Deep anterior lamellar keratoplasty (DALK) is the ideal surgery for corneal stromal diseases with a healthy endothelium. This technique offers substantial advantages compared with penetrating keratoplasty, primarily the avoidance of endothelial rejection and longer graft survival. Several DALK techniques have been described and classified into 2 categories, descemetic DALK (dDALK) and predescemetic DALK (pdDALK) depending on whether Descemet membrane-endothelium was thought to be exposed or minimal residual stroma was left behind. This classification was crucial to identify the conditions to achieve good visual outcomes with pdDALK techniques. The recent description of Dua's layer, also known as the pre-Descemet layer, has demonstrated that a very thin layer of stroma exists in some instances where Descemet membrane was thought to be completely exposed. This concept has generated a discrepancy between the previous and current applications of the terms “dDALK” and “pdDALK.” We offer a summary of the published literature and a proposal for a new and more appropriate DALK nomenclature. We suggest adding the terms subtotal anterior lamellar keratoplasty (STALK) and total anterior lamellar keratoplasty (TALK).
*Ospedale Oftalmico di Torino, Struttura Complessa Oculistica 2, Turin, Italy;
†Ospedale San Giovanni Bosco, Struttura Complessa Oculistica 2, Turin, Italy;
‡Clinica degli Occhi Sarnicola, Grosseto, Italy;
§Department of Ophthalmology, Cincinnati Eye Institute, University of Cincinnati, Cincinnati, OH;
¶Department of Biomedical and Specialty Surgical Sciences, University of Ferrara, Ferrara. Italy; and
‖Virginia Eye Consultants, Norfolk, VA.
Correspondence: Vincenzo Sarnicola, MD, Ambulatorio di Chirurgia Oculare Santa Lucia, Via Mazzini n°62, Grosseto 58100, Italy (e-mail: firstname.lastname@example.org).
E. J. Holland has consulted for Alcon Laboratories, Allergan, Bausch & Lomb, Kala Pharmaceuticals, Mati Pharmaceuticals, Omeros, PRN, RPS, Senju Pharmaceuticals, Shire, TearLab, and TearScience. The remaining authors have no funding or conflicts of interest to disclose.
Received August 19, 2018
Accepted November 12, 2018