Toric iris-fixated phakic IOLs cause significant cell loss

The annual cumulative cell loss in eyes implanted with toric iris-fixated phakic intraocular lenses (IOLs) is two to three times greater than in normal eyes without surgery, according to the results of a study published in the February issue of the Journal of Refractive Surgery.

Mana Tehrani, MD from the Johannes Gutenburg-University, Mainz and Burkhard Dick, MD from the Center for Vision Science, Ruhr University Eye Hospital, Bochum, Germany conducted a prospective, randomized, self-controlled clinical trial of 40 eyes (28 myopic, 12 hyperopic) of 23 patients with high ametropia and astigmatism. Non-contact computer-assisted endothelial microscopy was performed before implantation and one, two and three years after.

The mean preoperative cell count in the myopic group was 3,179±531 cells/mm² (range: 1,800 to 3,900 cells/mm²). The mean intra-individual cell loss was -1.83±2.25% in the first year, -1.83±2.95% in the second year and -3.20±4.43% in the third year. In the hyperopic group, mean preoperative cell count was 3,107±125 cells/mm² (range: 2,932 to 3,300 cells/mm²). The mean cell loss was -1.63±1.76% in the first year, 0.05±1.25% in the second year and -2.88±2.03% in the third year. The annual cumulative cell loss was -1.9% and -1.6% for the myopic and hyperopic groups respectively.

The authors concluded that such as high cell loss means that an endothelial cell count analysis should be performed annually in order to detect potential progressive cell loss at an early stage.