Diagnosing Cataracts

Detection of cataracts may begin as symptoms are experienced, however it is through a comprehensive dilated eye exam that cataracts are diagnosed. Through a series of visual tests, your eye care professional can examine the overall health and potential challenges to your eyes. Should you suspect your eyes to have developed cataracts your doctor will commonly perform the following eye exams:

Visual Acuity Test (The Big “E”):

As part of the standard eye exams, the visual acuity test measures your vision in relation to distance. By identifying a series of letters, numbers, and characters, displayed to represent distance, the visual acuity test serves as the most common vision test. Though this test may not reveal or rule out eye disease, it will give an indication of how much your overall vision is being affected.

Dilated Eye Exam:

Procedural for diagnosing cataracts, the dilated eye exam consists of formulated drops placed in the eye, causing the widening (or dilating) of the pupil, allowing your eye care specialist to examine the retina and optic nerve. By examining the retina and optic nerve for signs of damage or eye disease your doctor will have greater information necessary to determine what further tests may be needed, as well provide possible treatment options if necessary. Following the dilated eye exam, it is common to experience blurred close up vision for several hours as the formulated drops wear off.

SlitLamp Examination:

Used to diagnose cataracts, the slit‐lamp examination includes the dilation of the pupil followed by a hand‐held tool called the Ophthalmoscope. The Ophthalmoscope projects a high insensitive light beam in a thin line vertical slit, providing a three dimensional view of various parts of the eye. Slowly projecting the light across the eye, the slit‐lamp eye exam is able to reveal the presence of cataracts.

Tonometry:

In this test the pressure behind the eye is measured. There are several methods for performing this test, of which some may include the administering of numbing eye drop to assist in comfort. The non‐contact method of the Tonometry test is often referred to as the “puff test”. Air is expressed briefly into your eye while a machine measures the eye pressure, achieved through the data present as light reflections change based on the air pressure upon contact with the eye. This test is most commonly known as the IOP test, (Intraocular Pressure). The function of IOP
test is to rule out eye diseases such as Glaucoma.

Keratometry Test or AScan:

Used for measuring the length of the eye and the corneal curvature through the usage of ultrasonic waves, this test is fast and painless. High frequency sound waves are used to create an image of the eye structure. Necessary use of this test includes the pre‐operation measuring for proper fitting artificial lenses prepared for cataract surgery.

Specialty Test Used for Diagnosing Cataracts

Contrast Test:

Mentioned above, the common visual acuity test examines an Individuals ability to see images and characters at various distances. The images used in the test are displayed as black print characters on a white background. This black and white combination for vision testing is high contrast, meaning the eyes experience nearly 100% contrast between black and white. This contrast provides clear testing and defined images, however rarely is the world around us in such extreme color contrast as black and white. Color, Brightness, Shadowing, Time of Day, and more, all affect contrast. The perception of a curb and the road may blur
together as the contrast is low between the two visual objects. Steps my not be clearly defined creating an illusion of where the steps may or may not be. Diagnosing cataracts and how severely the cataracts have developed may require a contrast test, designed to provide information regarding the eyes sensitivity to contrasting images. As the fogging of the eyes lens occurs, contrast and colors will fade and blur.

Glare Disability Test:

Individuals with cataracts may become visually disabled or experience increased blurred vision in bright light situations. These situations may include streetlights, vehicle headlights, computer screen, television, reading lights, direct sunlight, and more. As the lens is partially responsible light entering the eye, individuals with cataracts will experience scattered light, producing increased glare resulting in reduced visibility. The glare disability (or glare sensitivity) test will
measure your sensitivity to glare and give indication concerning the stage of the opacity. The test will include a simulated environment, replicating lighting
conditions for:

• Direct Sunlight
• Partially Cloudy
• Fluorescent Lighting

The result of your visual ability will be compared to that of your ideal lighting score.

Potential Acuity (PAM):

The primary purpose for the potential acuity test is to measure the potential visual acuity which may be achieved by each eye. Most often performed before deciding to have cataract surgery, the potential acuity test reveals what vision improvements are possible. This test is designed to eliminate the possibility of retinal or neurological damage potentially preventing a successful cataract surgery in which clearer vision is restored. By projecting an eye chart
image directly on to the retina, bypassing the cataract, your eye care specialist is
able to determine the potential acuity of your eye without the interference of
cataracts. Painless and quick, the eye drops used for dilating the eyes may be
effective for up to 6 hours.

Corneal Endothelium Test:

The corneal endothelium is the layer of tissue lining
the posterior surface of the cornea. This tissue is highly susceptible to damage
during a cataract surgery. By examining the corneal endothelium, your eye care
specialist can determine how well your cornea will function post surgery. This test may not be used in the diagnosing cataracts but is more commonly used during preprocedural examinations.

Wavefront Mapping:

The new line of diagnosing cataracts uses computer analysis
and laser beam technology to observe the passing of light through the eye. This advance technology is able to verify an Individuals need for treatment, often facilitating treatment, which would have otherwise taken longer to address.