Abstract
Purpose:
To study the influence of two different surgical intraocular light sources on the functional outcomes of the surgical treatment of epiretinal membrane and to assess their potential phototoxic effect on the retinal pigment epithelium (RPE) .
Methods:
Study included 20 patients (20 eyes)with a primitive epiretinal membrane with negative autofluorescence at baseline. All patients underwent central 23-guage pars-plana vitrectomy with an internal limiting membrane peeling stained with brilliant peel. For the vitreo- retinal illumination during the vitrectomy, xenon light source (420 nm) was used in 10 eyes (group I) and amber filter (515 nm)was used in 10 (group II).BCVA, OCT values of central foveal thickness (CFT) and autofluorescence image were collected and analysed at baseline at first week and at 1, 3, and 6 months after the surgery.
Results:
At 6 month follow up, central macular thickness decreased by 61.1 μm in group I ( 426.1 μm before surgery; 365 μm after surgery) and by 82 μm in group II ( 405.5 μm before surgery 323.8 μm after surgery) compared to baseline. BCVA improved in both groups more than 2 lines.At first month follow up, 2 patients of the group I (20%) showed a positive autofluorescence and a corresponding irregular RPE profile at the OCT scan,while all patients of group II showed a negative autofluorescence.During the follow-up period no complication due to the surgical procedure was observed.
Conclusions:
Data show an improvement of anatomical and functional findings in all treated patients. We found no significant differences in the final CRT and BCVA between the two groups. We noticed, however,a greater protective effect of the amber filter on the retinal pigment epithelium compared to xenon light source. Several authors reported retinal pigment epithelial damage attributed to light toxicity from an endoillumination probe.We can alter the phototoxic hazards of light using a filter.The amber filter is the most effective, with 118% more safety margin. Infact when using the 515-nm filter, the safety is increased by almost 30 times, compared with the standard 420-nm filter. Although currently, there are no guide lines to select a color filters during vitreous surgery, this study suggests the use of amber filter to achieve a higher protective effect on the retina during vitrectomy.
Keywords: 585 macula/fovea •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
762 vitreoretinal surgery