PURPOSE: Limited information is available on morphological and functional regeneration of photoreceptors after retinal detachment (RD) surgery. This observational clinical study compared morphological and functional changes of cones after vitrectomy for macula-off retinal detachment. DESIGN PROSPECTIVE: fellow-eye comparative case series METHODS STUDY POPULATION: Five eyes after vitrectomy with gas for macula-off retinal detachment (retinal detachment eyes, RDE) and five healthy fellow-eyes (HFE) of five patients (mean age 59.8 years, macula-off duration 0.5 days to 5.5 days) OBSERVATION PROCEDURES: Eyes were examined with AO-OCT, spectral domain OCT (SD-OCT) and microperimetry (MP) at 6 (baseline, BL) and 56 weeks (follow-up, FUP) after 23 gauge pars-plana vitrectomy and SF6 gas tamponade. Eight corresponding regions at foveal eccentricities of 2.5° (ecc 2.5) and 6.5° (ecc 6.5) were analysed in every eye. AO-OCT en-face images and SD-OCT B-Scans were graded regarding irregularity and loss of photoreceptor signals ranging from none to severe changes. The number of detectable cones at height of the inner-outer segment junction (IS/OS) and cone outer segment tips (COST) was counted manually in AO-OCT images. MP with a custom grid was used to assess retinal sensitivity at these locations.

MAIN OUTCOME MEASURES: Cone density, cone pattern regularity and signal attenuation, retinal sensitivity.

RESULTS: In comparison to HFE, RDE showed highly irregular cone patterns in AO-OCT and irregular outer retinal bands in SD-OCT. Despite significant improvement of cone pattern regularity compared to BL (p<.001), 63% of AO images showed remaining cone pattern irregularity and 45.5% of SD-OCT B-Scans severe signal reduction at FUP. In HFE, mean cone density retrieved from IS/OS & COST remained around 20 000/mm (ecc 2.5°) and 16 000/mm (ecc 6.5°) at BL and FUP. Cone density of RDE was significantly reduced and ranged between 200/mm and 15 600/mm (p<.001) at BL. Despite improvement at FUP (p<.001), mean cone density at IS/OS and COST was still lower compared to HFE and ranged between 7 790 and 9 555 cones/mm (p<.001). Mean retinal sensitivity of all measured locations remained 18dB in HFE and was significantly lower in RDE with 14.30dB at BL and 14.64dB at FUP. Both, SD-OCT grading and microperimetry sensitivity showed strong correlation with AO-OCT grading and cone density (rho-values >.750).

CONCLUSIONS: The combination of AO-OCT, SD-OCT and microperimetry is a powerful tool to capture cone regeneration after vitreoretinal surgery. Our study shows that cone morphology and function improve within 56 weeks after RD surgery but structural and functional impairment is still present.