Eyeworld

92 | EYEWORLD | SPRING 2024 C ORNEA OP-ED by Edward Holland, MD, and Albert Cheung, MD About the authors Albert Cheung, MD Virginia Eye Consultants Norfolk, Virginia Edward Holland, MD Professor of Ophthalmology University of Cincinnati Cincinnati, Ohio References 1. Holland EJ. Epithelial transplan- tation for the management of severe ocular surface disease. Trans Am Ophthalmol Soc. 1996;94:677–743. 2. Croasdale CR, et al. Keratolim- bal allograft: recommendations for tissue procurement and preparation by eye banks, and standard surgical technique. Cornea. 1999;18:52–58. 3. Holland EJ, et al. Systemic im- munosuppression in ocular sur- face stem cell transplantation: results of a 10-year experience. Cornea. 2012;31:655–661. 4. Movahedan A, et al. Long- term outcomes of ocular surface stem cell allograft transplan- tation. Am J Ophthalmol. 2017;184:97–107. 5. Cheung AY, et al. Cincinnati protocol for preoperative screening and donor selec- tion for ocular surface stem cell transplantation. Cornea. 2018;37:1192–1197. 6. Cheung AY, et al. Clinical outcomes of allogeneic ocular surface stem cell transplantation in pediatric patients. Cornea. 2021;40:54–60. 7. Orphanet. Limbal stem cell deficiency. www.orpha.net. Accessed October 15, 2022. 8. Cheung AY, et al. Limbal stem cell deficiency: demographics and clinical characteristics of a large retrospective series at a single tertiary referral center. Cornea. 2021;40:1525–1531. rior stromal scarring. 8 Ultimately, this strategy will be unsuccessful, as it fails to address the underlying problem of limbal stem cell failure. Penetrating keratoplasty (PK) is the most common erroneously applied corneal procedure we encounter for total LSCD patients. 8 Corneal specialists should be well aware that there is no chance of long-term success with a primary PK for these patients. 1,8–10 The total LSCD leads to a failed PK due to ocular surface failure, inflam- mation, and neovascularization of the cornea with subsequent rejection and worse vision. 8,11 Many corneal specialists perform the Bos- ton keratoprosthesis (KPro) for LSCD. Overall, KPros have a reasonable success rate in non-in- flamed eyes, such as failed PKs or high-risk PKs due to immunologic reasons. However, KPro for LSCD is a different story. Studies have noted worse KPro outcomes in the setting of LSCD and OSD. In a large multicenter cohort of Boston type 1 KPro eyes, Srikumaran et al. noted the following rates of sterile corneal necrosis (19.5%), retinal detachment (18.6%), endophthalmitis (15.5%), and infectious ker- atitis (without endophthalmitis, 3.4%) for all KPro eyes. 12 They noted that in eyes with severe OSD (defined as severe keratoconjunctivitis sicca, LSCD, and cicatrizing conjunctivitis) had significantly lower retention rates (35% at 84 months) compared to eyes without OSD (78% at 84 months). Aravena et al. found that eyes undergoing a KPro implantation for failed ker- atoplasty had a retention failure rate of 0.052/ year while eyes with SJS, chemical injury, and MMP had retention failure rates of 0.299/year, 0.094/year, and 0.147/year. 13 D espite breakthroughs in our ability to manage severe ocular surface disease (OSD) with limbal stem cell deficiency (LSCD) effectively both medically and surgically, the majority of patients with this condition are either not treated or are not treated appropriately. Safe and effective treatment options with Ocular Sur- face Stem Cell Transplantation with Systemic Immunosuppression (OSSTx with SI) have been developed and presented at major meetings, in peer-reviewed journals as well as textbooks. Techniques and protocols for OSSTx with SI have been published for more than 25 years. 1–6 Despite this, only a few corneal specialists have adopted these treatments, and many of these patients are not referred to the few centers that perform these procedures. Misdiagnosis and mismanagement of these patients are sadly all too common. This has led to the inappropriate application of penetrating keratoplasty or ker- atoprosthesis, often worsening an already bad situation. While it is difficult to assess the exact prev- alence of LSCD, approximately 1–5 per 10,000 has been estimated. 7 Given the U.S. population of greater than 335 million, that would affect approximately 33,500 to 167,500 people. Too often, LSCD patients are only medically managed based on a diagnosis of dry eye dis- ease or viral keratitis. When they are managed surgically, substandard surgeries are commonly offered. Superficial keratectomy (with or with- out amniotic membrane) and phototherapeutic keratectomy can buy time with only short-term visual improvement for mild disease with ante- Physician perspective: Why are cornea specialists failing patients with limbal stem cell deficiency? Chemical injury with severe symblepharon and total limbal stem cell deficiency Two years postop after a living-related con- junctival limbal autograft and keratolimbal allograft with subsequent PK Sixteen years postop after a living-related con- junctival limbal autograft and keratolimbal allograft with subsequent PK

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