This healthy 19YO male presented with 9 months of decreased vision in his left eye. He was previously diagnosed with a combined hamartoma of the RPE. Vision was 20/20 in his normal OD and 20/200OS.
Color photography shows a complex macular pucker. OCT scanning shows a diffusely hyperreflective retina with complete loss of all inner retinal band detail. The inner macular surface and epiretinal membrane have a variable shredded appearance. A hyperreflective loop is noted within this shredded material nasally.
Learning Points:
In 2017, Govetto et al. described an OCT finding of ectopic inner foveal layers (EIFL) associated with epiretinal membranes (AJO 2017;175:99-113). Findings range from mild underlying retinal changes (stage 1: thin ERM with foveal depression), widening of the ONL and loss of foveal depression (stage 2), to an ERM continuous with EIFL crossing the entire foveal area (stage 3). All retinal layers are clearly visualized in stages 1 through 3. In stage 4, as in our patient, the ERM is thick, and all retinal layers are disrupted. Vision is worse with increasing stage severity. It is also associated with worse postoperative visual recovery (Yang et al, Retina 2022;42:1472-1478).
Combined hamartomas are classically described as benign congenital lesions composed of glial cells, vascular tissue, and pigmented RPE cells. However, more recent data indicate that these lesions primarily arise from the inner retinal layers (Chawla et al, AJO 2017;181:88-96). Hamartomas and severe macular puckers can look very similar, even to some of the most seasoned retina specialists. OCT may help differentiate these entities (Ophthalmic Surg Lasers Imaging Retina 2017;48:122-125). In our experience, we feel that many ‘combined hamartomas’ described in the literature are most likely severe macular puckers with EIFL as in our case.
Fibrillary changes overlying an epiretinal membrane (ERM) were initially noted by Kim et al (AJO 2012;153:692-697), and termed schisis of the retinal nerve fiber layer by Hussnain et al (AJO 2019;207:304-312). More recently, Patel et al. described an internal limiting membrane loop configuration in some of these lesions (AJO 2026;291:292-300). Although rarely described in the medical literature, it is present in over 50% of ERMs (Russell et al., Ophthalmology Retina 2023;7:325-332). It is thought to arise from tangential tractional forces from the overlying epimacular tissue and can appear clinically as whitish retinal areas overlying a pucker. During intraoperative membrane peeling, this tissue can be mistaken for residual epimacular proliferation and should not be removed to avoid iatrogenic retinal damage.