Intraocular lens power calculation using total keratometry and ray tracing in eyes with previous small incision lenticule extraction - A case series.

Purpose: To assess the IOL power calculation accuracy in post-SMILE eyes using ray tracing and a range of total keratometry based IOL calculation formulae. Observations: Ray tracing showed excellent predictability in IOL power calculation after SMILE and its accuracy was clinically comparable with the Barrett TK Universal II and Haigis TK formula. Conclusions and importance: Incorporating posterior corneal curvature measurements into IOL power calculation after SMILE seems prudent. The ray tracing method as well as selected TK-based formulae yielded excellent accuracy and should be favored in post-SMILE eyes.

IOL Power Calculations and Cataract Surgery in Eyes with Previous Small Incision Lenticule Extraction.

Small incision lenticule extraction (SMILE), with over 5 million procedures globally performed, will challenge ophthalmologists in the foreseeable future with accurate intraocular lens power calculations in an ageing population. After more than one decade since the introduction of SMILE, only one case report of cataract surgery with IOL implantation after SMILE is present in the peer-reviewed literature. Hence, the scope of the present multicenter study was to compare the IOL power calculation accuracy in post-SMILE eyes between ray tracing and a range of empirically optimized formulae available in the ASCRS post-keratorefractive surgery IOL power online calculator. In our study of 11 post-SMILE eyes undergoing cataract surgery, ray tracing showed the smallest mean absolute error (0.40 D) and yielded the largest percentage of eyes within ±0.50/±1.00 D (82/91%). The next best conventional formula was the Potvin-Hill formula with a mean absolute error of 0.66 D and an ±0.50/±1.00 D accuracy of 45 and 73%, respectively. Analyzing this first cohort of post-SMILE eyes undergoing cataract surgery and IOL implantation, ray tracing showed superior predictability in IOL power calculation over empirically optimized IOL power calculation formulae that were originally intended for use after Excimer-based keratorefractive procedures.

OCT- versus Scheimpflug-based Total Corneal Power Measurements Changes in Myopic Astigmatic SMILE Procedures.

PURPOSE: To evaluate the value of total keratometry (TK) to estimate corneal power in eyes that underwent SMILE for treatment of myopia or myopic astigmatism in subgroups of low and high astigmatism. METHODS: The difference between preoperative and postoperative measurements of corneal power (ΔTCRP, ΔTK) was compared with the surgically induced refractive change at the corneal plane (ΔSEco) by Pearson correlation. Vector analysis of TCRP- and TK-derived astigmatism was performed to evaluate the corneal astigmatism. Single-angle plots were generated with the AstigMATIC tool for standard astigmatism vector analysis. RESULTS: Paired t-test revealed statistically significant differences in preoperative (p = .02) and postoperative (p = .0455) measurements between TK and TCRP in the group of high-level astigmatism and the postoperative low astigmatism group (p < .01). No significant differences were found in preoperative data in the group of low-level astigmatism (p = .60). The correlation of ΔSEco and TK (low astigmatism, R2 = 0.978; high astigmatism R2 = 0.980) was stronger than the correlation of TCRP 4.0 mm and ΔSEco (low astigmatism, R2 = 0.743; high astigmatism R2 = 0.959) in both astigmatic groups. The vector analysis demonstrated nearly identical results concerning the correction index (CI) for TK and TCRP. Comparing the difference vector (DV) between both parameters, TK-derived results were closer to the optimum. CONCLUSIONS: The findings endorse TK as a reliable measure of corneal power after SMILE in patients with low and high astigmatism.

Total keratometry for determination of true corneal power after myopic small-incision lenticule extraction.

PURPOSE: To gauge the value of total keratometry (TK) to estimate corneal power change in eyes that underwent small-incision lenticule extraction (SMILE) for treatment of myopia or myopic astigmatism. SETTING: Department of Ophthalmology, Ludwig-Maximilians-University, and SMILE Eyes Clinic Munich Airport, Munich, Germany. DESIGN: Prospective cross-sectional trial. METHODS: A total of 40 eyes of 40 patients who had undergone myopic SMILE were enrolled in this prospective study. Total corneal refractive power (TCRP; Pentacam HR) and TK (IOLMaster 700, Carl Zeiss Meditec AG) values were compared with the clinical history method (CHM). The surgically induced changes in TCRP (ΔTCRP) and TK (ΔTK) were also compared with the changes in spherical equivalent on the corneal plane (ΔSEco). RESULTS: Of the 40 eyes analyzed, the correlation between TK and CHM (R2 = 0.91, P < .001) was stronger than that between TCRP and CHM (R2 = 0.87, P < .001). When compared with the CHM, TCRP underestimated corneal power by a mean relative error of 0.59 diopter (D) and TK by 0.17 D. Linear regression analysis of ΔTCRP/ΔTK and the difference between preoperative and postoperative manifest refraction spherical equivalent at the corneal plane (ΔSEco) showed stronger correlation in ΔTK (R2 = 0.88) than that in ΔTCRP (R2 = 0.82). CONCLUSIONS: The findings endorse TK as an accurate measure for corneal power after myopic SMILE.

Cardiac tumours - a brief review.

This short review of cardiac tumours presents a case that clearly demonstrates the manifestation of embolic and cardiac symptoms of an intracardiac mass. Acute onset and rapid progression of a neoplastic process in the heart leading to arrhythmia, cardiac conduction disorders and heart failure combined with highly mobile fragments of tumour, which can cause emboli in cerebral vessels, are characteristic signs of an intracardiac mass. Early diagnosis and immediate treatment may improve the long-term prognosis, but overall the prognosis is poor. Cardiac tumours present to the cardiologist when the patient presents with cardiac symptoms, and the neurologist when there are cerebral symptoms. Most cardiac masses are not amenable to percutaneous biopsy; therefore, definitive diagnosis often awaits surgical excision.