How is it Diagnosed?
Cataract is diagnosed primarily through a detailed eye examination by an
ophthalmologist. The first step involves recording the patient’s medical history and
vision complaints, especially blurring, glare, difficulty with night vision, and changes in
color perception. A visual acuity test is conducted to determine how clearly a person
can see at various distances. This is typically performed using an eye chart.
The next key diagnostic tool is a slit-lamp examination, which provides a magnified view
of the structures at the front of the eye. This allows the doctor to closely examine the
lens for cloudiness or opacification, the hallmark sign of a cataract. Dilated eye
examination follows, in which special drops are used to widen the pupil, allowing the
doctor to examine the lens and retina more thoroughly.
Additionally, retinal examination and tonometry may be done. Retinal examination helps
rule out other vision-affecting diseases such as macular degeneration or diabetic
retinopathy, while tonometry measures intraocular pressure, important in excluding
coexisting glaucoma.
In some cases, potential acuity meter (PAM) and brightness acuity test (BAT) may be
used to assess how much vision might improve after cataract surgery. Ultrasound of the
eye (A-scan biometry) may be performed before surgery to measure the eye and help
select the appropriate lens implant.
The diagnosis of cataract is confirmed when the lens shows significant opacity and is
responsible for the visual symptoms experienced by the patient. Early detection enables
timely treatment and prevention of vision loss.