Purpose
To describe sequential chorioretinal changes in presumed ocular histoplasmosis syndrome (POHS) using spectral-domain optical coherence tomography (SD-OCT).
Methods
Patients with clinical diagnosis of POHS who underwent Spectralis SD-OCT on more than two visits were retrospectively included. Those with other concurrent posterior segment disease, history of intraocular surgery and prior treatment for choroidal neovascularization (CNV) secondary to POHS were excluded. SD-OCT volume scans consisting of 19 or 25 B-scans covering ~20 degrees of the retina centered at fovea were used. Eyes were divided into 3 groups: (1) no CNV at initial SD-OCT but active CNV formation on follow up (primary group, 4/28 eyes), (2) active CNV at initial SD-OCT (progressive group, 8/28 eyes), and (3) contralateral asymptomatic control eyes of patients with active CNV (control group, 16/28 eyes). SD-OCT volumes were analyzed for sequential chorioretinal changes at each visit.
Results
28 eyes were included. Mean age was 57±16.7 (20-87) years. Mean duration of follow up was 19.5±10.9 (1-40) months and mean SD-OCT volumes analyzed for each eye was 6±3.5 (2-14). Initially, primary group demonstrated disruption of external limiting membrane (ELM), ellipsoid zone and retinal pigment epithelium (RPE)/Bruch’s complex in 100%, pigment epithelial detachment (PED) in 75% and hyper-reflective foci in the choroid in 25% of eyes. All these eyes developed active CNV during follow up (Figure). Progressive group had CNV with intraretinal, subretinal or sub-RPE fluid in all eyes. Initally, control group showed disruption of ELM, ellipsoid zone and RPE/Bruch’s complex and PED in 19%, 38%, 50% and 19% of eyes respectively. On follow up, 2 and 3 additional eyes respectively developed ELM disruption (5/16, 31%) and PED formation (6/16, 38%).
Conclusions
SD-OCT is a useful tool to sequentially follow eyes with POHS for subtle chorioretinal changes. Such changes may occur independent of the chorioretinal histoplasmosis lesions seen clinically, may suggest impending CNV development, and hence, may require close monitoring. Future larger studies of eyes followed prospectively are expected to help understand the natural progression of POHS and secondary CNV formation.