Diabetic eye disease can be a devastating diagnosis for patients, as it leads to sight-threatening complications for an estimated 4.4% of those with diabetes.1 And while newer therapies such as anti–vascular endothelial growth factor injections have been a boon for most patients with nonproliferative diabetic retinopathy, the mainstay therapy for the proliferative form remains panretinal photocoagulation (PRP).2
Unfortunately, laser photocoagulation can cause its own problems, including nyctalopia, reduced contrast sensitivity, visual field constriction and optic atrophy.3 A new study suggests clinicians should add reading ability to the list of activities affected by the therapy—and testing a patient’s visual acuity may not uncover the deficit.4
Researchers studied 30 patients treated with PRP and 15 controls and recorded best-corrected visual acuity, the Minnesota reading test, frequency-doubling perimetry (FDP) and fundus photography. They found PRP-treated patients had worse reading acuity and needed bigger critical print size compared with the controls, although their reading speed was no different than it was for controls. The investigators also found reading acuity was positively correlated with acuity and negatively correlated with perimetry foveal threshold.
They concluded that the Minnesota reading test may be a useful tool for better understanding patients’ reading abilities post-treatment and how that may affect quality of life. “These findings may lead to improved means to evaluate and enhance vision following treatment for PDR,” they stated.
1. Zhang X, Saaddine JB, Chou CF, et al. Prevalence of diabetic retinopathy in the United States, 2005-2008. JAMA. 2010;304(6):649-56.
2. Wong TY, Kawasaki R, Ruamviboonsuk P, et al. Guidelines on diabetic care: the international council of ophthalmology recommendations for screening, follow-up, referral and treatment based on resource settings. Ophthalmology. 2018;125(10):1608-22.
3. Fong DS, Girach A, Boney A. Visual side effects of successful scatter laser photocoagulation surgery for proliferative diabetic retinopathy: a literature review. Retina. 2007;27(7):816-24.
4. Omari A, Niziol LM, Gardner TW. Reading deficits in diabetic patients treated with panretinal photocoagulation and good visual acuity. Acta Ophthalmol. April 9, 2019. [Epub ahead of print].