H35.32 Exudative Senile Macular Degeneration of Retina

Age-related macular degeneration describes any type of acquired maculopathy that affects people over 50-years old.

Wet Macular Degeneration:  The exudative form of the disease is characterized by neovascularization under the macula.  These abnormal blood vessels leak, bleed, and scar the retina, distorting or destroying central vision.  Visual distortion tends to be unilateral and may progress to affect the other eye later.  Vision loss may be rapid in the wet type of macular degeneration in comparison to the dry form.

Structural Damage to the Eye

• New blood vessels (e.g., neovascularization) of the macula and retina
• Retinal hemorrhages

Functional Damage to the Eye

• Sudden or gradual blurred or distorted central vision
• Patient reports difficulty seeing faces or doing normal task like reading
• Sudden or gradual decreased visual acuity
• Patients report straight lines appear crooked, wavy or distorted
• Objects appear smaller in one eye than the other

The main goal of the diagnostic evaluation in a patient with exudative macular degeneration is to accomplish the following:

• Evaluate the extent of structural changes such as exudates, edema or atrophy in the macula
• Determine the presence or absence of vascular abnormalities secondary to the macular degeneration
• Determine the presence or absence of atrophy secondary to the macular degeneration
• Prescribe a treatment program to treat the macular degeneration and slow the vision loss

Patient History

Patients present with symptoms of unilateral central vision loss which is usually gradual, but can be sudden if it is the wet form of macular degeneration.  Most of the time, patients describe the vision loss as distortions of faces, lines or metamorphopsia. 

DIAGNOSTIC TESTS

Refraction

• Allows for the measurement of visual function and acuity

Fundus Photography

• Used to evaluate the structure of the macula and retina
• Help plan a treatment program for exudative macular degeneration

Extended Ophthalmoscopy

• Patients with miotic pupils and dense cataracts may not allow a good view of the internal structures with fundus photography
• Extended ophthalmoscopy may be an alternative to view internal structures
• Document any other associated structural changes to the macula and the retina
• Help plan a treatment program for the macular degeneration

Retinal Scanning Laser

• Document the location and extent of the macular degeneration at a structural level
• Document any other associated structural changes to the macula and the retinal
• Help plan a treatment program for the macular degeneration

Visual Field Examination

• Used to determine the extent of functional damage to vision in comparison to structural damage

The information provided by these tests are used for medical decision-making in the following manner:

• To document the progress of the macular degeneration
• To document the delivery of the medical treatment
• To document the response to treatment

Wet age-related macular degeneration is not separated into stages.

		Conditions that affect the Retinal Pigment Epithelium and Choriocapillaries Hereditary diseases (Stargardt’s disease, Best’s disease, Angioid Streaks) Bilateral idiopathic juxtafoveal telangiectasis Toxic lesion (Chloroquine, phenothiazines, canthaxanthin)
		Toxic Lesion Bull’s eye maculopathy seen in plaquenil-induced toxic maculopathy
		Conditions that cause Choroidal Neovascularization Hereditary diseases (Best’s disease, Angioid Streaks) Ocular histoplasmosis Toxoplasmosis retinochoroiditis Traumatic choroidal rupture Sarcoidosis Multifocal choroiditis Choroidal Neovascularization Secondary to presumed ocular histoplasmosis 50-year-old black female 20/100 visual acuity

Other causes of subretinal hemorrhages

Other causes of subretinal fluid

• Central serous retinopathy

Laser Therapy

Exudative macular degeneration can be treated with laser surgery, however, this treatment is not a cure.  The disease and loss of vision may progress despite treatment.

Laser surgery:  A laser is used to destroy the fragile, leaky blood vessels.  A small percentage of people with wet AMD can be treated with laser surgery.  Laser surgery is more effective if the leaky blood vessels have developed away from the fovea.  This procedure does destroy health tissue.

Pharmaceutical Agents

Exudative macular degeneration can be treated with photodynamic therapy and injections into the eye.  These treatments are not a cure and the disease and loss of vision may progress despite treatment.

Photodynamic therapy:  A drug called verteporfin (Visudyne) is administered intravenously.  The drug is allowed to travel throughout the body.  The drug is activated by a light and destroys the new blood vessels, which leads to a slower rate of vision decline.  This drug does not destroy surrounding healthy tissue.

Injections:  New drugs with anti-VEGF therapy is injected into the eye.  Patients with exudative maculopathy have abnormally high levels of a specific growth factor in the eye that promotes the growth of new blood vessels.  This drug treatment blocks the effects of the growth factor and can help slow down vision loss.  In some cases, treatment can result in improved vision.

Newly approved and investigational drugs:  There are now several newly approved and investigational drugs for macular degeneration in the United States.  Most of these medications are given directly into the eye or around the eye, and include the following:

Pegaptanib (Macugen) was FDA approved in December 2004.  It blocks VEGF and helps stabilize vision.  Pegaptanib is beneficial in treating both classic and occult subfoveal choroidal neovascular membranes.  The drug is administered by injection into the eye.

Ranibizumab (Lucentis, formerly called RhuFab) is a newly approved anti-VEGF for wet AMD by the FDA in 2006.  It is administered inside the eye via the pars plana.  Preliminary studies have shown improved vision in patients with many forms of wet age-related macular degeneration.

Triamcinolone acetonide is an intraocular injection of corticosteroids.  It was FDA approved in November 2007 forTriesence (Alcon) and June 2008 for Trivaris (Allergan).

Bevacizumab (Avastin) is another anti-VEGF drug that is currently approved for cancer of the colon or rectum.  It is being investigated for intravitreal use in the eye for the treatment of choroidal neovascularization and macular degeneration.

Squalamine lactate (Evizon) is an investigational anti-VEGF drug that is administered intravenously.  This drug may have the potential in treating choroidal neovascular membrane formation.

Anecortave acetate (Retaane) is an investigational drug aimed at inhibiting the abnormal growth of blood vessels in macular degeneration.  The drug is injected behind the eye rather than into the eye.  Alcon discontinued investigations of this medication when statistical endpoints were not met in preliminary studies.  The major difficulty was determining the exact dosage to the interior of the eye.  Reformulations with better predictability promise improved results and further investigation.

Surgery

There are several investigative surgical treatments being used for exudative age-related macular degeneration lesions that may not qualify for laser treatment.

• Macular translocation to a healthier area of the eye
• Displacement of submacular blood using gas
• Removing membranes by surgery

1.  Prall R.  Exudative ARMD.  Medscape/EMedicine.  http://emedicine.medscape.com/article/1226030-overview. Last accessed August 17, 2014.
2.  Olsen T. Knobloch W.  Treatment of Exusdative Age-Related Macular Degeneration:  Many Factors To Consider. National Library of Medicine.  1 Aug 2008.  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2040182/.  Last accessed August 17, 2014.
3.  Fong D.  Age-Related Macular Degeneration:  Update For Primary Care.   Am Fam Physician. 2000 May 15;61(10):3035-3042.  http://www.aafp.org/afp/2000/0515/p3035.html.  Last accessed August 17, 2014.