Source: DGNews  |  Posted 1 year ago

By Karen Dente

BERLIN -- June 14, 2010 -- Acetazolamide may reverse loss of visual acuity due to cystoid macular oedema (CME) in patients with retinitis pigmentosa, according to a study presented here at the World Ophthalmology Congress (WOC) 2010.

"Approximately 20% of patients with retinitis pigmentosa will develop cystoid macular oedema which can lead to loss of visual acuity," said Antje S. Bernd, MD, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany, on June 9. "We set out to evaluate the treatment effect on visual acuity of the carboanhydrase inhibitor acetazolamide."

Dr. Bernd and colleagues enrolled 29 consecutive patients who presented with CME in both eyes among 500 patients with retinitis pigmentosa seen in their clinic between March 2007 and November 2009.

The mean age was 25 years and the prevalence of binocular CME was 17% in the retinitis pigmentosa cohort of 500 patients.

All patients included in the study were treated with acetazolamide 250 to 750 mg/d.

In 16 patients, a follow-up exam was performed following 6 to 8 weeks of treatment in which best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) were repeated.

Initially, BCVA was 0.4/0.4 (median OD/OS) and central foveal thickness as measured by OCT was 440.5/380 mcm.

Of the 16 patients who were re-examined, the BCVA improved in both eyes in 5 patients, in 1 eye in 5 patients, did not change in 2 patients, and decreased in 4 patients.

After treatment median BCVA was 0.4/0.45 and central foveal thickness improved to 332/298.5 mcm. The decrease of the foveal thickness shown by OCT was 92.5/140 mcm and was significant in both eyes (P = .008/.004) but resulted in varying visual function.

Median BCVA improved by 1 line in OS and did not change in OD.

In OS, the improvement in visual acuity was inversely correlated with the reduction in central foveal thickness.

"Our study shows that the loss of visual acuity due to cystoid macular oedema formation in patients with RP may be reversed with the administration of systemic carbonic anhydrase inhibitors such as acetazolamide," said Dr. Bernd.

Daily oral administration was shown to lead to a reduction in the central foveal thickness and cystoid macular oedema on OCT examinations.

[Presentation title: The Effect of Acetazolamide Treatment on Cystoid Macular Edema and Visual Function in Retinitis Pigmentosa. Poster 219]