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

Corneal Clarity and Tomographic Patterns in Pseudoexfoliation Syndrome: A Severity-Based Investigation

PURPOSE

The aim of the study was to investigate the corneal and anterior segment characteristics in pseudoexfoliation syndrome (PXS), depending on the severity of the disease.

MATERIALS AND METHODS

This cross-sectional study was conducted at a tertiary care hospital, in the ophthalmology department, in Turkey. Pseudoexfoliation syndrome group was classified into three groups. Pseudoexfoliative material on the part of the pupillary border was classified as group 1, on the entire pupillary border was classified as group 2, and pseudoexfoliative material on the entire pupillary border and iris surface was classified as group 3. The control group was composed of age and gender-matched individuals who had undergone a completely normal ophthalmologic examination. Scheimpflug tomography was performed to record tomographical data.

RESULTS

The PXS groups 1, 2, and 3, along with the control group, consist of 29, 32, 33, and 42 participants, respectively. There was no significant difference in age-gender distribution between patients and the control group (P>0.05). Group 3 showed significant differences in central corneal thickness compared with the control group (P=0.001). In addition, anterior chamber angle was found to be significantly lower in group 3 than the control group (P<0.001). In corneal densitometry (CD) values, significant increases compared with the control group were observed in groups 2 and 3 across all anterior annuli (P<0.001). In group 1, significant increases observed in the anterior 6-10 mm and 10-12 mm annuli (P<0.001). In the middle 6-10 mm annuluses, only group 3 showed a significant increase compared with the control group (P<0.001). In the posterior 0-2, 2-6, and 6-10 mm annuli, significant increases compared with the control were observed only in groups 2 and 3 (P=0.001, P=0.001, P<0.001, respectively).

CONCLUSIONS

Corneal densitometry values, even without an increase in intraocular pressure, have a tendency to increase in PXS depending on the severity of the disease. While minimal changes were observed in the middle layer, it was particularly noted that the effects of the disease were more prominent in the peripheral cornea.

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.

Corneal densitometry: an innovative method to quantitatively evaluate corneal changes after phacovitrectomy

BACKGROUND

To quantitatively investigate corneal changes and the correlation between corneal densitometry (CD) and endothelial parameters after phacovitrectomy.

METHODS

Thirty-eight eyes with idiopathic full-thickness macular holes (iFTMHs) and cataracts underwent phacovitrectomy. Examinations were conducted at baseline and Day 1, Day 7, Month 1, and Month 3 postoperatively. CD and central corneal thickness (CCT) were measured using Pentacam. Corneal endothelial cell density (ECD), coefficient of variation (CV), and hexagonality (HEX) were measured using specular microscopy.

RESULTS

ECD and HEX significantly decreased after surgery and the change in HEX occurred prior to CV. CCT increased immediately after surgery and recovered 3 months postoperatively. CD values increased significantly 1 day after surgery and then gradually decreased. For CD in the 0-2 mm zone, it took 1 month to recover in the central and posterior layers and 3 months in the anterior and total layers. For CD in the 2-6 mm zone, the central layer recovered at Day 7, the anterior and total layers recovered at 1 month, and the posterior layer did not recover until 3 months postoperatively. The CD within all layers in the 0-2 mm zone was positively correlated with CCT. Posterior CD in the 0-2 mm zone was negatively correlated with ECD and HEX.

CONCLUSIONS

CD is not only correlated with CCT, ECD, and HEX but also reflects the state of the whole cornea and each layer. CD can be an objective, rapid, and noninvasive tool that reflects corneal health and undetectable edema and monitors the process of lesion repair.

TRIAL REGISTRATION

This study was registered with the Chinese Clinical Trial Registry (31/10/2021, ChiCTR2100052554).

Hammered silver appearance of the corneal endothelium in Fuchs uveitis syndrome: A case report

BACKGROUND

Hammered silver appearance of the corneal endothelium is considered a characteristic change in iridocorneal-endothelial syndrome. Herein we report an interesting case of hammered silver appearance of the corneal endothelium in Fuchs uveitis syndrome (FUS).

CASE SUMMARY

A 49-year-old man with progressive vision loss in the right eye for one year was admitted to our hospital. The clinical manifestations of the patient’s right eye were mild conjunctival hyperemia, scattered stellate keratic precipitates on the corneal endothelium, normal depth anterior chamber, 2+ cellular reaction in the aqueous humor, diffuse iris depigmentation, absence of synechia, Koeppe nodules, opalescent lens, and vitreous opacity. FUS and a complicated cataract were diagnosed based on the typical clinical manifestations. The corneal endothelial changes were recorded in detail by slit-lamp examination, specular microscopy, and in vivo confocal microscopy before cataract extraction, revealing a hammered silver appearance of the corneal endothelium in the affected eye, a wide-band dark area, as well as irregular corneal endothelial protuberances and dark bodies of various sizes. Subsequently, the patient underwent phacoemulsification combined with intraocular lens implantation, and his postoperative visual acuity recovered to 1.0.

CONCLUSION

Hammered silver appearance of the corneal endothelium in FUS, which is considered a more serious manifestation of endothelial damage, is rare and may be caused by many irregular protrusions in the corneal endothelium.

Anterior segment structures in dark iris Chinese patients with unilateral Fuchs' uveitis syndrome

Purpose

To compare binocular anterior segment structures in Chinese patients with dark iris and unilateral Fuchs’ uveitis syndrome (FUS).

Methods

This was a cross-sectional study including 34 phakic eyes (17 patients) with unilateral FUS. Anterior segment parameters were measured by rotating Scheimpflug imaging camera, noncontact specular microscopy, and anterior segment optical coherence tomography.

Results

Corneal volume was higher in FUS eyes compared to unaffected eyes (p < 0.05). The iridocorneal angles were larger in FUS eyes compared to contralateral eyes (p < 0.05). Mean endothelial cell density (ECD) was lower, and the coefficient of variation in endothelial cell size and average cell area of endothelial cells (ACA) were higher, in FUS eyes (p < 0.05). Mean densitometry values of the midstromal cornea (zones with a diameter of 0–2, 2–6, or 10–12 mm), posterior (0–2, 2–6, 10–12, or 0–12 mm), or total thickness (0–2 or 2–6 mm) were higher in FUS eyes compared with unaffected eyes (p < 0.05). ECD, percentage of hexagonal cells, and ACA were strongly related to densitometry values of the midstromal and posterior cornea in the FUS eyes (p < 0.05). Smoothness index of iris was lager in affected eyes (p < 0.05).

Conclusion

In Chinese patients with unilateral FUS, loss of endothelial cells, wider iridocorneal angle, thicker cornea, higher corneal densitometry of midstromal and posterior layer, and smoother iris were observed in affected eyes compared to contralateral eyes. These data can help to elucidate anterior segment characteristics of unilateral FUS in this population.

The effect of smoking on corneal densitometry and endothelial cell morphology

PURPOSE

We investigated corneal endothelial morphology and corneal densitometry in smokers and compared our results with findings observed in non-smokers.

MATERIALS AND METHODS

This cross-sectional observational study included 100 participants (50 smokers, 50 non-smokers) aged 18-80 years in whom corneal endothelial morphology was analysed using a non-contact Tomey EM-4000 specular microscope (Tomey Corporation, Japan). The Pentacam HR system was used to measure corneal densitometry spatially in three concentric zones (from the centre to the periphery) and at three different corneal depths (from the anterior to the posterior aspects). Endothelial morphology findings and corneal densitometry values were recorded in all participants, and these results were compared between smokers and non-smokers.

RESULTS

Endothelial morphology and corneal densitometry analysis showed significantly lower endothelial cell counts (Num) in smokers (228 cells/mm² vs. 246 cells/mm², p = 0.02) in addition to increased maximum cell area (Max) values (986.5 µm² vs. 935 µm², p = 0.04). We observed no statistically significant intergroup difference in corneal densitometry values (p > 0.05 for each zone); however, we observed a moderately positive correlation between densitometry values in the 6-10 mm concentric zone and between the all total corneal zones and number of pack-years in smokers.

CONCLUSIONS

Our study highlights that among the morphometric corneal endothelial variables analysed in this study, only the Num value was significantly correlated with smoking. We observed no statistically significant intergroup difference in corneal densitometry values in this study; however, a positive correlation was observed between the number of pack-years and corneal densitometry findings. Therefore, as the pack-years increase, the increase in corneal densitometry values may indicate a decrease in corneal clarity, considering the possible contribution of secondary factors such as age.