Retinada Kullanılan Güncel Lazer Uygulamaları
Özet
Lazer, uyarılmış radyasyon salınımı ile ışığın güçlendirilmesiyle elde edilen, koherent, monokromatik ve doğrusal özelliklere sahip yoğun bir ışık kaynağıdır. Gözün optik ortamının saydamlığı sayesinde oftalmoloji, intraoküler patolojilerin tedavisinde lazerin en sık kullanıldığı tıp alanıdır. Non-invaziv bir yöntem olan retinal lazer fotokoagülasyon, iskemik ve neovasküler retina hastalıklarında altın standart kabul edilir; melanin ve hemoglobin tarafından absorbe edilerek ısı yoluyla hipoksiyi azaltmayı amaçlar. Ancak, devamlı modda uygulanan geleneksel lazer fotokoagülasyonun çevre dokulara pasif termal yayılım nedeniyle görme alanı kaybı, ağrı ve skar genişlemesi gibi yan etkileri bulunmaktadır. Bu komplikasyonları önlemek amacıyla geliştirilen "fovea dostu" mikropulse lazer, sürekli enerji yerine mikrosaniyelik kısa atım zincirleri kullanarak ısının hedef dokuda kalmasını sağlar ve nöral retinayı korur. Benzer şekilde, Pattern Scan Lazer (PASCAL), pedala tek basışta önceden belirlenmiş çoklu paternleri kısa atım süreleriyle (10-20 msn) uygulayarak tedaviyi daha hızlı, düzenli ve konforlu hale getirir. Günümüzde, RPE hücresini hasarlamak yerine yeniden şekillenmesini uyaran 3 nanosaniyelik atımlı yeni nesil lazer sistemleri (Ellex 2RT) ve fluorescein anjiyografi ile canlı retina görüntüsünü birleştiren navigasyonlu lazerler (Navilas) geliştirilmektedir. Gelişen teknolojiyle birlikte, mavi dalga boyunun yerini alan yeşil lazer de artık yerini maküler lezyonlarda daha güvenli ve etkili olan sarı dalga boyuna bırakmaktadır.
Laser is an intense light source characterized by coherent, monochromatic, and colinear properties, achieved through light amplification by stimulated emission of radiation. Due to the transparency of the eye's optical environment, ophthalmology is the medical field where lasers are most frequently utilized for treating intraocular pathologies. Retinal laser photocoagulation, a non-invasive procedure, is considered the gold standard for ischemic and neovascular retinal diseases, aiming to reduce hypoxia via heat generation through absorption by melanin and hemoglobin. However, conventional photocoagulation applied in continuous wave mode presents side effects such as visual field loss, pain, and scar expansion due to passive thermal diffusion to adjacent tissues. Developed to mitigate these complications, the "fovea-friendly" micropulse laser delivers energy in microsecond pulse packets instead of continuous beams, trapping heat within the retinal pigment epithelium and protecting neural retina. Similarly, the Pattern Scan Laser (PASCAL) delivers predetermined multiple patterns rapidly in a single pedal press with short pulse durations (10-20 ms), making the treatment faster, more uniform, and comfortable. Furthermore, next-generation systems like the 3-nanosecond pulse laser (Ellex 2RT) stimulate cellular remodeling rather than damaging cells, while navigated lasers (Navilas) combine real-time retinal imaging with fluorescein angiography. Driven by these technological advances, the widely used green wavelength is progressively being superseded by the yellow wavelength, which offers enhanced safety and efficacy for macular lesions.
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