When is scleral grafting indicated?

When is Scleral Grafting Indicated?

Scleral grafting is indicated when there is significant scleral tissue loss, thinning, or perforation that threatens globe integrity, most commonly from necrotizing scleritis, post-pterygium surgery complications, trauma, or failed previous intraocular surgery.

Primary Indications for Scleral Grafting

Necrotizing Scleritis

• Scleral grafting serves as a critical adjunct to systemic immunosuppressive therapy when progressive necrotizing scleritis causes profound scleral thinning or imminent perforation 1
• The graft maintains globe integrity while immunosuppressive drugs take effect, as the onset of chemotherapy action may be too slow to prevent perforation 1
• Grafts remain stable in patients receiving both surgical and drug therapy, but grafting alone without concomitant immunosuppression typically fails, with grafts melting within 14-45 days 1

Post-Pterygium Surgery Complications

• Severe scleral necrosis after pterygium excision (particularly with mitomycin C or beta-irradiation) represents the most common indication, accounting for 40% of cases in one series and 80% in another 2, 3
• Scleral melting can present anywhere from 1 month to 20 years after initial pterygium surgery 3
• Tectonic corneal lamellar grafting achieves 95% success in preserving globe integrity for severe post-pterygium scleral melts 3

Ocular Perforation and Trauma

• Scleral grafting is indicated when standard repair techniques fail, particularly with star-shaped wounds, delayed presentation, or lost corneal/scleral tissue 4
• The technique provides adequate functional and structural stability with acceptable complication rates 4

Failed Previous Intraocular Surgery

• Scleral defects following previous intraocular surgery require grafting to restore structural integrity 5
• Combined surgical history and trauma cases also benefit from this approach 5

Specific Clinical Scenarios

Infectious Scleritis

• When progressive infection does not respond to maximal medical treatment, therapeutic scleral grafting combined with aggressive antibiotic therapy is indicated 3
• Some cases of infectious scleritis require repeat lamellar grafting to successfully eradicate infection 3
• One critical pitfall: fungal infections (particularly fusarium) can cause graft necrosis and intraocular spread despite grafting 3

Device-Related Complications

• Conjunctival erosion over implanted devices (such as retinal prostheses) requires coverage with processed pericardium or donor corneal graft when the array cable and anterior coil edge are exposed 6
• Persistent hypotony from inadequate sclerotomy closure may necessitate reopening with pericardial graft placement 6

Surgical Approach Algorithm

Preoperative Assessment

• Remove all devitalized or infected scleral tissue surrounding the defect 3, 2
• Ensure concurrent systemic immunosuppression is initiated for autoimmune-related cases before or at the time of grafting 1

Graft Material Selection

• Alcohol-preserved full-thickness sclera is the standard choice, tailored to fit the defect exactly or 0.25mm larger 3, 2
• Alternative materials include lamellar or full-thickness donor corneal tissue for scleral defects 3
• Fascia lata represents another effective option 5
• Lamellar scleral autograft can be harvested from the same eye 4

Graft Coverage

• The graft must be covered with either a pedicled/free conjunctival flap or amniotic membrane 2, 3
• Epithelialization and vascularization typically occur within 3-4 weeks 2

Expected Outcomes

Structural Success

• Tectonic success is achieved in 76.9-95% of cases 2, 3
• Globe integrity is preserved in the majority of properly managed cases 4

Visual Outcomes

• Visual acuity remains stable in 60% of cases, improves in some, and deteriorates in others 2
• Intraocular pressure significantly increases postoperatively in most eyes 4

Complications to Monitor

• Endophthalmitis, graft necrosis, and graft dehiscence with uveal prolapse can occur 2
• Regrafting is rarely needed but may be required for recurrent infection or defects 3, 5

Critical Pitfall

Never attempt scleral grafting for necrotizing scleritis without concurrent systemic immunosuppressive therapy—grafts will melt rapidly without it 1. Even if chemotherapy is discontinued after successful grafting, graft melting can occur, requiring regrafting and renewed immunosuppression 1.