Objective: To compare Corvis ST (Oculus Wetzlar, Germany) and Pentacam (Oculus) derived indices to detect normal cornea, keratoconus and for mefruste keratoconus. Study Design: Comparative cross sectional study. Place and Duration of Study: Armed Forces Institute of Ophthalmology (AFIO), Rawalpindi, from Feb to Jul 2019. Methodology: Following strict inclusion criteria 90 patients were enrolled that were divided into 3 equal groups of normal, Keratoconus and Formefruste kertoconus. One eye of the patient was selected and underwent ophthalmic examination followed by assessment of Corvis ST (Oculus Wetzlar, Germany) and Pentacam (Oculus). Classification analysis between normal, keratoconus and formefruste keratoconus was evaluated using receiver operating characteristic (ROC) curves. The area under the ROC curve (AUC) was compared. Results: Several corneal response parameters generated by Corvis St (Oculus Wetzlar, Germany) were statistically significant (p-value <0.05) in keratoconus group. The Area under the curve (AUC) ROC values for the keratoconus and normal comparison were 0.84(SPA1), 0.864 (BAD-D), 0.865 (PRFI), 0.92 (CBI), 0.96 (TBI). Among the combined indices TBI showed increase sensitivity of 98.3 % and 94.7% specificity to detect keratoconus. The AUC ROC value for the formefruste and normal control comparison were 0.75 (SPA1), 0.81 (BAD-D), 0.82 (PRFI), 0.81 (CBI), 0.91 (TBI) with 94% sensitivity and 90% specificity to detect formefruste keratoconus. Conclusion: Our study concluded that among the combined indices TBI demonstrated greater precision to detect keratoconus and formefruste keratoconus thus aiding and augmenting the recent technology.

Objective: The primary aim of this study was measure and compare the axial length (AXL), keratometric indices (K1, K2) and anterior chamber depth (ACD) by biometric devices; IOL Master and OB 820, to seek evidence on level of agreement for these parameters between these two devices. Study Design: Quasi-experimental study. Place and Duration of Study: Armed Forces Institute of Ophthalmology, Rawalpindi Pakistan, from Jul 2016 to Apr 2018. Methodology: This study was carried out at Armed Forced Institute of Ophthalmology on seventy eyes of 53 patients with senile grade II and grade III cataract. All patients underwent comprehensive ophthalmic and biometric examination using two different optical biometry devices the IOL-Master (Carl Zeiss Meditec, Jena, Germany) and OB-820 (Wave Light, Germany). Parameters of study were axial length (AXL), kera to metric indices (K1, K2) and anterior chamber depth (ACD). The results were evaluated using Bland–Altman analyses for level of agreement (LoA). The differences between both methodologies were assessed using the paired samples t test, and their correlation was evaluated by intra class correlation coefficient (ICC). Results: The mean age was 62.97 ± 7.97 years with the male/female ratio of 28/25. Mean axial length assessed by OB820 and IOL Master differed significantly in two groups, with a p-value of 0.018. Bland-Altman analysis further confirm significant difference range and 95% limits of agreement and ICC=0.659) of agreement for AXL. While, other parameters, K1, K2 and ACD showed an outstanding agreement (range within 95% confidence interval by Bland -Altman analysis) and internal consistency and.................