Comparison of keratoplasty outcomes at the scar versus edema stages of keratoconus.

PURPOSE: To assess the outcomes of deep anterior lamellar keratoplasty or penetrating keratoplasty at the scar and the edema stages. METHODS: Forty-five patients (45 eyes) with keratoconus scar stage (scar group, n=26; penetrating keratoplasty a subgroup, n=7; deep anterior lamellar keratoplasty b subgroup, n=19) and keratoconus edema stage (edema group, n=19; penetrating keratoplasty c subgroup, n=12; deep anterior lamellar keratoplasty d group, n=7) who received penetrating keratoplasty or deep anterior lamellar keratoplasty from 2000 to 2022 were retrospectively studied. At 1, 6, and 12 months after surgery, the best-corrected visual acuity, astigmatism, spherical equivalent, corneal endothelial cell density, and complications were analyzed. RESULTS: The best-corrected visual acuity and average corneal endothelial cell loss rate were not significantly different between the scar and edema groups (p>0.05). At 6 and 12 months after surgery, the astigmatism and spherical equivalent in the scar group were significantly lower than those in the edema group (p<0.05). The spherical equivalent of the deep anterior lamellar keratoplasty b subgroup was lower than that of the penetrating keratoplasty a subgroup in the scar group 6 months after surgery (p<0.05). In the edema group, there was no significant difference in spherical equivalent between subgroups (p>0.05). There were no significant differences in best-corrected visual acuity and astigmatism between subgroups within the two groups (p>0.05). In comparison to the scar group, the edema group experienced more complications. According to a survival analysis, there was no statistically significant difference between the scar group and the edema group regarding the progression of vision. CONCLUSIONS: In terms of the outcomes and prognosis for vision after keratoplasty with edema stage and scar stage, deep anterior lamellar keratoplasty may be as effective as penetrating keratoplasty.

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

PURPOSES: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Management of corneal melting after collagen cross-linking for keratoconus: a case report and a review of the literature.

PURPOSE: We describe the management of a case of severe corneal melting after corneal cross-linking (CXL) treated with a staged approach using a conjunctival flap followed by deep anterior lamellar keratoplasty (DALK). METHODS: A 12-year-old male developed severe corneal melting with pending perforation after an accelerated epithelium-off CXL protocol. We initially treated the patient with a conjunctival flap to prevent perforation. Three months later, we performed DALK to restore vision. RESULTS: Conjunctival flap surgery allowed us to avoid corneal perforation and penetrating keratoplasty (PK) à chaud. Once the inflammation had resolved, we recessed the conjunctiva and performed DALK for optical purposes. Twelve months later, the graft was clear and the corrected visual acuity was 20/25 (Snellen). No complications occurred after surgery. CONCLUSIONS: Although CXL is considered a safe procedure, in rare cases it can lead to serious complications, such as corneal haze, infectious and non-infectious keratitis, stromal melting and perforation. Corneal melting and perforation are usually managed by emergency PK. Herein we suggest a staged approach involving an emergency conjunctival flap followed by DALK at a later time that allowed us to avoid PK à chaud.

Allogeneic limbo-deep anterior lamellar keratoplasty (Limbo-DALK)-A novel surgical technique in corneal stromal disease and limbal stem cell deficiency.

PURPOSE: To describe a novel corneal surgical technique combining Deep Anterior Lamellar Keratoplasty (DALK) with grafting of allogeneic limbus (Limbo-DALK) for the treatment of eyes with corneal stromal pathology and limbal stem cell deficiency (LSCD). METHODS: Clinical records of six Limbo-DALKs performed in five patients diagnosed with LSCD and corneal stromal pathology requiring keratoplasty were retrospectively reviewed. All patients were diagnosed with LSCD due to various pathologies including thermal and chemical burns, congenital aniridia or chronic inflammatory ocular surface disease. Parameters analysed included demographics, diagnoses, clinical history, thickness measurements using anterior segment OCT, visual acuity, and epithelial status. Regular follow-up visits were scheduled at 6 weeks as well as 3, 6, 9, and 12 and 18 months postoperatively. Main outcome measures were time to graft epithelialisation and the occurrence of corneal endothelial decompensation. RESULTS: Two grafts showed complete epithelial closure at 2 days, two at 14 days. In one eye, complete epithelial closure was not achieved after the first Limbo-DALK, but was achieved one month after the second Limbo-DALK. No endothelial decompensation occurred except in one patient with silicone oil associated keratopathy. Endothelial graft rejection was not observed in any of the grafts. CONCLUSION: Based on the data from this pilot series, limbo-DALK appears to be a viable surgical approach for eyes with severe LSCD and corneal stromal pathology, suitable for emergency situations (e.g. corneal ulceration with impending corneal perforation), while minimising the risk of corneal endothelial decompensation.

Pediatric keratoconus epidemiology: a systematic scoping review.

BACKGROUND: Pediatric keratoconus (pediatric KC) causes progressive deformation of the cornea in children and adolescents, leading to a gradual loss of vision and a need for rehabilitation. However, new treatments may halt the disease and prevent worse outcomes that require penetrating keratoplasty and its associated morbidity and high cost, irreversible loss of vision, and amblyopia. Few systematic reviews focus on keratoconus-and even fewer, on pediatric KC. METHODS: Here, we report a systematic scoping review of pediatric KC epidemiology and discuss the studies reporting data on pediatric KC. We used PRISMA-ScR methodology and checklists in the elaboration of the manuscript. The inclusion criteria were: English language; publication between August 7, 1998, and August 7, 2019 (20 years); theme of the study pediatric KC epidemiology. The search strategy: searches of the PubMed-MEDLINE database and Cochrane Database of Systematic Reviews, using eight combinations of the following MeSH terms: keratoconus; child; incidence; prevalence; pediatrics; adolescent; epidemiology. RESULTS: We charted and reviewed the selected articles. Initial searches included 1802 records; after the exclusion of article duplicates, we screened 777 records, read 97 articles in full text, and included 76 articles in this review. CONCLUSIONS: Recent epidemiological studies with better methodologies demonstrated increased prevalence rates in comparison to the older literature. This effect may be due to better diagnostic methods and better sample selection than those in historical studies. Diagnosis remains a major challenge as the early disease is usually asymptomatic. Economic and social aspects of pediatric KC remain understudied in the pediatric literature. Global, inclusive, and proactive screening studies in schools are imperative to better understand the great impact of this disease in the young.

Comparative posterior corneal profile of keratoconus hydrops versus Haab's striae in congenital glaucoma.

Keratoconus eyes develop corneal decompensation more often compared to eyes with primary congenital glaucoma (PCG) following Descemet's membrane (DM) tear. This study was conducted to compare the posterior corneal morphology in areas with DM breaks with regards to DM and pre-Descemet's layer (PDL) between the two. In this cross-sectional comparative study, anterior segment optical coherence tomography (AS-OCT) scans of the posterior cornea of advanced keratoconus eyes with hydrops ( n = 12), PCG eyes with Haab's striae ( n = 15), and healthy control eyes ( n = 14) were compared for DM-PDL morphology. These were further corroborated by the histopathology of corneal buttons from keratoconus ( n = 14) and PCG ( n = 13) cases obtained following penetrating keratoplasty and compared with controls (enucleated retinoblastoma globes, n = 6) on light microscopy and collagen IV immunostaining. AS-OCT showed a thicker median DM/PDL complex in PCG (80 µm) versus keratoconus eyes (36 µm, P = 0.01; Kruskal-Wallis test). The median height and length of detached DM-PDL were significantly more in keratoconus versus PCG (145 µm, 1766.1 ± 1320.6 µm vs. 26.5 µm, 453.3 ± 303.2 µm, respectively, P = 0.012; Kruskal-Wallis test). Type-1 DM/PDL detachment (seen as a characteristic taut chord) in keratoconus (90%) was the most common morphological pattern versus intracameral twin protuberance (92%) following DM breaks in PCG. Histopathology confirmed thicker DM in PCG (median: 63.4 µm) versus keratoconus eyes (median: 33.2 µm) or controls (27.1 µm) ( P = 0.001; Kruskal-Wallis test). Greater height/length of DM/PDL detachment compounded by poor healing response (lower DM/PDL thickness) probably causes more frequent corneal decompensation in keratoconus eyes when compared to PCG eyes following DM tears.

Intraoperative collagen imaging of sutured cornea: A way towards managing post-penetrating keratoplasty astigmatism.

The birefringent nature of the human cornea plays an important role in comprehending its structural behavior in both diseased and surgical conditions. During corneal transplantation, irregular astigmatism is a common post-surgical complication that depends on the characteristics of suturing. Four human cadaver corneas are subjected to an in-vitro model of a typical full-thickness penetrating keratoplasty (PK) procedure using 16 simple interrupted 10-0 vicyrl sutures. The birefringence of these four corneas is analyzed using digital photoelasticity and compared with the control cornea (without PK). It is found that the sutures and their mutual interaction influence the morphology of the peripheral birefringence of the cornea. The findings of the present investigation are pertinent to intraoperative suture management during PK. Results suggest conserving the typical diamond-shaped morphology of peripheral birefringence would ensure uniform distribution of sutures. Therefore, birefringence imaging could be useful in suture management to ensure proper apposition of the graft-host junction, thus minimizing the risk of irregular astigmatism.

Comparative evaluation of platelet-rich plasma, autologous blood serum, and umbilical cord serum for corneal healing after penetrating keratoplasty in New Zealand rabbits.

This study aimed to evaluate the effects of platelet-rich plasma (PRP), autologous blood serum (ABS), and umbilical cord serum (UCS) on corneal healing following penetrating keratoplasty (PK). A total of 120 New Zealand white rabbits, forty were designated as donors, while the remaining eighty rabbits were randomly divided into four groups after undergoing PRP Group (n = 20), ABS Group (n = 20), UCS Group (n = 20) and Control Group (n = 20). Corneal opacity score, corneal vascularization, corneal staining, histopathological analysis, and immunohistochemical analysis (including CD4+, CD8+, and major histocompatibility complex [MHC] II) were assessed at postoperative 1, 2, 3, and 12 weeks. The results showed that corneal opacity score and corneal vascularization did not differ significantly among the groups. However, corneal staining was found to be statistically higher in the PRP group (0.40 ± 0.60) compared to the other groups (p = 0.011). Immunohistochemical examination revealed no significant differences in CD4+, CD8+, and MHC II levels among the groups. Notably, in all groups, CD4+, CD8+, and MHC II levels were significantly higher at 12 weeks compared to other time points. PRP, ABS, and UCS demonstrated positive effects on corneal healing after PK. However, among the three products, PRP exhibited a superior healing effect compared to ABS and UCS crucial in the postoperative period following PK procedures, as they significantly impact visual quality, graft transparency, graft survival, and prevention of stromal resorption caused by infections. Despite the avascular nature of the cornea and its immune privilege, failure to resolve epithelial defects (ED) commonly observed after PK can result in irreversible scarring and ulceration, leading to graft rejection. While epithelial defects are observed in 14-100% of cases on the first postoperative day, approximately 3-7% of them persist as non-healing ED in subsequent periods. In conclusion, our study demonstrated that PRP, ABS, and UCS have a positive effect on corneal healing after PK.

[Chinese expert consensus on corneal endothelial transplantation (2024)].

Endothelial keratoplasty (EK) is an effective therapy for corneal endothelial diseases and mainly includes Descemet stripping endothelial keratoplasty and Descemet membrane endothelial keratoplasty. Compared with penetrating keratoplasty, EK has better vision rehabilitation and a lower rate of allograft rejection after surgery. However, EK poses a series of technical challenges, and varied complications may occur intraoperatively and postoperatively. A successful EK surgery depends on the standardized technical manipulations and the management of surgical complications. In order to standardize the surgical procedure of EK in China, the Cornea Group of Ophthalmology Branch of Chinese Medical Association has made a comprehensive discussion about indications of surgery, preoperative evaluation, surgical manipulations, and the management of complications based on the literature available thus far and clinical practice in China, and eventually established this consensus, which may guide corneal surgeons in performing the EK surgery.

Lenticule addition keratoplasty for the treatment of keratoconus: A systematic review and critical considerations.

Keratoconus is a corneal disorder characterized by the progressive thinning and bulging of the cornea. Currently, the major goal of management is to halt its progression, restore normal corneal strength, prevent acute complications, and save vision. Penetrating keratoplasty and deep anterior lamellar keratoplasty as conventional surgical methods for advanced keratoconus are limited by relatively high rates of immune intolerance, slow post-operational recovery, high costs, and shortage of donor corneas. Recently, the development of lenticule addition keratoplasty enables the restoration of corneal thickness simply by implanting a lenticule into the stromal pocket created with the femtosecond laser, which can originate from cadaver corneas or more appealing, be extracted from patients via a small-incision lenticule extraction (SMILE) surgery. As the first systematic review in this field, we critically review publications on lenticule addition keratoplasty and provide our perspectives on its clinical application and the focus of future research.

Long-Term Risk of Steroid-Induced Ocular Hypertension/Glaucoma With Topical Prednisolone Acetate 1% After Descemet Stripping Endothelial Keratoplasty.

PURPOSE: The aim of this study was to assess the long-term risk of steroid-induced ocular hypertension and the need for glaucoma treatment with long-term use of topical prednisolone acetate 1% in patients without preexisting glaucoma. METHODS: We retrospectively reviewed the charts of 211 patients without previous glaucoma, who underwent Descemet stripping endothelial keratoplasty (DSEK) and used topical prednisolone acetate long-term to prevent graft rejection. Dosing was 4 times daily for 4 months and tapered to once daily. The main outcomes were ocular hypertension (defined as intraocular pressure ≥24 mm Hg, or increase of ≥10 mm Hg over baseline) and initiation of glaucoma treatment. RESULTS: The median patient age was 70 years (range: 34-94 years). The indications for DSEK were Fuchs dystrophy (88%), pseudophakic corneal edema (7%), failed DSEK (3%), and failed penetrating keratoplasty (2%). The median follow-up period was 7 years (range, 1-17 years). At 1, 5, and 10 years, the cumulative risks of steroid-induced ocular hypertension were 29%, 41%, and 49%, respectively, and the risks of requiring glaucoma treatment were 11%, 17%, and 25%, respectively. Among 35 eyes treated for glaucoma, 28 (80%) were managed medically and 7 (20%) had filtration surgery. CONCLUSIONS: Long-term use of potent topical corticosteroids, such as prednisolone acetate 1%, entails substantial risk of developing steroid-induced ocular hypertension, so frequent monitoring of intraocular pressure is required. With corneal transplantation, the risk can be mitigated by using techniques with a low inherent risk of rejection, such as Descemet membrane endothelial keratoplasty, whenever possible, to allow earlier reduction of steroid potency.

Patch endothelial keratoplasty for corneal perforations secondary to ocular surface disease: case series.

BACKGROUND: Corneal perforation is an ophthalmic emergency. The conventional management of corneal perforation can be associated with severe complications especially in patients with ocular surface disease. Endothelial keratoplasty has been suggested as an alternative surgical technique for the management of corneal perforations. We present a case series of nine patients with corneal perforation and ocular surface disease managed with secondary patch endothelial keratoplasty. METHODS: This is a retrospective case series of nine patch endothelial keratoplasties performed between 2016 and 2022 at a quaternary eye hospital in Australia. The surgical technique is similar to conventional endothelial keratoplasty except descemetorhexis was not performed. RESULTS: A total of 9 cases were treated during the review period. Eight of the nine cases had an improvement in visual acuity. One case failed to achieve corneal tectonic objective. CONCLUSION: Patch endothelial keratoplasty is a safe secondary procedure for the management of corneal perforations in patients with ocular surface disease.

Triple Procedure: A Stepwise Combination of Deep Anterior Lamellar Keratoplasty and Cataract Surgery.

PURPOSE: The aim of this study was to evaluate clinical outcomes of the combined surgery (triple procedure) of deep anterior lamellar keratoplasty (DALK), phacoemulsification, and intraocular lens (IOL) implantation using a new surgical strategy. METHODS: The study included 43 eyes of 43 patients who underwent a triple procedure. Twenty-six eyes with good visibility through the cornea underwent phacoemulsification before the stromal dissection. Seventeen eyes with bad visibility underwent the DALK procedure first until achieving enough visibility to perform the lensectomy. IOL power calculation was performed for a postoperative estimated flat keratometry of 43.5 and aiming to avoid hyperopic postoperative refraction. The postoperative visual examination included uncorrected and corrected distance visual acuity (CDVA) measurements and manifest refraction. RESULTS: The mean follow-up time after suture removal was 3.06 ± 2.14 years. Mean CDVA significantly changed from 0.86 ± 0.56 logMAR preoperatively to 0.37 ± 0.28 logMAR in the last visit ( P < 0.0001). The percentage of eyes with CDVA ≤0.3 logMAR changed from 6.9% preoperatively to 62.8%. No eyes lost lines of vision after surgery, and 80% experienced an improvement of 2 or more lines. The safety index was 2.2. The mean postoperative refractive sphere was +0.13 ± 2.04 D, and the postoperative refractive cylinder was -4.02 ± 2.24 D. Only 2 cases (4.65%) obtained postoperative hyperopic astigmatism. No intraoperative complications were found. CONCLUSIONS: Combined surgery of DALK, phacoemulsification, and IOL implantation is an effective and safe procedure. Depending on the corneal transparency, different surgical strategies can be established to provide more efficacy and safety.

Suture Fixation to Reduce Graft Detachment in Descemet Stripping Endothelial Keratoplasty.

PURPOSE: The aim of this study was to report the outcomes of graft fixation using interrupted, full-thickness sutures on graft detachment after Descemet stripping endothelial keratoplasty (DSEK). METHODS: All DSEK procedures performed at Mayo Clinic, Rochester, MN, from 2015 through 2022 were retrospectively reviewed. Risk factors for graft detachment were defined as previous incisional glaucoma surgery, previous penetrating keratoplasty, or absence of the normal lens-capsule barrier. Cases were categorized into sutured, high-risk grafts; unsutured, high-risk grafts; and unsutured, low-risk grafts. The primary outcome was graft detachment, and secondary outcomes were early graft failure and graft clarity at 12 months after surgery. RESULTS: Demographics between the high-risk groups were similar for sex and age at the time of surgery. Graft detachment occurred in 4 of 97 sutured, high-risk eyes (4.1%) and 24 of 119 unsutured high-risk eyes (20.2%) ( P = 0.002). In comparison, graft detachment occurred in 18 of 181 unsutured low-risk eyes (9.9%). The incidence of early graft failure was 2.1%, 5.0%, and 3.3% and late graft failure by 12 months was 9.8%, 12.8%, and 4.2%, respectively. CONCLUSIONS: In eyes with high-risk factors for graft detachment, suture fixation of the graft in DSEK decreased graft detachment to a rate at least as low as that in low-risk eyes.

Outcomes of large-diameter deep anterior lamellar keratoplasty and converted two-piece mushroom penetrating keratoplasty for herpetic corneal scars.

PURPOSE: To report the clinical outcomes of large diameter deep anterior lamellar keratoplasty (DALK) and converted two-piece microkeratome-assisted mushroom keratoplasty (MK) for herpetic corneal scars. METHODS: In this single-centre study, large diameter (9 mm) DALK was attempted in consecutive patients with herpetic corneal scars. In case of macroperforation or unsatisfactory clearance of the optical zone, the procedure was intraoperatively converted to two-piece microkeratome-assisted MK. Outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism, endothelial cell density (ECD), immunologic rejection, herpetic recurrence and graft failure rates in the two groups. RESULTS: DALK was successfully performed in 98 of 120 eyes, while the remaining 22 eyes required intraoperative conversion to MK. At 5 years, mean logMAR BSCVA was 0.10 ± 0.12 in the DALK group and 0.09 ± 0.15 in the MK group (P = 0.75). Refractive astigmatism at 5 years was 2.8 ± 1.4 D in the DALK group and 3.0 ± 1.7 D in the MK group (P = 0.67). ECD was higher in the DALK group than in the MK group at all time points (P < 0.001), with a mean annual cell loss of 10.9% after MK and 4.2% after DALK. The 5-year risk for immunologic rejection (DALK: 3%, MK: 5%, P = 0.38), herpetic recurrence (DALK: 6%, MK: 9%, P = 0.38), and graft failure (DALK: 4%, MK: 5%, P = 0.75) were comparable in both groups. CONCLUSION: Large diameter (9 mm) DALK yields excellent visual and clinical outcomes in eyes with herpetic corneal scars. In case of intraoperative complications, DALK can be converted to two-piece microkeratome-assisted MK to maximize the refractive benefit of a large diameter graft while minimizing the risk of endothelial failure.

Customized therapeutic deep anterior lamellar keratoplasty in perforated Mooren's ulcer: A novel technique.

We describe customized therapeutic deep anterior lamellar keratoplasty (DALK) for treating a perforated Mooren's ulcer. Slit-lamp biomicroscopy revealed corneal perforation (3.5 mm × 3.0 mm) with iris prolapse. The corneal melt extended from 9.0 o'clock to 4.0 o'clock. The peripheral edge of the ulcer was sloping, whereas the medial edge showed undermining. Immunological tests did not reveal any evidence of systemic autoimmune disease. In view of extensive peripheral corneal melt with large corneal perforation, the patient needed tectonic keratoplasty. The penetrating graft is not only technically demanding but also results in a poor visual outcome. We advised customized tectonic DALK. We used two different-sized trephines to obtain appropriate-sized donor tissue and avoided manual dissection. The post-surgery period was uneventful. He was prescribed topical steroids and oral methotrexate. He achieved 6/9 aided visual acuity at 4 months and maintained it until the last follow-up at 36 months.

DALK combined intralamellar tectonic patch graft: an alternative approach to treat frank corneal perforation.

BACKGROUND: Deep anterior lamellar keratoplasty (DALK) has gained popularity in cases of corneal thinning and leaking descemetocele. In this study, we introduced an intralamellar tectonic patch graft in addition to conventional DALK procedures to treat frank cornea perforation. METHODS: This retrospective case series included 13 patients (13 eyes) with frank corneal perforations who underwent DALK combined with intralamellar tectonic patch graft between December 2015 and December 2021. In addition to the standard DALK procedure, the perforation site was repaired with an extra intralamellar tectonic patch graft. The collected data included patient demographics, aetiology, size and location of the corneal perforation, visual acuity, surgical details, and postoperative complications. RESULTS: Seven patients underwent autologous intralamellar patch grafts, whereas six received allogeneic ones. Anatomical success was achieved in all patients. The mean postoperative follow-up was 33.31 ± 25.96 months (6-73 months). The postoperative visual acuity (0.90 ± 0.65 logMAR) was significantly improved (P = 0.003) compared to the preoperative score (1.74 ± 0.83 logMAR). Best corrected visual acuity (BCVA) improved in 12 eyes (92.3%). The mean endothelial cell density was 2028 ± 463 cells/mm2, 6-12 months postoperatively. There was no recurrence of perforation, and the anterior lamellar graft remained transparent in 12 patients (92.3%). Postoperative complications included epithelial defects (23.1%), ocular hypertension (15.4%), and cataract (7.7%). CONCLUSIONS: DALK combined with intralamellar tectonic patch graft may serve as a secure and effective alternative in treating frank corneal perforation, with reduced complications compared to conventional penetrating keratoplasty.

Long-term outcomes of deep anterior lamellar versus penetrating keratoplasty for keratoconus.

AIMS: To compare the long-term outcomes of deep anterior lamellar keratoplasty (DALK) with penetrating keratoplasty (PK) in keratoconus. METHODS: Retrospective comparative case series (228 DALKs and 274 PKs). A biphasic linear model was used to describe the postoperative outcome of the endothelial cell density (ECD). Visual acuity, specular microscopy, corneal topography and optical coherence tomography findings were recorded. RESULTS: Graft survival of the 502 keratoconus eyes was 96.7 at 10 years and 95.6% at 20 years. Visual acuity improved from 20/378±5.1 lines preoperatively to 20/32±2.1 lines at 30 months. The corneal ECD decreased from 2494±382 cells/mm2 to 1521±659 cells/mm2 at 10 years. The mean simulated keratometry increased from 44.88±2.54 D at 1 year to 46.60±3.0 D at 3 years. The mean follow-up was 103.4 months for DALKs and 106.1 months for PKs. The cumulated incidence of postoperative ocular hypertension requiring treatment was significantly higher in PKs than in DALKs. The early- and late-phase rates of ECD loss were significantly lower in DALKs than in PKs. These figures in DALKs were 50% of those observed in PKs. The simulated mean keratometry was significantly higher in DALKs than in PKs in the mid but not in the long term. No significant differences in visual acuity were observed between both groups. Manual dissection-DALK featured slower visual recovery than PK and big bubble-DALK, whereas big bubble-DALK and PK featured similar visual recovery. CONCLUSIONS: DALK featuring higher endothelial survival and lower risk of postoperative ocular hypertension may be superior to PK when indicated for keratoconus.

Comparison of Femtosecond Laser Assistance and Manual Trephination in Deep Anterior Lamellar Keratoplasty in the Treatment of Keratoconus: A Meta-Analysis.

PURPOSE: To compare the efficacy and safety of femtosecond laser-assisted deep anterior lamellar keratoplasty (F-DALK) with those of manual-trephination DALK (M-DALK) in treating keratoconus. DESIGN: Systematic review and meta-analysis. METHODS: Through November 2022, we comprehensively searched PubMed, EMBASE, the Cochrane Library, and 4 Chinese databases. Studies that involved comparisons between F-DALK and M-DALK groups and that reported on relevant efficacy and/or safety parameters were included. Primary outcomes were uncorrected- and corrected-distance visual acuity and intraoperative complication rates. Secondary outcomes were spherical equivalent, topographic astigmatism, refractive cylinder, mean keratometry, endothelial cell density, suture removal time, and postoperative complication rates. These data were analyzed using Cochrane Review Manager software version 5.3. RESULTS: This meta-analysis included 9 nonrandomized controlled studies involving 1713 eyes. In eyes treated with F-DALK, corrected-distance visual acuity at 1 to 6 months (weighted mean difference = -0.07 [95% confidence interval {CI} -0.10 to -0.03]; I2 = 0%; P < .001) after surgery was better and intraoperative Descemet membrane perforation occurred less often (odds ratio = 0.53 [95% CI 0.31-0.92]; I2 = 6%; P = .02) than in eyes treated with M-DALK. No clinically significant differences in other outcomes were found among the groups. CONCLUSIONS: Both F-DALK and M-DALK are safe and efficacious for patients with keratoconus. Compared with M-DALK, F-DALK can provide better early visual acuity and reduce the intraoperative perforation rate, and its likely improvements to long-term visual quality and endothelial cell preservation warrant further investigation. In addition, the 2 techniques seem to be comparable regarding refractive outcomes and other complications.

Effect of Nd:YAG laser capsulotomy on graft endothelium after penetrating keratoplasty.

BACKGROUND: To investigate the safety of Nd:YAG laser capsulotomy in eyes with Penetrating Keratoplasty (PK) and its impact on corneal endothelium as well as graft survival. METHODS: Thirty patients who underwent Nd: YAG laser capsulotomy after PK and 30 pseudophakic control eyes were included in this prospective study. Endothelial cell density (ECD), hexagonality (HEX), coefficient of variation (CV), central corneal thickness (CCT), and the change of these values during follow-up measured at the 1st hour, first week, and first month after the laser and the data were compared between groups. RESULTS: The mean time passed between the PK procedure and the subsequent YAG laser procedure was i.e. of YAG laser after PK was 30.5 ± 15.2 months (range 6 to 57 months). Baseline ECD was 1648.2 ± 669.77 cells/mm² in the PK group and 2008.27 ± 347.42 cells/mm² in the control group. In the first month, ECD was 1545.2 ± 639.35 cells/mm² in the PK group and 1979 ± 350.95 in the control group. The loss was significantly higher in PK group (-103 ± 153.67 cells/mm²) (6.25%) compare to the control group (-28.73 ± 82.31 cells/mm²) (1.44%) (p = 0.024). A significant increase in CV was observed in the PK group, and not in the control group (p = 0.008, p = 0.255, respectively). There were no significant changes in HEX and CCT values in either group. CONCLUSION: Nd:YAG laser provides a significant increase in visual acuity in first month in patients with PK with no significant harmful effect on graft transparency. Endothelial cell density measurements during follow-up will be beneficial.