retinitis pigmentosa

1. Retinitis Pigmentosa

2. Practice Essentials
• Retinitis pigmentosa (RP) is a group of inherited disorders
characterized by progressive peripheral vision loss and night
vision difficulties (nyctalopia) that can lead to central vision
loss.

3. Signs and symptoms
• Nyctalopia (night blindness): Hallmark; most commonly the
earliest symptom in RP
• Visual loss, usually peripheral; in advanced cases, central
visual loss
• Photopsia (seeing flashes of light)
A careful family history with pedigree and possible examination of
family members can be useful. In addition, a drug history is
essential to rule out phenothiazine/thioridazine toxicity.

4. ETIOLOGI
• RP is an inherited disorder that results from harmful changes in any one of
more than 50 genes. These genes carry the instructions for making proteins
that are needed in cells within the retina, called photoreceptors.
• Some of the changes, or mutations, within genes are so severe that the
gene cannot make the required protein, limiting the cellís function. Other
mutations produce a protein that is toxic to the cell. Still other mutations
lead to an abnormal protein that doesnít function properly. In all three
cases, the result is damage to the photoreceptors
• There are three inheritance patterns that can occur in retinitis pigmentosa,
namely autosomal dominant 30-40%, x-linked 5-15%, and autosomal
recessive 50-60%

5. Diagnosis
• Because RP is a collection of many inherited diseases,
significant variability exists in the physical findings. Ocular
examination involves assessment of visual acuity and pupillary
reaction, as well as anterior segment, retinal, and funduscopic
evaluation.

6. Management
• There is currently no cure for RP; therefore, therapies are
limited. Nonetheless, it is essential to help patients maximize
the vision they do have with refraction and low-vision
evaluation.
Pharmacotherapy
Medications sometimes used in the management of RP include
the following:
• Supplements: (eg, Lutein, Zeaxanthin, Omega-3 Fatty Acids)
• Carbonic anhydrase inhibitors (eg, acetazolamide,
methazolamide, dorzolamide)
• Triamcinolone, dexamethasone

8. Monitoring progression of retinitis pigmentosa
Assessment of Visual Function
• ETDRS letters Visual acuity (VA)
• Low-luminance visual acuity, colour vision and contrast sensitivity
• Visual Field (Manual/ tools Goldmann visual fields)
• Electrophysiology
• Multi-luminance mobility test (MLMT), Full-field stimulus threshold
(FST)
Assessment of Retinal Structure
genotyping
doi: 10.1080/21678707.2020.1735352

9. low vision
• Blindness is defined as visual acuity of less than 3/60 or
corresponding visual field loss in the better eye with best possible
correction.
• Low Vision corresponds to visual acuity of less than 6/12 but equal to
or better than 3/60 in the better eye with best correction.
• Mild vision impairment – visual acuity worse that 6/12 to 6/18
• Moderate vision impairment – visual acuity worse than 6/18 to 6/60
• Severe vision impairment – visual acuity worse than 6/60 to 3/60

10. distant optical devices

13.  google talk back

17. Normal funduscopy