Abstract
Purpose: :
To assess the postoperative retinal function, according to the topography of the detachment, with multifocal electroretinography (mfERG) in recent primary retinal detachment (RD) treated with vitrectomy and gas tamponade. We hypothesized that buoyancy of the gas tamponade displaces fluid to the inferior part, impairing the recovery of the inferior area.
Methods: :
Patients with recent-onset primary RD treated with vitrectomy and gas tamponade, and at least 2 months of follow-up, were included. Exclusion criteria were postoperative VA inferior to 0.1, previous macular or retinal disease, amblyopia and anterior pole opacities (except cataract). 23 patients were selected from a prospective cohort, all of them operated by the same surgeon. Written informed consent was obtained. Topography of the RD was registered at the time of the surgery. mfERG (103 elements) was carried out according to ISCEV recommendations. Two consecutive measures were performed for each patient, obtaining first order kernel (FOK) for each hexagon. Mean density of response (nV/deg2) were obtained for each quadrant, using group measures. To assess reliability between measures, intraclass correlation coefficients (ICC) were estimated.
Results: :
Mean time of follow-up was 8.8 months. Mean age was 59 years (Range 39-77). 17 patients were male. 11 patients were phakic at the time of surgery. Preoperative VA mean was 0,1359 (0,8668 LogMAR units). Postoperative VA mean was 0,5232 (0,2813 LogMAR units). 13 patients had a macula on RD. ICC between repeated mfERG measures were: Temporal Superior (TS): 0,978. Nasal Superior (NS): 0,962. Temporal Inferior (TI): 0,958. Nasal Inferior (NI): 0,944. Globally, the mean density of response (nV/deg2) in each quadrant was: TS: 27.4 (SD 11.7). NS: 34.1 (SD 9.5). TI: 21.6 (SD 9.5). NI: 24.4 (SD 8.1). No statistically significant differences were found in the density of response in a given retinal quadrant between patients who had this quadrant preoperatively detached and those with no detachment of the same area. The mean density of response (nV/deg2) was higher for the superior part of the retina than for the inferior one: globally (30.7 vs 23.0, p<0.0005); in 10 patients with pure superior RD (30.9 vs 23.1, p=0,007); in 7 patients with pure inferior RD (34.3 vs 22.9, p=0,018); in 6 cases with superior and inferior RD (26.4 vs 22.9, p=0,173).
Conclusions: :
There were no postoperative differences in the density of response between preoperatively attached and detached quadrants. However, retinal function in the superior retina was consistently better than in the inferior part, independently of the preoperative topography of the detachment.
Keywords: retinal detachment • electroretinography: clinical • vitreoretinal surgery