Short-term in vivo morphological changes of amniotic membrane after fibrin glue-assisted pterygium surgery on anterior segment optical coherence tomography: a case presentation

A 65-year-old Korean male patient (Case 1) visited the authors’ clinic with conjunctival injection in his right eye. He had undergone scleral buckling surgery due to rhegmatogenous retinal detachment 7 years earlier at another hospital. He reported taking metformin for diabetes. His uncorrected visual acuity was counting fingers in the right eye and 20/20 in the left, right eye was improved to 20/200 with pinhole. A slit-lamp biomicroscopic examination showed a thick fibrovascular ingrowth in the cornea, which extended across the pupil and obscured vision in his right eye (Fig. 1a) Thus, we decided to perform pterygium excision with a fibrin glue-assisted AM transplantation. In the operation room, the cryo-preserved AM was grafted using a permanent, inlay technique (epithelial side up) with fibrin glue (Greenplast Kit®, Green Cross Inc., Seoul, Korea) by mixed use of component. The AM was secured to host tissue using two additional anchoring sutures (10–0 nylon) parallel to limbus (Fig. 1b). Fourier-domain AS-OCT (RTVue-100, Optovue, Inc., Fremont, CA, USA) using 1310-nm examination revealed thick fibrin glue materials under the grafted AM on postoperative day 1 (POD1) and a gradual reduction over the first 2 postoperative weeks. Measured AM graft thickness were 112 μm on POD1, 106 μm on POD 8, and complete re-epithelialization over the grafted AM was observed at POD15. Integrated amnion within sclera underwent progressive changes over the first postoperative month (Fig. 1c-f). At 1 month postoperatively, uncorrected visual acuity improved to 20/50 and this improved to 20/40 with pinhole. Intraocular pressures (IOP) were measured using a Goldmann tonometer to be 14 mmHg in the right eye and 17 mmHg in the left eye at 1 month postoperatively. And we did not observe difference in the amniotic membrane integrated into the sclera of the patient that had undergone the scleral buckling compared to Case 2 and Case 3.

A 74-year-old Korean male patient visited our clinic complaining of ocular discomfort in his right eye. He had no significant medical history, was not on any medication, and his ophthalmic history was unremarkable with no history of prior ocular surgery or any significant ocular disease. Slit-lamp biomicroscopic examination showed mild posterior blepharitis and primary pterygium in the right eye. Uncorrected visual acuity was 20/20 in both eyes, and IOP was 14/15 mmHg. He was also treated by pterygium excision and amniotic membrane transplantation using fibrin-glue (without suturing). On POD7, AS-OCT showed corneal epithelium had migrated over the grafted AM, and at 1 month postoperatively AM stroma had integrated into sclera (Fig. 2).

An 82-year-old Korean male patient presented at our clinic for ocular injection. The patient’s ocular history included cataract surgery (phacoemulsification) in both eyes and ocular surface disease treated with cyclosporine ophthalmic emulsion 0.05% twice daily. His medical history was significant for stroke more than 10 years previously. His current medications included aspirin and clopidogrel. His best-corrected visual acuity was 20/20 in the both eyes, and his IOP was 17/19 mmHg. Slit-lamp biomicroscopic examination revealed pterygium in his right eye but no other ocular comorbidity.

In this patient, massive subconjunctival hemorrhage was encountered on the day following uneventful pterygium surgery with fibrin glue assisted permanent AM transplantation. At 4 weeks postoperatively, AS-OCT images revealed re-absorption of the subconjunctival hemorrhage and fibrin glue material under the AM. Bullous detachment of the AM and fluid collection under the membrane were noticed at POD1, but under close follow-up, these were found to decrease gradually, and at 4 weeks AS-OCT showed epithelial migration was complete (Fig. 3).