Local diabetic retinopathy prediction by multifocal ERG delays over 3 years.
OBJECTIVE
To derive and validate a model for use in predicting local retinal areas in which nonproliferative diabetic retinopathy (NPDR) lesions will develop over a 3-year period, by using primarily the implicit time (IT) of the multifocal electroretinogram (mfERG).


METHODS
Eighteen diabetic patients were examined at baseline and at three annual follow-ups. Ophthalmic examinations, including fundus photographs and mfERG testing, were performed at each visit. Thirty-five retinal zones were constructed from the 103-element stimulus array, and each zone was assigned the maximum IT z-score within it based on 30 age-similar control subjects. Logistic regression was used to investigate the development of retinopathy in relation to baseline mfERG IT delays and additional diabetic health variables. Receiver operating characteristic (ROC) curves were used to evaluate the models.


RESULTS
Retinopathy developed in 77 of the 1208 retinal zones, of which 25 had recurring retinopathy. Multivariate analyses yielded baseline mfERG IT, duration of diabetes, and blood glucose concentration as the most important predictors of recurring retinopathy. mfERG ITs were not predictive of transient retinopathy. ROC curves based on the multivariate model for the prediction of recurring retinopathy resulted in an area under the curve of 0.95, sensitivity of 88%, and specificity of 98%. Ten-fold cross-validation confirmed the high sensitivity and specificity of the model.


CONCLUSIONS
The development of recurring retinopathy over a 3-year period can be well predicted by using a multivariate model based on mfERG implicit time. Multifocal ERG delays are promising candidate measures for trials of novel therapeutics directed at preventing or slowing the progression of NPDR.
Ng
Jason S
JS
Vision Science Program, School of Optometry, University of California at Berkeley, Berkeley, California 94720-2020, USA. jsnng@berkeley.edu
Bearse
Marcus A
MA
Schneck
Marilyn E
ME
Barez
Shirin
S
Adams
Anthony J
AJ
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000503:physiopathology*; D004596:Electroretinography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D012160:Retina / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D013997:Time Factors
D001786:Blood Glucose