Changes in corneal endothelial cell density in patients with primary open-angle glaucoma

Abstract

BACKGROUND Glaucoma is a group of diseases characterized by a specific pattern of optic nerve neuropathy and retinopathy. Increasing evidence demonstrates glaucoma associated corneal endothelium loss. Direct-compression mechanism due to elevated intraocular pressure (IOP), cell toxicity after long term exposure to preservatives and glaucoma surgery have been reported to be the possible mechanism. Herein, we compare the specular endothelial microscopy in primary open-angle glaucoma (POAG) patients and healthy controls of the same age group to observe the corneal endothelium changes and the correlations to the mean IOP in a Chinese case control study. AIM To investigate corneal endothelial cell density in Chinese patients with POAG. METHODS A case control study was performed on 60 eyes of 60 patients with POAG. Exclusion criteria included history of corneal diseases, intraocular diseases, contact lens use, ocular trauma or surgery (including intraocular surgery and laser treatment), congenital abnormalities or systemic diseases such as diabetes. Intraocular pressure was measured using Goldmann tonometry. Indirect specular microscopy (TOPCON SP-2000P) was performed on central corneas and endothelial images were acquired. Endothelial cell density, area and cell counts were analyzed. RESULTS Endothelial cell density was 2959 ± 236 cells/mm 2 in healthy controls and 2757 ± 262 cells/mm 2 in patients with POAG. The POAG eyes had significantly lower endothelial cell density compared to healthy control eyes ( P < 0.001). In the POAG group, endothelial cell density was 2686 ± 233 cells/mm 2 in the patients receiving medication and 2856 ± 272 cells/mm 2 in the untreated subgroup. The eyes receiving medication had significantly lower endothelial cell density compared to untreated eyes. There was a negative correlation between cell density and mean IOP ( r = −0.286, P = 0.004), positive correlation between the average cell area and mean IOP ( r = 0.228, P = 0.022), maximum cell area and mean IOP ( r = 0.218, P = 0.029) and minimum cell area and mean IOP ( r = 0.290, P = 0.003). The percentage of hexagonal cells was not correlated with mean IOP. CONCLUSION Patients with POAG have lower corneal endothelial cell density than healthy controls of the same age. This may be attributed to mechanical damage from elevated IOP and toxicity of glaucoma medications.

Long-term Effects of Uncomplicated Traumatic Hyphema on Corneal and Lenticular Clarity

“…However, the lack of correlation between both ECL and change in Lens Zone 1 densitometry and the degree of hyphema supports the idea that the severity of trauma is not related to the amount of blood in the anterior chamber. Former studies have discerned an association between high IOP and ECL, charging the mechanism of direct compression damage and glaucoma medication toxicity [26,27]. In spite of absence of cases with a permanent IOP increase in this series, high IOP values due to hyphema were reported in the early period and antiglaucomatous treatment was started rapidly and discontinued after hyphema resolution and IOP remained at normal levels after discontinuation of medications.…”

Progression of Corneal Endothelial Insult by Chronic Elevation of intraocular Pressure: A prospective Observational Comparative Study Among Primary Open Angle Glaucoma Patients

“…This study revealed early affection of CV% and HEX% but not CEC density, which occurred in the interval period of chronic IOP elevation before the diagnosis of glaucoma has been made. Yu ZY et al reported that elevated IOP cause destruction of the HEX% and the damage of the cells causes further deformation and loss, but he didn't correlate these changes of corneal endothelial cells to PRNFL thickness nor macular GCC thickness 23 Morphological changes detected in early glaucoma with controlled IOP could be attributed only to IOP changes as eyes with previous surgical and LASER procedures-known to affect corneal endothelium in other studies were excluded [24][25][26] . The effect of topical antiglaucoma medication on corneal endothelium is negligible according to Kwou-Yeung Wu et al, 19 .…”

Topical onion juice mitigates the morphological alterations of the cornea in the aged male rats

“…Elevated IOP may have these adverse effects on corneal endothelium either by direct pressure or indirectly through flow turbulence of aqueous humor [52]. On the other hand, if high IOP is controlled, corneal endothelium can be structurally and functionally recovered [53].…”