Pupil Dilation for Retinal Photography
Diabetic retinopathy remains the number-one cause of blindness and moderate to severe vision loss in the developed world with resultant drain on productivity and health care costs. While treatments can arrest its development they rarely restore lost vision. Therefore, in spite of proven effective treatment, diabetic retinopathy and the accompanying maculopathy remain the leading cause of new blindness and blindness in the working population, not only in the United States, but throughout the developed world. Repeated screenings with progressive evaluation of changes occurring in an individual to evaluate the development and progression of the disease appear to be the only method to limit or prevent the vision loss.
Although annual fundus examination by an eye care provider has been the traditional method recommended pursued for screening and may be adequate when completed with pupil dilation by a provider with experience and training, however only 35%-55% of the patients are screened annually. Although most diabetic patients believe that yearly eye examinations are needed, several factors appear to underlie the reduced rate of their compliance. While patients may be aware of the potential severe problems of retinopathy, as long as they perceived no visual complaints, they do not personalize the risk of this complication or potential for injury. In addition, the problem of compliance was significantly compounded by the required maximal pupil dilation that caused loss of an entire day’s work.
Retinal photography appears to offer a viable and even preferable, cost-efficient method for screening, not just for diabetic retinopathy, but macular degeneration, HIV/Aids associated retinopathy, glaucoma, among others. Non-mydriatic cameras, which have the potential for photographing the retina without pupil dilation, are focused through the pupil in the dark using infra-red light that allows the patient’s pupil to dilate naturally, and then a flash is taken before the pupil can constrict. Subsequent photographs must await pupil relaxation again in the same eye or the fellow eye. While these cameras can be utilized by a relatively inexperienced technician, the requirement for 5 overlapping fields prolongs the photography acquisition time, including focusing, etc. to 15-20 minutes or more. In the elderly with smaller pupils and coexistant cataracts the images often are poorer than desired for adequate documentation of the retinopathy. New cameras which require a small degree of dilation are also available. Sinclair Technologies has developed a dilating agent that can accomplish the required small degree of dilation in approximately 10 minutes, but after photography does not interfere with work or outdoor activities. This we believe will significantly improve the efficiency, efficacy of the photography while at the same time improving compliance.
The topical medication is undergoing FDA approval.