Certified Ophthalmic Assistant Practice Exam

The estimation of anterior chamber depth is done by shining a penlight in what area of the patient's eye?

1. Side

2. Center

3. Above

4. Below

The correct answer is: Side

The estimation of anterior chamber depth is effectively assessed by shining a penlight on the side of the patient's eye. This method utilizes a technique known as the "shadow test," where lateral illumination creates a shadow across the anterior chamber. By observing the size of the shadow cast by the iris, practitioners can gain insights into the depth of the anterior chamber. A deeper chamber typically produces a smaller shadow, whereas a shallower chamber casts a larger shadow. This practice is crucial for evaluating potential risks for conditions like angle-closure glaucoma, where inadequate anterior chamber depth can cause the iris to obstruct the drainage angle. When using light directly on the center of the eye, the illumination might not provide clear information about the amplitude of the anterior chamber due to the potential for over-illumination, which can obscure the related shadows. Shining the light above or below may not effectively target the area needed to observe the anterior chamber's depth accurately. Hence, lateral illumination remains the most appropriate technique for this assessment.