Oral Mucosal Epithelial Transplantation and Limbal-Rigid Contact Lens: A Therapeutic Modality for the Treatment of Severe Ocular Surface Disorders

Strategic combination of cultivated oral mucosal epithelial transplantation and postoperative limbal-rigid contact lens-wear for end-stage ocular surface disease: a retrospective cohort study

PURPOSE

To provide the long-term outcome of patients with end-stage severe ocular surface disease (OSD) consecutively treated with cultivated oral mucosal epithelial transplantation (COMET) followed by limbal-rigid contact lens (CL)-wear therapy.

DESIGN

Retrospective cohort.

METHODS

In 23 eyes of 18 patients with severe OSD who underwent COMET surgery between 2002 and 2019 and who were followed with limbal-rigid CL-wear therapy for at least 1 year postoperative, patient demographics, best-corrected visual acuity (BCVA, logMAR), Ocular Surface Grading Scores (OSGS), surgical indication and adverse events were reviewed. Primary and secondary outcomes were BCVA and OSGS changes at baseline and final examination, respectively.

RESULTS

This study involved 16 patients with Stevens-Johnson syndrome and 2 patients with mucous membrane pemphigoid (mean age: 59±15 years). The indications for COMET were as follows: corneal reconstruction for vision improvement (10 eyes (43.5%)), corneal reconstruction for persistent epithelial defect (4 eyes (17.4%)) and conjunctival (fornix) reconstruction for symblepharon release (9 eyes (39.1%)). The mean duration of CL-wear postsurgery was 6.4±3.9 years (range: 1.4 to 13.3 years). The mean BCVA at baseline and at final follow-up was logMAR 1.9±0.5 and 1.3±0.7, respectively (p<0.05). Compared with those at baseline, the OSGSs for symblepharon and upper and lower fornix shortening showed significant improvement at each follow-up time point post treatment initiation. No serious intraoperative or postoperative adverse events were observed.

CONCLUSION

In patients afflicted with severe OSD, COMET combined with limbal-rigid CL-wear therapy postsurgery was found effective for vision improvement and ocular surface stabilisation.

Insights into the clinical development of regenerative medical products through a comparison of three cell-based products recently approved for limbal stem cell deficiency

Three regenerative medical products for limbal stem cell deficiency (LSCD), a rare and intractable ocular surface disease, have recently been approved in Japan. To our knowledge, this is the first time multiple stem-cell-based medical products have been approved for the same ocular disease. Development plans and study designs for each product differ, resulting in differences in indications. Since cell-based products have a heterogeneous formulation and often target rare diseases, they require a flexible approach to development. This review article describes the status and prospects of the clinical development of regenerative medical products by summarizing the issues of the three products from the Pharmaceuticals and Medical Devices Agency (PMDA) standpoint. Implementing stem cell-based products is challenging, requiring scientific and flexible review by regulatory authorities. To overcome these issues in the development process, developers and regulatory authorities need to communicate and fully discuss study protocols from the early stage of development.

Limbal-Rigid Contact Lens Wear for the Treatment of Ocular Surface Disorders: A Review

ABSTRACT

Recently, the prescription of large-diameter rigid gas-permeable contact lenses (CLs), also known as "scleral lenses," "corneoscleral lenses," and "limbal-rigid CLs," is on the rise for the treatment of both moderate and severe ocular surface disorders (OSDs). Compared with scleral lenses, the diameter of limbal-rigid CLs is generally smaller, that is, a diameter ranging from 13.0 to 14.0 mm, and they are designed so that the peripheral edge bears on the limbus. The Suncon Kyoto-CS (Sun Contact Lens Co., Ltd.) is a novel limbal-rigid CL design with multistep curves on the peripheral edge for easy tear exchange during blinking that removes debris and prevents lens clouding or fogging, thus allowing patients to enjoy a longer daily duration of CL wear. In severe OSD cases, limbal-rigid CL wear after surgery is a noninvasive therapeutic approach that can neutralize corneal irregularities, decrease dry eye symptoms, prevent the progression or recurrence of symblepharon, and improve the patient's visual acuity and overall quality of life. Thus, surgeries such as amniotic membrane transplantation and cultivated oral mucosal epithelial transplantation, as well as limbal-rigid CL wear, which is noninvasive, are valuable and effective treatment strategies that can now be applied for the management of patients afflicted with severe OSDs.

Current Advancements in Corneal Cell-Based Therapy

Corneal epithelial stem cells (CEpSCs) mostly reside at the limbal area and are responsible for tissue homeostasis throughout life. Once complete CEpSC deficiency occurs, regenerative medicine cell-based therapy using CEpSCs or their alternatives can provide successful clinical outcomes. Due to an improved understanding of CEpSCs and mucosal epithelial stem cells, major advancements have been made over the past few decades in in vivo and ex vivo cell-based ocular surface reconstruction therapies for the treatment of severe ocular surface diseases. New therapeutic concepts and clinical strategies are emerging for the treatment of corneal endothelial dysfunction. For example, unlike corneal epithelial cells, in vivo corneal endothelial cells (CECs) stop proliferating and are arrested in the G1 phase of the cell cycle due to cell-to-cell contact inhibition and exposure to a high concentration of transforming growth factor-beta in the aqueous humor. Thus, the production of CECs with good functionality in culture has consistently been difficult. To solve this problem, Rho-associated protein kinase inhibition has taken center stage, as it not only makes the production of human CECs in culture closely mimic the functional characteristics of in vivo healthy CECs possible but also helps sustain those biological properties. Thus, cultured human CEC injection therapy is now moving to the forefront for the treatment of corneal endothelial failure. Herein, we summarize key historical discoveries in corneal cell-based regenerative medicine and illustrate the concept of corneal cell therapy for the treatment of refractory corneal epithelial and endothelial diseases.

Challenges in the management of bilateral eyelid closure in Stevens-Johnson Syndrome

Purpose

Observations

Conclusion and importance

Japan: Diagnosis and Management of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis With Severe Ocular Complications

In 2005, the “Japanese Research Committee on Severe Cutaneous Adverse Reaction” (J-SCAR) presented the official “Diagnostic Criteria” for SJS/TEN, and the specific ocular findings are included in these very important criteria. In SJS/TEN cases involving ocular disorder, conjunctivitis often occurs prior to the onset of the high fever. In a Japanese survey, ocular involvement was observed in 77% of the cases, and the incidence of ocular sequelae increased depending on the score of the acute ocular severity findings. Pseudo-membrane formation and epithelial defects are considered to be high-risk signs of ocular sequelae. At the chronic stage, limbal stem cell deficiency, visual disturbance, and severe dryness of the ocular surface are the primary disease characteristics. In 2002, we started performing Cultivated Oral Mucosal Epithelial Transplantation (COMET) for the treatment of severe ocular disorders, including SJS/TEN. As an additional treatment method, we developed a new type of rigid contact lens (CL) that is 13 to 14.0-mm in diameter, known as the “Limbal Rigid Contact Lens (Limbal CL).” Our Limbal Rigid CL greatly enhances the postoperative outcome of COMET. The detection rate of ocular surface bacteria is high in SJS/TEN cases. Thus, appropriate use of topical antibiotics reduces the risk of ocular surface inflammation. Moreover, rebamipide is an ophthalmic solution for dry eye that was developed in Japan, and it also has the effect of suppressing ocular surface inflammation. From disease onset until the chronic stage, the control of inflammation and stem cell loss is key to successfully treating eyes afflicted with SJS/TEN.