Limbal Autograft Stem Cell Transplantation: More Than 20-Year Follow-up

Abstract

Limbal stem cell deficiency (LSCD) is a very challenging situation and difficult to manage. A great works and ideas were conducted over the past 50 years. Numerous surgical techniques were proposed. We are reporting more than a 20-year follow-up of a case of limbal autograft stem cell transplantation due to LSCD secondary to chemical injury.

Introduction

Limbal stem cell deficiency (LSCD) is a challenging condition, which compromises the corneal clarity and integrity which leads to persistent epithelial defects (EDs) and exposure to corneal infection and secondary complication as well as scaring. First report by Barraquer[1] in 1960s addressed the management of LCSD due to chemical injuries through a conjunctivocorneal tissue taken from the other eyes. Several techniques were carried on till 1989 when Kenyon and Tseng[2] were the first to apply limbal autograft transplantation for unilateral LSCD. We hereby report a novel technique in managing LSCD and presenting autograft LSC transplantation for a patient with chemical injury for more than 20-year follow-up.

Case Report

A 7-year-old male not known to have any medical illness, referred to the King Khalid Eye Specialist Hospital in December 1999, as a case of postchemical injury to the left eye 20 days before the presentation. Ophthalmic examination showed visual acuity of 20/20 right eye and 20/300 left eye, intraocular pressure (IOP) of the left eye was 12 mmHg and 18 mmHg for the right eye. Slit-lamp examination of the right eye was within the normal limits. Examination of the left eye shows lids with mild superficial burns, severely injected conjunctiva, superior and inferior symblypharons, total limbal ischemia, total ED with irregularities, and necrotic tissues mainly at the periphery with severe corneal haze and peripheral vascularization. IOP was normal, and +3 cells reaction was noticed in the anterior chamber. Medical management was given, and the patient was admitted for amniotic membrane transplantation (AMT). Six weeks later, the patient presented to our hospital with melted AM, ED, and increase corneal haze and vascularization with visual acuity of hand motion. Medical treatment given to suppress the inflammation and another AMT was done for the second time. Two months later, a limbal autograft stem cell transplantation with AMT using Motowa’s sandwich technique to protect and restore corneal integrity and prevent more adhesion.

Surgical technique

The patient was prepped in the usual sterile technique.

Right eye

a LSC was taken from two areas (superior and inferior) [Figure 1]; the dissection was started from the corneal side anteriorly toward the conjunctiva posteriorly with the involvement of some conjunctival tissues. The LSC was 3 mm size in each. The orientation of the corneal side was marked with 8/0 vicryl suture and 10/0 nylon. Both of them placed in a balanced salt solution. Then, both areas were covered with AMT and sutured with 10/0 nylon to the episclera. Conjunctiva was closed over the AM with 8/0 vicryl suture.

Figure 1.

Right eye from which the limbal stem cells were taken from

Left eye

Three hundred and sixty periotomy was done with good hemostatsis and careful dissection of conjunctiva since it was fragile and necrotic and excision of scared, and necrotic tissue, the with release of all symblepharon. The application of mitomycin C 0.02% for 30 s in the affected scarred conjunctiva a way from episclera. Then, a large layer of AM was placed over the patient cornea. AMT stroma was facing the patient cornea, which was covering the whole limbus and episclera that was fixed to the episclera behind the limbus using 10/0 nylon suture. The two stem cell tissues were brought to the limbal area superiorly and inferiorlyand fixed using 10/0 nylon with the careful orientation of the stem cell to keep the corneal side anterior and the conjunctival side posterior. A second layer of AM was used and placed over the whole corneal limbus covering also the implanted stem cell and episclera as a sandwiched and fixed to episclera using 10/0 nylon. Symblepharon ring was placed and fixed to nasal and temporal limbal area using 8/0 vicryl suture, then mega contact lens was applied, and maxitrol eye drops were installed.

Upon follow-ups, the eye was quite with no episodes of EDs, and lamellar keratoplasty was planned to restore his vision and prevent amblyopia, but the patient disappeared and showed up 2 years later. The diagnosis of amblyopia was established at that time, and the benefit of keratoplasty was doubted. The patient was advised not to proceed with the surgery, since he has difficulty to keep up with regular follow-up, being living outside the country.

Last follow-up in March 2017 [Figure 2a], the vision in the left eye was hand motion (deeply amblyopic) with full extraocular movement and minimal symblepharon [Figure 2b] with accepted looking eye for the cosmetic purposes [Figure 2c].

Figure 2.

Left eye follow up after 1 year with completely healed ocular surface with minimal vascularization and symblepharon as well as deep amblyopia (a). Full ocular motility without restriction and with good closure of the lids (b) and intact corneal surface with vascularization (c)

Discussion

LSC works as a barrier against conjunctival epithelium not to invade the cornea and helping the corneal epithelium to repopulate itself. Once the number of LSC decreases or the function ability decreased or both, the LSCD will occur and the conjunctiva epithelium will invade the cornea causing conjunctivalization.[3] Conjunctival epithelium has a very loose cellular interconnection,[4] lacking the hemidesmosomal attachment at the base and unable to secret antianiogenic factors.[5] These weak points are the factors behind the issue of conjunctivalization of the cornea. LSCD exists due to various reasons either congenital or acquired-like chemical burns. LSCD is a very difficult condition to manage, especially if it is bilateral. The challenges rely on many factors including difficulties in maintaining stem cell viability, which sometimes need multiple medications for a very long period of time, and sometimes, the need for repeated surgeries with the risk of general anaesthesia, especially in the pediatric population. Many techniques were proposed over the past 50 years.[6] Conjunctival-corneal autograft in 1964 and keratoepithelioplasty from cadaveric donors were used in 1984, limbal autograft in 1989, keratolimbal allograft from cadaver corneas also in 1994, and living-related conjunctival limbal alloraft from a living relative were used. Since 1995, the work on ex vivo expansion of corneal LSC technique were performed.[7] The advancements in those techniques were carried out after the great work done to understand and localize the stem cell area between 1970s and 1980s. Before proceeding to any intervention, it is wise to assess the ocular surface stability, presence or absence of inflammation, extent of LSCD, and to select the proper timing. In 2013 Ang et al.,[8] proposed a preoperative staging system based on the status of LSC and conjunctiva. First, they categorized according to the extent of LSCD; <50% is Stage I and more than 50% is Stage II. Second, the patient is categorized based on the status of the conjunctiva; normal conjunctiva “a,” abnormal conjunctiva due to previous inflammation “b,” and active conjunctival inflammation “c.” Based on that, Stage Ia carries the best and Stage IIc carries the worst and poorest prognosis. Our patient lies under Stage IIc, and we found the sandwich technique as prescribed in the surgical technique part very helpful and promising. Hence, in very advanced cases or cases not responding to medical treatment and AMT alone, we recommend this technique to restore the globe integrity and suppress the inflammation and prevent facial deformity, especially in children if complication happens and the globe was contracted due to adhesion or evaciration.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.