Association between the short-term natural history of diabetic macular edema and the vitreomacular relationship in type II diabetes mellitus

Purpose: The authors ascertain the association between the short-term natural history of untreated diabetic macular edema and the vitreomacular relationship. Methods: The authors prospectively studied 82 type II diabetic patients with clinically significant macular edema over a six-month period. They used multiple linear regression analysis to evaluate the effect of ten variables on the short-term natural history of macular edema 6 months after diagnosis: age; gender; diabetes duration at diagnosis of macular edema; hemoglobin A1; insulin use; presence of proteinuria; presence of systemic hypertension, cardiac disorders, or both; degree of diabetic retinopathy; history of panretinal photocoagulation; and vitreomacular relationships, as determined by preset lens biomicroscopy. Results: At study entry, 22 (27%) eyes had vitreomacular separation and 60 (73%) eyes did not. Macular edema spontaneously resolved in 27 (33%) eyes 6 months after diagnosis. Of the 22 eyes with vitreomacular separation at study entry, 12 (55%) had spontaneous resolution of macular edema after 6 months, whereas only 15 of 60 (25%) of the eyes with vitreomacular adhesion at study entry had spontaneous resolution (P = 0.01). Stepwise regression analysis indicated that vitreomacular separation (P = 0.01) and diabetes duration (P = 0.03) contribute to resolution of macular edema. Of the 27 eyes with resolved macular edema, 17 (63%) had improved visual acuity of more than two lines, whereas no eyes had improved visual acuity if macular edema persisted. The prevalence of improved visual acuity of more than two lines was significantly higher in eyes with vitreomacular separation at study entry (36%, 8/22) than in eyes without (15%, 9/60; P = 0.04). Conclusion: Our findings suggest that vitreomacular separation may promote the spontaneous resolution of diabetic macular edema and consequently improve visual acuity.