OBJECTIVETo observe the characteristic morphological changes of corneal endothelial dysfunction induced by phacoemulcification in rhesus monkey models under confocal microscope.

METHODSThe corneal endothelial dysfunction models were established by phacoemulcification power on the central corneal of 7 to 9 mm diameter in the right eyes of 4 rhesus monkeys (the modeling group). The left eyes of 4 rhesus monkeys were set as blank control group. The structural changes in different corneal layers were evaluated by slit lamp microscope and in vivo confocal microscope before surgery and 1, 2, 3, and 4 weeks after surgery. SPSS 19.0 software was applied to analyze data. Paired-t test was used to compare the number of nerve plexus in Bowman's layer and corneal endothelial cell density. Analysis of variance (ANOVA) was used to analyze corneal thickness.

RESULTSAfter phacoemulcification, the changes of cornea occurred gradually in the endothelial layer, stroma, Bowman's membrane, and basal epithelial layer. In the early stage, the interspace of corneal endothelial cells enlarged and few activated stromal cells were detected in the stroma. The cell morphology of stroma altered. The thickness of stroma increased. Two weeks after surgery, the nerve plexus in Bowman's layer decreased and edema of stroma and endothelial layer increased. Three weeks after surgery, the interspace of basal epithelial cells increased with a few Langerhans' cells infiltration and edema of stroma and endothelial layer increased. Four weeks after the surgery, a large amount of Langerhans' cells presented in basal epithelial layer. Only a few nerve lexus could be seen in Bowman's layer. The stroma and endothelial cells had severe edema. A large number of activated stromal cells could be found in stromal layer. Two weeks after the surgery, the number of nerve plexus in Bowman's layer (t=6.9192, P=0.002) and corneal endothelial cell density (t=7.8936, P<0.0001) in the modeling group were significantly lower than that in control group. Compared with corneal thickness in control group, it was significantly larger in the modeling group at 1 (t=28.31, P<0.0001), 2 (t=63.56, P<0.0001), 3 (t=123.22, P<0.0001), and 4 weeks (t=180.80, P<0.0001) after the surgery.

CONCLUSIONSThe changes in corneal endothelial dysfunction induced by phacoemulcification in rhesus monkey models can be clearly shown under in vivo confocal microscope. Gradual increase of endothelial cells interspace, activated stromal cells, increase of Langerhans' cells, and decrease of plexus in Bowman's layer are the main changes.