Abstract
Purpose:
It has been observed in patients with diabetes that mfERG amplitudes are more variable than implicit times (IT). Sources of amplitude variation are not fully understood and need to be better characterized in this patient group. Mean ocular perfusion pressure (MOPP), a function of systolic, diastolic, and intraocular pressure, is a measure which can be altered in patients with diabetes and its co-morbidities. It is also known to fluctuate over time. This study evaluates the association between MOPP, systemic blood markers and retinal function in patients with and without vascular diseases.
Methods:
10 subjects with systemic vascular disease and 25 control subjects participated in this pilot study. Placement in the vascular disease group required the subject to be formally diagnosed and under treatment for both diabetes and hypertension. Each subject had the following measured: mfERG implicit time and mfERG amplitude (VERIS 6.3) which was averaged over the entire eye; systolic and diastolic blood pressure, intraocular pressure, and an extensive blood panel. A multivariate regression model, evaluating the association between mfERG amplitude and other factors, was created. Differences between groups were evaluated with T-Tests.
Results:
The results indicate that mfERG amplitude is associated with perfusion pressure as long as the age of the patient is controlled for properly. The best multivariate model for average amplitude included perfusion (p<0.010), mfERG IT (p<0.0001), and age (p<0.004). It was also found that the systemic vascular disease group was older (p<0.0001), had higher cholesterol (p<0.024), higher triglycerides (p<0.0001), higher CRP levels (p<0.003) and reduced amplitudes (p<0.043).
Conclusions:
mfERG amplitude is a useful, but often variable, measure of retinal function. Results of this pilot study indicate that MOPP may be one source of mfERG Amp variation in patients with and without vascular disease. Further studies with serial measures are needed to learn more about the relationship of perfusion and function in these patient groups.
Keywords: 509 electroretinography: clinical •
498 diabetes •
436 blood supply