PURPOSE: To examine the potential of abnormal mfERGs to predict the development of diabetic retinopathy at corresponding retinal locations 1 year later. METHODS: One eye of 11 diabetic patients with nonproliferative diabetic retinopathy (NPDR) and 11 diabetic patients without retinopathy were retested 12 months after initial testing. At each time, mfERGs were recorded from 103 retinal locations, and fundus photographs were taken within 1 month of each recording. Local mfERG implicit times were measured and their z-scores were calculated based on results obtained from 20 age-matched control subjects. mfERG abnormalities were defined as z-scores of 2 or more for implicit time and z-scores of -2 or less for amplitude (P < or = 0.023). mfERG z-scores were mapped onto fundus photographs, and the relationship between baseline abnormal z-scores and new retinopathy at follow-up was examined. RESULTS: New retinopathy developed in 7 of the eyes with NPDR after 1 year. In these eyes, 70% of the mfERGs in areas of new retinopathy had abnormal implicit times at baseline. In contrast, only 24% of the responses in regions that remained retinopathy free were abnormal at baseline. Relative risk of development of new retinopathy over 1 year in the areas with abnormal baseline mfERG implicit times was approximately 21 times greater than that in the areas with normal baseline mfERGs (odds ratio = 31.4; P < 0.001). Eyes without initial retinopathy did not develop new retinopathy within the study period, although 4 of these 11 eyes had abnormal implicit times at baseline. mfERG implicit times tended to be more delayed at follow-up than at baseline in NPDR eyes, but not in eyes without retinopathy and control eyes. mfERG amplitudes had no predictive power. CONCLUSIONS: Localized functional abnormalities of the retina reflected by mfERG delays often precede the onset of new structural signs of diabetic retinopathy. Those functional abnormalities predict the local sites of new retinopathy observed 1 year later.
PURPOSE: To examine the potential of abnormal mfERGs to predict the development of diabetic retinopathy at corresponding retinal locations 1 year later. METHODS: One eye of 11 diabeticpatients with nonproliferative diabetic retinopathy (NPDR) and 11 diabeticpatients without retinopathy were retested 12 months after initial testing. At each time, mfERGs were recorded from 103 retinal locations, and fundus photographs were taken within 1 month of each recording. Local mfERG implicit times were measured and their z-scores were calculated based on results obtained from 20 age-matched control subjects. mfERG abnormalities were defined as z-scores of 2 or more for implicit time and z-scores of -2 or less for amplitude (P < or = 0.023). mfERG z-scores were mapped onto fundus photographs, and the relationship between baseline abnormal z-scores and new retinopathy at follow-up was examined. RESULTS: New retinopathy developed in 7 of the eyes with NPDR after 1 year. In these eyes, 70% of the mfERGs in areas of new retinopathy had abnormal implicit times at baseline. In contrast, only 24% of the responses in regions that remained retinopathy free were abnormal at baseline. Relative risk of development of new retinopathy over 1 year in the areas with abnormal baseline mfERG implicit times was approximately 21 times greater than that in the areas with normal baseline mfERGs (odds ratio = 31.4; P < 0.001). Eyes without initial retinopathy did not develop new retinopathy within the study period, although 4 of these 11 eyes had abnormal implicit times at baseline. mfERG implicit times tended to be more delayed at follow-up than at baseline in NPDR eyes, but not in eyes without retinopathy and control eyes. mfERG amplitudes had no predictive power. CONCLUSIONS:Localized functional abnormalities of the retina reflected by mfERG delays often precede the onset of new structural signs of diabetic retinopathy. Those functional abnormalities predict the local sites of new retinopathy observed 1 year later.
Authors: Wendy W Harrison; Marcus A Bearse; Jason S Ng; Nicholas P Jewell; Shirin Barez; Dennis Burger; Marilyn E Schneck; Anthony J Adams Journal: Invest Ophthalmol Vis Sci Date: 2011-02-09 Impact factor: 4.799
Authors: Marcus A Bearse; Anthony J Adams; Ying Han; Marilyn E Schneck; Jason Ng; Kevin Bronson-Castain; Shirin Barez Journal: Prog Retin Eye Res Date: 2006-09-01 Impact factor: 21.198
Authors: Bruce A Berkowitz; Marius Gradianu; David Bissig; Timothy S Kern; Robin Roberts Journal: Invest Ophthalmol Vis Sci Date: 2008-12-13 Impact factor: 4.799
Authors: Marilyn E Schneck; Marcus A Bearse; Ying Han; Shirin Barez; Carl Jacobsen; Anthony J Adams Journal: Doc Ophthalmol Date: 2004-05 Impact factor: 2.379