFL) thickness (μm) at eight equal sectors and two equal hemispheres were automatically calculated in peripapillary region via OCTA.

RESULTS

This study included 105 eyes of 71 patients: 34 FUS-positive eyes of 34 patients, 34 fellow eyes of FUS-positive patients, and 37 control eyes of 37 patients. RPCvd was significantly lower in study eyes than in fellow and control eyes in the peripapillary region (p = 0.044 and p = 0.005, respectively). There was no significant difference between fellow eyes and control eyes regarding RPCvd in any region (p > 0.05 for all). There were no significant differences between the three groups regarding peripapillary RNFL values (p > 0.05 for all).

CONCLUSION

OCTA is a novel technology for imaging of the RPC network in patients with FUS. Lower radial peripapillary capillary vessel density in FUS could induce capillary insufficiency and impairment of ocular blood flow to optic nerve head.