To the Editor.
—There is little factual information on the effect of pregnancy on diabetic retinopathy. Some studies seem to demonstrate that pregnancy has no effect on progression of retinopathy, while others demonstrate deterioration, which is why the excellent study by Phelps et al1 is so welcome. The views expressed in their article are provocative and intuitively appealing, but caution must be exercised in interpreting the results. Phelps and coworkers state that their study provides the first detailed evidence that deterioration of background diabetic retinopathy may be related to the degree of improvement in glycemia during pregnancy. If true, this has important clinical implications and suggests that tight metabolic control, or abrupt institution of improved diabetic regulation, could be a major factor in causing deterioration of diabetic retinopathy. Their results provide strong support for a significant correlation between deterioration in retinopathy and the degree of hyperglycemia at entry. However,
Pakalnis VA, Harp RJ. The Effect of Pregnancy on Diabetic Retinopathy. Arch Ophthalmol. 1987;105(11):1475-1476. doi:10.1001/archopht.1987.01060110021003