A scleral protector for the safe delivery of local adjuvants in ocular surface surgery

Abstract

Purpose : Treatment of conjunctival malignancies and pterygia frequently include the intraoperative use of topical pharmacotherapy agents such as mitomycin C (MMC) to prevent recurrences. Targeted to the conjunctiva, use of these agents poses a risk of melting and perforation if leaked onto the sclera. We introduce and test a novel scleral protector (Provisional Patent: 63435503) (Figure 1) designed to aid in controlled delivery of these medications.

Methods : A scleral protector was 3D-printed from polylactic acid and tested in an ex-vivo experiment using 10 human eyes obtained postmortem. For each, a sectorial conjunctival flap was created, and an ophthalmic surgical sponge was soaked in 1:1000 black tissue-marking dye (Cancer Diagnostics, Inc.). The cases were divided into three groups to test dye leakage in three surgical approaches (Figure 2): Group 1 (n=3): the sponge placed on the bare sclera and the conjunctival flap pulled over the sponge, Group 2 (n=3): the sponge held against the inner conjunctival surface and pulled off the sclera, Group 3 (n=4): the sponge placed on the scleral protector and the conjunctiva over the sponge and protector. In all cases, the sponge was held in place to treat the conjunctiva for 1 minute and then removed, followed by 1 minute of water irrigation of the eye, and dissection of the conjunctival flap and adjacent sclera. Dissected tissues were submitted for histological dye localization.

Results : Scleral staining was observed macroscopically in all samples of Groups 1 and 2, and only one sample of Group 3. Histological examination demonstrated intense black dye presence on the episcleral surface in all cases in Group 1 and 2; however, in Group 3, two cases had no black dye staining in scleral tissue, and two had subtle staining. As expected, all conjunctival flaps showed intense black-dye staining.

Conclusions : When treating the conjunctiva, the novel scleral protector prevents from substantial liquid dye leakage onto the sclera and suggest a potential benefit if used with agents such as MMC intraoperatively.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Figure 1. Illustration of our scleral protector.

 

Figure 2. Three experimental approaches to test dye leakage. (A) The sponge placed on the sclera and the conjunctiva pulled over the sponge. (B) The sponge held against the inner conjunctival surface and pulled off the sclera. (C) The sponge placed on the scleral protector and the conjunctiva over the sponge and protector.