Structure of intracorneal femtosecond laser pulse effects in conical incision profiles

Abstract

At higher laser energies, the intrastromal laser lesions were larger and more confluent, suggesting that, with the prototype of femtosecond laser used, a higher laser energy may lead to more confluent intrastromal laser effects. It may facilitate the complete cutting of the corneal tissue with the laser. Neither discernable debris nor stainable collateral damage were detected, suggesting a purely mechanical action of the laser.

Femtosecond infrared intrastromal ablation and backscattering-mode adaptive-optics multiphoton microscopy in chicken corneas

“…Their evaluation has often been carried out by means of histological sections [10,22,26,35] and confocal microscopy [36], but multiphoton imaging has not been used very often.…”

“…Then, the affected area is reduced to a tiny region around the focal volume, what allows generating arbitrary geometries with improved accuracy and smoothness. When the analysis of the tissue effects is done through histological slices, artifacts in the size and the shape of the cavities of the ablation might appear as a result of the excessive manipulation of the samples [26]. Alternatively, nonlinear microscopy offers an efficient tool to analyze the morphology of the corneal stroma in a minimally invasive manner [27,36–39].…”

“…However, to our knowledge, there is a lack of efficient techniques to evaluate the performance of intrastromal corneal ablation procedures. Most experiments included a postmortem analysis by means of histological techniques [10,22,26]. This is a tedious operation which requires fixation, staining and slicing of very thin histological corneal sections.…”

A microscopic study of the corneal stromal lenticules extracted during femtosecond laser‑assisted small incision lenticule extraction

“…During SMILE surgery, the lenticule surface is the ablating focus of the femtosecond laser and the photo-decomposing function of the femtosecond laser makes it possible to break the chemical bonds between molecules and to produce a number of bubbles. Once the bubbles expand and merge to form a separate plane in the corneal tissue, the corneal stroma may be separated (20,21). However, due to the existence of discontinuous cavitation bubbles, certain tissue bridges remain and the collagen fibers tend to curl and wrinkle, which results in a not-so-smooth surface of the corneal stromal bed.…”

Benzer Kırma Kusuru İçin Uygulanan Farklı Keratorefraktif Cerrahi Yöntemlerinin Keratometrik Değerler Üzerine Etkileri

“…Bu cerrahide, korneal flap dokusu oluşturulur ve flap dokusunun kaldırılması sonrası korneal stromada önceden belirlenen miktardaki doku, laser enerjisi aracılığıyla fotoablasyona uğratılır ve geniş bir aralıktaki kırma kusuru düzeltilir. LASIK cerrahisinin en kritik aşaması olarak kabul edilen korneal flap dokusu oluşturulmasında mekanik mikrokeratoma alternatif kullanılan femtosaniye laser teknolojisi, LASIK cerrahisinde daha güvenilir sonuçlar elde edilmesini sağlayan yenilikçi bir yaklaşımdır (4)(5)(6).…”