Corneal Endothelial Changes in Behçet's Patients with Inactive Ocular Involvement

Quantitative changes in the corneal endothelium and central corneal thickness during anterior chamber inflammation: A systematic review and meta-analysis

PURPOSE

To establish the effects of anterior chamber inflammation (ACI) on the corneal endothelium parameters and central corneal thickness (CCT).

METHODS

We conducted a comprehensive literature review using medical databases (PubMed, EMBASE, VHL, and medRxiv) on March 8, 2023, for studies that included patients with ACI who had undergone specular microscopy or pachymetry. Case series with >10 patients, cross-sectional, case-control, and cohort studies were included. The risk of bias was assessed using CLARITY tools and validated scales such as those by Hassan Murad et al. and Hoy et al. A narrative synthesis and a quantitative standardized mean difference meta-analysis, I2 heterogeneity assessment, and publication bias tests were conducted. The study was registered in PROSPERO (CRD42023420148) and approved by the Universidad del Rosario ethical committee (DVO005 2277- CV1712).

RESULTS

Thirty-four studies, encompassing 1,388 eyes with ACI, were included. Compared with healthy controls, overall, ACI eyes show significant mean differences in endothelial parameters (endothelial cell density (ECD), coefficient of variation (CV), and hexagonality (HEX)) (P < 0.05). In the subgroup analysis compared with healthy controls, both active and chronic-recurrent ACI demonstrated a reduced ECD. An increased CV was observed in active, inactive, and chronic-recurrent ACI. Lower HEX was evident in inactive, acute, and chronic-recurrent ACI, while both active and acute ACI exhibited high CCT.

CONCLUSION

ACI leads to significant alterations in endothelial parameters and CCT. The primary contributors to these changes are increased IOP, uveitis duration, and intraocular surgeries. Further studies are needed to explore the impact of ACI etiology on the endothelium, potential biases in IOP measurements during acute ACI episodes, and the potential necessity for monitoring the endothelial parameters and CCT in patients with chronic ACI.

Investigation of anterior segment structures of the eye in Behçet's disease using in vivo confocal microscopy

PURPOSE

We sought to investigate alterations in the corneal subbasal nerve plexus and endothelium in patients with Behçet's disease (BD).

METHODS

This cross-sectional study included 64 patients with BD and 30 age- and gender-matched healthy control subjects. Those with BD were classified as having ocular or non-ocular disease. All subjects underwent a corneal endothelial and subbasal nerve density evaluation using in vivo confocal microscopy (IVCM). The differences among groups were analyzed using the Kruskal-Wallis test followed by Dunn's multiple comparison procedure.

RESULTS

The mean age of study participants was 35.7 ± 10.2 years (16-58) in the ocular BD group, 39.6 ± 14.9 years (11-66) in the non-ocular BD group, and 34.1 ± 11.2 years (21-55) in the control group. No statistical significance was found in terms of age (p = 0.259) or sex (p = 0.560) between groups. The mean endothelial cell density determined with IVCM was 2124.9 [Formula: see text] 417.4 cells/mm² (1811-3275) in the ocular group and 2546 [Formula: see text] 335 cells/mm² (1798-3280) in the control group (p = 0.000). In the ocular group, the mean density of the subbasal nerve plexus was significantly lower (p = 0.004), and nerve tortuosity was significantly higher (p = 0.002).

CONCLUSIONS

Ocular BD could be responsible for changes in the corneal layers, especially endothelial and corneal nerve structures. Nerve density and tortuosity differences could be inflammatory indicators for BD.

Evaluation of corneal endothelial cell morphology by specular microscopy in patients with acute anterior uveitis

PURPOSE

To determine the structure and morphology of corneal endothelial cell layer in patients with acute anterior uveitis.

METHODS

Thirty-four eyes of 34 acute anterior uveitis patients and 34 eyes of 34 healthy subjects were included. Mean cell density, coefficient of variation, maximum cell area, minimum cell area, average cell area and hexagonality ratio values were evaluated by non-contact specular microscopy. Parameters recorded in both groups were compared.

RESULTS

The mean maximum cell area was 1054,44 ± 251,14 µm², minimum cell area was 152.29 ± 53.65 µm² and average cell area was 386.91 ± 41.73 µm² in acute anterior uveitis group and the mean maximum cell area was 1057.65 ± 261.23 µm², minimum cell area was 147.26 ± 20.45 µm² and average cell area was 383.53 ± 43.12 µm² in the control group. There were no significant differences between the two groups in terms of maximum, minimum and average cell area (respectively, p = 0.080, p = 0.72, p = 0.62, p = 0.67). The mean cell density was 2607.74 ± 277.63 cells/ µm² in acute anterior uveitis group and 2669.35 ± 265.22 cells/µm² in the control group. (p = 0.358). In acute anterior uveitis group the mean coefficient of variation was 31.68 ± 8.16, hexagonality ratio was 63.85 ± 11.14 and mean central corneal thickness was 571.47 ± 55.99 µm; in control group the mean coefficient of variation was 25.29 ± 3.00, mean hexagonality ratio was 72.6 ± 4.80% and mean central corneal thickness was 534.82 ± 33.84 µm. Statistically significant differences were seen between the two groups (respectively, P = 0,00, P = 0,00, P = 0.02).

CONCLUSION

The mean central corneal thickness and coefficient of variation values were found higher, and the hexagonality ratio was found lower in acute anterior uveitis group. Our findings suggest that intraocular inflammation in anterior chamber negatively affects the endothelial function in patients with acute anterior uveitis.

Corneal Endothelial Morphology and Thickness Changes in Patients with Gout

Objectives:

To investigate corneal endothelial cell density (ECD), morphology, and central corneal thickness (CCT) in patients with gout compared with healthy subjects.

Materials and Methods:

Fifty eyes of 50 gout patients and 50 eyes of 50 healthy subjects without gout or any other systemic disease were included in this study. After detailed ophthalmologic examination, specular microscopy (Tomey EM-4000; Tomey Corp) measurement was performed for all participants. ECD, average cell area (ACA), coefficient of variation (CV), hexagonality ratio, and CCT values were recorded.

Results:

Mean ECD and hexagonality ratio were lower (p=0.004 and p=0.002) and CV, ACA, and CCT values were higher (p=0.001, p=0.007, and p=0.001) in patients with gout when compared to healthy subjects. There were significant correlations between gout disease duration and CD and hexagonality ratio (p=0.019 and p=0.043) and also between uric acid value and hexagonality ratio and CCT (p=0.044 and p=0.003).

Conclusion:

Altered corneal endothelial function was found in patients with gout when compared to healthy subjects and the alteration increased as gout duration and uric acid value increased.