What is the recommended approach for a scleral graft?

Scleral Graft: Recommended Approach

For scleral defects requiring grafting, use alcohol-preserved or glycerin-preserved donor sclera tailored to fit the defect, sutured in place, and covered with either a conjunctival flap or amniotic membrane to achieve optimal structural and functional outcomes. 1, 2

Graft Material Selection and Preparation

• Preserved donor sclera is the standard graft material, with alcohol-preserved or glycerin-preserved human sclera being most commonly used 1, 2
• Donor sclera grafts are prepared by removing all other tissues from the donor bulb including retina, choroid, cornea, vitreous, and lens 3
• Grafts can be stored dry or in ethanol until transplantation, with dry storage for at least 1 year being the common approach 3
• The graft should be tailored to fit the specific defect size and shape before placement 1

Surgical Technique

Core Procedural Steps:

• Remove all devitalized tissue from the defect site before graft placement 1
• Suture the full-thickness scleral graft directly into the prepared defect using appropriate suture technique 1
• Cover the graft with either a conjunctival flap or amniotic membrane as the overlying protective layer 1, 2

Coverage Options:

• Conjunctival flap coverage is traditional and effective 1
• Amniotic membrane transplantation (AMT) is particularly advantageous when large scleral defects or conjunctival scarring is present, as it is simpler, faster, and avoids the need for conjunctival mobilization 2
• When using AMT, select amniotic membrane with a thick basement membrane for optimal results 2

Common Indications

The most frequent scenarios requiring scleral grafting include:

• Necrotizing scleritis following pterygium surgery (40% of cases) 1
• Severe corneal fistula complicated by other corneal diseases 4
• Scleromalacia with impending perforation 2
• Traumatic scleral laceration or avulsion 4
• Localized staphyloma 4

Expected Outcomes and Timeline

Structural Success:

• Tectonic success is achieved in approximately 77% of cases 1
• All grafts typically heal within an average of 20 days 4
• Epithelialization and vascularization occur after an average of 3-4 weeks 1
• Grafts remain intact with no recurrence of scleromalacia when properly performed 2

Visual Outcomes:

• Visual acuity remains stable in the majority (60%) of patients 1
• Visual improvement occurs in some cases, with marked improvement in visual acuity reported when combined with resolution of inflammation 2
• Intraocular pressure returns to normal following successful grafting 4

Critical Pitfalls and Complications

Known Complications:

• Endophthalmitis (most serious complication) 1
• Graft necrosis 1
• Graft dehiscence with uveal prolapse 1
• However, regrafts are rarely needed even when complications occur 1

Prevention Strategies:

• Ensure complete removal of devitalized tissue before grafting 1
• Achieve secure suture fixation with adequate scleral passes 1
• Provide adequate coverage with conjunctiva or amniotic membrane 1, 2
• Monitor closely for signs of infection or inflammation postoperatively 2

Special Considerations

Autogenous Scleral Grafting:

• In resource-limited settings or when donor material is unavailable, normal sclera from the same damaged eye can serve as donor material for cornea-sclera defect repair 4
• This approach shows good fusion with host tissue, no rejection reaction, and gradual increase in transparency over time 4
• Follow-up of 3-36 months demonstrates sustained effectiveness 4

Device-Related Applications:

• For specialized procedures like retinal prosthesis implantation, processed pericardium or donor corneal graft can be used to cover array cables and anterior coil edges to prevent conjunctival erosion 5
• This represents an alternative application of grafting principles in complex anterior segment reconstruction 5