Diagnostic and Therapeutic Challenges Edited by H. Richard McDonald Submitted by Drs. Naresh Mandava and Heather Bartlett; Commented by Dr. Lucy H. Y. Young and Dr. H. Logan Brooks Jr. T his case was submitted by Drs. Naresh Mandava and Heather Bartlett of the Rocky Mountain Li- ons Eye Institute in Aurora, Colorado. Case Report A 47-year-old female native of American Samoa was referred for 3 months of gradual, severe loss of vision in both eyes. She stated that her vision had previously been normal by eye exami- nation. The patient had been treated for pneumonia 1 week before the onset of visual loss, and the infection resolved with 2 weeks of antibiotic treatment. Visual acuity was hand motions in the right eye and 20/100 in the left eye. The pupils were unremarkable. Results of slit-lamp examination were within normal limits, with no anterior chamber cell or flare. Intraocular pressure by applanation tonometry was 14 mmHg in both eyes. Vitreous examination revealed no cells and a clear vitreous cavity. Funduscopic examination of the right eye showed a dense vascularized membrane centered over the papillo- macular area (Fig. 1A). The membrane appeared to be predomi- nantly epiretinal and had a round, whitish yellow lesion in its center. The optic nerve was obscured by the membrane. Peripheral retinal vasculature appeared normal. Funduscopic examination of the left eye showed a dense avascular epiretinal membrane that distorted the macular area (Fig. 1B). The optic nerve and peripheral vasculature were normal. Fluorescein angiography was performed at the initial visit (Fig. 2). Evaluation A complete history was obtained, and physical examination was performed. The patient had previously been diagnosed with mild hypertension and borderline non–insulin-dependent diabetes. Her blood pressure was well managed with a single antihypertensive agent, and good glycemic control was obtained with an oral agent. Additional systemic evaluation included determination of complete blood cell count with differential cell count and hemoglobin elec- trophoresis. These studies excluded sickle-cell disease, but the findings were consistent with previously undiagnosed -thalasse- mia minor. Levels of serum electrolytes, angiotensin-converting enzyme, lysozyme, antinuclear antibodies, and rapid plasma reagin were all within normal limits. Findings of chest roentgenography and urinalysis were normal. We asked experts for their opinion. Dr. Lucy H. Y. Young (Boston, MA): The authors describe a 47-year-old woman with severe visual loss in both eyes from bilateral macular epiretinal membrane (right eye greater than left eye) without any signs of vitreous inflammation or periph- eral retinal vascular abnormalities. Her medical his- tory was significant for well-controlled hypertension and non–insulin-dependent diabetes. A complete blood count with differential cell count and electro- phoresis excluded sickle-cell disease but confirmed -thalassemia minor. Unfortunately, the photographs are not of the best quality, and without a stereo view, it is not clear where the yellowish amorphous lesion is exactly located. Assuming that the authors’ description of the macular lesion is accurate (i.e., epiretinal membrane and not subretinal), the yellow lesion may be old hemolyzed sub–internal limiting membrane hemorrhage. The presence of retinal hemorrhage around the fibrovas- cular lesion in the right eye is suggested in the pre- operative fundus photograph and is much better de- picted by fluorescein angiography as a sheet of 214