Observation of topical tacrolimus on high-risk penetrating keratoplasty patients: a randomized clinical trial study

Topical tacrolimus for high-risk corneal transplantation: a randomized, clinical trial

BACKGROUND

The prevalence of rejection is 10-30% in penetrating keratoplasty (PKP) case, and the rate is higher in cases of high-risk patients. Although using topical corticosteroids is a standard method for management the rejection of post-PKP patients, it may not be sufficiently potent in high-risk patients. Topical administration of tacrolimus (TAC) may be effective in suppression rejection after corneal transplantation. This study aimed to investigate the efficacy and safety of topical TAC in high-risk PKP patients in Japan.

METHODS

This study was a single centre, single-blinded, randomized controlled trial. Patients with a history of PKP, graft rejection, atopic dermatitis, or deep corneal neovascularisation who underwent PKP were enrolled. They were randomly assigned to receive 0.1% TAC ophthalmic suspension or artificial tear (AT) up to week 52 after surgery. All participants received 0.1% betamethasone up to week 13 after surgery then they received 0.1% fluorometholone up to week 52. The incidence of immunological rejection during the observation period was the main outcome measure in this study.

RESULTS

Thirty patients were enrolled in this study, and 12 eyes in the TAC group and 13 eyes in the AT group completed the study, respectively. Five out of 30 patients discontinued participation after providing informed consent. No serious adverse effects were developed in patients who received 0.1% TAC ophthalmic suspension. No rejection episodes occurred in the TAC group, while one eye in the AT group had rejection. Graft clarity, best spectacle-corrected visual acuity, intraocular pressure, and corneal endothelial cell density were not significantly different between the TAC and AT groups.

CONCLUSION

Our results demonstrated that good tolerability of 0.1% TAC ophthalmic suspension. However, we failed to demonstrate its efficacy in preventing immunological rejection in high-risk patients undergoing PKP.

TRIAL REGISTRATION

This study was first registered in the University Hospital Medical Information Network (UMIN000029669, Date of registration: November 1, 2017). With the enforcement of the Clinical Trial Act in Japan, the study re-registered in the Japan Registry of Clinical Trials (jRCTs031180342, Date of registration: March 18, 2019).

Nanoparticle-hydrogel composite as dual-drug delivery system for the potential application of corneal graft rejection

Immune rejection remains the major cause of corneal graft failure. Immunosuppressants (such as rapamycin; RAPA) adjunctive to antibiotics (such as levofloxacin hydrochloride; Lev) are a clinical mainstay after corneal grafts but suffer from poor ocular bioavailability associated with severe side effects. In this study, we fabricated a Lev@RAPA micelle loaded cationic peptide-based hydrogel (NapFFKK) as a dual-drug delivery system by integrating RAPA micelles with Lev into a cationic NapFFKK hydrogel to potentially reduced the risk of corneal graft rejection. The properties of the resulting hydrogels were characterized using transmission electronmicroscopy and rheometer. Lev@RAPA micelles loaded NapFFKK hydrogel provided sustained in vitro drug release without compromising their inherent pharmacological activities. Topical instillation of Lev@RAPA micelles loaded NapFFKK hydrogel resulted in the great ocular tolerance and extended precorneal retention over 60min, thus significantly enhancing the ocular bioavailability of both Lev and RAPA. Overall, such dual-drug delivery system might be a promising formulation for the suppression of corneal graft failure.

Management of corneal neovascularization: Current and emerging therapeutic approaches

Corneal neovascularization (CoNV) is a sight-threatening condition affecting an estimated 1.4 million people per year, and the incidence is expected to rise. It is a complication of corneal pathological diseases such as infective keratitis, chemical burn, corneal limbal stem cell deficiency, mechanical trauma, and immunological rejection after keratoplasties. CoNV occurs due to a disequilibrium in proangiogenic and antiangiogenic mediators, involving a complex system of molecular interactions. Treatment of CoNV is challenging, and no therapy thus far has been curative. Anti-inflammatory agents such as corticosteroids are the mainstay of treatment due to their accessibility and well-studied safety profile. However, they have limited effectiveness and are unable to regress more mature neovascularization. With the advent of advanced imaging modalities and an expanding understanding of its pathogenesis, contemporary treatments targeting a wide array of molecular mechanisms and surgical options are gaining traction. This review aims to summarize evidence regarding conventional and emerging therapeutic options for CoNV.

Topical Tacrolimus Compared With Oral Tacrolimus for Postoperative Immunosuppression in Primary Keratolimbal Allograft

PURPOSE

The aim of this study was to compare outcomes between topical tacrolimus and oral tacrolimus as the primary calcineurin inhibitor for postoperative immunosuppression after primary keratolimbal allograft (KLAL) transplantation for limbal stem cell deficiency (LSCD).

METHODS

We performed a retrospective, comparative cohort study at a single tertiary referral center (University of MN) of all patients who underwent primary KLAL between 2014 and 2021. Eyes were grouped into those which received topical tacrolimus as the only calcineurin inhibitor (topical group) and eyes in which patients received oral tacrolimus with or without topical tacrolimus (oral group). Clinical and donor tissue data were obtained and compared between the 2 groups.

RESULTS

In total, 27 eyes of 22 patients (median age 42 years, range 20-79 years) were included, of which 18 eyes were in the oral group and 9 eyes were in the topical group. The mean follow-up time was 33.2 ± 22.6 months. The most frequent etiology of LSCD was alkaline burn (33.3%). At 36 months, graft failure occurred in 6 eyes in the oral group (33.3%) and 2 eyes in the topical group (22.1%) ( P = 0.57). The failure rate in the oral group was 9.1 per 1000 person-months versus 8.4 per 1000 person-months in the topical group ( P = 0.96). The median improvement in BCVA was logMAR -0.975 and logMAR -0.45 for the oral and topical group, respectively ( P = 0.50).

CONCLUSIONS

With careful patient selection, topical tacrolimus may be a viable alternative to oral tacrolimus in KLAL.

Topical tacrolimus in high-risk corneal transplants

PURPOSE

The purpose of this study was to assess the use of topical tacrolimus ointment in preventing rejection in high-risk corneal grafts, when added to the standard immunosuppressive regimen.

METHODS

We conducted an observational, retrospective study using clinical data of high-risk patients subjected to penetrating keratoplasty, who were treated with topical tacrolimus ointment 0.2 mg/g twice a day plus topical dexamethasone 0.1 mg/ml 6 id and compared it with a similar control group treated with topical dexamethasone 0.1 mg/ml 6 id alone. High-risk status was attributed to patients with previous ipsilateral corneal graft failure, two or more quadrants with corneal neovascularization or an infectious or inflammatory corneal disease.

RESULTS

We analysed 53 patients in the trial group versus 53 patients in the control group, with similar age, baseline diagnosis and risk factors, and median follow-up times of 30 and and 24 months, respectively. Survival analysis showed a higher graft survival rate at all follow-up periods for patients treated with topical tacrolimus (p < 0.01). No adverse reactions were reported.

DISCUSSION

This study shows that topical tacrolimus ointment increases the survival rate of the graft if added to the previous topical steroid regimen in high-risk patients.

CONCLUSION

Topical tacrolimus is safe and effective in prolonging graft survival in high-risk patients.

Pharmacological treatment strategies of pterygium: Drugs, biologics, and novel natural products

Pterygium is a fibrovascular tissue growth invading the cornea. Adjunctive treatment post-surgery includes conventional immunosuppressants as well as antiviral drugs. The use of large- and small-molecule antivascular endothelial growth factor (VEGF) agents remains an integral part of pterygium treatment as well as other neovascular conditions of the eye. Naturally occurring polyphenolic compounds have favorable characteristics for treating neovascular and inflammatory eye conditions, including good efficacy, stability, cost-effectiveness, and the versatility of their chemical synthesis. In this review, we discuss pharmacological treatments of pterygium. Natural products, such curcumin, ellagic acid, and chalcones, are reviewed, with emphasis on their potential as future pterygium treatments.

Use of Topical Cyclosporine 0.1% in Therapeutic Penetrating Keratoplasty for Fungal Keratitis

PURPOSE

The efficacy and safety of topical cyclosporine 0.1% in preventing early graft failure after therapeutic penetrating keratoplasty (TPK) in eyes with fungal keratitis were evaluated.

METHODS

This prospective case series included patients with fungal keratitis undergoing TPK from May to December 2019 who were treated with cyclosporine A 0.1% eye drops (tCSA group). We compared the outcome with a historical cohort of patients who were treated conventionally (CT group) with topical prednisolone acetate 1% eye drops started 3 weeks after surgery.

RESULTS

There were 20 patients (male: 13; female: 7) in the tCSA group and 28 patients in the CT group (male: 23; female: 5). The number of clear grafts 3 months postoperatively was 10 (50%) in the tCSA group and 4 (14.3%) in the CT group ( P = 0.011). The mean logarithm of the minimum angle of resolution best-corrected visual acuity was 1.49 ± 0.74 in the tCSA group and 2.10 ± 0.62 in the CT group ( P = 0.003). There were 5 patients (17.9%) with recurrence of the primary fungal infection in the CT group, 4 of whom were using topical prednisolone. There was no recurrence in the tCSA group. A logistic regression analysis revealed higher odds of a clear graft at 3 months postoperatively with topical cyclosporine 0.1% [odds ratio: 14.35 (95% confidence interval, 2.38-86.5), P = 0.004].

CONCLUSIONS

Postoperative treatment with topical cyclosporine 0.1% seems to increase graft survival and postoperative vision with reduced risk of recurrence of primary infection in eyes with fungal keratitis undergoing TPK.

Recommendations for Off-Label Drug Use in Ophthalmology in China: A Clinical Practice Guideline

Off-label drugs use is widespread in ophthalmology due to the delay in drug approvals and package inserts update. It has been found to vary among different medical institutions in China, leading to safety problems since inappropriate use. Guidance is urgently needed regarding how best to use the drugs for unapproved indications and routes of administration. We aimed to develop an evidence-based guideline to guide off-label drugs used in ophthalmology in China. The practice guideline was developed by the Hospital Pharmacy Professional Committee, Chinese Pharmaceutical Association, following the WHO handbook for guideline development. The guideline was initially registered in the International Practice Guidelines Registry Platform (IPGRP-2021CN096). The clinical questions included in the guideline were identified through a three-round Delphi vote. Databases search was performed in PubMed, Embase, the Cochrane Library, ClinicalTrials.gov, Chinese National Knowledge Infrastructure, and WanFang Database from their inception to 31 March 2021. Systematic reviews and meta-analyses for each clinical question were conducted individually to synthesize available scientific evidence. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the quality of evidence and grade the recommendations’ strengths. The multidisciplinary guideline groups were set up, including ophthalmologists, pharmacists, methodology experts, pharmacologists, pharmacoeconomists, and lawyers. The guideline identified 25 clinical questions included. A total of 32 systematic reviews, including 24 conducted by the systematic review group and eight high-relevance published within 2 years, were referred to address these questions. Finally, the guideline presented 32 recommendations addressing 25 clinical questions, involving five strong recommendations and 27 weak recommendations for the treatment of ocular fundus, corneal disease, glaucoma, and endophthalmitis. Current evidence from clinical studies supports the off-label drugs used in ophthalmology. We developed an evidence-based guideline using a rigorous multidisciplinary approach to guide these usages in route clinical practice.

Topical administration of tacrolimus and corticosteroids in tapering doses is effective in preventing immune rejection in high-risk keratoplasty: a 5-year follow-up study

Background

To evaluate the efficacy of the topical administration of immunosuppressants and corticosteroids in tapering doses in the management of patients with high-risk keratoplasty.

Methods

One hundred and six patients treated with topical immunosuppressants (50 eyes in the FK506 group and 56 eyes in the CsA group) and corticosteroid eye drops in tapering doses were enrolled in the study. The rates of rejection episodes, irreversible rejection, graft survival, and related influential factors were evaluated.

Results

The mean follow-up period was 48.1 ± 7.9 months (range, 36–60 months). The rates of rejection episodes and irreversible rejection were 14.0% and 6.00% in the FK506 group and 37.5% and 7.1% in the CsA group, respectively. Kaplan-Meier survival analysis demonstrated a significantly higher graft survival rate in the FK506 group (81.6%±5.3%, 71.1%±6.3%) compared with that in the CsA group (71.1%±6.3%, 57.5%±7.5%) at 3 and 5 years after surgery (P = 0.006). Multivariate logistic regression revealed that preoperative risk score ≥ 3 (P = 0.016) and endothelial immune rejection (P = 0.033) were risk factors associated with graft survival.

Conclusions

Topical administration of tacrolimus and corticosteroids in tapering doses is effective in decreasing the incidence of immune rejection in high-risk keratoplasty. Careful instruction of patients on the reasonable use of topical tacrolimus is critical to avoid immune rejection induced by sudden discontinuation of medication.

Midterm outcomes of penetrating keratoplasty following allogeneic cultivated limbal epithelial transplantation in patients with bilateral limbal stem cell deficiency

AIM

To evaluate the midterm outcomes of penetrating keratoplasty (PK) following allogeneic cultivated limbal epithelial transplantation (CLET) for bilateral total limbal stem cell deficiency (LSCD).

METHODS

Ten patients (10 eyes) with bilateral LSCD were enrolled in this prospective noncomparative case series study. Each participant underwent PK approximately 6mo after a CLET. Topical tacrolimus, topical and systemic steroids, and oral ciclosporin were administered postoperatively. Best-corrected visual acuity (BCVA), intraocular pressure (IOP), ocular surface grading scores (OSS), corneal graft epithelial rehabilitation, persistent epithelial defect (PED), immunological rejection, and graft survival rate were assessed.

RESULTS

The time interval between PK and allogeneic CLET was 6.90±1.29 (6-10)mo. BCVA improved from 2.46±0.32 logMAR preoperatively to 0.77±0.55 logMAR post-PK (P<0.001). Kaplan-Meier analysis of mean graft survival revealed graft survival rates of 100% at 12 and 24mo and 80.0% at 36mo. PEDs appeared in 5 eyes at different periods post-PK, and graft rejection occurred in 4 eyes. The total OSS decreased from 12.4±4.4 before allogeneic CLET to 1.4±1.51 after PK.

CONCLUSION

A sequential therapy design of PK following allogeneic CLET can maintain a stable ocular surface with improved BCVA despite the relatively high graft rejection rate.

Sutured Custom Foldable Silicone Artificial Iris Implantation Combined With Intraocular Lens Implantation and Penetrating Keratoplasty: Safety and Efficacy Outcomes

PURPOSE

To assess safety and efficacy outcomes of sutured custom silicone artificial iris and intraocular lens implantation combined with penetrating keratoplasty (triple procedure).

METHODS

Prospective consecutive surgical case series of patients who underwent the triple procedure between 2010 and 2019 at Stein Eye Institute, UCLA, followed up for 1 year minimum. Safety outcomes were changes from preoperative to last follow-up in corrected distance visual acuity (CDVA), endothelial cell count, intraocular pressure (IOP), and postoperative complications. Efficacy outcomes included changes in subjective glare (none to severe), cosmetic appearance (worse to very much improved), and visual function as assessed by the Visual Function Questionnaire-25 at 1-year follow-up.

RESULTS

Among 82 eyes implanted with an artificial iris, 14 eyes (17.1%) underwent the triple procedure. The median follow-up was 18.1 months (range 12.0-54.9 months). The median CDVA improved from 2.0 log of minimum angle of resolution (logMAR) (range 0.9-2.3 logMAR) to 0.7 logMAR (range 0.2-2.6 logMAR) (P = 0.02). Average endothelial cell count decreased 57.6% (P < 0.01). Six eyes (42.9%) experienced IOP elevations, 13 eyes (92.3%) developed iritis, and 11 eyes (78.6%) underwent secondary surgery. Graft rejection or secondary graft failure occurred in 7 eyes each (50.0%). Cosmesis improved in 12 eyes (85.7%; P < 0.01). The Visual Function Questionnaire-25 score improved from 72 to 77 (P < 0.01). Glare symptoms did not change significantly.

CONCLUSIONS

The triple procedure was effective at improving CDVA, cosmesis, and quality of life; however, it was associated with frequent postoperative complications, of which iritis, IOP elevation, and secondary graft failure were the most common.

Penetrating Keratoplasty in Dogs using Acellular Porcine Corneal Stroma (BioCorneaVet™): A prospective pilot study of five cases

OBJECTIVE

This prospective pilot study was conducted to evaluate the outcome of a commercially available corneal stroma substitute, Acellular Porcine Corneal Stroma (APCS), in dogs undergoing penetrating keratoplasty (PK) to restore corneal integrity after having deep ulcers.

METHOD

Five dogs (1 eye in each dog) underwent a PK using APCS (BioCorneaVet™) as a graft. The surgical procedure and peri- and postoperative treatment were standardized. All cases required a minimum 6 months follow-up. Ease of keratoprosthetic tissue handling, graft survival, anterior chamber stability, corneal opacity, neovascularization and re-epithelialization were noted. Presence of secondary uveitis was investigated.

RESULTS

BioCorneaVet™ was easy to handle and, at all-time points, provided adequate tectonic support. Graft survival was achieved in all 5 cases. A minimum follow-up period of 10 months was available for the five eyes (22 months maximum). Degree and area of corneal graft opacity progressively improved resulting in minimal to moderate loss of transparency in all cases but one, where it was severe. Neovascularization degree was most severe 0.5-1 month after surgery and fully resolved 4-6 months post-surgery. Re-epithelialization was complete in the majority of grafts in 1 month. Secondary uveitis was not detected at any time in 4 of 5 dogs.

CONCLUSION

BioCorneaVet™ seems to be an effective graft for PK in the dog. In this case series, APCS was convenient to handle during surgery and provided excellent tectonic support. The material showed good tissue biocompatibility and resulted in the majority of cases in minimal to moderate graft opacity, that ameliorates with time.

Advances in corneal graft rejection

PURPOSE OF REVIEW

Immune rejection after corneal transplantation is a major risk for graft failure. We aim to summarize recent advances in the understanding and management of graft rejection.

RECENT FINDINGS

Immune rejection remains the leading cause of graft failure in penetrating keratoplasty (PKP). While ABO blood type and sex match between donor and recipient may reduce rejection, human leucocyte antigens class II matching in a randomized study did not reduce the risk of rejection in high-risk PKP. Compared with PKP, deep anterior lamellar keratoplasty, descemet stripping automated endothelial keratoplasty, and descemet membrane endothelial keratoplasty have lower immune rejection rates of 1.7-13%, 5-11.4%, and 1.7-2.8%, respectively, based on long-term (5 years and more) studies. Whether immune rejection is a major risk factor for graft failure in these lamellar keratoplasties is unclear. While there have not been major advances in the systemic management of graft rejection, topical nonsteroid agents such as tacrolimus and anti-vascular endothelial growth factor have shown promise in high-risk cases.

SUMMARY

Immune rejection remains the leading cause of graft failure in PKP. Lamellar keratoplasties have significantly lower rejection rates compared with PKP. The significance of rejection in the failure of lamellar grafts warrants further investigation.

Efficacy of Immunosuppressants in High Rejection Risk Keratoplasty: A Meta-Analysis of Comparative Studies

PURPOSE

To evaluate the prophylactic effects of immunosuppressants in corneal graft rejection after high-risk penetrating keratoplasty.

METHODS

We searched PubMed, Embase, and the Cochrane Library for comparative studies published between 1989 and 2019 that evaluated the efficacy of immunosuppressants for high-risk corneal graft. The primary outcomes were the 1- and 3-year rejection rates. A fixed-effects or random-effects model was used on the basis of the I2 value, and the results were reported as odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Topical tacrolimus (FK506) was more effective than topical cyclosporine A (CsA) at reducing the 1-year graft rejection rate (OR: 0.17; 95% CI, 0.08-0.37, P<0.01). However, the combination of steroid with either topical FK506 (OR: 0.4; 95% CI, 0.16-1.04, P = 0.09) or CsA (OR: 0.74; 95% CI, 0.32-1.71, P= 0.48) did not show significant superiority in preventing immune rejection compared with steroid monotherapy. Mycophenolate mofetil (MMF) was more effective than CsA at reducing the 1-year graft rejection rate (OR: 2.67; 95% CI, 1.50-4.76, P<0.01). However, MMF was not significantly superior to CsA at reducing the 3-year graft rejection rate (OR: 1.21; 95% CI, 0.45-3.25, P = 0.71). For reducing the 1-year rejection rate, MMF (OR: 0.12; 95% CI, 0.03-0.39, P < 0.01) and CsA (OR: 0.28; 95% CI, 0.10-0.76, P = 0.01) were each more effective than the control groups.

CONCLUSIONS

FK506 eye drops, MMF, and systemic CsA were considered to be promising management to prevent rejection in high-risk penetrating keratoplasty in the present study.

Effects of VEGF Inhibitor Conbercept on Corneal Neovascularization Following Penetrating Keratoplasty in Rabbit Model

Purpose

To evaluate the effects of the vascular endothelial growth factor inhibitor conbercept (KH902) on corneal neovascularization and wound healing following penetrating keratoplasty in rabbits.

Methods

Conbercept was administered to New Zealand white rabbits through topical and subconjunctival routes. Corneal neovascularization and wound healing were examined by slit-lamp photography and histological analyses. The expressions of vascular endothelial growth factor inhibitor, α-smooth muscle actin, and keratocan in the corneal grafts were measured by real-time quantitative polymerase chain reaction (RT-qPCR).

Results

The anterior segment photographs demonstrated that corneal neovascularization started in the 2nd week. In the 4th week, histologically, the superficial corneal stroma layer showed disordered arrangement, and there were large numbers of dense inflammatory cells and blood vessels in the stroma layer. Vascular endothelial growth factor in the experimental groups was significantly decreased at all time points compared with the control group (both P = 0.001). Expression of α-smooth muscle actin in corneal grafts demonstrated an increase in time even it was lower in experimental groups, but the difference was not statistically significant (P equaled to 0.507 and 0.723, respectively). There were no significant differences with the expression of keratocan in all groups except that it significantly declined at the 4th week as to the second week in all groups and P values were 0.022, 0.020 and 0.014 in control (C), topical (E1), and subconjunctival (E2) group, respectively.

Conclusion

The study found that conbercept inhibited the formation of corneal neovascularization without affecting keratocan-mediated corneal wound healing and there were no significant differences between topical administration of different doses of conbercept on the rabbit corneal neovascularization after penetrating keratoplasty in this study.

Updates on the Management of Ocular Vasculopathies with VEGF Inhibitor Conbercept

Purpose: To provide a detailed review on the therapeutic efficacy of conbercept for the management of ocular vasculopathies. Methods: A comprehensive literature search of various electronic databases was performed. Results: Ocular vasculopathy is one of the major causes of visual impairment and blindness which includes a range of disorders. Vascular endothelial growth factor (VEGF) regulates angiogenesis, enhances vascular permeability, and drives the formation of neovascularization. Anti-VEGF therapy has been shown to prevent vision loss or potentially improve vision in patients with exudative or neovascular retinal disease. The most recent anti-VEGF drug in China is conbercept. In the USA and Europe, bevacizumab is the most recently approved anti-VEGF agent. Conclusions: Conbercept serves as another anti-VEGF option for patients with neovascular AMD and other retinal vascular disorders. There have not been many clinical trials that study conbercept as compared with other currently available anti-VEGF drugs. There is a need for large-scale, well-designed, randomized clinical trials to ensure its long-term safety and efficacy and to determine if it has any advantages over other anti-VEGF agents.