Modified deep anterior lamellar dissection for corneal opacity during vitrectomy: case reports

A 62-year-old man presented with vision loss in his left eye after blunt trauma 2 weeks ago. He had undergone a discontinued PPV procedure because of inadequate fundus view at a local hospital 5 days ago. The vision in his left eye was light perception. Ocular examination showed conjunctival injection, complete hyphema associated with corneal blood staining. The intraocular pressure (IOP) was 11 mmHg. B-scan ultrasonography revealed retinal detachment and choroidal detachment. He was scheduled to undergo an urgent vitrectomy. After the hemorrhage in the anterior segment was cleared by irrigation, the lens was not seen, and the posterior segment could not be clearly viewed due to the corneal opacity. The technique of the modified deep anterior lamellar corneal dissection was performed. A shallow groove was gently made using a 7-mm trephine. Then a 15-degree slit knife was used to increase the incision depth and separate the deep anterior lamellar corneal tissue from the stroma anterior to the underlying Descemet membrane (DM) by cutting along the groove for about 3/4 circumference, leading to a corneal flap (Fig. 1a).The remaining deep stromal fibers were carefully peeled off using a forcep with the help of the retroillumination from a 25 gauge fiber optic illumination probe going through the peripheral anterior chamber (Fig. 1b). Finally, a moderately transparent corneal bed comprised of DM and a fine layer of deep stroma offered a clear enough view for pars plana vitrectomy (Fig. 1c). The dense vitreous hemorrhage was progressively removed, revealing a total retinal detachment in the shape of a closed funnel (Fig. 1d). Following the removal of epiretinal and subretinal proliferative fibrous membranes and peripheral retinotomy, the retina was reattached with application of perfluorocarbon liquid. Endolaser and silicone oil (Oxane 5700; Bausch & Lomb, Rochester, NY, US) tamponade were performed. Finally, the corneal flap was stitched back with interrupted 10–0 nylon (Video 1). Postoperatively, the cornea gradually became transparent, leading to a clear fundus view without impediment within 3 months (Fig. 1e). The silicone oil was removed 3 months after the surgery with a flat retina and improvement of vision to counting fingers (Fig. 1f). The IOP was 10 mmHg. The suture was removed 4 months postoperatively. The eye remained stable at the 6-month follow up.

A 45-year-old man suffered a recurrent retinal detachment associated with corneal endothelial decompensation in the right eye from a cataract combined with complicated retinal detachment surgery and subsequent repeat vitrectomies and silicone oil tamponade for complicated retinal detachment within 2 years. On examination, the vision was light perception in his right aphakic eye. The corneal stroma was entirely edematous while the epithelium showed intact. B-scan ultrasonography revealed retinal detachment (Fig. 2a). Poor visibility through the cloudy cornea precluded fundus view (Fig. 2b). The deep anterior lamellar dissection was also performed before vitrectomy. After the separation of anterior lamella as described above, the remaining corneal tissue could not provide adequate view of fundus. We thought the dissection was not deep enough because of the relatively thicker cornea. Then, the big-bubble technique was used to separate the posterior stroma from the DM (Fig. 2c). The deeper lamellar flap was also created and preserved. With good visualization of the intraocular structure through the transparent DM (Fig. 2d), retinal repair was performed with the application of retinectomy. After retinal reattachment and silicone oil tamponade as case 1, the two layers of corneal flap were sutured back (Fig. 2e). The cornea remained cloudy, but the retina was confirmed as attached by ultrasonography postoperatively. Three months later, the original corneal flaps were dissected again and the silicone oil was removed after intraoperative reconfirmation of retinal attachment. The opaque corneal flaps were sutured back. The eye was stable and asymptomatic within 4-month follow up (Fig. 2f). The vision was light perception and the IOP was 24 mmHg. Because the improvement of vision wouldn’t be possible, further surgery of corneal transplantation was not considered.