DALK is a successful form of transplantation in stromal corneal disorders with healthy endothelium, with higher long-term graft survival rates and stable ECD 6 months postoperatively. DALK survival rates do not vary significantly over time.

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).

Early therapeutic DALK could be considered a new approach to eradicate active infection in AK cases poorly responsive to medical treatment, with significant ulcer in the optical zone. Further studies are needed to validate this new indication for DALK.

The use of a smooth cannula during the DALK procedure yields a statistically higher percentage of dDALK and makes the maneuver more manageable compared with air injection with a needle. When BB fails, AVB seems to be a good rescue technique to achieve dDALK.

Fuchs endothelial corneal dystrophy (FECD) is the most common indication for corneal transplantation in the United States, accounting 36% of the almost 47,000 transplants performed in 2016. Although the surgical management of FECD has undergone a revolution over the past 20 years, its pathogenesis remains elusive, with multiple putative disease pathways and an ever increasing number of candidate genes thought to play a role. This review will summarize the recent advancements in our understanding of the biology of FECD, including potential parallels with neurodegenerative disease like amyotrophic lateral sclerosis and will highlight prospects for future treatment advances.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Deep anterior lamellar keratoplasty (DALK) is currently the procedure of choice to restore transparency and curvature in corneal stromal diseases with a healthy endothelium. Preserving the endothelium avoids endothelial rejection and provides a good and stable endothelial cell count, allowing good long-term graft survival. Several surgical techniques have been proposed over the last years, the most common of which include layer-by-layer manual dissection, hydrodissection, viscodissection, big bubble (needle or cannula) and air-viscobubble. Descemet's membrane rupture represents the most common complication, even in expert hands. The penetrating keratoplasty conversion rate gradually decreases as surgeons become more experienced and learn to manage Descemet's membrane ruptures. Being able to repair the ruptures would increase the success of DALK and allow patients to benefit from all of its advantages. a b cGüell JL (ed): Cornea.

PurposeTo investigate the efficacy of early therapeutic deep anterior lamellar keratoplasty (DALK) in eradicating fungal keratitis that is poorly responsive to medical treatment.Patients and methodsTwenty-three eyes (23 patients) underwent early therapeutic DALK within 15 to 50 days from the onset of symptoms. The adopted eligibility criteria for early DALK included the following: active fungal keratitis affecting the optical zone with ulcer confined in the 6.00 mm central cornea; deeper than 150 μm but not exceeding 300 μm; and poorly responsive to medical treatment.ResultsThe big bubble technique was accomplished in 74% (17) of eyes, whereas manual dissection was performed in the remaining 26% (6) of eyes. Histopathological examination did not show any sign of fungal colonization in the peripheral and deep stromal lamellae in any case. All grafts were transparent postoperatively, and no recurrence of infection occurred. Median best spectacle corrected visual acuity significantly improved from 2.0 (1.0 interquartile range) logMAR to 0.1 (0.1 interquartile range) logMAR (P<0.01). The mean follow-up was 32±10 months. Neither episode of rejection nor graft failure was noted during the follow-up period.ConclusionEarly DALK could represent a safe therapeutic approach to eradicate fungal keratitis that affects the optical zone and is poorly responsive to medical treatment.

Purpose: To report how to manage a specific type of Descemet’s membrane (DM) rupture during manual DALK with a concurrent donor–recipient disparity of curvature. Methods: Case report of two patients that had DM rupture during manual DALK with a concurrent donor–recipient disparity of curvature; the recipient bed was flatter (post-infectious scar, case 1) and steeper (keratoglobus, case 2) than the donor. Preoperative diagnosis, clinical exam, and best spectacle correct visual acuity (BSCVA) have been reported. A subtotal full-thickness circular cut of the recipient bed was performed to resolve a persistent double AC in case 1 (recipient flatter than donor). A total full-thickness circular cut of the recipient bed, creating a graft made by a DALK allograft and a “DSEK autograft,” was performed to avoid a refractory double AC in case 2 (recipient steeper than donor). Evaluated outcomes included postoperative BSCVA, endothelial cell count (ECC), graft clarity, rejection, and presence/absence of double AC. Results: Surgery was successful in resolving/avoiding double AC. VA improved in both cases. No episodes of rejection were recorded. Graft remained clear at the last follow-up (6 years for case 1 and 4 years for case 2). Conclusion: The existence of a donor–recipient curvature disparity should be investigated as a possible underlying mechanism of refractory double AC. Total or subtotal full thickness recipient bed cut may be considered to repair donor–recipient curvature disparity in cases of DM rupture occurring during manual DALK. Repairing the DM rupture and avoiding a conversion to PK in high-risk transplant cases are crucial.