Session Title: Imaging IV
Session Date/Time: Sunday 20/09/2015 | 11:00-13:00
Paper Time: 11:08
First Author: : I.Gama PORTUGAL
Co Author(s): : H. Proenca M. Faria L. Almeida T. Bernardo M. MonteiroGrillo
PURPOSE:To evaluate the long-term effect of pars plana vitrectomy with and without encircling scleral buckling surgery on choroidal thickness by Enhanced Depht Imaging-Optical Coherence tomography (EDI-OCT).
Ophthalmology Department, Hospital Santa Maria - Centro Hospitalar Lisboa Norte, Lisbon, Portugal
This observational study included 2 groups of patients who underwent unilateral vitreoretinal surgery for primary repair of unilateral macula-off rhegmatogenous retinal detachment (total of 60 eyes of 30 patients). Group 1 included 15 patients who underwent unilateral scleral buckling surgery with an encircling band (2,5mm wide) combined with 23-gauge pars plana vitrectomy(PPV) (total of 15 eyes submitted to surgery and 15 normal fellow eyes). Group 2 included 15 patients who underwent unilateral PPV without scleral buckling surgery (total of 15 eyes submitted to surgery and 15 normal fellow eyes). Choroidal thicknesses (CT) of eyes submitted to surgery(OE) were compared with CT in the fellow eyes(FE) in each group. CT of OE in both groups was compared. Exclusion criteria were: glaucoma, previous macular degeneration, uveitis, retinal vascular diseases, refractive errors≥6D,diabetes or previous ocular surgery other than uncomplicated cataract surgery. CT were obtained by manual segmentation of Enhanced Depht imaging(EDI)OCT scans provided by Heidelberg Eye Explorer software, at the fovea, at a distance of 1000,2000 and 3000µm from the fovea, at nasal, temporal, superior and inferior locations. Mean and standard deviation were calculated for each variable.
The mean time between surgery and EDI-OCT was 14,5±7,8months in Group1 and 11,20±5,0months in Group2.The mean age was 60,9±13,2years in Group1 and 62,2±6,9years in Group2. In Group1, the mean axial length(AL) was 25,89±2,55mm in OE and 24,27±1,03mm in the FE. In Group2, AL was 24,8±1,0 mm in OE and was similar to AL of the FE (p>0,05). In the Group1, the mean subfoveal CT(SFCT) was 233,93±93,75µm in OE and 194,87±77,63µm in the FE(p=0,001). Mean CT at a distance of 1000µm(CT1), 2000µm(CT2) and 3000µm(CT3) from the fovea were 221,77±87,49µm, 202,52±79,03µm and 197,55±64,33µm, respectively, in OE and 194,67±80,25µm, 176,40±74,70µm, 158,93±56,66µm, respectively, in the FE.All differences between the OE and FE of Group1 were statistically significant (p<0,05). In Group2, the mean SFCT was 155,2±35,0µm in OE and 156,6±27,4µm in FE. CT1, CT2 and CT3 of OE were 155,8±29,4µm; 143,4±21,4µm and 136,6±21,1µm, respectively, and they were similar in FE (p>0,05). The subfoveal choroid of OE was thicker in Group1 than in Group2 (p=0,019), whereas SCCT of FE was similar in both groups(p=0,22).
In this study, combined pars plana vitrectomy and encircling scleral buckle surgery for primary repair of macula-off rhegmatogenous retinal detachment caused choroidal thickening compared to fellow eyes (p<0,05). This fact was not verified when vitrectomy was performed alone. The choroidal thickening may be related to a reduction in blood circulation caused by the encircling procedure and consequent venous stasis, which may be long lasting.