EYE EXAM: NOT ALL EXAMS ARE CREATED EQUAL
Many people do not realize that an eye exam is more than a glasses check. An eye exam is also more than having our patient read the eye chart. Our clinic specializes in primary care eye exams. A primary care eye exam is composed of three elements: Refraction, functional vision evaluation, and ocular health assessment.
A refraction is the determination of the eye “power” (nearsighted, farsighted, astigmatism). All patients are usually first assessed using the auto-refractor. This automated instrument provides a very quick estimate of eye power. Next the doctor may use a technique called retinoscopy. By observing how light “bounces off” the back of the eye, the doctor is able to quantify eye power, usually more accurately than the auto-refractor. Finally, the subjective refraction is started. This is the part of the eye exam that everyone is familiar with: “Which is better, one or two?” Doctors may use different techniques that they have developed to best assess the eye power. The subjective refraction is done because the doctor wants to estimate how the patient will respond to various lens powers. The subjective refraction typically gives the best result in determining the lens that will provide the best vision and comfort for the patient.
However, this is a difficult test for many patients and the doctor must use his or her experience to determine if the patient’s responses are accurate. Children are notorious for giving responses leading to an overcorrection in glasses power. In these situations, retinoscopy is sometimes most accurate, usually performed under cycloplegia (where the focusing system is “paralyzed” temporarily). Finally, the refraction must take into consideration the patient’s working environment. Everyone works at different distances and glasses prescribed must be appropriate for the specific person and working distance. Ultimately, trial framing a patient’s prescription (letting a patient “see” what the new power will be like) is the most effective way to evaluate patient response.
Good functional vision means vision that allows a patient the ability to do whatever they need to do in life. For some, like an air traffic controller, this could mean the ability to move the eyes together in all positions of gaze; for others, like microbiologists, it could mean the ability to maintain focus throughout many near-point demands. Testing to measure focusing ability is essential in relieving symptoms of near-point stress. An essential test of eye alignment and pointing is the cover test. The cover test is the key to determining whether or not there is significant eye turn in various positions of gaze. Two tests of accommodative ability include the fused crossed cylinder and dynamic retinoscopy at near. Other testing may involve measurement of the ability to converge or diverge the eyes. Our doctors may refer to other specific tests that they feel provide the most useful information. Patients do not realize that sometimes a problem with the eyes may require treatment other than glasses or contact lenses. Functional vision disorders may require vision therapy/training or prism or a combination of both.
Finally, the eye health must be checked. We evaluate for glaucoma, cataracts, and macular degeneration, and perform diabetic eye exams. We treat eye infections, eye irritation, and perform foreign body removal. We prescribe topical and oral medication as appropriate. We can treat the majority of eye problems and refer appropriately in cases that we cannot. . We are the only office extensively performing Orthokeratology (vision correction without glasses or laser corrective surgery) in Hilo.
Dilated eye exams are recommended for all new patients. A dilated eye exam involves widening the pupil (the dark circular area in the center of the eye) with a pharmaceutical agent to provide a wider and clearer view of the retina, blood vessels, optic nerve, and lens. Established patients are dilated thereafter, frequency determined on a case-by-case basis. Please remember that your eyes may be slightly blurry and light-sensitive for several hours after the procedure. Please make appropriate arrangements if we are dilating your eyes.
Our clinic takes pride in providing thorough evaluation of the eye and visual system.