Age-Related Macular Degeneration
It is estimated that 6 million people in the US alone are affected and, with the aging Baby Boomer population, that figure is expected to grow at an explosive rate. AMD is a progressive disease with increased vision loss as the disease advances, particularly in the Advanced Stage.
Visual Acuity and AMD
Visual acuity testing is ineffective in determining the presence or stage of dry AMD as patients with even Moderate or Advanced Stages Dry AMD may score at or near 20/20.
Structural tests such as an OCT are a part of AMD retinal exams and are used to detect changes in the macula as a result of Dry AMD. However macular changes detected from an OCT exam are a result of permanent damage to the retina.
Research has shown Cone function degrades in early stages of Dry AMD and the Rabin Cone Contrast test to be predictive of Dry AMD Stage.
Macular Pigment Density Decrease
Case studies have shown that the Cone function degrades with a decrease in Macular Pigment Density, the part of the retina that protects the eye against oxidative stress.
Research has proven that a reduction in Macular Pigment Density is predictive of Dry AMD. The Rabin Cone Contrast test can identify patients with reduced Cone function as a result of Macular Pigment Density loss who are most at-risk for developing AMD.
Dry AMD Medication
Plaquenil is a medication frequently used for Rheumatoid arthritis, lupus as well as other connective tissue disorders.
There is a link between long-term use and subsequent development of retinal toxicity. It has been found in the pigmented ocular structures at concentrations much greater than in any other tissue in the body.
Visual acuity in retinal toxicity initially remains excellent making it difficult to identify. Symptoms include complaints of parafoveal metamorphopsia and difficulty in reading or performing fine visual tasks (due to central or paracentral scotomas). Some patients with retinopathy may be asymptomatic.
Many cases of retinal toxicity exist, but few are reported.
Regular screening helps identify toxicity early, but cannot prevent toxicity or guarantee no vision loss will occur.
Baseline ExamAll patients should have a baseline ophthalmologic exam within the first year to document any complicating ocular conditions and to establish a record of the fundus appearance and the visual field.
Types of TestsBaseline ancillary tests include Amsler Grid and perimetry (Humphrey)
Optional Color Testing
Optional Fundus Photography
Optional Specialized TestsOptional specialized tests, such as fluoreseein angiography or multifocal electroretinogram (ERG)
Possible-ExamPossible- Exam with red-free filter may enhance detection of changes.