Mitochondrial polymorphism A10398G and Haplogroup I are associated with Fuchs' endothelial corneal dystrophy

PURPOSE

We investigated whether mitochondrial DNA (mtDNA) variants affect the susceptibility of Fuchs endothelial corneal dystrophy (FECD).

METHODS

Ten mtDNA variants defining European haplogroups were genotyped in a discovery dataset consisting of 530 cases and 498 controls of European descent from the Duke FECD cohort. Association tests for mtDNA markers and haplogroups were performed using logistic regression models with adjustment of age and sex. Subset analyses included controlling for additional effects of either the TCF4 SNP rs613872 or cigarette smoking. Our replication dataset was derived from the genome-wide association study (GWAS) of the FECD Genetics Consortium, where genotypes for three of 10 mtDNA markers were available. Replication analyses were performed to compare non-Duke cases to all GWAS controls (GWAS1, N = 3200), and to non-Duke controls (GWAS2, N = 3043).

RESULTS

The variant A10398G was significantly associated with FECD (odds ratio [OR] = 0.72; 95% confidence interval [CI] = [0.53, 0.98]; P = 0.034), and remains significant after adjusting for smoking status (min P = 0.012). This variant was replicated in GWAS1 (P = 0.019) and GWAS2 (P = 0.036). Haplogroup I was significantly associated with FECD (OR = 0.46; 95% CI = [0.22, 0.97]; P = 0.041) and remains significant after adjusting for the effect of smoking (min P = 0.008) or rs613872 (P = 0.034).

CONCLUSIONS

The 10398G allele and Haplogroup I appear to confer significant protective effects for FECD. The effect of A10398G and Haplogroup I to FECD is likely independent of the known TCF4 variant. More data are needed to decipher the interaction between smoking and mtDNA haplogroups.

Genetic screen of African Americans with Fuchs endothelial corneal dystrophy

PURPOSE

Fuchs endothelial corneal dystrophy (FECD) is a genetically heterogeneous disorder that has been primarily studied in patients of European or Asian ancestry. Given the sparse literature on African Americans with FECD, we sought to characterize the genetic variation in three known FECD candidate genes in African American patients with FECD.

METHODS

Over an 8-year period, we enrolled 47 African American probands with FECD. All participants were clinically examined with slit-lamp biomicroscopy, and when corneal tissue specimens were available, histopathologic confirmation of the clinical diagnosis was obtained. The coding regions of known FECD susceptibility genes collagen, type VIII, alpha 2 (COL8A2); solute carrier family 4, sodium borate transporter, member 11 (SLC4A11); and zinc finger E-box binding homeobox 1 (ZEB1 [also known as TCF8]) were Sanger sequenced in the 47 probands using DNA isolated from blood samples.

RESULTS

Twenty-two coding variants were detected across the COL8A2, SLC4A11, and ZEB1 genes; six were nonsynonymous variants. Three novel coding variants were detected: a synonymous variant each in COL8A2 and SLC4A11 and one nonsynonymous variant in ZEB1 (p.P559S), which is predicted to be benign and tolerated, thus making its physiologic consequence uncertain.

CONCLUSIONS

Variation in the COL8A2, SLC4A11, and ZEB1 genes is present in only a small fraction of our African American cases and as such does not appear to significantly contribute to the genetic risk of FECD in African Americans. This observation is on par with findings from previous sequencing studies involving European or Asian ancestry patients with FECD.

Whole exome sequencing identifies a mutation for a novel form of corneal intraepithelial dyskeratosis

BACKGROUND

Corneal intraepithelial dyskeratosis is an extremely rare condition. The classical form, affecting Native American Haliwa-Saponi tribe members, is called hereditary benign intraepithelial dyskeratosis (HBID). Herein, we present a new form of corneal intraepithelial dyskeratosis for which we identified the causative gene by using deep sequencing technology.

METHODS AND RESULTS

A seven member Caucasian French family with two corneal intraepithelial dyskeratosis affected individuals (6-year-old proband and his mother) was ascertained. The proband presented with bilateral complete corneal opacification and dyskeratosis. Palmoplantar hyperkeratosis and laryngeal dyskeratosis were associated with the phenotype. Histopathology studies of cornea and vocal cord biopsies showed dyskeratotic keratinisation. Quantitative PCR ruled out 4q35 duplication, classically described in HBID cases. Next generation sequencing with mean coverage of 50× using the Illumina Hi Seq and whole exome capture processing was performed. Sequence reads were aligned, and screened for single nucleotide variants and insertion/deletion calls. In-house pipeline filtering analyses and comparisons with available databases were performed. A novel missense mutation M77T was discovered for the gene NLRP1 which maps to chromosome 17p13.2. This was a de novo mutation in the proband's mother, following segregation in the family, and not found in 738 control DNA samples. NLRP1 expression was determined in adult corneal epithelium. The amino acid change was found to destabilise significantly the protein structure.

CONCLUSIONS

We describe a new corneal intraepithelial dyskeratosis and how we identified its causative gene. The NLRP1 gene product is implicated in inflammation, autoimmune disorders, and caspase mediated apoptosis. NLRP1 polymorphisms are associated with various diseases.

Increased Rates of Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) Graft Failure and Dislocation in Glaucomatous Eyes with Aqueous Shunts

PURPOSE

To investigate the rates of Descemet's stripping automated endothelial keratoplasty (DSAEK) graft dislocation and failure in glaucomatous eyes, including eyes with history of trabeculectomy and/or aqueous shunts.

METHODS

A retrospective, case-control study on a total of 424 consecutive eyes undergoing DSAEK at an academic setting compared 96 glaucomatous eyes to a control group of 328 eyes. Pre- and post DSAEK procedure data was aggregated for up to 2 years (mean follow-up, 6.5±6.9 months) including rates of graft dislocation and failure.

RESULTS

Out of 96 glaucomatous eyes, 20 had undergone trabeculectomy, 27 had received one or more aqueous shunts, 12 had undergone both procedures and 37 were on medical therapy. Complete DSAEK graft dislocation and failure occurred in 2.7% and 3% of non-glaucomatous patients, respectively. Eyes with history of aqueous shunt surgery experienced graft dislocation and failure rates of 26.0% (OR=4.6, 95% CI 1.5-13.7, p=0.0067) and 26.0% (OR=10.3, 95% CI 3.8-27.1, p<0.0001), respectively. In contrast, glaucomatous eyes only on medical therapy (p=0.13) or with history of trabeculectomy (p>0.40) had no significant increase in graft dislocation or failure rates.

CONCLUSION

Eyes with medically controlled glaucoma or prior trabeculectomy demonstrated comparable rates of graft dislocation and failure as compared to controls. Aqueous shunt surgery was associated with increased rates of graft dislocation and failure after DSAEK.

Dislocation of the donor graft to the posterior segment in descemet stripping automated endothelial keratoplasty

PURPOSE

To report a series of dislocations of the donor graft into the posterior segment associated with Descemet stripping endothelial keratoplasty (DSAEK) and to identify possible risk factors for dislocation and clinical outcomes.

DESIGN

Retrospective case series.

METHODS

Cases of donor graft dislocation into the posterior segment associated with endothelial keratoplasty were identified from the clinical experience of 7 surgeons. Observations included the preoperative surgical history of each eye, preoperative and postoperative visual acuity, management of the complication, and the postoperative clinical course. No identified cases were excluded from this series.

RESULTS

Eight posterior graft dislocations were associated with DSAEK surgery. Each eye had a history of vitrectomy. Five eyes had sutured posterior chamber intraocular lenses, 1 eye had a sulcus intraocular lens, and 2 eyes were aphakic. Each eye required repeat grafting, and in 6 of 8 eyes, pars plana vitrectomy was used to remove the dislocated graft. Final visual acuities ranged from 20/30 to no light perception.

CONCLUSIONS

Graft dislocation into the posterior segment is a rare complication of DSAEK surgery that can lead to permanent vision loss. It has occurred in eyes that have undergone previous vitrectomy and complicated intraocular lens placement or were aphakic. As is the case with a dropped lens nucleus during cataract extraction, visual acuities after a dropped DSAEK graft range from very good to no light perception. Better postoperative results seem to be associated with prompt removal of the posteriorly dislocated graft.

The Genetics of Keratoconus: A Review

Keratoconus is the most common ectatic disorder of the corneal. Genetic and environmental factors may contribute to its pathogenesis. The focus of this article is to summarize current research into the complex genetics of keratoconus. We discuss the evidence of genetic etiology including family-based linkage studies, twin studies, genetic mutations, and genome-wide association studies. The genes implicated potentially include VSX1, miR-184, DOCK9, SOD1, RAB3GAP1, and HGF. Besides the coding mutations, we also highlight the potential contribution of DNA copy number variants in the pathogenesis of keratoconus. Finally, we present future directions for genetic research in the understanding of the complex genetics of keratoconus and its clinical significance. As new functional, candidate genes for keratoconus are being discovered at a rapid pace, the molecular genetic mechanisms underlying keratoconus pathogenesis will advance our understanding of keratoconus and promote the development of a novel therapy.

Endothelial Keratoplasty: From DLEK to DMEK

The last decade has heralded a revolutionary shift in the treatment of corneal endothelial disease. Only 15 years ago, the only surgical treatment for pseudophakic bullous keratopathy and Fuchs dystrophy was penetrating keratoplasty (PK). Although used successfully for over a century, PK requires many months of refractive adjustments before the eye achieves visual stability. Starting with the advent of posterior lamellar keratoplasty in the late 1990s, a number of procedures have been developed, refined, and widely adopted, which have given patients faster recoveries and improved globe stability in comparison to traditional corneal transplantation. Each iteration of endothelial keratoplasty (EK) has involved the increasingly selective transplantation of corneal endothelial cells. Preliminary results of the most recent form of EK, Descemet's membrane EK, suggest that pure endothelial cell transplantation is on the horizon.

Replication of TCF4 through association and linkage studies in late-onset Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD) is a common, late-onset disorder of the corneal endothelium. Although progress has been made in understanding the genetic basis of FECD by studying large families in which the phenotype is transmitted in an autosomal dominant fashion, a recently reported genome-wide association study identified common alleles at a locus on chromosome 18 near TCF4 which confer susceptibility to FECD. Here, we report the findings of our independent validation study for TCF4 using the largest FECD dataset to date (450 FECD cases and 340 normal controls). Logistic regression with sex as a covariate was performed for three genetic models: dominant (DOM), additive (ADD), and recessive (REC). We found significant association with rs613872, the target marker reported by Baratz et al.(2010), for all three genetic models (DOM: P = 9.33×10(-35); ADD: P = 7.48×10(-30); REC: P = 5.27×10(-6)). To strengthen the association study, we also conducted a genome-wide linkage scan on 64 multiplex families, composed primarily of affected sibling pairs (ASPs), using both parametric and non-parametric two-point and multipoint analyses. The most significant linkage region localizes to chromosome 18 from 69.94cM to 85.29cM, with a peak multipoint HLOD = 2.5 at rs1145315 (75.58cM) under the DOM model, mapping 1.5 Mb proximal to rs613872. In summary, our study presents evidence to support the role of the intronic TCF4 single nucleotide polymorphism rs613872 in late-onset FECD through both association and linkage studies.

Early outcomes of descemet stripping automated endothelial keratoplasty in pseudophakic eyes with anterior chamber intraocular lenses

PURPOSE

To evaluate complications and clinical outcomes of Descemet stripping automated endothelial keratoplasty in eyes with preexisting anterior chamber intraocular lenses.

DESIGN

Retrospective review.

METHODS

Thirty-one patients who underwent Descemet stripping automated endothelial keratoplasty and who had a preexisting anterior chamber intraocular lens were identified from May 2006 through March 2009. Patient follow-up ranged from a minimum of 1 month up to 30 months. Preoperative and postoperative best spectacle-corrected visual acuity, manifest refraction, comorbid conditions, and complications were recorded. Endothelial cell loss, graft dislocation, graft failure rates were calculated.

RESULTS

The mean age at surgery was 78 ± 9 years (range, 53 to 91 years). All eyes had pseudophakic bullous keratopathy, except 1 patient who had a failed penetrating keratoplasty graft. Excluding those patients with severely limited visual potential because of noncorneal pathologic features, the mean best spectacle-corrected visual acuity improved significantly from 20/200 to 20/400 before surgery to 20/63 at 3 months (P < .0001), 20/60 at 6 months (P = .0006), 20/50 at 12 to 15 months (n = 10; P = .004), and 20/40 between 23 and 30 months (n = 8; median, 25 months; P = .007). The preoperative mean spherical equivalent was -0.3 ± 1.8 diopters compared with -0.15 ± 1.5 diopters after surgery (P = .78). The graft dislocation rate was 13%, and the graft failure rate was 16%. For those patients with endothelial cell density data available, the average endothelial cell loss was 48% at a mean of 14 months.

CONCLUSIONS

Although Descemet stripping automated endothelial keratoplasty surgery in patients with an anterior chamber intraocular lens remains a controversial topic, the visual and anatomic outcomes from this limited study support this approach as a surgical option in selected cases.

Recurrent Corneal Erosion Syndrome: A Study of 364 Episodes

The purpose of the study was to investigate the management of recurrent corneal erosion syndrome (RES). A retrospective case series design was employed in which all RES cases presenting to the Duke University Eye Center from 1995 to 2002 were included. In total, 364 episodes of RES occurred in 261 patients during the study period. Of this 61% of patients were female (P < .001), average age was 46.0 years, and etiologies included trauma (51.3%), anterior basement membrane dystrophy (29.1%), other etiologies (10.3%) and unknown (9.2%). Treatments included conservative therapy (83.2%), anterior stromal puncture (ASP)(12.6%) and phototherapeutic keratectomy (PTK)(4.1%). Recurrence by treatment was 31.0% for conservative therapy, 23.9% for ASP and 26.7% for PTK. Subjects treated with ASP and PTK had failed prior treatment efforts. Conclusions include that RES was commonly associated with trauma and the female gender, and that one-third of conservatively treated episodes and one-quarter of surgically treated episodes (ASP or PTK) recurred.

Descemet's stripping automated endothelial keratoplasty in a patient with four glaucoma tubes

Descemet's stripping automated endothelial keratoplasty (DSAEK) is an increasingly popular techniquefor transplanting corneal endothelial cells. The presence of glaucoma, and especially glaucoma tubes, however, renders the DSAEK procedure more challenging. Here, we present a case of DSAEK in a patient with quadruple glaucoma tubes.

Air bubble-associated endothelial trauma in descemet stripping automated endothelial keratoplasty

PURPOSE

To evaluate endothelial cell trauma by anterior chamber (AC) air bubbles in Descemet stripping automated endothelial keratoplasty (DSAEK).

DESIGN

Laboratory investigation.

METHODS

Twelve human donor corneas (6 pairs) were sectioned using an automated microkeratome system (Moria ALTK System, Antony, France). One cornea of each pair was mounted on a Moria artificial AC, and an air bubble was injected to fill 40% of the AC. The apparatus was rotated 180 degrees for a total of 50 times to simulate air bubble trauma. The fellow corneas were used as controls. Each endothelial graft was stained with 0.25% Trypan blue for 90 seconds followed by 0.2% alizarin red for 2 minutes, and digital photomicrographs were obtained. Abnormally staining areas indicative of graft injury were removed digitally from the total graft area. The proportion of uninjured corneal endothelium was calculated, and differences were analyzed.

RESULTS

In this ex vivo model of air bubble trauma, the proportion of viable graft endothelium after air bubble injury was 79.8 +/- 0.04% (n = 6). The proportion of viable endothelium in the control group was 89.9 +/- 0.02% (n = 6). The statistically significant mean difference of 10.1% (P = .03) is indicative of greater endothelial injury after air bubble trauma.

CONCLUSIONS

Using this model, a moderate but significant amount of endothelial cell damage was associated with air bubble trauma compared with the control group. Air bubble trauma may account partially for the loss of endothelial cell density after DSAEK surgery and may impact graft survival.

The histology of graft adhesion in descemet stripping with endothelial keratoplasty

PURPOSE

To describe the histologic findings of full-thickness corneas from penetrating keratoplasty (PK) in 10 patients with a prior history of Descemet stripping with endothelial keratoplasty.

DESIGN

Retrospective review of the histopathology of 10 PK specimens.

METHODS

We reviewed histologic sections stained with hematoxylin and eosin, periodic acid-Schiff, and colloidal iron stains from 10 PK specimens, which had been trisected and submitted in their entirety. Clinical data were abstracted from the medical record.

RESULTS

The interface between host and graft in most cases was barely perceptible with minimal changes in the degree of tissue eosinophilia, a subtle increase in keratocyte cellularity focally, or the presence of melanin granules within keratocytes. Residual host Descemet membrane (DM) was found in 8 of the 10 cases, most often at the edges of the graft. In no case did the presence of DM appear to hinder graft adhesion.

CONCLUSION

The adhesion of Descemet stripping with endothelial keratoplasty grafts is not associated with significant scarring or keratocyte proliferation. Contrary to previous assumptions, retained DM did not appear to hinder graft adhesion, raising the possibility that removal of DM may be unnecessary for endothelial transplantation.

Presumed Oculoglandular Syndrome fromBartonella quintana

BACKGROUND

To describe a case of clinically diagnosed oculoglandular syndrome in a 17-year-old patient that was presumed to be due to Bartonella quintana, as suggested by a positive serologic titer.

METHODS

The patient presented to the Massachusetts Eye and Ear Infirmary emergency room with signs and symptoms suggestive of oculoglandular syndrome. He had a follicular conjunctivitis with a conjunctival granuloma of the right eye and an ipsilateral large, tender submandibular lymph node. He had recently acquired a kitten and a clinical diagnosis of cat-scratch disease was made. A laboratory workup was initiated to determine the cause of this clinical presentation and empirical treatment with antibiotics was started.

RESULTS

All laboratory results were negative or normal except for the IgM titer to Bartonella quintana, which was elevated. The patient responded well to treatment and his symptoms resolved within a few weeks.

DISCUSSION

Bartonella quintana infection, a pathogen prevalent in HIV-infected, homeless, or alcoholic patients, is a possible etiologic agent of cat-scratch disease and the associated condition of oculoglandular syndrome.

Trends in resistance to ciprofloxacin, cefazolin, and gentamicin in the treatment of bacterial keratitis

PURPOSE

The aim of this study was to evaluate the microbial profile, resistance patterns, and antibiotic sensitivity of bacterial keratitis to three commonly used ocular antibiotics.

METHODS

All cases of bacterial keratitis referred to the Massachusetts Eye and Ear Infirmary Microbiology Laboratory from two consecutive annual 10-month periods were reviewed. The bacterial profile and resistance to ciprofloxacin, cefazolin, and gentamicin was evaluated within the two intervals.

RESULTS

Of the 485 cultures analyzed, 66.4% (322) were positive for bacterial isolates. Of these, 19.2% were polymicrobial, 87.5% were gram-positive, and 12.5% were gram-negative. The most prevalent isolate was coagulase-negative Staphylococcus (45.5%), followed by S. aureus (15.2%). The resistance patterns for gram-positive bacteria for ciprofloxacin for the first versus second time interval were 12% and 22% (P = 0.04) respectively, for cefazolin 13% and 23% (P = 0.04), and for gentamicin 4% and 7% (P = 0.36). The resistance patterns for gram-negative bacteria for ciprofloxacin, cefazolin, and gentamicin were not significantly different in the two tested time periods (all P > 0.05).

CONCLUSIONS

There was increased resistance of gram-positive organisms to ciprofloxacin and cefazolin, but not gentamicin, in the two examined time periods. Increased resistance to these commonly used antibiotics emphasizes the need for close follow-up after initial empiric treatment, and maintaining a low threshold for selecting alternative therapy.

Descemet stripping automated endothelial keratoplasty in a child

We present the case of a 9-year-old patient with corneal decompensation that was treated with Descemet stripping automated endothelial keratoplasty (DSAEK) and followed for 18 months. Although the procedure has been used successfully in adult populations, to our knowledge, this is the first report of DSAEK with long-term follow-up in a child. The outcome suggests that endothelial keratoplasty may be a good alternative to penetrating keratoplasty in children. Endothelial keratoplasty is a new form of corneal transplantation that promises faster visual recovery compared with penetrating keratoplasty. With endothelial keratoplasty, the corneal architecture is preserved; therefore, large spherical and astigmatic errors are not induced, and stable refraction is achieved earlier in the course of therapy.

Genome-wide linkage scan in fuchs endothelial corneal dystrophy

PURPOSE

To perform a genome-wide linkage screen with a single-nucleotide polymorphism (SNP) linkage panel to identify regions of genetic linkage in Fuchs endothelial corneal dystrophy (FECD) and to analyze affected individuals for mutations in the COL8A2 gene.

METHODS

Ninety-two individuals from 22 families with FECD were identified from our multiplex FECD family cohort. A genome-wide linkage scan was performed using an SNP linkage panel. Parametric two-point linkage analyses were calculated and nonparametric multipoint linkage analyses were performed on chromosomes with two-point LOD scores (HLOD) > 1.0. All affected individuals were analyzed for the two previously reported FECD mutations in the COL8A2 gene (L450W and Q455K).

RESULTS

The genome-wide analysis identified five regions with linkage signals from all analyses on chromosomes 1, 7, 15, 17, and X. The highest two-point HLODs were found on the long arm of chromosome 15 with an HLOD of 3.26 for the recessive model and 2.48 for the dominant model. Multipoint linkage analysis also identified a linkage peak on the long arm of chromosome 15 with a LOD > 1. The region of linkage on chromosome 1p, driven by two multigenerational FECD families with a two-point LOD > 2, was adjacent to the previously identified COL8A2 gene; however, the two reported mutations in COL8A2 were not identified in any of the 56 affected individuals in the 92 samples tested.

CONCLUSIONS

Genome-wide linkage analysis was used to identify potential linkage regions on chromosomes 1, 7, 15, 17, and X for FECD. The previously reported mutations in the COL8A2 gene were not found in the 92 samples tested.

Atypical asymmetric lattice corneal dystrophy associated with a novel homozygous mutation (Val624Met) in the TGFBI gene

PURPOSE

To evaluate the TGFBI gene and the encoded transforming growth factor beta-induced protein (TGFBIp) in a 47-year-old African-American patient with an unusual atypical asymmetric lattice corneal dystrophy (LCD).

METHODS

The eyes of the proband and his brother were examined by slit-lamp biomicroscopy and their clinical records were reviewed. All 17 exons of TGFBI were evaluated in genomic DNA extracted from blood or buccal epithelial cell samples from the proband and his family members. The corneal tissue of the proband was examined histopathologically, and TGFBIp was analyzed in half of an excised corneal button.

RESULTS

The proband (who had an unusual atypical asymmetric LCD) and his brother (who had mild bilateral deep stromal opacities) were found to have homozygous Val624Met mutations in TFGBI. The proband's daughter who was heterozygous for the Val624Met mutation had no reported ophthalmic abnormalities. The corneal tissue from the proband contained TGFBIp with the Val624Met mutation. Patients with LCD have different clinical phenotypes based on their genotype. Molecular genetic analyses are becoming increasingly important in making precise diagnoses and prognostic predictions about inherited corneal disorders.

CONCLUSIONS

A novel Val624Met homozygous mutation in TGFBI was associated with atypical LCD in two family members. Symptomatic corneal disease was absent at the age of 24 years in the offspring of the proband who was heterozygous for this mutation. This is an apparent example of a TGFBI mutation that becomes evident when it is homozygous. The finding of Val624Met mutated TGFBIp in a approximately 65 kDa protein band in a reduced sodium dodecyl sulfate (SDS) gel suggests that the accumulated protein was intact TGFBIp and not a fragment of TGFBIp.

Novel delivery method to reduce endothelial injury in descemet stripping automated endothelial keratoplasty

PURPOSE

To present a novel technique to deliver the endothelial graft in small incision Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) and to compare graft trauma between forceps delivery and the novel technique.

DESIGN

Laboratory investigation with an interventional case report.

METHODS

Ten pairs of human donor corneas were sectioned using an automated microkeratome system (Moria ALTK System, Antony, France). The recipient model was prepared by creating a 3 mm clear corneal wound in another human donor cornea. For each pair of corneas, one endothelial graft underwent single-fold delivery with forceps, while the other was delivered with the novel cartridge based technique. Each graft was stained with 0.25% trypan blue and 0.2% alizarin red, and digital photomicrographs were taken. A proportion of graft injury was calculated and differences were analyzed. Subsequently, a patient requiring DSAEK underwent the modified novel insertion technique.

RESULTS

After insertion, the mean proportion of graft endothelial injury from forceps delivery through the ex vivo model was 26.02% (n = 10, standard deviation [SD] +/- 14.85%). The mean proportion of graft endothelial injury from cartridge delivery was 9.85% (n = 10, SD +/- 4.33%). The median difference between the two methods was -13%, representing less endothelial injury with the cartridge. This difference was statistically significant (P = .006). The patient who underwent DSAEK with this technique had improved visual acuity and a clear graft at five months.

CONCLUSIONS

In our surgical model, inserting an endothelial graft through a small corneal wound using a novel cartridge-based technique created significantly less endothelial damage than with forceps insertion. Clinically, this technique was performed without complication.