Vitreous changes and retinal detachment in highly myopic eyes

This report on 496 highly myopic eyes that underwent transcleral or vitreoretinal surgery for retinal detachment (RD) focuses particularly on how changes in the vitreous gel and the resulting modifications of the vitreoretinal interface produce typical characteristics and complications. According to the pattern of vitreous modifications the 496 eyes were divided into five groups: 1) eyes with uniform PVD (108 eyes) 2) eyes with PVD spreading towards the upper quadrants (231 eyes) 3) eyes with extensive vitreous liquefaction (EVL) and condensations of the vitreous base (51 eyes) 4) eyes with posterior vitreous lacuna (PVL, 87 eyes) 5) eyes with very limited PVD (19 eyes). Age, degree of myopia, surgical procedures and final results are reported for each group. A strong correlation was observed between vitreous changes and clinical picture of RD especially in the group of PVL and EVL. In the PVL group a higher degree of myopia was found and more pronounced posterior staphyloma. Frequently the posterior hyaloid, in the form of a thin, extremely smooth membrane, was hard to separate from the inner posterior retina during surgery. Posterior retinal breaks, including macular holes, were found in 56% of eyes. The presence of EVL with condensation of the vitreous base was correlated with giant retinal tear (GRT) in 70% of cases (36 of 51 eyes). Sixteen GRT were also found in the group of uniform PVD, but these were less extensive and located more posteriorly than in the EVL group. In the former group there were better surgical results because of a lower incidence of PVR. In 46% of the eyes of our series (group 2), PVD extended mostly in the upper quadrants with no vitreous detachment inferiorly. In these cases there was a clinical appearance of inferior vitreous collapse. These eyes had 92% of peripheral superior retinal breaks. Relapses of RD in this group almost invariably occurred in the inferior quadrants.