she has a disability due to very low vision. What’s the dx?
a. Glaucoma
b. Cataract
c. Macular degeneration
d. Retinitis pigmentosa
e. Keratitis
answer D
Retinitis pigmentosa
The age of onset, rate of progression, eventual visual loss
and associated ocular features are frequently related to
the mode of inheritance. RP may occur as an isolated
sporadic disorder, or be inherited as AD, AR or XL. Many
cases are due to mutation of the rhodopsin gene. XL is the
least common but most severe form and may result in complete
blindness by 3rd or 4th decade.
Clinical Features
• night blindness, decreased peripheral vision (“tunnel vision”), decreased central vision (macular
changes), glare (from cataract)
Investigations
• fundoscopy: areas of “bone-spicule” pigment clumping in mid-periphery of retina, narrowed
retinal arterioles, pale optic disc
• electrophysiological tests: electroretinography (ERG) and electrooculography (EOG) assist in
diagnosis
Age related macular degeneration
Risk factors- age: most patients are over 60 years of age
- smoking
- family history
- more common in Caucasians
- high cumulative
>40years 2%, >80 years 10% of people
risk factors: dm, htn, hyperthyroidism etc
chronic open angle glaucoma: Since the central field is intact, good acuity is maintained, so presentation is often delayed until irreversible optic nerve damage, e.g. age >60
closed angle glaucoma: acute course, red eye
Cataracts
Majority- age related
- UV light
- diabetes mellitus
- steroids
- infection (congenital rubella)
- metabolic (hypocalcaemia, galactosaemia)
- myotonic dystrophy, Down's syndrome
- trauma
- uveitis
- high myopia
- topical steroids
will be pain, redness, photophobia and vision is ok.
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