Goniometry with the Laser Tomographic Scanner (LTS) in ECCE

Abstract

OBJECTIVES: The Laser Tomographic Scanner (LTS) allows horizontal and frontal section images of the anterior segment to be obtained. Horizontal x/z-section images were used for precision measurement of the chamber angle. The clinical feasibility was studied, using extracapsular cataract extaction (ECCE) + intraocular lens (IOL) implant as a model. DESIGN AND PATIENTS: Reproducibility was assessed by serial measurements (coefficient of variation = 7.5%; mean standard deviation = 2 ° ). Fifty patients were examined before (CA1) and 5-10 days after ECCE (CA2) with intracapsular IOLs. Increase of CA depth (D) postoperatively was determined with regard to CA1 and patient age. RESULTS: The following results were obtained: (i) the smaller CA1 the bigger the increase in D, (ii) in cases with deep CA1, only a moderate increase in D was observed; (iii) CA1 and CA2 are directly proportional; (iv) the older the patient at the time of surgery, the bigger the chamber angle increase in D to be expected. CONCLUSION: In this study, the first clinical approach, LTS-goniometry proved to be clinically feasible—it is a safe, easy to perform, accurate and optically reproducible method.