Session Title: Free Paper Session 17: Imaging II
Session Date/Time: Saturday 09/09/2017 | 08:00-09:30
Paper Time: 09:18
Venue: Room 120
First Author: : L.Pierro ITALY
Co Author(s): : L. Iuliano A. Arrigo A. Rabiolo M. Gagliardi
The recently proposed classification of lamellar macular holes (LMH) divides them into degenerative and tractional ones, based on different OCT features. Degenerative lamellar macular hole presents association with epiretinal proliferation (ERM), considered as a non-tractional ERM, with an unusual appearance, named LMHEP. The purpose of this study is to describe changes of retinal vascular structures in this type of lamellar macular holes, compared to the controlateral healthy eyes as well as to control group ones by means of optical coherence tomography angiography (OCT-A).
Deparment of Ophthalmology, Vita-Salute University, San Raffaele Scientific Institute, Milan
Forty-five patients with diagnosis of LMHEP were enrolled. Five LMHEP without contralateral healthy eye, seven patients with tractional LMH and three patients with poor quality OCT-A were excluded. The final analysis included thirty eye of thirty patients (18 males, mean age 60.2) and thirty different control eyes (15 males, mean age 59.6). OCT-A acquisitions were obtained through of Topcon Triton OCT. Foveal avascular zone (FAZ) was manually segmented by an expert ophthalmologist. Images were binarized . Before calculating vessel density, a circle of 1.5 mm diameter centreed with the centre of the FAZ was placed; this allowed to conduct a peri-FAZ analysis (inner) and a peripheral one (outer). Superficial and deep vessel densities were obtained by calculating the percentages of white and black pixels with respect to the entire inner and outer surfaces; for the inner analysis, the FAZ was excluded by the total inner surface. Moreover, FAZ area was also calculated. One-way Anova was used to test statistical significance of the following measurements: macular hole (LMHEP) vs controlateral healthy eye (CH) vs control group (CG). Bonferroni’s correction was applied to correct for multiple comparisons. Statistical significance was set to p<0.05.
Superficial vessel density of the inner analysis resulted statistically different between groups (F=6,547; p=0,003). Post-hoc analysis revealed a statistically significant increment of the vascular density of the LMHEP eyes compared to the CG eyes (p=0,004) as well as the CH eyes compared to the CG eyes (p=0,015). Outer analysis of the superficial plexus did not reveal statistically significant differences (p>0,05). Moreover, no statistically significant differences were found both for the inner and the outer analyses of the deep vascular plexus (p>0,05). Regarding FAZ area, this resulted significantly increased both in LMHEP (p=0,006) and CH (p=0,02) eyes compared to CG ones.
Although the pathogenesis of LMH is not clearly established, our findings suggest that the etiopathological mechanism causing the LMHEP requires patient’s predisposition. This is suggested by the results of the CH. Moreover, our data confirm that OCT-A is a powerful promising technique for the deep non-invasive study of retinal vascular changes in pathological conditions. Further studies should be conducted with the help of histological analyses in order to definitely determine the mechanism underlying the formation of LMH.