Operating Room Waste Generated From Corneal and Conjunctival Surgeries.

PURPOSE: The purposes of this study were to bring awareness to the surgical waste generated from corneal and conjunctival surgeries and to compare those findings with the waste generated from cataract surgeries. METHODS: This was an observational prospective pilot cohort study at a tertiary corneal/anterior segment private practice. All waste related to cataract, cornea, and conjunctival surgical procedures (including anesthesia waste and corneal tissue storage) was weighed. The primary outcome was total waste generated while other outcomes included surgical setting (ambulatory surgical center, hospital, and minor operating room) and comparison of corneal/conjunctival surgeries with cataract surgery. RESULTS: Surgical waste data were collected from 119 surgeries (82 corneal/conjunctival surgeries and 37 cataract surgeries). Hospital surgeries produced more waste than ambulatory surgical center and minor operating room surgeries. Penetrating keratoplasty (2.22 kg, P = 0.483) and Descemet stripping only (2.11 kg, P = 0.326) procedures generated comparable mean waste with cataract surgery (2.07 kg) while endothelial keratoplasties produced more ( P < 0.001, 0.002). (Deep) anterior lamellar keratoplasty results depended on the surgical setting. All conjunctival surgeries produced less waste than cataract surgery. CONCLUSIONS: In comparison with cataract surgery, keratoplasties overall produced comparable or more waste while conjunctival surgeries produced less waste. The surgical setting and type of anesthesia played a substantial role in the amount of waste generated. Assessing waste production from different ophthalmic surgeries may increase awareness of the negative environmental impact of surgical waste and promote practice or legal changes to improve environmental sustainability.

Smoking and progressive retinal nerve fibre layer thinning in glaucoma.

BACKGROUND/AIMS: To investigate the relationship between smoking and smoking intensity, and the rate of retinal nerve fibre layer (RNFL) thinning in patients with primary open angle glaucoma (POAG). METHODS: In this longitudinal study, patients with POAG who had at least 3 years of follow-up with a minimum of 5 visits of optical coherence tomography (OCT) were enrolled. The smoking intensity was calculated as the pack-year at the baseline OCT. Univariable and multivariable linear mixed models were used to determine the effect of each parameter on the rates of RNFL thinning over time. Non-linear least-squares estimation with piecewise regression model was used to investigate the cut-off point for the relationship between circumpapillary RNFL thinning and smoking intensity. RESULTS: A total of 466 eyes of 314 patients were included over the mean (95% CI) follow-up of 6.6 (6.4 to 6.7) years. Of the 314 patients, 121 (39%) had reported any history of smoking. Greater smoking intensity was associated with faster RNFL thinning (-0.06 (95% CI -0.11 to 0.00) µm/year per 10 pack-year higher; p=0.031) after adjusted for confounding factors. RNFL thinning became significantly faster when smoking intensity was >8 pack-year. CONCLUSIONS: Smoking intensity is associated with faster rates of RNFL thinning. Evaluation of smoking intensity might add information to the assessment of risk of glaucoma progression. Future studies are required to explore if withdrawing smoking as a modifiable risk factor can decrease progression in patients with glaucoma.

Comparison of Persistent Epithelial Defect Treatment With Sutureless Cryopreserved and Dehydrated Amniotic Membrane.

PURPOSE: To compare cryopreserved sutureless amniotic membrane (C-SAM) and dehydrated SAM (D-SAM) outpatient treatment outcomes for persistent epithelial defects (PEDs), analyze risk factors for treatment failure, and identify adverse events. DESIGN: Retrospective, interventional comparative clinical study. METHODS: This study was a multicenter retrospective interventional cohort from 2 tertiary corneal referral practices from 2016 to 2020. The inclusion criteria were as follows: (1) PEDs treated (2) outpatient with (3) either C-SAM or D-SAM. PEDs were defined as epithelial defects present for ≥7 days after failing prior conservative therapy. The primary outcome measure was the resolution or improvement of a PED. The secondary outcomes included analysis of treatment failures and identification of adverse events. A total of 220 PEDs from 204 eyes (197 patients) treated with either C-SAM or D-SAM met the inclusion criteria. RESULTS: A total of 100 PEDs (45.5%) resolved after single amniotic membrane administration, 46.5% (59 of 127) in the C-SAM group and 44.1% (41 of 93) in the D-SAM group (P = .727). Forty-nine PEDs neither improved nor resolved without a significant difference between the C-SAM (21.3%) and D-SAM groups (23.7%, P = .673). There was no statistically significant difference for PED resolution, PED improvement, PEDs that did not resolve/improve, or those requiring surgery between the 2 groups for initial SAM. CONCLUSIONS: C-SAM and D-SAM were both effective for treating PEDs with comparable outcomes for resolution, improvement, and need for additional surgical intervention. Specific differences in adverse events may help dictate clinical use. Inflammatory disease was a risk factor for nonresolution of all PEDs.

Smoking Cessation May Reduce Risk of Visual Field Progression in Heavy Smokers.

PRCIS: The earlier a person quits smoking the more likely is the optic nerve be spared from damage. PURPOSE: To investigate the effect of smoking cessation on visual field (VF) progression in glaucoma. METHODS: Primary open angle glaucoma patients with a minimum of 3 years follow-up and 5 VFs were included. Linear mixed models were used to investigate the effects of smoking on the rates of 24-2 VF mean deviation loss after adjusting for confounding factors. Cox proportional hazard regression was used to identify whether different levels of smoking intensity were associated with VF progression with respect to different duration of quitting. RESULTS: Five hundred eleven eyes of 354 patients were included over the mean follow-up of 12.4 years. Mean baseline age (95% confidence interval) was 62.3 (61.2, 63.4) years. One hundred forty nine (42.1%) patients were smokers. In a multivariable model, smoking intensity was associated with faster VF loss (-0.06, 95% confidence interval (-0.10, -0.01) dB/year per 10 pack-years, P =0.01) among smokers. Heavy smokers (≥20 pack-years) who had quit ˂25 years prior had significantly greater odds of VF progression compared with never smokers (odds ratio=2.49 (1.01, 6.08); P =0.046). There was no significant difference in odds of VF progression in heavy smokers who had quit smoking more than 25 years compared with never smokers ( P =0.43). A significantly higher proportion of VF progression was found in heavy smokers who quit < 25 years compared with heavy smokers who quit ≥25 years by Kaplan-Meier analysis ( P =<0.001). CONCLUSIONS: After ≥25 years of smoking cessation, the risk of VF progression in former heavy smokers becomes similar to never smokers. Long-term smoking cessation may be associated with lower VF progression in glaucoma patients.

Effects of Smoking on Optic Nerve Head Microvasculature Density in Glaucoma.

PRCIS: Decreased superficial whole image capillary density was observed in open angle glaucoma (OAG) patients with high smoking intensity. PURPOSE: To investigate the effects of smoking on optic nerve head capillary density measured by optical coherence tomography angiography in patients with OAG. METHODS: In this retrospective cross-sectional study, perimetric and preperimetric glaucoma patients enrolled in the Diagnostic Innovations in Glaucoma Study (DIGS) with optical coherence tomography angiography follow-up were included. Univariable and multivariable linear mixed analysis were performed to determine the effects of different variables on the superficial whole image capillary density. RESULTS: A total of 432 eyes of 271 glaucoma patients comprising 63 preperimetric (106 eyes) and 208 perimetric OAG (326 eyes) were included. A history of tobacco consumption was reported in 105 (38.8%). Among smokers, mean (95% confidence interval) smoking intensity was 12.8 (10.2, 15.5) pack-years. After adjusting for age, glaucoma severity and other confounders, each 10 pack-year increase in smoking intensity (95% confidence interval) was associated with -0.54 (-1.06, -0.02) % lower whole image capillary density ( P =0.041). CONCLUSIONS: Smoking intensity is associated with reduced optic nerve vessel density in glaucoma.

Impact of Smoking on Visual Field Progression in a Long-term Clinical Follow-up.

PURPOSE: To investigate the effect of smoking on rates of progressive visual field (VF) damage over time in glaucoma. DESIGN: Retrospective cohort study. PARTICIPANTS: Five hundred eleven eyes of 354 patients with glaucoma followed up from multicenter glaucoma registries. METHODS: In this longitudinal study, 354 patients with primary open-angle glaucoma with a minimum of 3 years of follow-up and 5 VF tests were enrolled from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. Univariate and multivariate linear mixed models were used to investigate the effects of smoking on rates of 24-2 VF mean deviation loss. Visual field progression was defined using pointwise linear and significant negative VF mean deviation loss. Logistic regression was used to identify baseline factors and whether different levels of smoking intensity were associated with VF progression. Kaplan-Meier survival analysis and the log-rank test were used to compare the cumulative risk ratio of progression between smoker and never smoker groups. MAIN OUTCOME MEASURES: Visual field progression. RESULTS: Five hundred eleven eyes of 354 patients were included over the median follow-up of 12.5 years. Median baseline age was 64.8 years. Of the 354 patients, 124 (35%) were Black, and 149 (42.1%) and 168 (59.8%) had reported a history of smoking or alcohol consumption, respectively. In a multivariate model, higher smoking intensity was associated with faster VF loss (coefficient, -0.05 decibels (dB)/year per 10 pack-years; 95% confidence interval [CI], -0.08 to -0.01 dB/year per 10 pack-years; P = 0.010). Developing VF progression in eyes of heavy smokers (≥ 20 pack-years) was 2.2 times more than in eyes of patients without smoking history (odds ratio, 2.21; 95% CI, 1.02-4.76; P = 0.044). Statistically significant differences were found between heavy smokers (≥ 20 pack-years) and never smokers by Kaplan-Meier analysis (P = 0.011, log-rank test). CONCLUSIONS: Heavy smokers are more likely to sustain VF loss in eyes with glaucoma. The prospective longitudinal design of this study supports the hypothesis that levels of smoking may be a significant predictor for glaucoma progression. Additionally, this information can be used for clinically relevant tobacco prevention and intervention messages.

Preclinical Evaluation of the Safety and Efficacy of Cryopreserved Bone Marrow Mesenchymal Stromal Cells for Corneal Repair.

Purpose: Mesenchymal stromal cells (MSCs) have been shown to enhance tissue repair as a cell-based therapy. In preparation for a phase I clinical study, we evaluated the safety, dosing, and efficacy of bone marrow-derived MSCs after subconjunctival injection in preclinical animal models of mice, rats, and rabbits. Methods: Human bone marrow-derived MSCs were expanded to passage 4 and cryopreserved. Viability of MSCs after thawing and injection through small-gauge needles was evaluated by vital dye staining. The in vivo safety of human and rabbit MSCs was studied by subconjunctivally injecting MSCs in rabbits with follow-up to 90 days. The potency of MSCs on accelerating wound healing was evaluated in vitro using a scratch assay and in vivo using 2-mm corneal epithelial debridement wounds in mice. Human MSCs were tracked after subconjunctival injection in rat and rabbit eyes. Results: The viability of MSCs after thawing and immediate injection through 27- and 30-gauge needles was 93.1% ± 2.1% and 94.9% ± 1.3%, respectively. Rabbit eyes demonstrated mild self-limiting conjunctival inflammation at the site of injection with human but not rabbit MSCs. In scratch assay, the mean wound healing area was 93.5% ± 12.1% in epithelial cells co-cultured with MSCs compared with 40.8% ± 23.1% in controls. At 24 hours after wounding, all MSC-injected murine eyes had 100% corneal wound closure compared with 79.9% ± 5.5% in controls. Human MSCs were detectable in the subconjunctival area and peripheral cornea at 14 days after injection. Conclusions: Subconjunctival administration of MSCs is safe and effective in promoting corneal epithelial wound healing in animal models. Translational Relevance: These results provide preclinical data to support a phase I clinical study.

Clinical Outcomes of Allogeneic Ocular Surface Stem Cell Transplantation in Pediatric Patients.

PURPOSE: To describe the outcomes of allograft ocular surface stem cell transplantation (OSST) and the complication profile of systemic immunosuppression (SI) in pediatric patients with limbal stem cell deficiency. METHODS: This was a retrospective interventional case series from a single tertiary referral institution of 20 eyes from 13 patients who 1) underwent allograft OSST surgery, 2) were 18 years or less at time of OSST, and 3) received SI with 4) a minimum of 12-months follow-up. The main outcome measures were ocular surface stability, visual acuity, and SI adverse events. RESULTS: The mean age of patients was 15.1 ± 3.2 years (range 9-18 years). The mean follow-up was 5.6 ± 5.0 years after OSST. At the last follow-up, 15 eyes (75%) had a stable ocular surface, 1 eye (5%) developed partial failure, and 4 eyes (20%) developed total surface failure. Preoperative mean logarithm of the minimum angle of resolution visual acuity 1.5 improved to 1.1 at the last follow-up (P = 0.1); when 4 eyes of 3 nonadherent patients were excluded, the results were more pronounced and statistically significant (1.5 improved to 1.0, P = 0.002). SI was tolerated well by all patients with minimal adverse events. CONCLUSIONS: OSST provides a stable ocular surface and is a successful treatment option for pediatric patients with limbal stem cell deficiency. SI is well-tolerated with a minimal complication profile.

Reproducible Derivation and Expansion of Corneal Mesenchymal Stromal Cells for Therapeutic Applications.

Purpose: A reproducible protocol for the production of corneal mesenchymal stem/stromal cells (cMSCs) is necessary for potential clinical applications. We aimed to describe successful generation and expansion of cMSCs using an explant method. Methods: Corneoscleral rims of human cadaveric eyes were divided into four pieces and used as explants to allow outgrowth of cMSCs (passage 0, or P0). The cells were subcultured at a 1:10 ratio until passage 5 (P5). The characteristics as well as therapeutic effects of expanded cMSCs were evaluated both in vitro, using a scratch assay, and in vivo using epithelial debridement and chemical injury mouse models. Results: All explants demonstrated outgrowth of cells by 7 days. Although the initial outgrowth included mixed mesenchymal and epithelial cells, by P1 only cMSCs remained. By subculturing each flask at a ratio of 1:10, the potential yield from each cornea was approximately 12 to 16 × 1010 P5 cells. P5 cMSCs demonstrated the cell surface markers of MSCs. The secretome of P5 cMSCs induced faster closure of wounds in an in vitro scratch assay. Subconjunctival injection of P5 cMSCs in mouse models of mechanical corneal epithelial debridement or ethanol injury led to significantly faster wound healing and decreased inflammation, relative to control. Conclusions: cMSCs can be reproducibly derived from human cadaveric corneas using an explant method and expanded with preservation of characteristics and corneal wound healing effects. Translational Relevance: The results of our study showed that cMSCs produced using this scheme can be potentially used for clinical applications.

Long-term Outcomes of Living-Related Conjunctival Limbal Allograft Compared With Keratolimbal Allograft in Patients With Limbal Stem Cell Deficiency.

PURPOSE: To compare the long-term outcomes of living-related conjunctival limbal allograft (lr-CLAL) with keratolimbal allograft (KLAL) in patients with limbal stem cell deficiency. METHODS: A retrospective, comparative, interventional cohort of patients with bilateral total limbal stem cell deficiency who underwent surgical treatment with a KLAL or lr-CLAL procedure alone (not combined with any other ocular surface stem cell transplantation procedures) with a minimum follow-up of 1 year and who received systemic immunosuppression. Ocular surface stability, best-corrected visual acuity (BCVA), and postoperative complications at the last follow-up were the main outcome measures. RESULTS: There were 224 eyes that underwent KLAL alone and 63 eyes that underwent lr-CLAL alone, with a mean follow-up time for all eyes of 7.2 years (range 1.0-16.0 years). For lr-CLAL eyes, 82.5% maintained a stable ocular surface compared with 64.7% of KLAL eyes at the last follow-up. Only 6.3% of lr-CLAL eyes demonstrated a failed ocular surface compared with 15.6% of KLAL eyes. The mean BCVA was 20/158 for KLAL eyes compared with 20/100 for lr-CLAL eyes at the last follow-up. A smaller proportion of lr-CLAL eyes (30.2% compared with 43.3%) developed an episode of acute rejection, and a higher proportion of these episodes resolved with treatment in the lr-CLAL group (79.0% compared with 53.6%). CONCLUSIONS: lr-CLAL demonstrates lower rejection rates, improved graft survival, and better BCVA compared with KLAL. Both careful preoperative donor selection and triple-agent systemic immunosuppression (including tapered systemic corticosteroids) are critical to optimizing the ocular surface stem cell transplantation outcomes.

Long-term outcomes of conjunctival limbal autograft in patients with unilateral total limbal stem cell deficiency.

PURPOSE: To investigate the long-term clinical outcomes of conjunctival limbal autograft (CLAU) in patients with unilateral total limbal stem cell deficiency (LSCD). METHODS: In this retrospective interventional case series, the medical charts of patients with unilateral total LSCD were reviewed. Patients who underwent CLAU and no other allograft ocular stem cell transplantation with a minimum follow-up of 1 year were included. Main outcome measures were ocular surface stability, best-corrected visual acuity (BCVA), and postoperative complications. RESULTS: 27 eyes fulfilled the inclusion criteria with a mean follow-up period of 49.8 ±â€¯36.6 months (4.15 years; range 12-186.72 months; 1-15.56 years). Ocular surface stability was achieved in 77.8% (n = 21) of eyes at last follow-up, while 22.2% (n = 6) developed partial surface failure. Optical penetrating or deep lamellar anterior keratoplasty was performed in 44.45% (n = 12). BCVA improved from 1.42 ±â€¯0.95 mean LogMAR (equivalent to 20/400) preoperatively to 0.53 ±â€¯0.47 mean LogMAR (equivalent to 20/70) at last follow-up (p < 0.001). BCVA ≥20/40 was achieved in 44.45% (n = 12) at last follow-up. Microbial keratitis occurred in 14.81% (n = 4). Ocular hypertension secondary to corticosteroid use developed in 25.9% (7/27) eyes. There were no other complications in the donor or recipient eyes. CONCLUSIONS: CLAU can provide long-term ocular surface stability and successful visual outcomes in patients with unilateral LSCD.

Staphylococcus aureus alpha-hemolysin impairs corneal epithelial wound healing and promotes intracellular bacterial invasion.

Colonization by Staphylococcus aureus (S. aureus) has been implicated in many infectious and wound healing disorders. This study was performed to characterize the pathogenic role of S. aureus alpha-hemolysin (alpha-toxin) in corneal epithelial wound healing and infectious keratitis in the setting of a corneal wound. The effect of wild-type and isogenic Hla mutant (α-hemolysin gene deleted) S. aureus bacteria and conditioned media on corneal epithelial wound healing was tested in vitro using a scratch assay and in vivo using a murine epithelial debridement model. The invasiveness of wild-type and Hla mutant S. aureus was evaluated in vitro in human corneal epithelial cells and in vivo in a murine model of infectious keratitis following total epithelial debridement. S. aureus and its conditioned media significantly delayed epithelial wound closure both in vitro (P < 0.05) and in vivo (P < 0.05). The effect of S. aureus on wound healing was significantly diminished with the Hla mutant strain (P < 0.05). Likewise, compared to the wild-type strain, the Hla mutant strain demonstrated significantly reduced ability to invade corneal epithelial cells in vitro (P < 0.05) and infect murine corneas following total epithelial debridement in vivo (P < 0.05). In conclusion, S. aureus alpha-hemolysin plays a major role in the pathologic modulation of corneal epithelial wound healing and the intracellular invasion of the bacteria. Limiting colonization by S. aureus and/or blocking alpha-hemolysin may provide a therapeutic approach for corneal wound healing and infectious disorders.

Corneal Wound Healing Effects of Mesenchymal Stem Cell Secretome Delivered Within a Viscoelastic Gel Carrier.

Severe corneal injuries often result in permanent vision loss and remain a clinical challenge. Human bone marrow-derived mesenchymal stem cells (MSCs) and their secreted factors (secretome) have been studied for their antiscarring, anti-inflammatory, and antiangiogeneic properties. We aimed to deliver lyophilized MSC secretome (MSC-S) within a viscoelastic gel composed of hyaluronic acid (HA) and chondroitin sulfate (CS) as a way to enhance corneal re-epithelialization and reduce complications after mechanical and chemical injuries of the cornea. We hypothesized that delivering MSC-S within HA/CS would have improved wound healing effects compared the with either MSC-S or HA/CS alone. The results showed that a once-daily application of MSC-S in HA/CS enhances epithelial cell proliferation and wound healing after injury to the cornea. It also reduced scar formation, neovascularization, and hemorrhage after alkaline corneal burns. We found that combining MSC-S and HA/CS increased the expression of CD44 receptors colocalized with HA, suggesting that the observed therapeutic effects between the MSC-S and HA/CS are in part mediated by CD44 receptor upregulation and activation by HA. The results from this study demonstrate a reproducible and efficient approach for delivering the MSC-S to the ocular surface for treatment of severe corneal injuries. Stem Cells Translational Medicine 2019;8:478-489.

Management of advanced ocular surface disease in patients with severe atopic keratoconjunctivitis.

AIM & OBJECTIVE: Severe ocular surface disease, including limbal stem cell deficiency (LSCD) can occur as a consequence of severe atopic keratoconjunctivitis (AKC) that has been inadequately treated. Our goal was to describe the management and outcomes of severe ocular surface disease in AKC patients. METHODS: We performed a retrospective analysis of a case series of 13 eyes of 8 patients with advanced ocular surface disease associated with severe AKC. The clinical presentation, medical and surgical management, and visual and anatomic outcomes were analyzed. RESULTS: Five eyes were treated with medical interventions alone, which included topical or systemic immunomodulatory therapy (IMT) for all eyes. These eyes had a decline in mean visual acuity from LogMAR 0.96 to 2.04 between the initial and final visits related to recurrent epithelial defects or corneal ulceration. Eight eyes were treated with surgical approaches in addition to medical treatment. Initial surgical treatments included limbal stem cell transplantation (n = 5), Boston keratoprosthesis (n = 2), and superficial keratectomy (n = 1). Both eyes that underwent primary keratoprosthesis had severe post-operative complications and became no light perception. In the remainder of the surgically treated eyes, there was an improvement visual acuity from LogMAR 1.43 to 0.6 between the pre-operative and final post-operative visit. CONCLUSION: Visual rehabilitation in eyes severe ocular surface disease due to prolonged AKC is challenging. While some patients did experience improved vision, most eyes did not improve or experienced severe complications with vision loss. Early intervention with immunomodulatory therapy may prevent progression of the disease to advanced stages.

New ex vivo model of corneal endothelial phacoemulsification injury and rescue therapy with mesenchymal stromal cell secretome.

PURPOSE: To develop a reproducible ex vivo model of corneal endothelial cell injury using phacoemulsification in porcine eyes and to evaluate the effects of mesenchymal stromal cell secretome in this injury model. SETTING: Department of Ophthalmology, University of Illinois at Chicago, Illinois, USA. DESIGN: Experimental study. METHODS: A corneal endothelial injury model was optimized using different powers and durations of ultrasound energy inside ex vivo porcine eyes. Conditioned media from corneal mesenchymal stem cells was collected under serum-free conditions from passages 4 to 6. Immediately after the phacoemulsification injury, the anterior chamber fluid was replaced with unconditioned media or conditioned media and incubated at 37°C for 4 hours. At the end, endothelial cell viability was evaluated using trypan blue staining and analyzed with ImageJ software. RESULTS: Using specific parameters (50% power for 30 seconds), phacoemulsification inside fresh porcine eyes led to a consistent level of endothelial cell injury. Incubation with corneal mesenchymal stromal cell-conditioned media after the injury significantly reduced endothelial cells loss compared with unconditioned media (mean 1.29% ± 0.91% [SD] and 5.33% ± 3.24%, respectively, P < .05). CONCLUSIONS: Phacoemulsification inside fresh porcine eyes provided a reproducible model to study endothelial cell injury. Treatment with corneal mesenchymal stromal cell secretome after injury appeared to significantly enhance the survival of corneal endothelial cells. This might provide a new strategy for preventing corneal endothelial cell loss after phacoemulsification or other endothelial injuries. Further in vivo studies are necessary to determine the therapeutic potential.

Ocular Surface Stem Cell Transplantation for Treatment of Keratitis-Ichthyosis-Deafness Syndrome.

PURPOSE: To report our surgical experience with ocular surface stem cell transplantation (OSST) for limbal stem cell deficiency (LSCD) in the setting of keratitis-ichthyosis-deafness (KID) syndrome. METHODS: Retrospective interventional case series. RESULTS: We present 5 eyes of 3 patients with KID syndrome that developed LSCD and underwent OSST. Mean follow-up after OSST was 8.3 ± 4.3 years (range 3.4-11.4 years). Two eyes underwent living-related conjunctival limbal allograft (lr-CLAL), and 3 eyes were treated with keratolimbal allograft (KLAL). Four of the 5 eyes underwent subsequent keratoplasty. Both lr-CLAL eyes maintained a stable ocular surface at final follow-up. Conversely, all KLAL eyes developed a failed surface requiring repeat KLAL surgery. Because of multiple failed KLALs, 1 eye underwent placement of a keratoprosthesis. CONCLUSIONS: KID syndrome is a rare cause of LSCD. Although OSST can stabilize the surface, long-term treatment of KID syndrome can be challenging. An lr-CLAL may offer further benefit over a KLAL in these eyes because it is HLA- and ABO-matched tissue; it also helps to treat keratoconjunctivitis sicca, often a prominent feature of KID syndrome.

Effect of Human Corneal Mesenchymal Stromal Cell-derived Exosomes on Corneal Epithelial Wound Healing.

Purpose: Mesenchymal stromal cells (MSCs) have been used therapeutically to modulate inflammation and promote repair. Extracellular vesicles, including exosomes, have been identified as one of the important mediators. This study investigated the effect of human corneal MSC-derived exosomes on corneal epithelial wound healing. Methods: Corneal MSCs (cMSCs) were isolated from human cadaver corneas. The secretome was collected after 72 hours and exosomes were isolated using differential ultracentrifugation. Morphology and size of exosomes were examined by electron microscopy and dynamic light scattering. Expression of CD9, CD63, and CD81 by cMSC exosomes was evaluated by western blotting. Cellular uptake of exosomes was studied using calcein-stained exosomes. The effect of exosome on wound healing was measured in vitro using a scratch assay and in vivo after 2-mm epithelial debridement wounds in mice. Results: cMSC exosomes were morphologically round and main population ranged between 40 and 100 nm in diameter. They expressed CD9, CD63, and CD81, and did not express GM130, Calnexin, and Cytochrome-C. Stained cMSC exosomes were successfully taken up by human cMSCs, human corneal epithelial cells (HCECs), and human macrophages in vitro and by corneal epithelium in vivo. In scratch assay, after 16 hours, cMSC exosome treated HCECs had 30.1% ± 14% remaining wound area compared to 72.9% ± 8% in control (P < 0.005). In vivo, after 72 hours, cMSC exosome-treated corneas had 77.5% ± 3% corneal wound healing compared to 41.6% ± 7% in the control group (P < 0.05). Conclusions: Human cMSC exosomes can accelerate corneal epithelial wound healing, and thus, may provide a therapeutic approach for ocular surface injuries.

Infectious Keratitis After Ocular Surface Stem Cell Transplantation.

PURPOSE: To describe the rate, clinical/microbiological characteristics, and outcomes of infectious keratitis in eyes with limbal stem cell deficiency after ocular surface stem cell transplantation (OSST). METHODS: In this retrospective chart review of 278 eyes that underwent OSST between January 2006 and December 2016, eyes treated for previous infectious keratitis (bacterial, fungal, or viral) were included. Demographics, risk factors, course, microbiological characteristics, and outcomes were assessed. RESULTS: A total of 52 eyes (18.7%) of 48 patients (28 men and 20 women) developed 75 episodes (culture-proven or presumed) of infectious keratitis (range 1-4 episodes) with mean follow-up of 5.3 ± 3.6 years after OSST. The most common limbal stem cell deficiency etiologies included chemical/thermal (27 episodes), Stevens-Johnson syndrome (19 episodes), aniridia (8 episodes), and mucous membrane pemphigoid (8 episodes). There were 44 (58.7%) bacterial keratitis episodes, 24 (32%) fungal keratitis episodes, and 7 (9.3%) HSV keratitis episodes. Gram-positive bacteria (79%) and Candida species (73%) were the most common bacterial and fungal pathogens. Before infection, 33% had an epithelial defect, 69% had a bandage contact lens, 91% were on systemic immunosuppression, and 25% recently had undergone ocular surgery (<3 months). Although 75% resolved with antimicrobial treatment, 25% required a therapeutic keratoplasty (TPK; 2 cases needed multiple TPK). CONCLUSIONS: Despite successful OSST surgery, infectious keratitis is relatively common, and aggressive medical/surgical therapy is warranted. Prophylactic topical antibiotics and a cicatrizing conjunctivitis diagnosis may account for the high proportion of fungal keratitis in this population.

Comparison of Visual Acuity Outcomes Between Nanothin Descemet Stripping Automated Endothelial Keratoplasty and Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To compare the visual outcomes and complications between nanothin Descemet stripping automated endothelial keratoplasty (NT-DSAEK) and Descemet membrane endothelial keratoplasty (DMEK). METHODS: A prospective comparative case series of 28 consecutive cases of NT-DSAEK (less than or equal to 50 µm) and DMEK was undertaken. Inclusion criteria were a diagnosis of Fuchs dystrophy, presence of pseudophakia, or planned combined cataract surgery/endothelial keratoplasty, with a minimum of 6-month follow-up. Exclusion criteria were any concurrent ocular comorbidities. Primary outcomes measures were best spectacle-corrected visual acuity (BSCVA) and complications. RESULTS: Mean thickness of NT-DSAEK grafts was 41.0 ± 7.5 µm (range 26-50 µm). At 1 month postoperatively, the DMEK group had significantly better mean BSCVA of 0.18 ± 0.20 logarithm of the minimum angle of resolution (logMAR) (20/33) compared with 0.28 ± 0.16 logMAR (20/40) for NT-NSAEK (P = 0.049). At 3, 6, and 12 months postoperatively, mean BSCVA was comparable between both groups [3 months: NT-DSAEK 0.17 ± 0.12 logMAR (20/30) versus DMEK 0.13 ± 0.17 (20/27), P = 0.31; 6 months: NT-DSAEK 0.11 ± 0.10 logMAR (20/26) versus DMEK 0.09 ± 0.10 (20/25), P = 0.63; 12 months: NT-DSAEK 0.07 ± 0.09 logMAR (20/24) versus DMEK 0.07 ± 0.11 logMAR (20/24), P = 0.95]. Other than 1 NT-DSAEK graft that was successfully rebubbled, no other complications were encountered in either group. CONCLUSIONS: Compared with DMEK, NT-DSAEK provides comparable visual outcomes and complications rates.

Tomographic changes in eyes with hyperopic shift after triple Descemet membrane endothelial keratoplasty.

PURPOSE: To describe the tomographic changes in eyes with a hyperopic shift after triple Descemet membrane endothelial keratoplasty (DMEK). SETTING: Private cornea practice, Blue Ash, Ohio, USA. DESIGN: Retrospective case series. METHODS: Patients who had previous triple DMEK with preoperative and postoperative Scheimpflug corneal tomography (Pentacam) measurements and corresponding manifest refraction measurements were reviewed. Eyes with and without a hyperopic postoperative shift were compared at either the 1-month or 3- to 6-month follow-ups. Assessed parameters included demographics, cataract testing, visual acuity, manifest refraction, and Scheimpflug tomography data. RESULTS: Sixty-two eyes of 47 patients (21 men, 26 women) with Fuchs endothelial corneal dystrophy were included. Preoperative posterior flat keratometry (K), posterior steep K, posterior average K, central pachymetry, and asphericity (Q value) of the posterior cornea were significantly different when comparing the hyperopic and non-hyperopic group. At the postoperative 1-month and 3- to 6-month follow-ups, there was a significant between-group difference in change in postoperative anterior K (average), posterior K (average), central pachymetry, and posterior Q values compared with preoperative values. The combined preoperative criteria of posterior flat K (≥-5.25), central pachymetry (≥670 µm), and posterior Q value (≥0.5) had a sensitivity of 58% (11/19 correctly identified hyperopic shifts) and specificity of 81% (8/43 incorrectly identified). CONCLUSIONS: Eyes with a hyperopic surprise after triple DMEK demonstrated a significant change in posterior and anterior corneal curvature compared with eyes without a hyperopic surprise. This might be secondary to corneal edema because these eyes also demonstrated greater preoperative corneal pachymetry.