Clinical Outcomes of Modified Manual Deep Anterior Lamellar Keratoplasty for Eyes with Previous Radial Keratotomy.

Background: The aim of this study was to evaluate the intraoperative complications and visual outcomes of manual deep anterior lamellar keratoplasty (mDALK) in patients who underwent previous radial keratotomy (RK) for myopia. Methods: The notes of patients who underwent mDALK after RK at three different hospitals-San Giovanni Addolorata Hospital (Rome, Italy), Mount Saint Joseph Hospital (Vancouver, Canada), and Tor Vergata University Hospital (Rome, Italy)-were retrospectively reviewed. We analyzed the manual dissection success rate and conversion to penetrating keratoplasty (PK), the residual recipient stromal thickness, the postoperative corrected distance visual acuity (CDVA), postoperative refraction, and topographic astigmatism. Results: Thirteen eyes of eleven patients were included in the analysis (male 7/11, 63.6%). Preoperatively, mean topographic astigmatism was 5.4 ± 3.5 D (range 1.6-14.8 D), and mean CDVA was 0.47 ± 0.2 logMAR (range 0.3-1.0 logMAR) [Snellen equivalent 20/50]. Manual dissection was performed in all cases. None of the examined eyes were converted to PK. An improvement in both topographic astigmatism (2.8 ± 0.9 D, p = 0.0135) and CDVA (0.23 ± 0.2 LogMAR, p = 0.0122) was recorded at 12-month follow-up. Conclusions: mDALK is a safe and effective surgical technique when applied to eyes previously treated with RK, with an observed improvement in CDVA and topographic astigmatism.

Rediscovering a valuable manual Deep Anterior Lamellar Keratoplasty (DALK) technique: Outcomes of 42 "Peeling-off" DALK.

PURPOSE: Residual bed thickness in DALK should be less than 80µm to provide optimal visual outcomes. "Peeling-off" is a manual DALK technique, which separates the anterior stroma by pulling the deep stromal lamellae following the plane of their lowest adhesion, which is usually very deep. The purpose of this study is to measure the residual bed thickness achievable with this technique. METHODS: Retrospective case series of "Peeling-off" DALK cases performed between January 2014 and January 2021 with at least 1 year of follow-up. Indications for DALK, intraoperative and postoperative complications, residual recipient bed thickness at 1 day and at 1 month after surgery, and postoperative best corrected visual acuity (BCVA) at 1 year of follow up were evaluated. RESULTS: 42 eyes (42 patients) underwent DALK performed with "Peeling-off" technique. Indications for surgery were keratoconus in 33 eyes and stromal scar in 9 eyes. "Peeling-off" technique was used as a rescue approach to perform a DALK after a failed Big-Bubble in all cases, and also failed Air-Visco-Bubble in some cases. No intraoperative and postoperative complications were recorded. Residual recipient bed thickness was deep and regular, measuring 42 microns at 1 day postoperative (range 21-65 microns) and 23 microns (range 17-26 microns) at 1 month postoperative. Mean postoperative BCVA at 1 year of follow up was 0.18 logMAR ± 0.09. CONCLUSION: "Peeling-off" DALK is a valuable manual technique that achieves a deep stromal plane with optimal visual outcomes.

An optional surgical technique for obtaining lamellar donor grafts: a pilot study.

BACKGROUND: To evaluate the surface quality and thickness uniformity of lamellar donor grafts using an optional surgical technique called reversed manual dissection (RMD) in porcine corneas. METHODS: Twenty-four paired porcine corneas (48 eyes) were numbered 1 to 24 and divided into 6 groups. All left corneas were assigned to conventional manual dissection (CMD), and all right corneas were assigned to RMD. Each group contained 8 corneas. For Groups I, II, and III, 30, 50, and 70% of the entire corneal thickness was dissected using CMD. For groups IV, V, and VI, 70, 50, and 30% of the entire corneal thickness was dissected using RMD. The residual stromal thickness was examined by anterior segment optical coherence tomography (ASOCT) to assess the thickness uniformity and scanning electron microscopy (SEM) to assess the surface quality. RESULTS: The thickness uniformity of the lamellar grafts between each paired group was not significantly different (p > 0.05). The qualitative surface roughness grading (QiSR) evaluated by masked observers through SEM was significantly higher in the RMD groups (p < 0.001). The quantitative surface roughness grading (QnSR) acquired from the Mountains software was significantly lower in the RMD groups (p < 0.001). CONCLUSIONS: RMD is an optional surgical technique for obtaining porcine lamellar grafts. The thickness uniformity of RMD is comparable to that of CMD, and a smoother surface with fewer ridges and roughness is achieved compared to CMD.

Outcomes of Descemet stripping endothelial keratoplasty in cases of corneal endothelial dysfunction.

BACKGROUND: Automated microkeratome is commonly used to get donor lenticules for Descemet stripping endothelial keratoplasty (DSEK); however, manual dissection of donor lenticules is also being done with good outcomes. AIM: The aim of this study was to describe the results of manual DSEK performed in cases of corneal endothelial dysfunction caused due to pseudophakic bullous keratopathy, iridocorneal endothelial syndrome, and postpenetrating keratoplasty graft failure. MATERIALS AND METHODS: This was a retrospective observational study. The medical records of all patients with corneal decompensation who underwent DSEK at a tertiary care center performed by the same surgeon were reviewed. A standard DSEK with manually dissected donor lenticules was performed in all cases with the exception of the Descemet membrane not being removed in two cases. A comprehensive ophthalmic examination was performed preoperatively and at each postoperative visit in all patients. RESULTS: Eight eyes of seven patients (four males and three females) were included. The mean age was 64.8 years (range, 49-74 years). The average follow-up was 10.9 months (range, 5-22 months). There was one case of primary graft failure which was managed by repeat DSEK. In the rest, corneas remained clear at the last follow-up. No rebubbling was done as none of the cases showed graft detachment. The preoperative best-corrected visual acuity (BCVA) was 20/2000 or less, and postoperatively, BCVA attained was 20/30 in four eyes and one eye achieved 20/80. CONCLUSIONS: Manual DSEK performed in eyes with corneal decompensation allowed rapid restoration of corneal clarity while minimizing intraoperative and postoperative complications.

A simple surgical technique for splitting a single donor cornea for performing deep anterior lamellar keratoplasty and Descemet membrane endothelial keratoplasty without using a microkeratome.

PURPOSE: To describe a simple manual surgical technique for splitting a single-donor eye for performing both deep anterior lamellar keratoplasty (DALK) and Descemet membrane endothelial keratoplasty (DMEK) without using a microkeratome. METHODS: Twenty-three eyes with anterior stromal pathology and 23 eyes with irreversible endothelial dysfunction were evaluated for keratoplasty at a tertiary eye care referral center. Twenty-three healthy donor corneas were split into two parts. The Descemet's membrane was stripped and used for DMEK. The stripped stroma was used for DALK. Best-corrected visual acuity (BCVA) of both DALK and DMEK, endothelial cell density, and endothelial cell loss in DMEK were noted at 1-year follow-up, along with any intraoperative or postoperative complications and failures. RESULTS: In the DALK group, mean BCVA improved from 1.264 ± 0.25 log Mar preoperatively to 0.355 ± 0.27 log Mar at 12 months follow-up. There were no complications and failures. In the DMEK group, mean BCVA improved from 1.537 ± 0.61 log Mar preoperatively to 0.592 ± 0.67 log Mar and the mean donor ECD was 3071.66 (range, 2783-3487) cells/mm2 preoperatively, which was reduced to 1989.33 (range, 1546-2543) cells/mm2 at 12 months follow-up indicating a mean endothelial cell loss of 35%. The failure rate was 21.7%. CONCLUSION: This study demonstrates that with a single donor corneal tissue, both DALK and DMEK can be performed successfully without any complications. Our technique will help corneal surgeons in all developing countries to cost effectively perform more lamellar surgeries and help in reducing the magnitude of corneal blindness without the need for expensive microkeratomes.

Clinical Comparison of Two Methods of Graft Preparation in Descemet Membrane Endothelial Keratoplasty.

PURPOSE: Descemet membrane endothelial keratoplasty (DMEK) has been improved over the last decade. The aim of this study was to compare the clinical outcome of the recently introduced liquid bubble method compared to the standard manual preparation. METHODS: This retrospective study evaluated the outcome of 200 patients after DMEK surgery using two different graft preparation techniques. Ninety-six DMEK were prepared by manual dissection and 104 by the novel liquid bubble technique. The mean follow-up time was 13.7 months (SD ± 8, range 6-36 months). RESULTS: Best corrected mean visual acuity (BCVA) increased for all patients statistically significant from baseline 0.85 logMAR (SD ± 0.5) to 0.26 logMAR (SD ± 0.27) at the final follow-up (Wilcoxon, p = 0.001). Subgroup analyses of BCVA at the final follow-up between manual dissection and liquid bubble preparation showed no statistically significant difference (Mann-Whitney U Test, p = 0.64). The mean central corneal thickness was not statistically different (manual dissection: 539 µm, SD ± 68 µm and liquid bubble technique: 534 µm, SD ± 52 µm,) between the two groups (Mann-Whitney U Test, p = 0.64). At the final follow-up, mean endothelial cell count of donor grafts was statistically not significant different at the final follow-up with 1761 cells/mm2 (-30.7%, SD ± 352) for manual dissection compared to liquid bubble technique with 1749 cells/mm2 (-29.9%, SD ± 501) (Mann-Whitney U-Test, p = 0.73). The re-DMEK rate was comparable for manual dissection with 8 cases (8.3%) and 7 cases (6.7%) for liquid bubble dissection (p = 0.69, Chi-Square Test). CONCLUSION: Regarding the clinical outcome, we did not find a statistical significant difference between manual dissection and liquid bubble graft preparation. Both preparation techniques lead to an equivalent clinical outcome after DMEK surgery.