Abstract
Purpose: :
OCT was used to measure the thickness of various retinal cell layers of patients after successful macular-off retinal detachment repair. Findings were compared to a group of controls.
Methods: :
All patients were treated by vitrectomy, encircling band and SF6 tamponade. Spectralis OCT™ was used to perform OCT scans. Special analysis software was designed to perform sub-segmentation and thickness measurements on various retinal cell layers. Visual recovery was compared between groups.
Results: :
Eighteen patients were included in group 1 with a follow up period of up to 8 weeks (range 12 to 49 days), 16 patients were in group 2 with a follow up of > 8 weeks (range 60 to 438 days), and 21 age-matched controls were included. The OCT sub-segmentation algorithm worked well in all cases and various retinal tissue layers could be identified. The nerve fiber layer (NFL) was significantly thicker in controls (mean 30.28 μm) compared to group 1 (mean 41.89 μm, p<0.0001) and 2 (mean 36.24 μm, p=0.001). The ganglion cell layer-inner plexiform layer complex (GCL-IPL) was significantly thinner in group 2 (mean 62.63 μm) compared to controls (mean 73.71 μm, p=0.003) and group 1 (mean 73.16 μm, p=0.021). The outer nuclear layer (ONL) was significantly thicker in controls (mean 91.58 μm) compared to group 1 (mean 83.39 μm, p=0.0011) and to group 2 (mean 85.32 μm, p=0.025). The retinal pigment epithelium-photoreceptor inner/outer segment complex (RPE-IS/OS) was found to be significantly thicker in controls (mean 66.6 μm) compared to group 1 (mean 55.55 μm, p<0.0001) and group 2 (mean 64.26 μm, p=0.001). In addition, the RPE-IS/OS complex was significantly thicker in group 2 compared to group 1 (p=0.001). Mean post-operative logMAR snellen visual acuity improved from 1.54 to 0.74 in group 1 (p=0.001) and from 1.33 to 0.56 in group 2 (p=0.001).
Conclusions: :
Retinal sub-segmentation and thickness measurements in the early postoperative period (up to 8 weeks) reveals thickening/swelling of the NFL and significant reduction in ONL and RPE-IS/OS complex thickness. In patients with longer follow-up (> 8 weeks) NFL swelling shows regression. Interestingly the GCL-IPL complex shows marked thinning/atrophy and the ONL and RPE-IS/OS complex thickness seems to recover by increasing in thickness but not reaching values of controls. Visual improvement after surgery was significant and time dependent.
Keywords: retinal detachment • imaging/image analysis: clinical • vitreoretinal surgery