In general, conjunctival flap procedures have three indications: therapeutic, as in the treatment of corneal infections resistant to medical therapy or control of resistant surface corneal disease; palliative, for control of corneal pain, as in bullous keratopathy; and tectonic, providing structural support for corneal ulcers, descemetoceles or perforations. However, conjunctival flaps are rarely the primary choice of treatment, as alternative therapeutic options may provide better outcomes. For instance, the use of conjunctival flaps for the primary treatment of corneal lacerations, a frequent indication in the past, is now almost never indicated when modern microsurgical treatment is available.³

A few large series of cases over the last 40 years demonstrate the change in surgical indications over time (Table 33-1). Gundersen and Pearlson⁴ presented a series of 177 cases in 1969 of which 60 (34%) had herpes simplex keratitis; 44 (25%), bullous keratopathy; and 17 (10%), a history of trauma. In 1970, Paton and Milauskas presented 122 cases: 36 (30%) had herpetic keratitis; 33 (27%), bullous keratopathy; 23 (19%), nonherpetic ulcers; 12 (10%), descemetocele; and 7 (6%), alkali burns. In this series, conjunctival flaps failed to halt progression of Mooren ulcer in two patients, suggesting that this surgical procedure was not indicated in autoimmune peripheral ulcerative keratitis.⁵ Insler and Pechous⁶ reported 33 cases 18 years later: 8 (25%) had herpes simplex; 7 (22%), bacterial ulcers; and 3 (9%), herpes zoster. In 1998, Alino and colleagues⁷ presented 48 patients with total conjunctival flap and 13 with partial conjunctival flap. In this series, 12 (20%) had nonherpetic corneal ulcers; 9 (15%), herpes simplex keratitis; 9 (15%), bullous keratopathy; and 7 (11%), herpes zoster keratitis.⁸ In 2003, Khoudadoust and Quinter⁹ reported 50 cases treated with pedunculated conjunctival flaps, 14 (28%) due to herpes simplex keratitis; 11 (22%), secondary to bacterial ulcers; and 8 (16%), secondary to rheumatoid arthritis-related corneal melt. In 2009, Lim and colleagues¹⁰ reported a series of 25 patients treated with total conjunctival flaps. Compared with previous reports, the main indication was bullous keratopathy in 13 (52%), followed by painful band keratopathy in chronically inflamed eyes in 8 (32%), and herpes simplex keratitis in 1 (4%).

The development and refinement of effective antimicrobial agents over the last 50 years has greatly improved the treatment of corneal infections. However, resistant corneal ulcers may rarely need to be treated with a conjunctival flap. The flap brings in blood supply that promotes healing by increasing corneal access to humoral and cellular immune mechanisms. The conjunctival flap also provides a physical barrier, which reduces exposure keratopathy secondary to neurotrophic disease. In all cases of necrotic ulcers treated with conjunctival flaps, medical management with appropriate drug therapy must be tried first followed by debridement of necrotic tissue, often with lamellar keratectomy. Penetrating keratoplasty may have limited benefit in these cases due to high risk of graft rejection secondary to inflammation and vascularization of the cornea. However, a conjunctival flap may allow stabilization of the infection and persistent inflammation in preparation for corneal grafting and visual rehabilitation.

Conjunctival flaps have been used to halt the progression of refractory pseudomonas corneal abscess.¹¹ Conjunctival flaps can also be used to treat infectious keratitis occurring in the region of the corneal incisions after radial keratotomy.¹² Flaps have been promoted for the treatment of fungal keratitis resistant to medical treatment.¹³ This approach may reflect the limited success of topical ophthalmic antifungals. Fungal keratitis, as with any infection, can still progress beneath the conjunctival flap, and the flap itself may limit drug penetration postoperatively. Treatment of advanced acanthamoeba keratitis with deep lamellar keratectomy and conjunctival flap to control the infection and help relieve pain has also been reported.¹⁴

The use of flaps to treat herpes simplex keratitis has remained helpful despite the availability of antivirals.⁴,⁵,⁶,⁷ Persistent epithelial defects may be treated with conjunctival flaps. More often, chronic or painful herpetic stromal ulceration and keratouveitis requiring frequent examinations and medical therapy benefit from a conjunctival flap. Brown and colleagues⁷ found a marked decrease in the need for medications and office visits in such patients. They noted no recurrence of active viral keratitis, although perforation beneath the flap for herpetic keratitis may occur. However, Lesher and colleagues¹⁵ reported recurrence of herpetic stromal keratitis even after a conjunctival flap.