Evaluation of keratoconus progression.

AIM: To define variables for the evaluation of keratoconus progression and to determine cut-off values. METHODS: In this retrospective cohort study (2010-2016), 265 eyes of 165 patients diagnosed with keratoconus underwent two Scheimpflug measurements (Pentacam) that took place 1 year apart ±3 months. Variables used for keratoconus detection were evaluated for progression and a correlation analysis was performed. By logistic regression analysis, a keratoconus progression index (KPI) was defined. Receiver-operating characteristic curve (ROC) analysis was performed and Youden Index calculated to determine cut-off values. RESULTS: Variables used for keratoconus detection showed a weak correlation with each other (eg, correlation r=0.245 between RPImin and Kmax, p<0.001). Therefore, we used parameters that took several variables into consideration (eg, D-index, index of surface variance, index for height asymmetry, KPI). KPI was defined by logistic regression and consisted of a Pachymin coefficient of -0.78 (p=0.001), a maximum elevation of back surface coefficient of 0.27 and coefficient of corneal curvature at the zone 3 mm away from the thinnest point on the posterior corneal surface of -12.44 (both p<0.001). The two variables with the highest Youden Index in the ROC analysis were D-index and KPI: D-index had a cut-off of 0.4175 (70.6% sensitivity) and Youden Index of 0.606. Cut-off for KPI was -0.78196 (84.7% sensitivity) and a Youden Index of 0.747; both 90% specificity. CONCLUSIONS: Keratoconus progression should be defined by evaluating parameters that consider several corneal changes; we suggest D-index and KPI to detect progression.

Management of Interface Fluid Syndrome After LASIK by Descemet Membrane Endothelial Keratoplasty in a Patient With Fuchs' Corneal Endothelial Dystrophy.

PURPOSE: To report a case of interface fluid syndrome after LASIK in a patient with Fuchs' corneal endothelial dystrophy treated with Descemet membrane endothelial keratoplasty (DMEK). METHODS: Case report. RESULTS: A 74-year-old patient presented with interface fluid syndrome and was treated with DMEK. Its complications in the form of partial graft detachment and cystoid macular edema were successfully managed by rebubbling and topical treatment, respectively. The treatment led to amelioration of both visual acuity and patient satisfaction. At the examination 6 months after DMEK, the cornea was clear and corrected distance visual acuity improved to a satisfactory level. CONCLUSIONS: Interface fluid syndrome can develop many years after LASIK as a result of corneal endothelial decompensation and can be effectively treated with DMEK. Close postoperative monitoring of patients is paramount to intervene therapeutically in case of transplant detachment or development of cystoid macular edema requiring further surgical or conservative management. [J Refract Surg. 2017;33(5):347-350.].