Abstract
Purpose: :
To evaluate the morphological changes of cornea by in vivo laser scanning confocal microscopy (LSCM) in a large case series with silicone oil endotamponade after vitroretinal surgery and explore the value of LSCM in the early detection of silicone keratopathy (SK).
Methods: :
99 patients (99 eyes) with silicone oil endotamponade after vitroretinal surgery were included in the current study. Slit lamp examination and measurement of intraocular pressure (IOP) were performed at first. Then the central cornea of enrolled eyes was examined by in vivo LSCM. The images of each cornea layer were analyzed and endothelial cellular density (ECD), endothelial cellular area (ECA), coefficient variation of cell size (CoV) and percentage of hexagonal cells (PHC) were measured. Moreover, the total size of stromal deposits was measured and the correlation between the size of deposits and the parameters of endothelial cells was analyzed.
Results: :
Clinical recognizable abnormalities involving cornea were identified in only 12 eyes (12.1%) under slit lamp biomicroscopy, whereas in vivo LSCM revealed morphological abnormalities in 40 eyes (40.4%). The manifestations of endothelium lesion were various including decreased cellular density, increased polymegatism and pleomorphism, and hyperreflective silicone oil membrane or droplets adhering on the endothelium. Moreover, hyperreflective deposits with various shapes could be identified in both posterior and anterior stroma. The presence of morphological abnormalities on either endothelium or stroma was defined as the manifestation of SK. In eyes with SK, the average ECD and PHC was significantly lower than in those without, whereas the average ECA and CoA were significantly larger (all P<0.001). SK patients were significantly elder than those without (P=0.003). The rate of pseudophakic and aphakic eyes developing SK was significantly higher than that of phakic eyes (P=0.045). Interesting, the total size of stromal deposits had a significant negative correlation with ECD and PHC, as a significant positive correlation with ECA and CoA (all P<0.001).
Conclusions: :
In vivo LSCM was a useful tool in early detection of SK, which was characterized with varying corneal endothelium lesions and stormal abnormalities as well. Pseudophakic or aphakic eyes, as well as older patients should be paid more attention since they were more inclined to develop SK.
Keywords: cornea: endothelium • vitreoretinal surgery • imaging/image analysis: clinical