How to diagnose cataract????

It starts with blurred or cloudy vision. Then suddenly images aren't as sharp, colors aren't as bright and night driving is more difficult. Cataracts generally are associated with aging. Younger people, however, can have them too. Identifying the problem requires an ophthalmologist to administer a variety of tests before a diagnosis of cataracts can be made.

Things you will need:-

1. Medical history

2. Eye examination

3. Visual acuity test

4. Opthalmoscopy

5. Tonometry test

6. Glare test

7. Contrast sensitivity test

1. Medical history

· General health issues/related problems that may affect the diagnosis and prognosis of patient’s cataract and suitability for surgery.

· Medications taken by the patient is recorded. This may affect the surgical decisions/procedures.

· Allergies to antibiotics and anesthetics should be recorded.

2. Eye examination

· To determine the nature and severity of cataract.

· Overall eye health will also be assessed to discover any problems that may limit good vision following surgery/other treatment procedure.

· Measure refractive error with retinoscopy – using retinoscopy to shine light into the patient’s eye and observes the reflection off the patient’s retina.

3. Visual acuity test

· To determine the smallest letters a person can read on standardized chart/card (Snellen eye chart) held 14-20 ft away.

· Glasses and contact lens will be removed.

· Stand/ sit 20 ft from the eye chart.

· One eye is covered while the patient reads out loud the smallest letters he can see.

· Repeat with the other eye, if necessary the test is repeated with your glasses/contact lens on.

· The result is expressed as fraction. Top no. is the distance from the chart (usually 20 ft) and the bottom no. is the smallest letters that the patient can read, e.g. 20/40.

TEST FOR PRESBYOPIA

· Eyes are position at a close reading distance of about 14 ft from the test chart.

· Glasses are not removed.

· The patient is asked to read down the chart, line by line until the line that you cannot read comfortably and clearly.

4. Opthalmoscopy

· To examine the inside and back of the eye with opthalmoscope.

· Pupil is usually dilated with eye drops so the doctor has a larger ‘window’ to look through.

· Look for abnormalities in retina.

5. tonometry test

· To measure the intraocular pressure (IOP) with tonometer.

· Two types:-

a) Applanation tonometry – uses pressure sensitive tip that placed against the surface of eye, > accurate

Air puff tonometry – directs a brief puff of air onto the eye

6. Glare test

· Cataract patients often complain that their vision is slight reduced in brilliant sunlight and night time driving, this is due to increase light scatter within the eyes.

· Glare test + device the measures the effect of stimulated glare on vision function.

· To quantify the effect of glare on the person’s vision.

· Is a benchmark for testing after cataract surgery to see if situation is improved/not

7. Contrast sensitivity test

· To measure ability of eyes to distinguish images under varying degrees of lighting

· Person with low contrast sensitivity may do well in standard vision test and have difficulties in seeing traffic lights/cars at night, spots on clothes and facial gestures OR they may need great deal of light to read and experiences tired eyes while watching tv.

· Repeated after surgery to document the degree of improvement that has been achieved.