Comparison of laser vision correction outcomes with two excimer laser nomograms
Boyle, Matthew J.
MetadataShow full item record
BACKGROUND: The human eye is an incredible organ, capable of focusing and detecting light that passes through its specialized structures. These organs are responsible for the sensation of vision and are crucial to the ability to function and operate during daily life. Loss of the sense of vision can result in serious deficits that greatly reduce the quality of a person’s life. One of the most prevalent causes of vision impairment in the world is refractive error. Although this is a common and relatively simple problem to fix with modern technology, ophthalmologists are continuously searching for new methods of treating people’s eyes to correct refractive errors and improve vision. There are several popular methods for correcting refractive errors, including traditional glasses, contact lenses, and laser vision correction. Laser vision correction is the most modern method for improving visual acuity deficits caused by refractive errors. The two most favored techniques for laser vision correction are laser assisted in site keratomileusis (LASIK) and photorefractive keratectomy (PRK). The performance of these procedures requires a laser treatment input to be calculated based on the patient’s refractive error. These laser treatment inputs are often determined using a nomogram. Nomograms are mathematical functions utilizing a graphical display to calculate a given value based on a set of parameters. Nomograms are crucial for safe and effective LASIK and PRK procedures and there is much interest in enhancing these algorithms to improve the refractive and visual acuity outcomes. OBJECTIVES: The objective of the study was to determine if a newer, more complex laser vision correction nomogram could generate laser treatment inputs better than another more traditional nomogram in terms of refractive and visual acuity outcomes. METHODS: The study included 109 eyes belonging to 59 patients. Fifty-one eyes belonging to 28 patients were operated on using the Wellington nomogram and 58 eyes belonging to 31 patients were operated on using the Internet-based refractive analysis (IBRA) nomogram. Visual acuity and refractive outcomes were recorded at a six-week follow-up evaluation. Data were analyzed using statistical tests to determine significant values. RESULTS: No statistically significant difference was found between the recorded visual acuity and refractive outcomes of eyes operated on using the Wellington and IBRA nomograms. CONCLUSIONS: The two nomograms were found to perform at equal efficacy and to reach the established standards for safety. Although no significant difference was found between the two nomogram outcomes it is possible that there were variables limiting the external validity of the statistical analysis. With extra time, additional cases, and better sample matching the study could be expanded and developed to provide a more reliable and more representative dataset to elucidate conclusions with greater impact.