Age-Related Macular Degeneration

Age-related Macular Degeneration (ARMD) is a type of retinal degenerative disease that leads to gradual loss of central vision. This eye disease typically occurs after the age of 55 and is one of the leading causes of blindness among the elderly and senior. Most cases show that if one eye is affected by this eye disease, the other eye is also likely to be affected.

Macula is located at the central part of the retina and is responsible for fine vision functions, including central vision, colour differentiation, and the ability to see fine details such as threading a needle or reading.

Macula is responsible for:

  • Central vision

  • Color differentiation

  • Ability to see fine details

Symptoms:

  • Central vision becomes blurry

  • Visual distorted or crooked

  • Difficulty differentiating colors

  • Dark spots or blank areas appear in the center of vision

Types of Age-Related Macular Degeneration:

1. Dry Age-Related Macular Degeneration (Dry AMD)
Approximately 90% of individuals with age-related macular degeneration (AMD) have the dry form. Dry AMD is characterized by the accumulation of small yellow-white deposits, known as drusen, beneath the retinal pigment epithelium (RPE). These deposits interfere with the function of the macula's photoreceptor cells, leading to gradual degeneration of these cells. In some cases, dry AMD may progress to the more advanced wet AMD, which can result in a rapid deterioration of vision.

Treatment
Currently, there are no effective medical treatments for dry age-related macular degeneration. Management focuses on monitoring disease progression and supporting vision through lifestyle modifications, but no therapy has been proven to halt or reverse the condition.

2. Wet Age-Related Macular Degeneration (Wet AMD)
Approximately 10% of people who have AMD have the wet form. Wet AMD is characterized by the growth of abnormal blood vessels beneath the macula, known as choroidal neovascularization. These vessels often leak fluid or bleed, causing damage to the photoreceptor cells of the macula. Wet AMD typically progresses rapidly, leading to a sudden decline in central vision and distortion of images.

The leakage and hemorrhage can cause irreversible damage to the macular tissue, resulting in permanent vision loss.

Treatment
Currently, there is no effective treatment to restore vision once significant damage has occurred, such as severe vision loss or macular scarring. However, anti-VEGF (vascular endothelial growth factor) therapy can slow disease progression by reducing the growth of abnormal blood vessels, though it does not reverse vision loss.

Anti-VEGF Therapy (Anti-Vascular Endothelial Growth Factor Therapy)

Anti-VEGF therapy represents a contemporary treatment modality for wet age-related macular degeneration (wet AMD). This approach involves the intravitreal injection of VEGF inhibitors directly into the vitreous cavity of the eye. The medication travels through the vitreous humor to the macula, where it specifically targets and inhibits the action of vascular endothelial growth factor (VEGF), thereby reducing the formation of pathological neovascularization (abnormal blood vessels).

A typical treatment regimen consists of three injections, usually administered at four-week intervals. Following the initial series, patients undergo clinical evaluation to assess the efficacy of the treatment and determine the need for additional injections.

Due to the aggressive nature of wet AMD and its rapid impact on central vision, combination therapies are often employed to enhance therapeutic outcomes. When combined with photodynamic therapy (PDT), anti-VEGF treatment has been shown to provide superior results in terms of vision preservation and slowing disease progression, compared to monotherapy.

Diagnosis and Prevention

Early detection of age-related macular degeneration (AMD) is essential for preventing further impairment of central vision and minimizing the long-term impact on visual function. Interventions such as laser therapy or newer treatment modalities can significantly reduce the risk of vision loss when administered early, slowing the progression of macular degeneration.

It is critical for patients to seek immediate consultation with an ophthalmologist if they notice any signs of central vision blurring or distortion. To facilitate early detection, patients are encouraged to perform regular self-monitoring using an Amsler Grid, a tool consisting of a grid of parallel and perpendicular lines. This simple at-home test helps individuals detect any distortion or blurring of the lines, which may indicate the onset of macular degeneration. If abnormalities are observed, prompt clinical evaluation is recommended to assess the need for further diagnostic tests or treatment.

Prevention Strategies

  • Quit smoking

  • Antioxidant-rich diet: Consume foods like fresh vegetables.

  • UV protection: Wear sunglasses with UV protection to prevent retinal damage.

  • Regular eye exams: Early detection through routine ophthalmologic check-ups for timely treatment.