RISK FACTORS: Excess sunlight exposure, Blue or light iris color, Hyperopia, History of cardiovascular disease (hypertension, circulatory problems), Short height, History of lung infection, Cigarette smoking, Low dietary intake oantioxidant nutrients
GENERAL MEASURES
. Atrophic/nonexudative macular degeneration
. No specific treatment alters the course
. Free radical formation in the retina, induced by visible light may play a role in cellular damage that results in
ARMD.
. Vitamins A, E, C and beta-carotene may be useful in preventing cellular damage
. Oral zinc may retard visual loss
. Laser photocoagulation to treat drusen is being investigated
. Neovascular/exudative macular degeneration
. The Macular Photocoagulation Study (MPS) demonstrated a treatment benefit for laser treatment of CNVMs which were 200 microns (200 microns = 0.2 mm) or greater from the center of the macula.
- The MPS showed that the benefi ts of argon laser photocoagulation were greatest one year after treatment. At that time the proportion of eyes with severe visual loss was reduced 51% by treatment, from 43% in untreated eyes to 21% in treated eyes. The deterioration in treatment effect in the MPS is primarily due to recurrent CNVMs growing towards the center of the macula.
- Fluorescein angiogram usually can determine whether a CNVM is present, if it is well defi ned, and if it is in a treatable position.
- Recurrent CNVMs, after laser treatment, were seen in 59% of patients with ARMD. Recurrent CNVMs
develop early after treatment; 73% of the recurrences occurred within the fi rst year of treatment, usually within the fi rst 6 months.
. Treatment of CNVMs from 1 to 199 microns from the center of the macula has been studied by the Age-Related Macular Degeneration Study-Krypton Laser (ARMDS-K). The benefit of laser treatment was greatest among patients without evidence of hypertension. No benefit was observed among patients who had highly elevated blood pressure and/or used antihypertensive medication.
. Because patients in the ARMDS-K treatment group had CNVMs closer to the center of vision, the magnitude
of treatment benefi t after laser photocoagulation is smaller in the ARMDS-K treatment group than in the argon laser trial for CNVMs farther away from the center of the macula.
. Laser treatment can be applied to CNVMs directly underneath the center of vision; however, this can result in immediate worsening of vision. The long term benefi ts of laser treatment for these lesions makes this form of laser treatment an option.
. Vitrectomy has been used to remove CNVMs, but the benefits of this procedure are being studied
. CNVMs can bleed spontaneously leaving blood underneath the retina. Vitrectomy to remove subretinal
blood may be of benefi t and should be performed within 7 days of the bleed. Tissue plasminogen activator (tPA) instilled into the eye, may help remove a subretinal hemorrhage. Intravitreal gas with or without tPA may be capable in some cases of displacing submacular blood.
. Macular translocation involves intentionally creating a retinal detachment and attempting to shift the macula
away from the CNVM. Laser is then applied to the CNVM after the retina is translocated. This procedure is
currently being refi ned and is associated with potential serious surgical risks.
. Patients need to be monitored (usually with fluorescein angiography) after laser treatment, for recurrent CNVMs. After treatment, patients should report changes in the Amsler grid or their vision
. Photodynamic therapy (PDT) with verteporfi n reduces vision loss in patients with greater than 50% classic
subfoveal CNVMs. Verteporfin is administered intravenously and diode laser at 689 nm is applied to the
CNVM.
. When PDT was used to treat predominantly classic subfoveal CNVMs after 24 months of follow-up, 59%
of the verteporfi n-treated eyes versus 31% of the placebo-treated eyes lost fewer than 15 letters from
baseline
. In occult subfoveal CNVMs with no classic component, PDT significantly reduces the risk of moderate and severe vision loss
. PDT treatment benefit may not only depend upon lesion type, but also upon lesion size and presenting
visual acuity. The treatment benefi t may be related to smaller lesion size and worse presenting visual acuity.
. Patients should be informed that there is a small risk of acute, severe vision loss of approximately 4% after
PDT
. Intravitreal triamcinolone when combined with PDT may result in improved visual acuity for patients with
CNVMs
. Pegaptanib (Macugen) has been approved for the treatment of neovascular age-related macular degeneration. Pegaptanib is a selective vascular endothelial growth factor (VEGF) antagonist that can be injected intravitreally every 6 weeks.
. Low vision aids may be helpful
. Investigation/experimental treatments:
. Transplanting of fetal RPE cells, laser treatment to drusen, low dose radiation therapy, transpupillary
thermotherapy, via a diode laser at 810 nm, for occult subfoveal CNVMs, iron chelation therapy
. An implantable miniature telescope is being tested in patients with visual loss from ARMD
SURGICAL MEASURES
See General Measures
ACTIVITY Patients with the neovascular form of ARMD should avoid straining and anticoagulants if possible prior to laser treatment
DIET
. A diet high in vitamins A, E, C and beta-carotene along with zinc may be of benefit
. Eating dark green, leafy vegetables (spinach or collard greens) which are rich in carotinoids may decrease the risk of developing the neovascular/exudative stage
. May be a higher risk for ARMD with increasing intake of vegetable fat and monounsaturated and polyunsaturated fats, and linoleic acid. High concentrations of these substances tend to be found in highly processed, store-bought snack foods.
. Consumption of omega-3 fatty acids found in fish decreased the risk of ARMD when the intake of linoleic
acid was low
DRUG(S) OF CHOICE
β’ Zinc and antioxidants may be of benefit. Zinc sulfate 100 mg bid with food has been recommended.
β’ Age-Related Eye Disease Study (AREDS) found that a high-dose regimen of vitamin and mineral supplements reduces progression of ARMD in some cases. Recommended daily doses: vitamin C 500 mg, vitamin E 400 1U, beta-carotene 15 mg, zinc oxide 80 mg, and cupric oxide 2 mg.
ALTERNATIVE DRUGS
β’ Anecortave acetate is being tested in the treatment of exudative ARMD. This medicine is injected next to the eye, via a posterior juxtascleral injection.
β’ RhuFab is a promising anti-VEGF compound being tested in the treatment of exudative ARMD
PATIENT MONITORING
β’ Laser treated patients should be re-examined promptly if new visual symptoms occur
β’ The Amsler grid can aid in discovering visual disturbances
β’ Patients with soft drusen or pigmentary changes in the macula are at an increased risk of visual loss. They
should be instructed that it is important to monitor their vision, such as by Amsler grid testing and subjective
measures of visual acuity, such as reading vision and image clarity. If there are no new symptoms, follow-up
examination in 6-12 months.
β’ Follow-up examination for patients at increased risk of visual loss may permit early detection of treatable
lesions
PREVENTION/AVOIDANCE
β’ Ultraviolet protection for eyes
β’ Well balanced diet which includes zinc, vitamins A, E, C, and beta-carotene
β’ Routine ophthalmologic visits; q2-4 years for patients 40-64 and q1-2 years after age 65
β’ Daily Amsler grid testing
β’ Patients who take statin drugs, which modify lipid profiles, may have a reduced risk for ARMD
POSSIBLE COMPLICATIONS Blindness
EXPECTED COURSE/PROGNOSIS
β’ Patients with bilateral soft drusen, and pigmentary changes in the macula, but no evidences of exudation,
have an increased likelihood of developing CNVMs and subsequent visual loss
β’ Patients with bilateral drusen carry a cumulative risk of 14.7% over fi ve years of suffering significant visual loss in one eye from the neovascular stage of ARMD.
β’ Patientβs with neovascular stage in one eye and drusen in the opposite eye are at a risk of 5-14% annually of
developing the neovascular stage in opposite eye with drusen
β’ High incidence of recurrence after laser treatment for CNVMs