Background and Objective: Corneal neurotization is a novel surgical technique used to restore corneal sensation in patients with neurotrophic keratopathy. Neurotrophic keratopathy is a disorder characterized by dysfunction of the ophthalmic division of the trigeminal nerve, which provides sensory innervation to the cornea. Without sensation, the cornea is at risk of infection, ulceration, perforation, and ultimately, vision loss. Corneal neurotization has emerged as an innovative technique to reinnervate anesthetized corneas by transferring a healthy donor nerve to the affected eye around the corneoscleral limbus. As the field of corneal neurotization rapidly grows, there is a need to synthesize the existing body of literature on corneal neurotization and identify important areas for further research. In this review, we will discuss neurotrophic keratopathy and its current management strategies, followed by an overview of corneal neurotization techniques, outcomes, surgical considerations, and future directions. Methods: PubMed and Google Scholar searches were conducted to retrieve and analyze relevant original papers and reviews on neurotrophic keratopathy and corneal neurotization up until April 2022.Key Content and Findings: Currently, numerous techniques for corneal neurotization exist, including direct nerve transfers, as well as indirect neurotization via interposition nerve grafts. So far, corneal neurotization has been shown to be highly successful in restoring corneal sensation, improving visual acuity,and improving corneal epithelial health. To date, there have been no significant differences in outcomes between direct versus indirect neurotization techniques, different donor nerves, or autologous versus allogeneic interposition grafts. However, there is some evidence that corneal neurotization procedures may be more successful in pediatric patients.Conclusions: Corneal neurotization shows great promise in treating neurotrophic corneas and represents the first management option to date that addresses the underlying pathophysiological mechanism of neurotrophic keratopathy by restoring corneal sensation. As the use of corneal neurotization continues to broaden, additional studies will become important to compare techniques in a systematic manner, with larger sample sizes, as well as standardized outcome measures and follow-up time.

Background and Objective: Limbal stem cell deficiency (LSCD) is characterized by the insufficiency of limbal stem cells to maintain the corneal epithelium. Severe cases of LSCD may be treated with limbal transplantation from healthy autologous or allogeneic limbal tissue. Multiple cell-based therapies have been studied as alternative treatments to improve success rates and minimize immunosuppressive regimens after allogeneic transplants. In this review, we describe the success rates, and complications of different cell-based therapies for LSCD. We also discuss each therapy’s relative strengths and weaknesses, their history in animal and human studies, and their effectiveness compared to traditional transplants.

Methods: PubMed was searched for publications using the terms LSCD, cell-based therapy, cultivated limbal epithelial transplantation (CLET), cultivated oral mucosal epithelial transplantation (COMET),and mesenchymal stem cells from 1989 to August 2022. Inclusion criteria were English language articles.Exclusion criteria were non-English language articles.

Key Content and Findings: current cell-based therapies for LSCD are CLET and non-limbal epithelial cells. Non-limbal epithelial cell methods include COMET, conjunctival epithelial autografts, and mesenchymal stem/stromal cells (MSCs). Moreover, several alternative potential sources of non-limbal cells have described, including induced pluripotent stem cells (iPSCs), human embryonic stem cells (hESCs),human dental pulp stem cells, hair follicle bulge-derived epithelial stem cells, amniotic membrane epithelial cells, and human umbilical cord lining epithelial cells.

Conclusions: Cell-based therapies are a promising treatment modality for LSCD. While CLET is currently the only approved cell-based therapy and is only approved in the European Union, more novel methods have also been shown to be effective in human or animal studies thus far. Non-limbal epithelial cells such as COMET are also an alternative treatment to allogeneic transplants especially as a surface stabilizing procedure. iPSCs are currently being studied in early phase trials and have the potential to revolutionize the way LSCD is treated. Lastly, cell-based therapies for restoring the limbal niche such as mesenchymal stem cells have also shown promising results in the first human proof-of-concept study. Several potential sources of non-limbal cells are under investigation.

Although amniotic membrane transplantation (AMT) has long been used as an essential surgical technique for ocular surface reconstruction, its role continues to evolve and expand. In the management of numerous ocular surface disorders, ranging from inflammatory to infectious, traumatic to neoplastic, the ability to perform AMT is a valuable addition to the skillset of any ophthalmologist. The purpose of this paper is to provide ophthalmologists with an updated, evidence-based review of the clinical indications for AMT in corneal and conjunctival reconstruction, reviewing its common and even experimental applications known to date. The methods of amniotic membrane preservation, the available commercial amniotic membrane products to date, and future directions for amniotic membrane use, including amniotic membrane extract eye drops (AMEED), are also discussed. It is paramount for ophthalmologists to stay up-to-date on the applications of AMT so as to effectively incorporate this versatile treatment modality into their practice,both in the operating room and in the clinic. By familiarizing the general ophthalmologist with its diverse applications, we hope to motivate general ophthalmologists to incorporate the use of AMT into their clinical practice, or provide guidance on how to recognize when referral to a corneal specialist for amniotic membrane application is prudent.

Background and Objective: Ocular surface disease (OSD) is a common yet often overlooked consideration in the management of patients with glaucoma. Although there have been several review articles summarizing the relationship between glaucoma medications and OSD, there is a relative absence of such articles on the effects of glaucoma surgical treatments. Here, we present a comprehensive review of the literature regarding the relationship of glaucoma management and OSD, with an emphasis on surgical considerations.

Methods: PubMed, Google Scholar, and Cochrane Review searches were performed using the following search terms: ocular surface, dry eye, minimally invasive glaucoma surgeries (MIGS), trabeculectomy,glaucoma medications. The titles and abstracts from those searches were screened for relevance to our review topics. Publications were included if the subjects included glaucoma patients, and if ocular surface outcomes were described. Non-English papers were excluded.
Key Content and Findings: Topical glaucoma medications frequently cause adverse effects on the ocular surface, both through direct action of the medications themselves as well as through toxicity from their associated preservatives. Optimization of the ocular surface may improve medication compliance rates.Traditional surgical treatments for glaucoma, such as trabeculectomy, can exacerbate OSD by disrupting the ocular surface but can also reduce the need for chronic medications. Optimization of ocular surface health is imperative in reducing trabeculectomy complication rates, while also potentially reducing the need for trabeculectomy in patients that are able to achieve intraocular pressure control through improved drop tolerability. The introduction of MIGS represents a promising alternative to existing therapies and has been shown to alleviate the overall medication burden. It would be reasonable to assume that decreasing the medication burden could reduce OSD prevalence and severity. However, more research is needed to directly assess the extent of improvement seen after MIGS.

Conclusions: A comprehensive understanding of the importance of OSD in medical and surgical management of glaucoma is essential in optimizing patient care and improving outcomes.

Background and Objective: Limbal stem cell deficiency (LSCD) describes the clinical condition when there is dysfunction of the corneal epithelial stem/progenitor cells and the inability to sustain the normal homeostasis of the corneal epithelium. The limbal stem cells are located in a specialized area of the eye called the palisades of Vogt (POV). There have been significant advances in the diagnosis and management of LSCD over the past decade and this review focuses on the pathophysiology of LSCD, its clinical manifestations, diagnosis, and causes.

Methods: Papers regarding LSCD were searched using PubMed to identify the current state of diagnosis and causes of LSCD published through to June 2022. 
Key Content and Findings: LSCD is clinically demonstrated by a whorl-epitheliopathy, loss of the POV, and conjunctivalization of the cornea. The diagnosis of this condition is based on clinical examination and aided by the use of impression cytology, in vivo confocal microscopy, and anterior segment optical coherence tomography (asOCT). There are many causes of LSCD, but those which are most common include chemical injuries, aniridia, contact lens wear, and Stevens-Johnson syndrome (SJS).

Conclusions: While this condition is most commonly encountered by corneal specialists, it is important that other ophthalmologists recognize the possibility of LSCD as it may arise in other co-morbid eye conditions.

Conjunctival flaps have previously proven to be effective in preserving the globe for individuals with severe ocular surface disease. Infectious keratitis, neurotrophic keratitis, nontraumatic corneal melts, descemetoceles, perforations, and corneal burns are all indications for this procedure. The flaps promote nutrition, metabolism, structure, and vascularity, as well as reduce pain, irritation, inflammation, and infection. Furthermore, patients avoid the emotional and psychological repercussions of enucleation or evisceration, while requiring fewer postoperative medications and office visits. Currently, fewer flaps are performed due to the emergence of additional therapeutic techniques, such as serum tears, bandage lenses, corneal grafting, Oxervate, amniotic membrane, and umbilical cord grafting. However, despite newer conservative medical methods, conjunctival flaps have been demonstrated to be useful and advantageous. Moreover, future technologies and approaches for globe preservation and sight restoration after prior conjunctival flaps are anticipated. Herein, we review the history, advantages, and disadvantages of various surgical techniques: Gundersen’s bipedicle flap, partial limbal advancement flap, selective pedunculated conjunctival flap with or without Tenon’s capsule, and Mekonnen’s modified inferior palpebral-bulbar conjunctival flap. The surgical pearls and recommendations offered by the innovators are also reviewed, including restrictions and potential complications. Procedures for visual rehabilitation in selective cases after conjunctival flap are reviewed as well.

Background: To explore the safety and effectiveness of Sclera patch grafts in the management of scleral defects.

Methods: This is a retrospective uncontrolled study. Medical records were retrospectively reviewed for 8 eyes of 8 patients with sclera patch grafts. Two patients had necrotizing scleritis, 2 patients had scleral melting/perforation secondary to thermal burns, 4 patients had scleral staphyloma secondary to surgery. Sclera was reconstructed with allogenic sclera patch grafts, 6 in 8 patients combined autologous conjunctival pedicle flap, 1 patient combined partial medial rectus translocation, 1 patient combined autologous pedicle tenon graft, simultaneously. Treatment outcomes were evaluated using structural integrity, best corrected visual acuity (BCVA), scleritis remission, sclera rejection and melt, and ocular symptoms.

Results: Eight patients were reviewed. In all of these cases, satisfactory anatomic and functional outcomes were achieved. In the at least half a year follow-up, the BCVA of all the eight patients were no worse than that of preoperative. No eye pain, foreign body sensation and other discomforts showed in all the patients, except one woman, who showed sclera rejection and melt 1 month postoperative. In addition, one patient showed high intraocular pressure (28 mmHg), which can be controlled by a kind of medicine.

Conclusions: In this series, sclera patch grafts is an effective method for management scleral defects in the at least half a year following-up. Attention should be paid to the sclera patch rejection and melt post operatively.