A Clinical Prospective Study: Corneal alterations after cataract surgery with the technique of phacoemulsification

Abstract    The purpose of this study is to investigate the effect of ultrasound energy used during phacoemulsification on corneal structure, which is the most important refractive part of the eye. This will be achieved with the comparison of preoperative and postoperative parameters related to corneal thickness and endothelium and their correlation with clinical, intrasurgical and imaging diagnostic findings.    Methods: This is a clinical prospective study conducted in Evangelismos G.H.A. The patients’ enrollment was based on detailed medical history assessment, medication records as well as meticulous slit lamp examination, tonometry, best corrected visual acuity evaluation and thorough fundoscopy. Nuclear cataract sclerosis was evaluated with Lens Opacities Classification System III, and patients were scheduled for surgery. Preoperatively, with the use of specular microscopy (Tomey EM-3000; Tomey, Tennenlohe, Germany),  central corneal thickness and several endothelial indices were recorded. The same measurements took place the 1st, 7th and 30th postoperative day. All the surgical operations were done without complications.    Results: statistical analysis from preoperative and postoperative data showed that central corneal thickness, although elevated during the 1st and 7th postoperative day, did not present statistical significant difference in the final evaluation, with a mean elevation of only 3,9μm. Endothelial cell density levels though were reduced in all postoperative measurements (p<0,001). The final percentage endothelial cell loss was18,58%, with the most profound loss being accounted in the first postoperative week. Corneal edema and endothelial cell loss were correlated with poor visual acuity, reduced corneal curvature, increased nuclear sclerosis and prolonged time of ultrasound metrics.    Conclusion: the use of confocal microscopy is a useful tool in pointing significant differences of corneal structure after uneventfull cataract phacoemulsification. The evaluation of a larger cohort of patients and a prolonged follow up procedure could give further information concerning corneal alterations after surgery. Key words: cataract, phacoemulsification, cornea, lens, endothelium, ultrasound, confocal microscopy List of Abbreviations: CCT: central corneal thickness, SD: standard deviation, CV: coefficient of variation, , ECD: endothelial cell density, ECL%: endothelial cell loss%,