Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What is the primary purpose of a biometry A-scan?

1. Determine the health of the optic nerve

2. Measure distance for IOL calculations

3. Evaluate eye pressure

4. Assess retinal detachment

The correct answer is: Measure distance for IOL calculations

The primary purpose of a biometry A-scan is to measure distances for intraocular lens (IOL) calculations. This process is essential in preparing for cataract surgery, as accurate measurements of the eye's axial length help ophthalmologists select the appropriate IOL to achieve the desired refractive outcome post-surgery. The A-scan utilizes sound waves to determine the distance from the front of the cornea to the retina, providing critical data for calculating the power of the IOL needed based on the individual's anatomy. In the context of cataract surgery, obtaining precise measurements is crucial because the choice of IOL power directly impacts the patient's visual acuity and overall satisfaction with the procedure. The A-scan provides this quantitative data without invasive procedures, making it a standard tool in ophthalmic practice for surgical planning. Other options, such as determining the health of the optic nerve, evaluating eye pressure, or assessing retinal detachment, do not relate directly to the function of the A-scan. These tasks would typically involve different methods and technologies, such as optical coherence tomography (OCT) for optic nerve health or tonometry for measuring intraocular pressure. Thus, the focus and importance of the A-scan in IOL calculations highlight its essential role in