I. Case History • Demographics: 71-year-old African American male • Chief complaint: decline in vision over the last year with metamorphopsia, more noticeable in the left eye. He also noticed mild flashes of light and , which he reported were stable. • Ocular history: o History of bilateral proliferative sickle cell due to sickle cell trait, history of bilateral tractional retinal detachments, bilateral pseudophakia, history of chronic anterior with steroid response leading to in the right eye • Medical history: o Stage 3A chronic kidney disease, hyperlipidemia, anemia, hypertension and sickle cell trait • Medications: o Cosopt BID OU, Losartan 100 mg QD PO, Tamsulosin 0.4 mg QD PO II. Pertinent Findings • Clinical: o BCVA OD 20/200; OS 20/50+2; NIPH OU o ▪ OD: surgical , minimally reactive to light, (+) reverse APD ▪ OS: round, reactive to light o Confrontation Fields: 360 constriction OD>OS o IOP: 22 mmHg OD, 13 mmHg OS at 11:32 AM o Slit lamp examination: diffuse endothelial pigment OD, irregular pupil secondary to ACIOL OD o Dilated fundus examination: ▪ OD: 0.35 C/D ratio, (-)NVD; ERM with macular folds, thickening, and pseudohole; attenuated vessels; PRP scars 360; (-)NVE ▪ OS: unable to assess ONH cupping secondary to large fibrotic scar extending from ONH to superior temporal arcades, (-)NVD; ERM with macular folds, fibrosis, thickening, and exudates temporal to the macula with adjacent intraretinal hemes; attenuated vessels; PRP scars 360, (-)NVE • Additional testing: o Macular HD 5-Line: abnormal foveal contour, pseudohole with cystic spaces from ERM OD; absent foveal contour, ERM with large cystic spaces OS o 512x128 Macular Cube: central macular thickness 252 um, greatest thickness where pseudohole is present OD; central macular thickness 592 um, diffuse thickness OS • Laboratory studies: o (+) Sickle cell trait, elevated antithrombin III, elevated homocysteine, negative anticardiolipin, non- reactive RPR, normal activated protein C resistance III. Differential Diagnoses for Distorted Vision • Epiretinal membranes (ERMs) – collections of avascular fibrous cells that multiply and spread along the surface of the creating a sheet-like membrane. These cells have the ability contract, which can lead to metamorphopsia and decreased vision in the more advanced stages1. • Vitreomacular traction – occurs following the progression of a posterior vitreous detachment. A tractional force is applied to the macula as a result of persistent macular adherence2. • Age-related – includes macular pigmentary changes and in the early stages. In the late stages, clinical features include geographic atrophy and neovascular membranes3. • Tractional retinal detachments – occur secondary to strong adhesions between the retina and fibrovascular membranes4. IV. Diagnosis and Discussion • The patient presented with decreased vision and metamorphopsia that had been slowly worsening over the last year. The symptoms of epiretinal membranes can range from no visual disturbances to severe visual disability with metamorphopsia, Amsler grid changes, and/or reduced visual acuity. • Clinically, ERMs are seen as gray-white membranes that can vary from glistening and subtle in appearance to thick and opaque. Depending on the severity, ERMs can cause wrinkling and folding of the retina, dragging of the retinal vessels, , or macular holes and pseudoholes1. • The formation of secondary epiretinal membranes, such as those in this case, are thought to occur as an abnormal response to wound healing. Following damage to the macula and surrounding retina, inflammation occurs which releases a variety of inflammatory cells. This inflammatory response triggers the proliferation and migration of glial and collagen cells to form a contractile membrane over the area of damage5. • According to a study by Carney and Jampol, the incidence of epiretinal membranes in patients with sickle cell disease was 3.7%. Most ERMs observed were mild, while severe macular pucker was only observed in patients who had repairs6. • With extensive retinal damage, as seen in this patient, severe secondary ERMs are inevitable. His ERMs are severe, with bilateral macular folds and thickening. Diagnosis was made through clinical examination and confirmed using an OCT. V. Treatment and Management • Epiretinal membranes are treated in many ways depending on the clinical findings and visual function of the patient. Options include close monitoring, vitrectomy, peeling, and internal limiting membrane peeling1. • The visual prognosis for patients with epiretinal membranes is variable. The outcome depends on the presence or absence of macular edema, the severity of the membrane, comorbidities, and the treatment plan chosen. A study reviewing visual outcomes following epiretinal membrane surgery completed over 10 years showed that patients who had undergone surgery achieved the best visual outcome and subjective visual function1. • This patient had been provided the following treatments for proliferative : 1237 spots of PRP OD at 200 microns, 340 spots of PRP OS at 200 microns, pars plana vitrectomy OU, cryotherapy OD, ACIOL OD, and intravitreal Avastin OS. After consultation with the on-staff retinal specialist, it was determined that this patient is not a surgical candidate due to his essentially monocular status and potential for further visual detriment. He is being followed with dilated fundus examinations and OCT scans every 4 months to monitor for new and progression of the epiretinal membranes. VI. Bibliography 1. Theng, K., Oh, MD., Hampton, R., Sr, MD, & Drouillhet, J. H., MD. (2017, January 06). Epiretinal Membrane. Retrieved from http://emedicine.staging.medscape.com/article/1223882-overview#a5 2. Captain Christopher M. Putnam, O.D., and Lieutenant Colonel Randall S. Collins, O.D. (2010, April 16). When to Monitor or Treat VMT. Retrieved from https://www.reviewofoptometry.com/article/when-to-monitor- or-treat-vmt 3. Zarbin, M. A. (n.d.). Age-related macular degeneration: Clinical findings, histopathology and imaging techniques. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24732758 4. Pandya, H. K., MD. (2016, December 07). Retinal Detachment. Retrieved from http://emedicine.medscape.com/article/798501-overview#a5 5. Stevenson, W., Ponce, C. M., Agarwal, D. R., Gelman, R., & Christoforidis, J. B. (2016, March 29). Epiretinal membrane: Optical coherence tomography-based diagnosis and classification. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4820189/ 6. Carney, M. M. (1987, February 01). Epiretinal Membranes in Sickle Cell Retinopathy. Retrieved from http://jamanetwork.com/journals/jamaophthalmology/article-abstract/636515 VII. Conclusion • Although an epiretinal membrane is not one of the most common findings in sickle cell retinopathy, its presence should not be overlooked. It is important to carefully evaluate these patients regularly as their visual prognosis is guarded and their ocular findings can change rapidly. The treatment of an ERM in these patients must be carefully considered, as they often have a variety of retinal issues contributing to decreased vision, and surgery may not always improve the final visual outcome.