Retinal dystrophies are chronic and progressive disorders of visual function. 'Dystrophy' means a condition disorder in which an organ or tissue of the body wastes away, and 'retinal' means relating to the retina. The retina is located at the back of the eye and is made up of millions of light-sensitive cells called photoreceptors.

• Retinitis pigmentosa (RP) is the name given to a group of inherited conditions of the retina that lead to a gradual progressive reduction in vision. Loss of side vision (otherwise known as 'tunnel vision') and the reduced ability to see at night (otherwise known as 'night blindness') are the first notable symptoms of RP. Further down the track, sufferers may experience diminished reading vision (detailed vision), color vision, and central ('straight-ahead') vision.

• Macular degeneration is caused by the deterioration of the central portion of the retina, the inside back layer of the eye that records the images we see and sends them via the optic nerve from the eye to the brain.

  • There are two basic types of macular degeneration: "dry" and "wet." In the "dry" type of macular degeneration, the deterioration of the retina is associated with the formation of small yellow deposits, known as drusen, under the macula. This phenomenon leads to a thinning and drying out of the macula, causing the macula to lose its function. In the "wet" type of macular degeneration, abnormal blood vessels (known as choroidal neovascularization) grow under the retina and macula. These new blood vessels may then bleed and leak fluid, causing the macula to bulge or lift up from its normally flat position, thus distorting or destroying central vision. Approximately 85-90% of the cases of Macular Degeneration are the "dry" (atrophic) type, while 10-15% are the "wet" (exudative) type.

• Rod and/or cone dystrophy is the deterioration of photoreceptor cone and rod cells. In people with cone-rod dystrophy, vision loss occurs as the light-sensing cells of the retina gradually deteriorate.

Most retinal dystrophies are genetic, or inherited.

There are no known risk factors for RP other than genetic predisposition; it may occur as an isolated sporadic disorder or be inherited.

Macular degeneration - There are no predisposing systemic risk factors known, but age-related macular degeneration may be hereditary, and smoking may be a risk factor. In age-related atrophic macular degeneration (dry form), there is pigmentary disturbance in the macular region but no elevated macular scar, and no bleeding or oozing of fluids in the region of the macula. In exudative macular degeneration (wet form), there is the formation of a network of new growth in the vascular layer below the retina often associated with bleeding within the retina, fluid below the retina, pigment epithelial detachment, and increased pigmentation, leaving a distinct scar.

There are no known risk factors for cone-rod dystrophy other than genetic predisposition.

• Loss of side vision (peripheral vision), otherwise known as 'tunnel vision'

• Loss of central vision

• Reduced ability to see at night, otherwise known as 'night blindness'

• Diminished ability to see in dimly lit conditions

• Diminished ability to judge changes in the levels, such as steps and gutters

• Increased light sensitivity or glare

• Slower to adjust to changes to light sensitivity

• Vision test

  • Visual acuity - a test used to determine ones visual clarity. A patient is asked to read the letters from a chart at a distance. This a common visual test used by many optometrists and ophthalmologists worldwide.

  • Visual field - a test used to measure ones field of vision using spots of light projected on a dark background. This test finds any defects in the peripheral (side vision) which gradually decreases over time.

• Electroretinography (ERG) - a painless test used to measure tiny electrical responses generated by the retina to flashes of light. This is measured via electrodes placed on the surface of the eye.

• Retinal photography - a specialized camera is used to take a photograph of the inside of the eye, the images help establish the health of the retina.

• Blood test - a blood sample may be requested for genetic analysis of known mutations that cause retinitis pigmentosa or similar disorders.

Treatment is dependent upon the type of retinal dystrophy that is present.

There is currently no cure for RP, and no proven treatments are available to slow the progression of the disease. A number of experimental treatments have been proposed, however the evidence supporting their effectiveness is variable and limited.

For macular degeneration, patients older than 55 and those at risk for intermediate or advanced age related macular degeneration should consider taking the combination of antioxidants plus zinc to halt the progression of the disease. The only well-established treatments, photocoagulation and verteporfin in photodynamic therapy, is used to seal leaking blood vessels to prevent or slow further vision loss. For patients who have lost central vision, low-vision devices, such as magnifying lenses and amplification lamps are available, and counseling is advised. The patient may be asked to use a finely squared grid (Amsler's grid) viewed from a distance of 12 inches daily, to evaluate for subtle changes in vision.

There is no treatment for cone-rod dystrophy.

Vision impairment as related to the specific type of diagnosed retinal dystrophy.

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See  38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• Consider entitlement to specially adapted housing under 38 U.S.C. 2101(a)(2)(A)(i) if there is visual impairment to the degree specified in 38 CFR 3.809(b)(2).

• The veteran, spouse, surviving spouse or parent will be considered in need of regular aid and attendance if he or she is blind or so nearly blind as to have corrected visual acuity of 5/200 or less, in both eyes, or concentric contraction of the visual field to 5 degrees or less (38 CFR 3.351(c)(1)).

• Consider entitlement to automobile allowance and/or automobile adaptive equipment if there is visual impairment to the degree specified in 38 CFR 3.808(b)(3).

• Prior to the rating schedule change for eyes on May 13, 2018, this condition was evaluated analogously (6099-6006).

• Review for entitlement to special monthly compensation under 38 CFR 3.350.

• For the purposes of evaluation under 38 CFR 4.79, an incapacitating episode is an eye condition severe enough to require a clinic visit to a provider specifically for treatment purposes

• Examples of treatment may include but are not limited to: Systemic immunosuppressants or biologic agents; intravitreal or periocular injections; laser treatments; or other surgical interventions

• For the purposes of evaluating visual impairment due to the particular condition, refer to 38 CFR 4.75, 38 CFR 4.76, 38 CFR 4.77, 38 CFR 4.78,  and  38 CFR 4.79, diagnostic codes 6061-6091.