In the case discussed here, a maculopathy caused by a mitochondrial point mutation was misdiagnosed as “atypical” age-related macular degeneration, although it can also be confused with other macular dystrophies, such as Stargardt disease. Careful consideration of the factors discussed can help not only give patients the treatment they need but avoid giving them treatment that they don’t.
Patients who are misdiagnosed not only lose the opportunity of knowing what they really have but are also deprived of the proper treatment and/or knowledge of other systemic findings associated with their diagnosis. More seriously, they may be forced to undergo unnecessary treatments that have no chance of treating their disorders.
Presented here is an “atypical” case of misdiagnosis where the patient was proactive. The patient was told she had an atypical case of age-related macular degeneration. She did not like the word “atypical” and investigated further.
Case: Atypical AMD or not
A 56-year-old white female presented for a second opinion. Another eyecare practitioner had diagnosed her in her 40s with atypical age-related macular degeneration (AMD). She was concerned about the word “atypical.”
Having heard how macular degeneration can lead to legal blindness, she wanted to know if she was going to progress. In addition, her mother died in her 50s but was already using low-vision aids for her “macular degeneration” due to poor vision. Health history was notable for type 2 diabetes and high cholesterol. Her mother also had diabetes.
Best-corrected visual acuities were 20/25-2 OD and 20/25-3 OS. External examination of the eyes revealed normal pupils, clear corneas and lenses, full eye movements in all fields of gaze, and intraocular pressures (IOP) of 18 mm Hg in each eye.
Retinal exam revealed normal optic nerve heads with 0.25 cup-to-disc ratios, normal vasculature, and normal peripheral fundus grounds.
1. Rath PP, Jenkins S, Michaelides M, et al. Characterisation of the macular dystrophy in patients with the A3243G mitochondrial DNA point mutation with fundus autofluorescence. Br J Ophthalmol. 2008 May;92(5):623-9.