Abstract
Purpose: :
To evaluate vitreo-macular findings including cystic macular changes, epiretinal membrane (ERM), vitreomacular traction (VMT) and foveal atrophy in patients with retinitis pigmentosa (RP) using spectral-domain optical coherence tomography (SD-OCT).
Methods: :
: Records of 25 patients (48 eyes) with non-syndromic RP, who had undergone Spectralis OCT testing, were analyzed. Two eyes that were excluded had poor quality OCT scans, hence data could not be analyzed. The age, gender, mode of inheritance, and visual acuity obtained on each patient were noted. Spectralis OCT scans were performed using a 6 x 6 volumetric scan with 30 raster lines spaced 200 microns apart. Central subfield (CSF) thickness was analyzed using the retinal thickness profile. Cross-sectional scans were viewed to document the presence or absence of ERM. Those eyes that showed an ERM were then divided into 3 groups: Group 1 with extrafoveal ERM (>500 microns from fovea); Group 2 with foveal ERM and loss of foveal architecture + cystic changes; and, Group 3 associated with VMT. Foveal atrophy, based on OCT criteria, was defined as a CSF thickness of <224 µm.
Results: :
The age range of the patients was 34-74 years (average age = 52 yrs) and the visual acuity ranged from 20/20 to finger counting. Out of 48 eyes that were evaluated, ERM was detected in 28 eyes (58%) with an average CSF of 295 µm. ERM was present in at least 1 eye in 16 eyes, and bilateral in 12 eyes. Of the 28 eyes with ERM, 18 (64%) were in Group 1, 6 (22%) in Group 2 and 4 (14%) in Group 3. The mean CSF in the above groups was 245 µm, 335 µm, and 461 µm, respectively. Foveal cystic changes were present in 8 (17%) eyes with 2 eyes showing bilateral changes. Foveal atrophy, by OCT criteria, was seen in 10 (21%) eyes.
Conclusions: :
The new generation Spectralis SD-OCT is useful in identifying vitreo-macular changes in patients with RP that may be missed on clinical examination. Apart from the diagnostic and prognostic implications, it can be useful in selecting and predicting treatment outcomes in patients with RP and associated vitreo-macular changes.
Keywords: retinal degenerations: hereditary • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • macula/fovea