EVALUATION OF CORNEAL ENDOTHELIAL CELLS AFTER PARS PLANA VITRECTOMY

Document Type : Original Article

Abstract

Background: The corneal complications of vitreo-retinal surgery are rarely the
primary concern of the surgeon operating on a difficult retinal detachment.
However, the surgeon should be aware of which procedures are more likely to
induce corneal decompensation, because corneal abnormalities are a common
cause of visual loss following an otherwise successful surgery[1]. Thus it is
important to evaluate corneal endothelial cell changes after PPV.
Aim of the work: To evaluate corneal endothelial cell changes in patients
undergoing Pars plana vitrectomy with silicone oil (SO) injection.
Subjects and Methods: This prospective comparative observational study
evaluated the corneal endothelial cell characteristics of 27 SO filled
vitrectomizied eyes operated in Zagazig University Hospitals, Ophthalmology
department. Endothelial cell densities (ECD), coefficient of variation (CV),
central corneal thickness (CCT) and percentage of hexagonal cells
(hexagonality) at the corneal center were measured preoperatively, 1 week,1
month and 3 months after surgery using noncontact specular microscopy and
were compared pre and post operatively. Exclusion criteria were previous
vitreoretinal surgery, aphakia, any degree of anterior chamber inflammation,
history of previous eye trauma, SO bubbles in the anterior chamber and
increased intraocular pressure in the postoperative period.
Results: Three months after pars plana vitrectomy with silicone oil injection,
mean ECD was 2032.92±434.41cells/mm2in the vitrectomized eyeswhile mean
hexagonality (pleomorphism) was 65.66±8.05. Three months after operation,
CV (polymegathism) was 31.03±5.97 while mean CCT was 552.51±32.01μm
with no corneal edema reported at the end of the study.
Conclusion: Although the presence of SO in the vitreous cavity, PPV was
associated with corneal endothelial cell changes in the form of EC loss and
pleomorphism. Silicone oil could be a risk factor for increasing endothelial cell
loss after pars plana vitrectomy. The percentage of corneal endothelial cell loss
was higher in patients with SO injection than those left saline filled, but it was
statistically insignificant Thus, removal of SO after reaching the desired
tamponade effect is recommended.

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