Deep Anterior Lamellar Keratoplasty Using Dehydrated versus Standard Organ Culture-Stored Donor Corneas: Prospective Randomized Trial.

PURPOSE: To compare the outcomes of deep anterior lamellar keratoplasty (DALK) using dehydrated versus standard organ culture-stored donor corneas for eyes with keratoconus. DESIGN: Prospective, randomized, single-center trial conducted in Italy. PARTICIPANTS: Adult patients (age ≥ 18 years) with keratoconus scheduled for elective DALK. METHODS: Patients undergoing successful type 1 bubble pneumatic dissection using a standard DALK technique were randomized during surgery to receive either dehydrated (n = 30) or standard organ culture-stored (n = 30) donor corneas. MAIN OUTCOME MEASURES: The primary study outcome was best spectacle-corrected visual acuity (BSCVA) 12 months after surgery. Secondary outcomes were refractive astigmatism (RA), endothelial cell density (ECD), and complication rates. RESULTS: Postoperative BSCVA did not significantly differ between groups at both time points: mean difference at 6 months was 0.030 logarithm of the minimum angle of resolution (logMAR; 95% confidence interval [CI], -0.53 to 0.10 logMAR; P = 0.471) and at 12 months was -0.013 logMAR (95% CI, -0.10 to 0.08 logMAR; P = 0.764). No significant differences between groups were observed in terms of postoperative RA and ECD at all time points. In the first 3 days after DALK, an epithelial defect was present in 10 patients (33%) in the organ culture cornea group and in 29 patients (97%) in the dehydrated cornea group. Complete re-epithelialization was achieved by day 7 in all patients (100%) in both groups. CONCLUSIONS: The study provides evidence that the use of dehydrated corneas is noninferior to the use of standard organ culture donor corneas for DALK. Corneal tissue dehydration represents a viable solution that can allow long-term cornea preservation and avoid wastage of unused corneas. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Microsporidial Stromal Keratitis in Post-Keratoplasty Eyes.

PURPOSE: The purpose of this paper is to report the clinical manifestations, diagnostic evaluation, management and outcomes of microsporidial keratitis in post-keratoplasty eyes. METHODS: This is a retrospective review of three patients diagnosed with microsporidial stromal keratitis in post-keratoplasty eyes between January 2012 and December 2021 at a tertiary referral center (Ospedali Privati Forlì "Villa Igea", Forlì, Italy). RESULTS: All patients presented with fine multifocal granular infiltrates following keratoplasty for a presumed herpetic keratitis. No microorganisms were isolated from the corneal scrapings and no clinical response was observed with broad-spectrum antimicrobial therapy. In all cases, confocal microscopy demonstrated spore-like structures. The histopathologic examination of the excised corneal buttons confirmed the diagnosis of microsporidial stromal keratitis. Following therapeutic keratoplasty and treatment with an initial high dose and extended taper of topical fumagillin, clinical resolution was achieved in all eyes. The Snellen visual acuities at the final follow-up were 20/50, 20/63 and 20/32. CONCLUSIONS: Prior to definitive surgery, confocal microscopy can be employed for the in vivo detection of pathogenic microorganisms such as Microsporidium. In post-keratoplasty eyes, therapeutic keratoplasty and an initial high dose of topical fumagillin with extended taper can allow the resolution of microsporidial stromal keratitis with a satisfactory visual prognosis.

Outcomes of cataract surgery with toric intraocular lens implantation after keratoplasty.

PURPOSE: To evaluate the efficacy and predictability of cataract extraction with toric intraocular lens (IOL) implantation after deep anterior lamellar keratoplasty (DALK) or mushroom penetrating keratoplasty (PK). SETTING: Villa Igea Hospital, Forlì, Italy. DESIGN: Prospective case series. METHODS: Toric IOL implantation was offered to patients with cataract, corneal astigmatism >1.5 diopters (D) and regular central corneal topography after complete suture removal. Phacoemulsification was performed through a 2.4 mm scleral tunnel and an enVista monofocal toric MX60T or Eyecryl monofocal toric IOL was inserted in the capsular bag. Main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, total prediction error, and IOL misalignment. RESULTS: 37 consecutive patients who had previously undergone either DALK (n = 27, 73%) or 2-piece mushroom PK (n = 10, 27%) were included. All patients completed the 6-month follow-up. The mean toric IOL power was 5.3 ± 1.1 D. Both UDVA and CDVA significantly improved (from 1.02 ± 0.27 to 0.46 ± 0.31 logMAR and from 0.65 ± 0.27 to 0.11 ± 0.12 logMAR, respectively; P < .001). 20 eyes (54%) reached UDVA ≥20/40, whereas 35 eyes (95%) reached a CDVA ≥20/40. Final refractive astigmatism was 0.93 ± 0.87 D, with 35 eyes (95%) within 2 D. Prediction error was ≤1 D in 18 eyes (49%). Absolute IOL misalignment was 3.3 ± 3.5 degrees. CONCLUSIONS: Toric IOL implantation in postkeratoplasty eyes allowed reduction of refractive astigmatism to predictably low levels with concomitant improved visual outcomes.

Stromal peeling for deep anterior lamellar keratoplasty in post-penetrating keratoplasty eyes.

BACKGROUND/AIMS: To evaluate the clinical outcomes of deep anterior lamellar keratoplasty performed by stromal peeling in eyes that have previously undergone penetrating keratoplasty (PK) for keratoconus. METHODS: Standardised stromal exchange included (1) 9 mm trephination of the recipient bed outside the old PK wound, (2) creation of a partial anterior corneal flap through lamellar dissection across the PK wound, (3) opening the stromal component of the old PK wound using blunt-tipped Vannas scissors until a plane of separation is reached, (4) severing the attachment of the PK surgical scar from the recipient host, (5) peeling the stroma of the PK graft from the underlying tissue and (6) suturing the donor anterior corneal lamella prepared by microkeratome dissection (450 µm depth, 9 mm diameter). Main outcome measures were success rate, best spectacle-corrected visual acuity (BSCVA) and endothelial cell loss (ECL). RESULTS: Of 21 post-PK eyes, stromal exchange succeeded in all but three cases, which were converted to a two-piece mushroom PK. After complete suture removal, mean BSCVA significantly improved from 0.95±0.39 logMAR preoperatively to 0.23±0.17 logMAR (p<0.001). Mean ECL was 5.4±23.2%. Double anterior chamber formation occurred in eight cases (44%), which all resolved after a single re-bubbling. CONCLUSION: In post-PK eyes, stromal exchange can be performed by means of simple peeling without deep anterior lamellar dissection of the previous PK graft. Large-diameter (9 mm) repeat keratoplasty through stromal peeling yields excellent visual outcomes and minimal ECL. Double anterior chamber formation may complicate the postoperative course, but prompt intervention allows successful management.

Corneal neovascularisation following deep anterior lamellar keratoplasty for corneal ectasia: incidence, timing and risk factors.

BACKGROUND: The purpose of this study was to evaluate the incidence, timing and risk factors of corneal neovascularisation (NV) after deep anterior lamellar keratoplasty (DALK) for corneal ectasia. METHODS: This study included 616 eyes who underwent DALK between 2012 and 2020 in two tertiary referral centres. In one centre topical corticosteroids were discontinued after complete suture removal 1 year after surgery, whereas in the other they were discontinued 3-4 months after surgery. The presence and severity of corneal NV was ascertained based on slit lamp photographs. Potential risk factors for corneal NV were evaluated using the Cox proportional hazards model. RESULTS: The cumulative incidence of corneal NV was 8.7% at 1 year after surgery and 13.2% at 5 years. Mean time interval from surgery to development of corneal NV was 12.8±16.2 months, with 68.9% of cases occurring before complete suture removal. Early discontinuation of topical steroids, older age and ocular allergy were associated with an increased risk of developing corneal NV (respectively, HR=2.625, HR=1.019, HR=3.726, all p<0.05). CONCLUSIONS: The risk of corneal NV is higher in the first year following DALK. Early discontinuation of topical steroids, ocular allergy and older age are significant predictors of corneal NV.

Interface Drainage and Antimicrobial Irrigation Avoid Repeat Keratoplasty for Post-DSAEK Cold Interface Abscess.

PURPOSE: To describe a surgical technique for the diagnosis and treatment of post-Descemet stripping automated endothelial keratoplasty (DSAEK) infectious interface keratitis presenting as a cold abscess. METHODS: This study included 2 eyes of 2 patients that developed delayed-onset interface infections after DSAEK. Through an anterior keratotomy, diagnostic samples for microbial culture and histopathology examination were collected, and empiric antibiotic therapy was delivered directly to the site of the infection at the graft-host interface. RESULTS: In both cases, microbiological examinations confirmed a fungal etiology consistent with Candida. Resolution of infection was achieved, and no signs of posterior segment involvement or recurrence of infection were observed. Both corneas remained clear with final visual acuity of 20/25 and 20/32. No case required additional surgical intervention or repeat keratoplasty after more than 15 months of follow-up. CONCLUSIONS: Interface drainage with antimicrobial irrigation may be considered for the management of post-DSAEK interface infections presenting as a peripheral cold abscess. By avoiding intraocular seeding of infectious pathogens, the anterior approach can achieve clinical resolution of infection, maintain visual function, and preserve the DSAEK graft, thereby obviating the need for a therapeutic keratoplasty.

Pneumatic Dissection for Large-Diameter (9-mm) Deep Anterior Lamellar Keratoplasty in Eyes With Previous Anterior Lamellar Keratoplasty.

PURPOSE: To evaluate the surgical and 3-year clinical outcomes of modified big-bubble 9-mm deep anterior lamellar keratoplasty (DALK) in eyes with previous ALK (ALK). METHODS: In this interventional case series, 21 consecutive eyes with unsatisfactory vision after ALK (superficial ALK n = 9; laser-assisted ALK n = 7; and epikeratophakia n = 5) underwent large-diameter (9-mm) DALK. The surgery involved deep trephination based on the anterior segment optical coherence tomography pachymetry measurement at 9-mm diameter, pneumatic dissection from the base of the trephination and limited stromal clearance of the optical zone (6 mm). Main outcome measures were success rates of pneumatic dissection, best spectacle-corrected visual acuity, and complication rates. RESULTS: Pneumatic dissection with type 1 bubble formation succeeded in 19 (90%) eyes. In the 2 remaining cases, the 6-mm optical zone was cleared by manual dissection. Perforation occurred in one of the latter cases; no procedure was converted to penetrating keratoplasty. One month after complete suture removal, the preoperative mean best spectacle-corrected visual acuity (0.75 ± 0.23 logMAR) improved to 0.09 ± 0.10 logMAR (P < 0.001) and remained stable up to 3 years after surgery. At the final follow-up, refractive astigmatism was ≤4.5 and <6 D in 20 (95%) and 21 (100%) eyes, respectively. Stromal rejection was observed in 2 eyes (10%) and was treated successfully with steroids. CONCLUSIONS: Even in eyes with previous ALK, pneumatic dissection can be achieved through a modified DALK technique with a low risk of complications and excellent visual and refractive outcomes.

Ten-year outcomes of microkeratome-assisted lamellar keratoplasty for keratoconus.

BACKGROUND/AIMS: To report the 10-year outcomes of modified microkeratome-assisted lamellar keratoplasty (LK) for keratoconus. METHODS: In this single-centre interventional case series, 151 consecutive eyes with keratoconus underwent modified microkeratome-assisted LK. Eyes with scars extending beyond the posterior half of the corneal stroma and preoperative thinnest-point pachymetry value of less than 300 µm were excluded. Outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), endothelial cell density, immunological rejection, ectasia recurrence and graft failure rates. RESULTS: Baseline BSCVA (0.89±0.31 logarithm of the minimum angle of resolution (logMAR)) significantly improved to 0.10±0.12 logMAR at year 3 (p<0.001), and remained stable up to 10 years. At 10 years, 94% of eyes saw ≥20/40, 61% saw ≥20/25 and 24% saw ≥20/20 Snellen BSCVA. At final follow-up, RA exceeding 4.5 dioptres was observed in 5 cases (4%). Endothelial cell loss was 25±17% at 1 year with an annual decline of 2% over 10 years. The 10-year cumulative risk for immunological rejection and graft failure was 8.5%, and 2.4%, respectively. No case developed recurrent ectasia at 10 years. CONCLUSION: Modified microkeratome-assisted LK results in stable visual and refractive outcomes with low rates of immunological rejection and graft failure in the absence of recurrence of ectasia for at least 10 years.

Initial High-Dose Prophylaxis and Extended Taper for Mushroom Keratoplasty in Vascularized Herpetic Scars.

PURPOSE: To report the outcomes of initial high-dose and extended taper of antiviral and steroid prophylaxis for the treatment of eyes with high-risk vascularized herpetic corneal scars that underwent 2-piece mushroom keratoplasty (MK). DESIGN: Prospective interventional case series. METHODS: In this single-center study, 52 consecutive eyes with vascularized (≥2 quadrants) herpetic corneal scars underwent 2-piece microkeratome-assisted MK. Initial high-dose and extended taper of combined oral and topical antiviral and steroid prophylaxis was administered. Outcome measures were best spectacle-corrected visual acuity (BSCVA), refractive astigmatism (RA), endothelial cell density, immunologic rejection, herpetic recurrence, and graft failure rates. RESULTS: Excluding patients with vision-impairing comorbidities, baseline BSCVA (1.73 ± 0.67 logMAR) significantly improved annually during the first 2 years (P < .001, P = .016), reaching 0.17 ± 0.18 logMAR at year 2, and remaining stable up to 10 years (P = .662). At 2 years, 86% of eyes saw ≥20/40, 55% saw ≥20/25, and 18% saw ≥20/20 Snellen BSCVA. RA exceeded 4.5 diopters in 7% of cases after wound revision for high-degree astigmatism in 7 cases. Endothelial cell loss was 40.9% at 1 year with an annual decline of 3.1% over 10 years. The 10-year cumulative risk for immunologic rejection, herpetic recurrence, and graft failure was 9.7%, 7.8%, and 7.6%, respectively. CONCLUSIONS: Initial high dose and extended taper of antiviral and steroid prophylaxis for MK in high-risk, vascularized herpetic corneal scars achieves clinical outcomes that remain stable for up to 10 years after surgery with minimal risk of immunologic rejection, herpetic recurrence and graft failure.

Anti-VEGF Treatment in Corneal Diseases.

BACKGROUND: Corneal neovascularization (CN) is a clue feature of different ocular pathological conditions and can lead to corneal edema and opacification with subsequent vision loss. Vascular endothelial growth factor (VEGF), which plays a key role in new vessels formation, proliferation and migration, was found to be up-regulated in these conditions. Nowadays, it is possible to downregulate the angiogenic process by using anti-VEGF agents administered by different routes. OBJECTIVE: To evaluate the efficacy, safety and possible future directions of anti-VEGF agents used for the treatment of CNV owing to different aetiologies. METHODS: A computerized search of articles dealing with the topic of anti-VEGF therapy in CN was conducted in PubMed, Scopus and Medline electronic databases. The following key phrases were used: anti-VEGF agents, corneal neovascularization, bevacizumab, ranibizumab, vascular endothelial growth factor, angiogenesis. RESULTS: The use of anti-VEGF therapy in the treatment of CN reduced pathological vessel density without causing significant side effects. Various administration routes such as topical, subconjunctival and intrastromal ones are available, and the choice depends on patient and disease characteristics. Much more effectiveness is achieved in case of early administration before mature and wellestablished vessels take place. A combined approach between various drugs including anti-VEGF agents should be adopted in those cases at higher risk of neovascularization recurrence such as chronic long-standing diseases where ischemic and inflammatory stimuli are not definitively reversed. CONCLUSION: The efficacy and safety of anti-VEGF agents support their adoption into the daily clinical practice for the management of CN.

Sutureless superficial anterior lamellar keratoplasty for recurrent corneal haze after repeat excimer laser surface ablation.

BACKGROUND/AIMS: To evaluate the 5-year outcomes of sutureless superficial anterior lamellar keratoplasty (SALK) in the treatment of surface ablation-related corneal haze recurring after phototherapeutic keratectomy (PTK). METHODS: Prospective interventional study at a tertiary referral centre in Forli, Italy. Ten consecutive eyes with corneal haze following photorefractive keratectomy, recurring after treatment with PTK with or without mitomycin C, undergoing sutureless SALK. Sutureless SALK was performed using a microkeratome in donor and recipient. MAIN OUTCOME MEASURES: best spectacle-corrected visual acuity (BSCVA), surgically induced astigmatism (SIA), rate of recurrence and complications. RESULTS: There were no intraoperative complications and there was no recurrence of haze in any eye postoperatively. BSCVA showed significant improvement at all postoperative time points. Mean preoperative visual acuity improved from 0.46 logMAR units (SD=0.12) to 0.12 (SD=0.12, p=0.0001) at 5 years. At 6 months, SIA was 2.50±1.04 with no further significant change at 5 years (2.53±1.39, p=0.95). There was no significant change in mean spherical equivalent and no significant difference between preoperative and postoperative astigmatism vector values at 5 years. CONCLUSIONS: Sutureless SALK provides a useful treatment option in patients with recurrent haze after excimer laser treatment. It can eliminate haze recurrence for at least a period of 5 years and can improve BSCVA, although there may be significant SIA.

In Vivo and Ex Vivo Comprehensive Evaluation of Corneal Reinnervation in Eyes Neurotized With Contralateral Supratrochlear and Supraorbital Nerves.

PURPOSE: To use an automated morphometric analysis system of in vivo confocal microscopy (IVCM) images for evaluating reinnervation occurring at the subbasal nerve plexus (SNP) after direct corneal neurotization (DCN) and to further report neurophysiological and histopathological findings. METHODS: Prospective interventional case series including 3 eyes with neurotrophic keratitis that underwent DCN. Deep anterior lamellar keratoplasty was performed 18 months after DCN in patient 1. The following evaluations were performed before and at 3, 6, and 12 months after DCN: clinical evolution of keratitis; corneal sensitivity; IVCM images of the SNP analyzed with "ACCMetrics;" neurophysiological study of corneal reflex. Protein gene product 9.5 immunofluorescence staining assay and transmission electron microscopy were conducted on the neurotized button excised during deep anterior lamellar keratoplasty. RESULTS: Complete healing was obtained in all patients by 3 months postoperatively. Corneal sensitivity was absent preoperatively in all eyes and improved after surgery, reaching an average value of 30 mm 1 year postoperatively. The corneal SNP was not visible at IVCM in any of the cases preoperatively and became visible by 3 months postoperatively, showing IVCM metrics comparable to normal contralateral eyes at 1 year. In all cases, neurophysiological evaluation showed a partial recovery of the electrical activity of the cornea. In patient 1, protein gene product (PGP) 9.5 staining of neurotized cornea showed nerve fascicles at the SNP, whereas transmission electron microscopy showed amyelinic nerve axons and nerve endings. CONCLUSIONS: The corneal SNP exhibited IVCM metrics comparable to the normal contralateral eye 1 year after DCN. Ex vivo histopathological assessment of neurotized corneas confirmed the presence of nerves with normal ultrastructure.

Peripheral Intrastromal Hydration Facilitates Safe, Deep Trephination in Corneas of Irregular Thickness.

PURPOSE: To evaluate the feasibility of regularizing the peripheral corneal thickness before deep trephination in highly irregular corneas undergoing deep anterior lamellar keratoplasty (DALK) by means of intrastromal hydration with saline. METHODS: This is an interventional case series including all eyes with irregular peripheral corneal thickness undergoing DALK for any indication between January 1, 2016, and January 1, 2017, at a single tertiary center in Forli, Italy. Before trephination, 1 mL of normal saline was injected intrastromally into each clock hour of peripheral thinning (determined using preoperative pachymetry) using a 30-gauge needle. A deep trephination of 400 to 450 µm was then performed, and DALK was completed as per our previously described technique. Primary outcome measures were perforation during trephination and intraoperative complications, with secondary outcomes of best corrected visual acuity and refraction. RESULTS: Peripheral intrastromal hydration was performed in 61 eyes of 61 patients. Intrastromal hydration ensured a safe trephination without perforation into the anterior chamber (AC) in 59 of 61 eyes. In the 2 cases in which perforation occurred, the perforation site was sutured with a full-thickness suture and the surgery was completed successfully. No cases required conversion to penetrating keratoplasty. Intrastromal injection of 1 mL of normal saline resulted in an increase in corneal thickness of 31%. After surgery, double AC was observed in 3 cases (4.9%), with all cases being managed successfully by air injection into the AC. CONCLUSIONS: Zonal peripheral intrastromal hydration is a feasible technique to enable safe, deep trephination even in corneas of highly irregular thickness.

Evaluation of the risk factors associated with conversion of intended deep anterior lamellar keratoplasty to penetrating keratoplasty.

BACKGROUND/AIMS: To identify and evaluate risk factors associated with the need to convert intended deep anterior lamellar keratoplasty (DALK) to penetrating keratoplasty (PK). METHODS: Retrospective institutional cohort study including all consecutive eyes undergoing intended DALK between May 2015 and October 2018 at 'Villa Igea' Hospital (Forli, Italy). The indications for surgery were categorised as (1) keratoconus without scarring; (2) keratoconus with scarring; (3) non-keratoconus without scarring; and (4) non-keratoconus with scarring. Multivariate binary logistic regression analysis was performed, introducing, as independent variables, those that reached a significance level of less than 0.05 in univariate analysis. The main outcome measure was whether or not conversion to a PK occurred. RESULTS: 705 eyes were included, with conversion to PK occurring in 16.2% (n=114) of cases. The factors that remained significant in multivariate analysis were corneal scarring (OR=3.52, p<0.001), manual dissection (OR=42.66, p<0.001), type 2 bubble (OR=90.65, p<0.001) and surgeon inexperience (OR=10.86, p<0.001). A receiver operating characteristic (ROC) curve based on the factors significant in the multivariate binary logistic regression analysis achieved a sensitivity of 89.5% (95% CI 82.3% to 94.4%) and a specificity of 80.2% (95% CI 76.8% to 83.3%) with an area under the ROC curve of 0.91 (95% CI 0.88 to 0.93) (p<0.001) CONCLUSION: Occurrence of a type 2 bubble, the need for manual dissection, the presence of scarring and surgeon inexperience are independent risk factors for the need to convert intended DALK to PK. Correct identification and management of the type of bubble achieved during pneumatic dissection is instrumental in minimising the rate of conversion to PK.

Factors Predictive of Double Anterior Chamber Formation Following Deep Anterior Lamellar Keratoplasty.

PURPOSE: To identify risk factors predictive of postoperative double anterior chamber formation after deep anterior lamellar keratoplasty (DALK). DESIGN: Retrospective institutional cohort study. METHODS: The study group included all consecutive eyes undergoing primary DALK between May 2015 and October 2018 at Villa Igea private hospital (Forli, Italy). The indications for surgery were categorized as (1) keratoconus without scarring; (2) keratoconus with scarring; (3) non-keratoconus without scarring; and (4) non-keratoconus with scarring. Multivariate binary logistic regression analysis was performed, introducing, as independent variables, those that reached a significance level of less than .05 in univariate analysis. The main outcome measure was whether or not postoperative double anterior chamber (AC) occurred. RESULTS: A total of 591 eyes of 591 patients were included. The main indication for DALK was keratoconus (67.2%, n = 397), and pneumatic dissection was achieved in 72.9% (n = 431) of patients. Postoperative double AC was observed in 8.1% (n = 48) of cases. Age, intraoperative central DM perforation, type 2 bubble formation, and presence of scar in keratoconic and nonkeratoconic corneas were all associated with an increased risk of postoperative double AC formation in the univariate analysis. Manual dissection was not associated with double AC formation. The factors that remained significant in multivariate analysis were keratoconus with scarring (odds ratio [OR] = 3.56, P = .02), non-keratoconus with scarring (OR = 5.09, P = .002), intraoperative central perforation (OR = 6.09, P = .03), and type 2 bubble formation (OR = 14.17, P < .001). CONCLUSIONS: Scarred corneas of both normal and abnormal shape are independent risk factors for double AC formation following DALK, along with intraoperative perforation and the occurrence of a type 2 bubble.

Outcomes of a Modified Technique for Successful Pneumatic Dissection in Pediatric Eyes With Corneal Scars.

PURPOSE: To report the outcomes of a modified deep anterior lamellar keratoplasty (DALK) procedure for the treatment of scarred corneas in otherwise healthy pediatric eyes. METHODS: All pediatric eyes undergoing DALK by the same surgeon (M.B.) between July 2013 and June 2017 were enrolled. The standard DALK procedure was modified by including a large (9 mm) and deep (150 µm from the thinnest pachymetric measurement) trephination, a minimal cannula advancement from the base of the trephination, and a clearing of a central 6 mm optical zone. The success rates of pneumatic dissection, visual and refractive outcomes, and complications were reported. A complete ophthalmologic examination was performed preoperatively and a few days after suture removal (6-months post-DALK) for all patients as well as 12, 24, and 36 months postoperatively for available patients. RESULTS: Fourteen eyes of 13 patients with various indications were included in this study. The mean age at the time of surgery was 11.7 ± 2.5 years. Pneumatic dissection succeeded in all but one case (13/14 eyes = 92.8%), which was completed by hand dissection. All sutures were removed within 6 months of surgery. With a minimum postoperative follow-up of 6 months, best spectacle-corrected visual acuity improved from ≤20/50 to ≥20/40 in all but one eye, which was known to be amblyopic. CONCLUSIONS: Despite impaired corneal transparency and increased tissue consistency, a modified DALK technique allows successful pneumatic dissection in an extremely high percentage of scarred pediatric eyes. Visual results compare favorably with those obtained in children after penetrating keratoplasty, while vision threatening complications are minimized.

Immunologic Stromal Rejection After Deep Anterior Lamellar Keratoplasty With Grafts of a Larger Size (9 mm) for Various Stromal Diseases.

PURPOSE: To evaluate the rate and outcomes of immunologic stromal rejection occurring after large deep anterior lamellar keratoplasty (DALK) and the effect of the underlying disease on the cumulative probability of rejection. METHODS: This was a retrospective chart review of all eyes that underwent a 9-mm DALK at Ospedali Privati Forlì (Forlì, Italy). On the basis of preoperative diagnosis, eyes were assigned to group 1: keratoconus, group 2: stromal disease with a low risk for rejection, or group 3: stromal disease with a high risk for rejection. The cumulative probability of experiencing a rejection episode over time was assessed by Kaplan-Meier analysis and was compared among the 3 groups using the log-rank test. Values of corrected distance visual acuity, central corneal thickness, and endothelial cell density before and 6 months after rejection were compared. RESULTS: Twenty of 377 eyes (5.3%) experienced an episode of stromal rejection [17/265 (6.4%) in group 1, 2/71 (2.8%) in group 2, and 1/41 (2.4%) in group 3]. The mean time interval between DALK and the rejection onset was 11.8 months (range 1-24). The cumulative probability of rejection episodes did not differ significantly among the 3 groups. All episodes resolved within 6 months after the onset, with no significant differences between prerejection and 6-month postrejection values of corrected distance visual acuity, central corneal thickness, and endothelial cell density. CONCLUSIONS: The rate of immunologic stromal rejection after large 9-mm DALK is within the range reported in the literature for conventional DALK, regardless of the indication for surgery.

Results of viscobubble deep anterior lamellar keratoplasty after failure of pneumatic dissection.

AIM: To report the outcomes of bubble formation obtained by means of intrastromal injection of ophthalmic viscoelastic device (OVD) after failure of pneumatic dissection for deep anterior lamellar keratoplasty (DALK). METHODS: DALK was performed in 140 keratoconic eyes of 130 patients by injecting air and OVD only secondarily, after pneumatic dissection had failed; the bubble formation rates after air and OVD injection were recorded; complications, best spectacle-corrected visual acuity (BSCVA) and corneal tomographic parameters were evaluated 3 months, 6 months and 12 months postoperatively, as well as after complete suture removal. RESULTS: Air injection created a big bubble in 106/140 eyes (75.71%); OVD injection was not attempted in 4 eyes (perforation during cannula insertion n=2; air bubble burst n=2) and created a big bubble in 28 of the remaining 30 eyes (93.33%, 20% of the total). Manual dissection was required in 2/30 eyes (6.66%, 1.42% of the total) after failed OVD-assisted dissection.Deep folds, interface opacity and reduced BSCVA were noted in both eyes after failed OVD-assisted dissection. BSCVA was statistically better after pneumatic-assisted than after OVD-assisted dissection (P 0.01) only up to 3 months postoperatively; no statistically significant differences were recorded between the two techniques at later examinations. CONCLUSION: Intrastromal injection of OVD after failed pneumatic dissection increases considerably the success rate of bubble formation (from 75.71% to 95.71% in our series); however, when bubble formation fails, infiltration of OVD into the residual stroma makes manual dissection particularly challenging and causes severe interface haze resulting in poor visual outcomes.

Corneal Epithelial Stem Cells Repopulate the Donor Area within 1 Year from Limbus Removal for Limbal Autograft.

PURPOSE: To determine whether limbal epithelial stem cells (LESCs) repopulate the site harvested for limbal autograft transplantation (LAT), the expression of LESCs markers was evaluated in bioptic specimens obtained from the donor area 12 months or more after surgery. DESIGN: Interventional case series. PARTICIPANTS: Patients who underwent LAT for unilateral acquired limbal stem cell deficiency after chemical burn. METHODS: Corneal limbal explants were obtained from 2 sites, the harvested area and the untouched control area, in the donor eyes of 6 patients who previously underwent LAT for unilateral acquired limbal stem cell deficiency after chemical burn. Limbal epithelial stem cells were isolated, and cellular, immunohistochemistry, and histologic parameters were assessed to compare differences between LESCs isolated from harvested or control sites. MAIN OUTCOME MEASURES: Presence of LESCs 1 year or more after LAT. RESULTS: Specific markers (p63, Ki67, K12), percentage of LESCs, cell doubling, and number of passages in culture did not differ significantly between harvested and control sites. However, the distinctive structure of the palisades of Vogt was found only in 2 of 6 harvested sites. CONCLUSIONS: Limbal epithelial stem cells repopulate the donor site as early as 1 year after limbus removal for LAT. Autologous transplantation of conjunctiva and limbus are safe procedures and can be performed in cases that cannot be treated by simple grafting of LESCs cultured ex vivo.

Preloaded donor corneal lenticules in a new validated 3D printed smart storage glide for Descemet stripping automated endothelial keratoplasty.

PURPOSE: To design and validate the efficacy of three-dimensional (3D) printed smart storage glide (SSG) which is capable of preserving and delivering posterior lenticules for Descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: Laboratory investigation (A) was followed by clinical validation (B). Unsuitable corneas for transplantation (n=20) were used for study A. These tissues were cut using a standard microkeratome, punched and loaded into the SSG and preserved for 7 days in transport media. Endothelial cell density (ECD), Trypan blue and Alizarin red staining for endothelial morphology, thickness measurements and glucose uptake, cell apoptosis and immunostaining post preservation were analysed. For study B, clinical grade corneas (n=14) were preloaded in SSG and grafted in patients with indications of Fuchs' dystrophy (n=8), pseudophakic bullous keratopathy (n=3), posterior polymorphous dystrophy (n=2), and previous DSAEK failure (n=1). Standard DSAEK included descemetorhexis under air and bimanual delivery of the tissue under infusion of buffered saline solution through an anterior chamber maintainer placed at the 12 o'clock position. Main outcome measures for study B were less surgical time, best spectacle-corrected visual acuity (BSCVA), speed of visual recovery, and ECD. RESULTS: For study A, an average ECD loss was 2.30±3.21%, thickness increased by 30.80±20.85% and one-third of glucose was utilised during the preservation phase. Alizarin red showed hexagonality of the cells. Cell apoptosis was not observed and expression of ZO-1 was noted on the preserved tissues. In study B, 25% ECD loss was observed after 6 months. BSCVA improved to 20/25 or better within 3 months after DSAEK. Mean surgical time recorded was 21 min. CONCLUSIONS: This paper describes the development, design, laboratory and clinical validation of a 3D printed SSG which helps to store and deliver posterior lenticules, therefore allowing transportation of quality-controlled precut tissues.