Purpose:
To identify clinical and morphologic characteristics of epiretinal membranes in patients with uveitis and to pilot a new classification system for epiretinal membrane (ERM) using spectral domain optical coherence tomography (SD-OCT) and color fundus photography.
Methods:
The National Eye Institute (NEI) electronic medical record (EMR) database was queried for the terms "uveitis," "epiretinal membrane," and "ERM" over the period between 1/1/2008 and 10/31/2011. Charts thus identified were reviewed and the designation of epiretinal membrane was made using Cirrus (Carl Zeiss Meditec, Dublin, CA) OCT images when there was evidence of both an increased signal over the inner surface of the macula and tractional forces. Eyes with ERM were further classified as "OCT only," "cellophane maculopathy" (CM), and "preretinal fibrosis" (PRF) using stereo color fundus photographs. The designation "increased interface signal" (IIS) was used for eyes with increased SD-OCT signal over the inner surface of the retina without evidence of traction.
Results:
173 ERMs were identified in 118 patients with uveitis. IIS was diagnosed in 70 eyes of 52 patients. OCT only ERM was found in 52 eyes (32%), CM in 93 eyes (57%), and PRF in 19 eyes (12%). Nine ERMs could not be classified due to missing data. The mean age of ERM patients was 51 years (range 14-83), while the mean age in patients with IIS only was 41 years (range 8-79) (P=0.0041). The duration of uveitis was longer in patients with PRF (mean 14.2 years, standard deviation 13.4) than in patients with other forms of ERM (mean 8.7 years, standard deviation 8.3) (P=0.045). The mean visual acuity was 59 ETDRS letters in the OCT only ERM group, 71 letters in the CM group, and 49 letters in the PRF group. The differences between the CM and PRF groups (P= 0.0002) and the CM and OCT only groups (P= 0.0019) were statistically significant.
Conclusions:
Cellophane maculopathy is the most common type of ERM in uveitis patients, and many uveitic ERMs are detectable only with OCT. Preretinal fibrosis, which may be a more advanced form of ERM, is associated with greater duration of uveitis and more visual impairment. This new classification system using SD-OCT can aid in the detection and description of ERM in patients with uveitis, and it is useful when media opacities limit clinical or photographic assessment.
Keywords: uveitis-clinical/animal model • retina • imaging/image analysis: clinical