Deep Anterior Lamellar Keratoplasty Group Research Articles

Deep anterior lamellar keratoplasty and penetrating keratoplasty in macular corneal dystrophy: comparison of visual and topographic outcomes and complications.

This study aims to assess and compare the postoperative visual and topographic outcomes, complications, and graft survival rates following deep anterior lamellar keratoplasty and penetrating keratoplasty in patients with macular corneal dystrophy. In this study we enrolled 59 patients (23 male; and 36 female) with macular corneal dystrophy comprising 81 eyes. Out of these, 64 eyes underwent penetrating keratoplasty, while 17 eyes underwent deep anterior lamellar keratoplasty. The two groups were analyzed and compared based on best-corrected visual acuity, corneal tomography parameters, pachymetry, complication rates, and graft survival rates. After 12 months, 70.6% of the patients who underwent deep anterior lamellar keratoplasty (DALK) and 75% of those who had penetrating keratoplasty (PK) achieved a best-corrected visual acuity of 20/40 or better (p=0.712). Following surgery, DALK group showed lower front Kmean (p=0.037), and Q values (p<0.01) compared to the PK group. Postoperative interface opacity was observed in seven eyes (41.2%) in the DALK group. Other topography values and other complications (graft rejection, graft failure, cataract, glaucoma, microbial keratitis, optic atrophy) did not show significant differences between the two groups. The need for regrafting was 9.4% and 11.8% in the PK and DALK groups, respectively (p=0.769). Graft survival rates were 87.5% and 88.2% for PK and DALK; respectively (p=0.88 by Log-rank test). Both PK and DALK are equally effective in treating macular corneal dystrophy, showing similar visual, topographic, and survival outcomes. Although interface opacity occurs more frequently after DALK the visual results were comparable in both groups. Therefore, DALK emerges as a viable surgical choice for patients with macular corneal dystrophy without Descemet membrane involvement is absent.

Deep Anterior Lamellar Keratoplasty-Treated Keratoconic Eyes With Descemet Membrane Rupture.

The aim of this study was to evaluate the outcomes of deep anterior lamellar keratoplasty (DALK) and compare it with penetrating keratoplasty (PKP) in keratoconic eyes with Descemet membrane (DM) rupture. In this comparative retrospective case series, 33 keratoconic eyes with a history of hydrops underwent DALK and 27 received PKP. Baseline and postoperative visual acuity, corneal astigmatism, mean keratometry, endothelial cell density, and complication rates were measured. The median follow-up of patients who underwent DALK was 45 months (range, 4-76 months) and that of patients who underwent PKP was 84 months (range, 4-136 months). Both procedures had comparable postoperative visual acuity, astigmatism, and mean keratometry. Significantly higher endothelial cell densities were observed in DALK than in PKP at 2, 3, and 5 years postsurgery (2043 ± 767 vs. 1165 ± 683 cell/mm2, P = 0.007, n = 12 in both groups at 2 years). Intra-DALK, 15 perforations occurred (44.12%) and 1 (2.94%) was converted to PKP. Graft rejection was diagnosed in 1 (3.03%) DALK procedure versus 8 (29.63%) PKP (P = 0.008), and other long-term complication rates were equivalent. Kaplan-Meier survival analysis also revealed a higher rejection-free survival rate for the DALK group (P = 0.012). Subgroup analysis within both groups based on the severity of preoperative DM rupture revealed no significant difference in any major 2-year outcomes. DALK showed similar beneficial visual outcome and safety but significantly better endothelial protection over PKP in eyes with keratoconus and previous hydrops. Therefore, DALK is recommended in posthydrops cases irrespective of the DM rupture severity.

The role of corneal endothelium in macular corneal dystrophy development and recurrence.

Macular corneal dystrophy (MCD) is a progressive, bilateral stromal dystrophic disease that arises from mutations in carbohydrate sulfotransferase 6 (CHST6). Corneal transplantation is the ultimate therapeutic solution for MCD patients. Unfortunately, postoperative recurrence remains a significant challenge. We conducted a retrospective review of a clinical cohort comprising 102 MCD patients with 124 eyes that underwent either penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK). Our results revealed that the recurrence rate was nearly three times higher in the DALK group (39.13%, 9/23 eyes) compared with the PKP group (10.89%, 11/101 eyes), suggesting that surgical replacement of the corneal endothelium for treating MCD is advisable to prevent postoperative recurrence. Our experimental data confirmed the robust mRNA and protein expression of CHST6 in human corneal endothelium and the rodent homolog CHST5 in mouse endothelium. Selective knockdown of wild-type Chst5 in mouse corneal endothelium (ACsiChst5), but not in the corneal stroma, induced experimental MCD with similar extracellular matrix synthesis impairments and corneal thinning as observed in MCD patients. Mice carrying Chst5 point mutation also recapitulated clinical phenotypes of MCD, along with corneal endothelial abnormalities. Intracameral injection of wild-type Chst5 rescued the corneal impairments in ACsiChst5 mice and retarded the disease progression in Chst5 mutant mice. Overall, our study provides new mechanistic insights and therapeutic approaches for MCD treatment by high-lighting the role of corneal endothelium in MCD development.

Etiology-Specific Comparison of the Long-Term Clinical Outcome of Repeat Deep Anterior Lamellar Keratoplasty for Optical Indications.

The aim of this study was to evaluate the etiology-specific clinical outcomes and complications of repeat deep anterior lamellar keratoplasty (DALK) after failed DALK. This retrospective case study included 32 eyes of 27 patients who underwent repeat DALK of 450 cases of DALK performed for optical indications between 1997 and 2013. The patients were divided into 4 etiology-specific subgroups (the corneal dystrophy, ocular surface disease, stromal scar, and others) or those with or without limbal stem cell deficiency (LSCD). The clinical outcomes evaluated were graft survival, best-corrected visual acuity, endothelial cell density, and complications. The mean postoperative follow-up duration was 69.6 ± 54.8 months. The 1-, 3-, and 5-year overall graft survival rate were 76.7%, 57.5%, and 38.8% respectively. The graft survival rate was the highest in the corneal dystrophy group ( P = 0.0014) and was significantly ( P = 0.0010) higher in eyes without LSCD than in eyes with LSCD. There were no significant differences in the graft survival rates between the previous and current DALK groups. The postoperative best-corrected visual acuity of all subjects improved significantly. The postoperative endothelial cell density did not decrease after repeat DALK. There were no significant differences in the incidence of complications between patients with and without LSCD, except the incidence of persistent epithelial defects. Repeat DALK had favorable outcomes in all etiology-specific groups, whereas eyes with LSCD required careful assessment of the ocular surface to avoid graft failure due to persistent epithelial defects.

Penetrating Keratoplasty Versus Deep Anterior Lamellar Keratoplasty for Advanced Stage of Keratoconus

To compare visual acuity, refractive error, and complications after penetrating keratoplasty (PK) versus deep anterior lamellar keratoplasty (DALK) in the management of advanced stage of keratoconus. Retrospective, comparative, interventional study. This study enrolled 411 consecutive keratoconus eyes with preoperative mean keratometry ≥60 D that received either PK (218 eyes) or DALK (193 eyes). The outcome measures were postoperative visual acuity, refraction, complications, and further surgical interventions. The mean follow-up duration was 77.9±46.5 and 72.9±47.8 months in the PK and DALK groups, respectively (P=0.28). Compared to baseline values, postoperative visual acuity and refraction significantly improved in both groups. Postoperative corrected distance visual acuity was 0.18±0.13 and 0.26±0.19 logMAR in the PK and DALK groups, respectively (P<0.001). Postoperative spherical equivalent refraction was -2.89±2.89 D after PK and -4.58±3.62 D after DALK (P<0.001). Final keratometric astigmatism was comparable between the two groups (P=0.82). Suture-related complications were observed in 48.6% of the PK eyes and 72.0% of the DALK eyes (P<0.001). The incidence of graft rejection was 33.5% after PK and 19.7% after DALK (P=0.002). At the last visit, 98.2% of PK grafts and 94.8% of DALK grafts remained clear (P=0.06). Both techniques of corneal transplantation led to a significant improvement in the visual and refractive variables in eyes with advanced keratoconus. PK resulted in a better visual acuity and refraction with less suture-related complications compared to DALK. However, PK was associated with higher rate of graft rejection. The two techniques were comparable in terms of graft survival.

Outcomes of Conventional 8.0-mm Versus Large 9.0-mm Diameter Deep Anterior Lamellar Keratoplasty for Keratoconus.

The purpose of the study was to compare the clinical outcomes of large 9.0-mm diameter and conventional 8.0-mm big-bubble deep anterior lamellar keratoplasty (DALK). In this comparative, retrospective interventional case series, medical records of 124 cases of large 9.0-mm diameter DALK from January 2017 to December 2019 and 133 conventional 8.0-mm DALK from January 2014 to December 2016 performed by a single surgeon for the indication of keratoconus were reviewed. Main outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), and postoperative complication rates. Postoperative logarithm of the minimum angle of resolution BSCVA did not significantly differ between 9.0-mm and 8.0-mm DALK at any time points. Although the cumulative percentage of eyes achieving Snellen BSCVA of 20/40 or better was comparable between groups (9.0-mm DALK: 93%, 8.0-mm DALK: 90%, P = 0.571), the cumulative percentage of eyes achieving 20/20 or better (9.0-mm DALK: 44%, 8.0-mm DALK: 26%, P = 0.01) and 20/25 or better (9.0-mm DALK: 74%, 8.0-mm DALK: 59%, P = 0.03) was significantly higher in the 9.0-mm DALK group. RA was significantly lower in the 9.0-mm DALK group compared with the 8.0-mm DALK group during all time points ( P < 0.001). The percentage of eyes with RA less than or equal to 4.0 D was significantly lower in the 9.0-mm DALK patients (90%) compared with in 8.0-mm DALK group (72%) ( P = 0.002). Postoperative complication rates were similar between groups. Compared with conventional 8.0-mm DALK, large 9.0-mm DALK can provide superior visual outcomes at higher levels of Snellen BSCVA and significantly lower degrees of astigmatism without an increased risk of immune rejection and graft failure.

Outcomes of deep anterior lamellar keratoplasty and penetrating keratoplasty in keratoconic eyes with and without previous hydrops.

The study aims to compare outcomes after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in keratoconic eyes with or without previous hydrops. Retrospective analysis of 211 eyes who received PK (group 1, n = 74 [history of hydrops: n = 33]) or DALK (group 2, n = 137 [history of hydrops: n = 9]) from 2012 to 2019 at the Department of Ophthalmology, University of Cologne, Germany. Analysis included best spectacle-corrected visual acuity (BSCVA), complications, immune reactions, graft survival and keratometry, and subgroup analyses for subjects with or without previous hydrops. Follow-up was 34.0 ± 23.6months in group 1 and 30.7 ± 22.5months in group 2. No significant difference was found in the course of BSCVA between groups 1 and 2 (p = 0.182) and in postoperative BSCVA between eyes with and without previous hydrops, regardless of the surgical method (p = 0.768). Endothelial immune reactions occurred exclusively in group 1 and did not occur more frequently in eyes with previous hydrops (p = 0.377). A higher risk of complications for eyes with previous hydrops was observed (p = 0.022). There was no difference in astigmatism and maximum keratometry (Kmax) preoperatively and postoperatively between eyes with and without history of hydrops. The prognosis for visual outcome after keratoplasty including visual acuity, astigmatism, and Kmax for keratoconic eyes with previous hydrops is as good as for keratoconic eyes without previous hydrops, irrespective of the surgical method. However, eyes after hydrops seem to have an increased risk of complications.

Surgical management of glaucoma following different keratoplasty techniques.

To investigate the results of surgical management of glaucoma following different keratoplasty techniques. Medical records of 628 cases who underwent keratoplasty were reviewed. One hundred and eighty-eight patients (29.9%) who developed post-keratoplasty glaucoma were evaluated. Patients who could not be controlled with maximal medical treatment and underwent glaucoma surgery were included in this study. Trabeculectomy, Ahmed glaucoma valve (AGV) implantation or diode laser cyclophotocoagulation (DLC) were applied. Glaucoma surgery was performed in 55 (29.3%) patients who had uncontrolled post-keratoplasty glaucoma. In penetrating keratoplasty group (n = 42), DLC was applied to 30 (71.4%) eyes, AGV to 11 (26.2%) eyes, and trabeculectomy in 1 (2.4%) eye. InDescemet'smembrane endothelial keratoplasty group (n = 8), DLC was applied to 4 (50%) eyes, trabeculectomy for 3 (37.5%) eyes and AGV for 1 (12.5%) eye. In deep anterior lamellar keratoplasty group (n = 5), DLC was applied to 2 (40%) eyes, trabeculectomy to 2 (40%) eyes and AGV to 1 (20%) eye. While a statistically significant decrease was found in intraocular pressure (IOP) and anti-glaucomatous medication after surgery (p < 0.05 for each), no significant difference was found in best corrected visual acuity (BCVA). During follow-up, DLC was applied as re-glaucoma surgery in 19 (34.5%) cases. A significant reduction in IOP together with number of anti-glaucomatous medications was found with re-operation; however, a significant decrease in BCVA was noted (p < 0.05 for each). Glaucoma surgeries after keratoplasty are effective in decreasing IOP and the number of anti-glaucomatous medication. While BCVA doesn't change after the first glaucoma surgery, after re-operation significant decrease may occur.

Penetrating Keratoplasty versus Deep Anterior Lamellar Keratoplasty for Keratoconus: A Systematic Review and Meta-analysis.

Keratoconus is the most common form of primary corneal thinning. Different methods have been suggested to deal with the condition, including glasses, contact lenses, and surgical interventions, like penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK), well-known methods of the latter. This study was conducted to compare the outcomes and side effects of the two mentioned keratoplasty techniques. First, we systematically reviewed all original articles studies on PubMed, Scopus, Web of Science, and Embase. Then, the extracted data were pooled and meta-analyzed on each of the intended outcomes. A total of 30 studies were included in which PKP was more commonly performed compared to DALK. We found that adverse outcomes consisting of cataracts, graft rejection, graft failure, High-IOP, and corneal infection, were all more common findings in the PKP groups compared to the DALK groups. However, only for the high-IOP, cataracts, and graft rejection, the analysis of the extracted results demonstrated statistical significance. Overall, the DALK groups demonstrated significantly better results when considering the improvement levels by measuring the Endothelial Cell Count (ECC) and Spherical Equivalent (SE). In addition, though statistically insignificant, the Central Corneal Thickness(CCT), Best Corrected Visual Acuity(BCVA), Topographic Cylinder(TC), Refractive Cylinder values were greater in the PKP groups. Based on our study and with its limitations in mind, we can conclude that DALK can be a relatively safer and more effective procedure. Though, a larger number of high-standard randomized clinical trials still need to be conveyed for more definite conclusions.

Deep anterior lamellar keratoplasty versus penetrating keratoplasty: comparison of clinical outcomes in contralateral eyes.

This study aimed to compare the clinical outcomes following deep anterior lamellar keratoplasty and penetrating keratoplasty in contralateral eyes of the same patients. In this retrospective, comparative case series, clinical outcome data included best-corrected visual acuity, refractive spherical equivalent, refractive astigmatism, endothelial cell density, endothelial cell loss, central corneal thickness, and intraocular pressure, which were evaluated at 6, 12, 24, and 36 months after deep anterior lamellar keratoplasty and penetrating keratoplasty. Additionally, complications were assessed. Fifty-two eyes (26 patients) were included, of which 19 patients had keratoconus, 6 had stromal dystrophy, and 1 had post-laser-assisted in situ keratomileusis ectasia. The mean follow-up was 44.1 ± 10.5 months in the deep anterior lamellar keratoplasty Group and 47.9 ± 11.9 months in the penetrating keratoplasty Group. No significant differences were observed in the mean best-corrected visual acuity, refractive spherical equivalent, refractive astigmatism, and central corneal thickness between the deep anterior lamellar keratoplasty and penetrating keratoplasty Groups during follow-up. The endothelial cell density was significantly higher in the deep anterior lamellar keratoplasty Group than in the penetrating keratoplasty Group at 24 and 36 months postoperatively (p=0.022 and 0.013, respectively). Endothelial cell loss was significantly lower in the deep anterior lamellar keratoplasty Group than in the penetrating keratoplasty Group at 24 and 36 months postoperatively (p=0.025 and 0.001, respectively). Intraocular pressure was significantly lower in the deep anterior lamellar keratoplasty Group than in the penetrating keratoplasty Grroup at 6 months postoperatively (p=0.015). Microperforation occurred in 4 eyes (15%) during deep anterior lamellar keratoplasty surgery; however, penetrating keratoplasty was not required. No endothelial rejection occurred in the penetrating keratoplasty Group during follow-up. Over the 3-year follow-up, endothelial cell loss and intraocular pressure in the deep anterior lamellar keratoplasty Group were significantly lower than those in the penetrating keratoplasty Group, while visual and refractive results were similar.

Early intraocular pressure changes following different keratoplasty techniques and association with cornea parameters and anterior chamber depth.

Background:Corneal transplantation surgery is associated with an increased risk of intraocular pressure (IOP) elevation. Increased IOP may cause irreversible vision loss and graft failure.Purpose: We aimed to evaluate early IOP changes following different keratoplasty techniques and to investigate the relationship between corneal thickness (CT), keratometry values, anterior chamber depth (ACD), and IOP changes.Methods:We included patients who underwent penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), and Descemet membrane endothelial keratoplasty (DMEK) in this observational study. ACD, CT, and keratometry measurements were repeated postoperatively at hour 24, week 1, and month 1. IOP measurements were repeated at postoperative hours 6 and 24, week 1, and month 1 by Tono-Pen XL.Results:In total, 22 patients underwent PK, 12 patients underwent DALK, and 19 patients underwent DMEK. The difference between the IOP preoperatively and postoperatively hour 6, and between the IOP preoperatively and postoperatively hour 24 was statistically significant in the three types of surgery (p < 0.05 for each). The difference between preoperative and postoperative week 1 IOP was statistically significant only in the PK group (p = 0.023). When the IOP was compared between the three types of surgeries, the IOP at postoperative week 1 in the PK group was significantly higher than the DALK and DMEK groups (p = 0.021). There was no correlation between ACD, CT, K values, and IOP in any group.Conclusion:IOP may increase in all types of keratoplasty during the first hours after surgery, but PK has a risk of high IOP longer in the early postoperative period. PK patients should be followed more carefully during postoperative week 1 to check for an increase in IOP.

Comparison of deep anterior lamellar keratoplasty and corneal cross-linking in patients with advanced keratoconus.

To compare outcomes of deep anterior lamellar keratoplasty (DALK) and corneal cross-linking (CXL) in patients with advanced keratoconus, with the primary aim of assessing CXL as a potential therapeutic alternative. Retrospective, multi-center, comparative study. Patients with advanced keratoconus (maximum keratometry reading (K-max) > 58D, best spectacle-corrected visual acuity worse than 0.52logMAR), undergoing either DALK or CXL treatment at four tertiary ophthalmic centers in Wenzhou, Hangzhou, Nanjing and Wuhan were included. Visual acuity, refractive error, corneal topography and complications were evaluated at baseline and at least 2 year postoperatively. 75 eyes of 72 patients were included, of which 37 eyes underwent DALK and 38 eyes, CXL. A larger reduction in Kmax was observed in the DALK group (-18.18 ± 9.44 D versus -1.10 ± 2.70D, p < 0.001). Seven eyes (18%) in the CXL group showed progression of keratoconus. No disease progression was observed in the DALK group. Greater improvements in best spectacle-corrected visual acuity (logMAR) were observed in the DALK group (-0.59 ± 0.25 versus -0.24 ± 0.44, p < 0.001). Compared to CXL, DALK leads to larger reductions in Kmax and better improvement in visual acuity in advanced keratoconus.

Femtosecond laser-assisted deep anterior lamellar keratoplasty: A safer option in keratoconus surgery.

To evaluate postoperative safety of femtosecond laser deep anterior lamellar keratoplasty performed with an innovative anvil profile in keratoconus patients. This is a single-center, retrospective cohort study. We reviewed medical records of 89 keratoconus patients that underwent femtosecond laser deep anterior lamellar keratoplasty surgery (46 eyes) and manual deep anterior lamellar keratoplasty (47 eyes). Inclusion criteria required: age > 18 years old, best-corrected visual acuity < 0.3 LogMAR, continuous suture of the graft, postoperative immunomodulant regimen with dexamethasone 0.1% for 6 months and at least 12 months follow-up. Previous eye surgery, hydrops, and other ocular disease were excluded. The main outcome measures were postoperative events: rejections, persistent epithelial defects, and graft failures. During the follow-up (20 ± 6 months) graft rejection was diagnosed in 0 of femtosecond laser deep anterior lamellar keratoplasty versus 6 (17%) of manual deep anterior lamellar keratoplasty [p 0.027], persistent epithelial defect in 0 of femtosecond laser deep anterior lamellar keratoplasty versus in 4 (11%) of manual deep anterior lamellar keratoplasty [p 0.048] and graft failure occurred in 4 (11%) of manual deep anterior lamellar keratoplasty. The best-corrected visual acuity, after removal of sutures, was better in the femtosecond laser deep anterior lamellar keratoplasty group 0.09 ± 0.08 LogMAR versus 0.16 ± 0.13 LogMAR in manual deep anterior lamellar keratoplasty [p 0.035] group although refractive spherical equivalent and cylinder, topographic average keratometry and cylinder were similar. Anvil-shaped femtosecond laser deep anterior lamellar keratoplasty in keratoconus surgery increases safety and readiness of recovery, decreasing the incidence of corneal rejection, epithelial defects, graft failures, and producing better best-corrected visual acuity after removal of sutures.

Глубокая передняя послойная и сквозная кератопластика `при развитой и далекозашедшей стадии кератоконуса

This article presents the results of surgical treatment of 30 patients (30 eyes) with keratoconus stage 3-4, which were divided into two groups depending on the performed surgery technique. Deep anterior lamellar keratoplasty (DALK) was performed on 20 eyes using a femtosecond laser and the surgery technique including separation of the residual corneal stroma using the "big bubble" technique, and in some cases using the manual dissection technique. In 25% of cases (5 out of 20 eyes), the DALK operation was complicated by Descemet's membrane perforation and therefore, the surgical intervention was completed by switching to penetrating keratoplasty (PK). These patients were excluded from the DALK group and included in the PK group, who underwent penetrating keratoplasty (15 eyes). The maximum follow-up period was 2 years. After DALK transparent engraftment was achieved in all cases, and after PK in 93.4% of cases, in one case (6.6%) graft rejection was observed. Key words: keratoconus, surgical treatment, deep anterior lamellar keratoplasty, penetrating keratoplasty.

Medium-Term Clinical Outcomes of Deep Anterior Lamellar Keratoplasty versus Penetrating Keratoplasty for Macular Corneal Dystrophy.

PurposeTo compare the postoperative outcomes of deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP) for macular corneal dystrophy (MCD).DesignSingle-center, retrospective, interventional case series.MethodsA chart review was performed of 100 patients (157 eyes) who underwent primary DALK (DALK group) and PKP (PKP group) for histopathologically confirmed MCD for whom at least 12 months of follow-up were available. Between-group comparisons were performed of visual acuity (VA), graft survival, and postoperative complications.ResultsThere were 22 eyes in the DALK group and 135 in the PKP group. Postoperative best-corrected visual acuity (BCVA) of 20/40 or better was achieved in 90.9% of the DALK group and 76.3% of the PKP group (P=0.12). At last visit, graft survival was 95.5% (21 eyes) and 91.1% (123 eyes) in DALK and PKP groups, respectively (P=0.69, Log rank test). Corneal graft rejection episodes occurred in 1 (4.5%) DALK graft and 19 (14.1%) PKP grafts. Five of the 19 graft rejections in the PKP group were irreversible. Microbial keratitis and cataract occurred in 6 (4.5%) and 15 (11.1%) PKP eyes. One (4.5%) eye in the DALK group had cataract and none of the DALK cases developed microbial keratitis. Clinically significant recurrence was observed in 4 (2.9%) PKP eyes and 1 (4.5%) DALK eye (P=0.69), respectively.ConclusionDALK is a viable option for MCD without Descemet membrane involvement. DALK had comparable medium-term visual and survival outcomes to PKP. DALK has the advantage of lower open sky intraoperative complications and lower graft rejection episodes.

Comparison of Long-Term Outcomes of the Lamellar and Penetrating Keratoplasty Approaches in Patients with Keratoconus.

We compared the visual and refractive outcomes, intraocular pressure (IOP), endothelial cell loss (ECL), and adverse events in keratoconus patients after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) with the best corrected visual acuity (BCVA) below 0.3 (logMAR 0.52). This is a prospective, comparative cohort study of 90 eyes (90 patients) with a clinical diagnosis of keratoconus. Patients underwent a complete eye examination before the surgical approach, 6 and 12 months postoperatively that consisted of BCVA, refractive astigmatism (AS), central corneal thickness (CCT), IOP, and ECL. Secondary outcomes were adverse events related to the surgical procedure. With lower ECL and less adverse events, DALK was revealed to be beneficial over PK with similar visual outcomes. Results: There was no significant difference between the BCVA in the DALK and PK groups (at 6 months: 0.49 ± 0.17 vs. 0.48 ± 0.17; p = 0.48; at 12 months: 0.54 ± 0.17 vs. 0.52 ± 0.14; p = 0.41). The mean value of AS was significantly lower after the PK procedure when compared to DALK, after both 6 and 12 months of follow up (p < 0.001). The CCT in the DALK group was significantly lower when compared to the PK group (at 6 months: 452.1 ± 89.1 µm vs. 528.9 ± 69.9 µm, p < 0.0001; at 12 months: 451.6 ± 83.5 µm vs. 525.5 ± 37.1 µm). The endothelial cell loss at 12 months after surgery was significantly lower after DALK when compared to PK (p < 0.0001). DALK transplantation should be considered as an alternative procedure in the surgical treatment of keratoconus.

Penetrating Keratoplasty Versus Deep Anterior Lamellar Keratoplasty in Children and Adolescents With Keratoconus

To compare the outcomes of penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) for pediatric keratoconus. Retrospective comparative interventional case series. This study included consecutive pediatric keratoconus cases (≤18 years of age) who received PK (n=45) or DALK (n=54) in 2 different time periods. Postoperative best spectacle-corrected visual acuity (BSCVA), refraction, and complications were compared between the study groups. The mean follow-up was 83.3±46.1 and 63.3±45.6 months in the PK and DALK groups, respectively (P=.10). Postoperatively, BSCVA was 0.20±0.19 logMAR in the PK group and 0.26±0.19 logMAR in the DALK group (P=.11), with a BSCVA of ≥20/40 in 91.1% and 83.3% of eyes, respectively (P=.25). Two groups were comparable regarding postoperative refractive outcomes. Graft epitheliopathy and suture-associated complications were more commonly encountered after DALK, which was attributable to the effect of low-quality grafts on the clinical outcomes of DALK. Ten PK eyes (22.2%) and 9 DALK eyes (16.7%) experienced at least 1 episode of graft rejection within 5 years of corneal transplantation (P=.49). Rejection was reversible in 93.1% and 100% of episodes in the PK and DALK groups, respectively (P=.63). At the postoperative year 5, 95.6% of grafts in the PK group and 98.2% in the DALK group remained clear (P=.45). No significant difference was observed in the outcomes between PK and DALK in pediatric keratoconus. Low-quality donor tissues in DALK increased the incidence of graft epithelial problems and suture-related complications as compared to PK.

Causes of corneal transplant failure: a multicentric study.

To identify the causes of failure of the different surgical corneal graft techniques: penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK). This multicentric retrospective study enrolled a consecutive cohort of patients who had undergone any type of keratoplasty between 2001 and 2016. The clinical data were obtained from the patient's medical records, following ethical guidelines, permissions and data protection. The main outcome measured in the study was the cause of graft failure, defined as any irreversible loss of graft transparency capable of compromising vision. The main causes of graft failure were classified as follows: (A) primary graft failure (PGF), (B) immunological rejection, (C) non-rejection (which includes endothelial decompensation without rejection, IOP elevation/glaucoma, diseases of the ocular surface, recurrence of the primary disease, wound dehiscence/hypotonia and trauma, among others) and (D) specific causes of lamellar keratoplasty failure. A descriptive study of the obtained data was carried out. The distribution of the causes of failure was evaluated according to the type of corneal transplant. Our research included a cohort of 571 keratoplasty failures, of which 509 met the inclusion criteria. The analysis of the causes of the PK failure showed that immunological allograft rejection represented the main cause, with 28.2% of the failures, followed by surface diseases (17.8%) and endothelial decompensation without rejection (17.3%). For the PK re-grafts group, the main cause of failure was immunological allograft rejection (34.0%), followed by diseases of the ocular surface (18.5%). For the DALK group, the failures mainly occurred due to surface diseases such as limbal stem cell insufficiency, infectious keratitis, keratolysis or persistent epithelial defect (37.8%). However, the main reason for failure in the DSAEK group was endothelial decompensation without rejection (31.9%) while primary graft failure was the main cause of failure in the DMEK group (64.1%). The main reason for failure in PK was immunological allograft rejection, both in primary and secondary transplants. The leading causes for failure were diseases of the ocular surface in the DALK population, endothelial decompensation without rejection in DSAEK and primary graft failure in DMEK.

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.

Comparison of penetrating keratoplasty and deep anterior lamellar keratoplasty in keratoconus eyes with vernal keratoconjunctivitis.

Purpose:The purpose of the study is to compare outcomes after penetrating keratoplasty (PK) against deep anterior lamellar keratoplasty (DALK) for keratoconus in patients with vernal keratoconjunctivitis (VKC).Methods:Keratoconic patients with VKC who received PK (n = 55, group 1) or DALK (n = 62, group 2) were retrospectively enrolled. The Student’s t test, Mann–Whitney test, Fisher’s exact test, chi-square test, and Kaplan–Meier survival curve were used to compare outcomes between the groups.Results:The follow-up period was 59.4 ± 44.1 and 62.4 ± 38.9 months in groups 1 and 2, respectively (p = 0.70). Postoperative best spectacle-corrected visual acuity was 0.24 ± 0.18 and 0.29 ± 0.19 logMAR, respectively (p = 0.13). Graft rejection occurred in 34.6% and 25.8% of eyes in groups 1 and 2, respectively (p = 0.30). Groups 1 and 2 were comparable in the rates of cataract (3.6% and 12.9%, respectively, p = 0.07) and high intraocular pressure (3.6% and 8.1%, respectively, p = 0.31). Compared with the eyes with inactive VKC, PK eyes that experienced postoperative disease reactivation had a higher rate of suture abscesses (10.9% versus 50.0%, respectively, p = 0.01) and suture-tract vascularization (6.5% versus 33.3%, respectively, p = 0.03). Similarly, disease reactivation significantly increased suture abscesses from 27.3% to 51.7% (p = 0.03) and suture-tract vascularization from 18.2% to 49.6% (p = 0.005) in the DALK group. The graft survival rates were 95.3% in group 1 and 87.9% in group 2 at the 4-year follow-up, with mean durations of 14.4 and 11.1 months, respectively (p = 0.20).Conclusion:The results indicate no difference in outcomes between PK and DALK for keratoconus in patients with VKC. Postoperative VKC reactivation increased the rate of suture-related problems after both techniques of keratoplasty.