Article Type : Review Article
Title :   An Updated Appraisal of Therapeutic Keratoplasty
Authors :   Monal Kolhe
Abstract :   Therapeutic keratoplasty (TKP) remains a critical surgical intervention in the management of severe corneal infections, perforations, and non-healing ulcers unresponsive to medical therapy. Despite advances in antimicrobial agents, imaging, and lamellar keratoplasty techniques, TKP continues to play a decisive role in globe salvage and visual rehabilitation. The objective of TKP has gradually shifted from mere tectonic restoration to combined anatomical, therapeutic, and optical success. This review reassesses the evolving indications, surgical techniques, outcomes, complications, and future directions of therapeutic keratoplasty in the modern era. Emphasis is placed on advances such as lamellar therapeutic keratoplasty, antifungal resistance, donor tissue challenges, and postoperative management strategies. A better understanding of these evolving parameters is essential for optimizing patient outcomes.
Introduction :   Therapeutic keratoplasty is a form of corneal transplantation primarily performed to eliminate active corneal disease and preserve the structural integrity of the globe. Unlike optical keratoplasty, where the goal is visual rehabilitation, the primary aim of TKP is the removal of infected or necrotic tissue and restoration of ocular integrity 1. Since its first successful application in severe corneal infections, TKP has remained indispensable, particularly in regions with a high prevalence of microbial keratitis2. With improvements in antimicrobial therapy, early diagnosis, and surgical instrumentation, the role of TKP has evolved 3. However, rising antimicrobial resistance, delayed patient presentations, and limited availability of quality donor tissue have reinforced its continued importance 4. This review reassesses the current role of TKP in the context of modern ophthalmic practice.
Review of Literature :  Indications for Therapeutic Keratoplasty5-8 The indications for TKP can broadly be classified as: Infectious Keratitis • Fungal keratitis (especially refractory cases) • Bacterial keratitis unresponsive to maximal medical therapy • Acanthamoeba keratitis • Viral keratitis with progressive stromal necrosis Corneal Perforation and Impending Perforation • Descemetocele • Traumatic perforation • Autoimmune-mediated melts (e.g., rheumatoid arthritis) Non-Healing Corneal Ulcers • Neurotrophic keratitis • Chemical injuries • Exposure keratopathy Tectonic Indications • Peripheral corneal thinning • Post-infective corneal scarring with poor integrity • Failed prior grafts with perforation Surgical Techniques in Therapeutic Keratoplasty9-12 • Penetrating Therapeutic Keratoplasty (PTK) Penetrating keratoplasty involves full-thickness excision of the diseased cornea with donor replacement. It is traditionally used for: Deep stromal infections Large perforations Endothelial involvement • Lamellar Therapeutic Keratoplasty Recent years have seen increased adoption of lamellar techniques: Deep anterior lamellar keratoplasty (DALK) Anterior lamellar keratoplasty (ALK) Advantages include: Reduced risk of endothelial rejection Lower incidence of graft failure Better long-term graft survival • Tectonic Keratoplasty This is performed to restore corneal integrity in cases of extensive thinning or perforation, often using oversized or patch grafts. • Preoperative Evaluation13
Discussion :  Key aspects include: • Detailed slit-lamp examination • Corneal scraping and microbiological workup • Anterior segment optical coherence tomography (AS-OCT) • Assessment of scleral and intraocular involvement • Evaluation of systemic autoimmune disease when indicated Timing of surgery is crucial. Early intervention is preferred in rapidly progressive infections or imminent perforation. Outcomes of Therapeutic Keratoplasty14 • Anatomical Success Defined as maintenance of globe integrity, anatomical success rates range from 75–90% depending on etiology. Therapeutic Success Complete eradication of infection is achieved in approximately 70–85% of cases. • Visual Outcomes Visual outcomes are typically limited due to: Graft scarring Irregular astigmatism Secondary glaucoma Graft failure Most patients require secondary optical keratoplasty for visual rehabilitation. • Postoperative Management15 Postoperative therapy is guided by the underlying pathology: Tailored antimicrobial therapy Delayed introduction of corticosteroids (especially in fungal keratitis) Lubrication and epithelial healing support Monitoring intraocular pressure Management of immune-mediated graft reactions Close follow-up is essential in the early postoperative phase. • Complications of Therapeutic Keratoplasty. Common complications include:9 Graft rejection Recurrent infection Secondary glaucoma Graft failure Persistent epithelial defects Endophthalmitis (rare but serious) • Risk is higher in:10 Actively infected eyes Large grafts (>9 mm) Patients with autoimmune disorders • Therapeutic Keratoplasty in Fungal Keratitis Fungal keratitis remains the commonest indication for TKP in tropical countries. Delayed response to antifungals and deep stromal invasion necessitate early surgical intervention. TKP significantly improves anatomical survival but visual prognosis remains guarded. • Pediatric Therapeutic Keratoplasty Outcomes in children are poorer due to: Aggressive infections Higher rejection rates Amblyopia risk Poor postoperative compliance Despite this, TKP is often vision- and globe-saving. • Donor Tissue Challenges4 Key issues include: Scarcity of good-quality donor corneas Use of glycerol-preserved corneas in emergencies Increased risk of graft failure with poor-quality tissue Advances in tissue banking and preservation techniques may improve availability. • Advances in Therapeutic Keratoplasty7 Integration of lamellar keratoplasty Use of amniotic membrane transplantation as a temporizing procedure Femtosecond laser-assisted keratoplasty Adjunctive intracameral and intrastromal antimicrobials Role of collagen cross-linking as adjuvant therapy • Role of Therapeutic Keratoplasty in the Era of Advanced Medical Therapy Despite newer antifungals, antibiotics, and targeted drug delivery systems, drug resistance, delayed presentation, and poor penetration of drugs into deep stroma ensure that TKP remains indispensable. It also serves a dual role by providing tissue for histopathological diagnosis. • Prognostic Factors3 Better outcomes are associated with: Early surgery Smaller graft size Absence of scleral extension Good postoperative compliance Prompt control of infection Poor prognosis factors include: Large perforations Panophthalmitis Severe autoimmune disease Multiple prior grafts • Future Directions Future research is focused on: Bioengineered corneas Artificial corneal substitutes (keratoprosthesis) Improved antifungal drug delivery Regenerative therapies using stem cells Automated lamellar dissection techniques
Conclusion :  Therapeutic keratoplasty continues to be a cornerstone in the management of severe corneal disease. Although originally designed as a globe-salvaging procedure, evolving surgical techniques and improved postoperative care have expanded its role toward functional rehabilitation as well. Early decision-making, appropriate patient selection, and meticulous postoperative management remain the key determinants of success. As medical therapy and surgical technology advance, TKP will continue to evolve but will remain an irreplaceable tool in corneal surgery.
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