Macular Degeneration Surgery (黃斑手術)

Macular degeneration is the leading cause of severe vision loss in people over age 50. It occurs when the small central portion of the retina, known as the macula, deteriorates. Because the disease develops as a person ages, it is often referred to as age-related macular degeneration (AMD). Although macular degeneration is almost never a totally blinding condition, it can be a source of significant visual disability.

There are two main types of age-related macular degeneration: Dry and Wet form. The “wet” form is characterised by the growth of abnormal blood vessels from the choroid underneath the macula. This is called choroidal neovascularization. These blood vessels leak blood and fluid into the retina, causing distortion of vision that makes straight lines look wavy, as well as blind spots and loss of central vision. These abnormal blood vessels eventually scar, leading to permanent loss of central vision.

The treatment of wet AMD has evolved over the last 20 years. The treatment options include: laser, photodynamic therapy (PDT), injection of steroid into the eye, and injections of anti-VEGF drugs (Avastin, Lucentis, or Eylea) into the eye.

Anti-vascular endothelial growth factor treatment helps reduce the number of abnormal blood vessels in your retina. It also slows any leaking from blood vessels. This medicine is delivered to your eye through a very small needle. Visudyne photodynamic laser therapy may also be used on the abnormal blood vessels to treat some types of wet AMD. PDT is no longer considered a first line treatment for neovascular, or wet AMD. It is typically used in combination with injections of anti-VEGF medicine.

黃斑病變/ 退化是50歲以上人士的主要致盲眼疾。其主要影響視網膜視力最清晰的中央位置 — 黃斑區。由於患上此眼疾的風險會隨著年齡增長,因此亦稱為老年黃斑病變(AMD) 。雖然黃斑病變一般不會引致完全失明,但對中央視力能構成嚴重的損害。

老年黃斑病變主要分為2種: 乾性與濕性。濕性黃斑病變的特徵是異常的脈胳膜血管增生。這些異常的血管會引致視網膜出血及滲漏的情況,造成視像扭曲變形,出現盲點及中央視力下降,最終出現結痂及中央視力永久受損。

濕性黃斑病變的治療方法在近20年中不斷改良。其療法包括: 激光、光動力療法 (PDT)、類固醇球內注射及抗血管新生藥物球內注射 (Anti-VEGF drugs)。

抗血管新生藥物注射能有效抑制異常血管的生長,從而減少視網膜的出血與滲漏。藥物主要透過一支幼細的針管注射入眼球內。有時光動力療法亦會被應用於治療濕性黃斑病變,但此療法不再是第一線的治療方案; 其主要作用是連同抗血管新生藥物作結合治療。