Certified Ophthalmic Medical Technologist (COMT) Practice Exam

Which instruments are commonly used to measure anterior chamber depth?

1. IOL Master, Pentacam, A-scan biometer

2. Optical coherence tomography, Fundus camera, B-scan ultrasound

3. Slit lamp, Retinoscope, Corneal topographer

4. Pachymeter, Keratometer, Visual field analyzer

The correct answer is: IOL Master, Pentacam, A-scan biometer

The use of specific instruments to measure anterior chamber depth is crucial in various aspects of ocular assessment, particularly when determining the appropriate intraocular lens (IOL) for cataract surgery and evaluating conditions such as glaucoma. The IOL Master, Pentacam, and A-scan biometer are all designed to provide precise measurements of the anterior segment of the eye. The IOL Master employs partial coherence interferometry, which allows for high-resolution measurements of axial length, anterior chamber depth, and more, making it highly effective for IOL calculations. The Pentacam utilizes a rotating Scheimpflug camera to create a detailed 3D image of the anterior segment, enabling accurate anterior chamber depth measurement along with other topographical and tomographic data. A-scan biometry, often used during pre-operative assessments, uses ultrasound to measure the distance from the cornea to the lens and posterior segment, which includes anterior chamber depth. These instruments are specifically designed to assess the anterior segment's dimensions, while the other provided choices include instruments that are tailored for different diagnostic purposes. For instance, optical coherence tomography and B-scan ultrasound are more suited to evaluating posterior segment structures, and a retinoscope is primarily utilized for assessing refractive errors rather than measuring anterior chamber depth