Glaucoma monitoring important in corneal dystrophy

Jul 18 2012

By Sarah Guy

The prevalence of glaucoma and/or ocular hypertension (G/OHTN) is more frequent in individuals with severe Fuchs' endothelial corneal dystrophy (FECD) than those without the condition, suggesting the importance of glaucoma screening in such patients, suggest US researchers.

Their findings emerge from a review of data from the FECD Genetics Multi-Center Study, and include an association between severe FECD ‑ as measured on a 7-point severity scale based on guttae confluence ‑ and G/OHTN in affected family members as well as FECD patients (index cases).

The results indicate a possible genetic link between the two processes, say the researchers.

"FECD… can result in vision loss through progressive stages of endothelial dysfunction and corneal edema," explain Jonathan Lass (University Hospitals Case Medical Center, Cleveland, Ohio) and colleagues in the Archives of Ophthalmology.

"Additionally, recent high-resolution corneal shape analyses identified posterior corneal thickness and elevation into the anterior chamber angle in eyes with FECD, presumably contributing to a narrow or crowded angle and a resulting glaucomatous process," they add.

A total of 107 participants of the FECD Genetics study had G/OHTN, as did 33 of the 551 control participants with an FECD grade 0 (indicating no guttae) recruited for comparison.

The researchers grouped index cases according to severity: FECD grade 1 through 3 indicating mild or moderate severity; grade 4 through 6 indicating severe FECD. Close relations of the index participants who also had FECD were categorized in the same way.

Both index cases and family members with FECD grade 1‑3 had a lower prevalence of G/OHTN, at 0.0% and 2.1%, than their peers with FECD grade 4‑6, at 11.2% and 8.5%, respectively.

Severe FECD index patients had higher odds for G/OHTN relative to the control group, with an odds ratio of 2.10 after adjustment for potentially confounding factors. Mild-to-moderate FECD showed no association with increased G/OHTN odds, however.

Similarly, write Lass et al, affected family members with severe FECD had a 7.06-fold increased odds for G/OHTN compared with unaffected family members after adjustment.

G/OHTN prevalence was not significantly different between index cases or affected family members for either moderate or mild FECD, the team reports.

More conclusive glaucoma diagnosis with visual field testing would have been useful, remark the authors, who say that despite the associations they report, "it becomes difficult to establish causality."

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