To evaluate the clinical effect of extensive retinal condensation combined with mitomycin C infiltration and trabeculectomy in the treatment of neovascular glaucoma. Methods Thirty-five cases of neovascular glaucoma were treated with extensive retinal condensation combined with mitomycin C infiltration and trabeculectomy. Results Six months after surgery, IOP was controlled in 33 cases with 1 operation and 2 cases with 2 operations. 35 eyes had regression of iris and trabecular neovascularization. 12 cases had 2 lines of visual acuity improvement after surgery. Conclusion Extensive retinal condensation combined with mitomycin C infiltration + trabeculectomy for neovascular glaucoma can effectively control IOP and preserve residual visual function and ocular shape.
Neovascular glaucoma is a refractory glaucoma secondary to retinal ischemic diseases such as retinal vein occlusion, diabetic retinopathy, or inflammatory diseases. The treatment of this disease is tricky and the efficacy is poor. In our hospital, patients with neovascular glaucoma were successively treated with extensive retinal condensation + mitomycin C infiltration + trabeculectomy surgical method, after which the patients had pain relief and the efficacy was confirmed, which is reported below.
Materials and Methods
1.Data
From June 2000 to May 2003, 35 patients with neovascular glaucoma were admitted to our hospital, including 15 males and 20 females, aged 25-68 years old, with an average age of 41 years. There were 17 cases of ischemic retinal vein obstruction, 11 cases of proliferative diabetic retinopathy, 3 cases of retinal perivasculitis, 2 cases of uveitis, and 2 cases of other unknown causes. There were 10 cases of early and progressive stage, and 25 cases of late and absolute stage. There were 15 cases with extensive neovascularization on the iris surface and 14 cases with neovascularization in the atrial angle. preoperative intraocular pressure was 35-89 mmHg, with a mean of 65 mmHg. visual acuity was not light perception – manual/in front of the eyes.
2.Surgical method
(1) Circumferential cutting of the bulbar conjunctiva along the corneal limbus, separation of 4 rectus muscles, 1-0 silk threaded under the 4 rectus muscles for traction; 2mm diameter freezing head, condensing from the end point of the rectus muscles (12mm after the corneal limbus) to the equator in turn (18mm after the corneal limbus), a total of 4 rows, each quadrant each row from front to back are 4, 3, 2, 1 points, a total of 10 points, each point about 10 seconds, freezing temperature – 60 — 80 degrees, the points are fused with each other.
(2) A rectangular scleral flap of 5w4mm size with 1/2-1/3 scleral thickness was made above.
(3) A 0.02% (2mg/10ml) mitomycin C infiltrated cotton pad was placed under the bulbar conjunctival flap and scleral flap with scleral bed in the upper nasal quadrant for 5 minutes, and 100ml saline was flushed.
(4) Vitreous drainage/anterior chamber puncture and drainage to reduce IOP before opening of the eye, occlusion of trabeculae 1.5w2mm, iris root excision after thermal cautery.
(5) Postoperative treatment with 0.007% (2mg/30ml) mitomycin C ophthalmic solution spotting, continuous pupil dilatation, posthemispheric injection of prednisolone 0.5ml anti-inflammatory, and ocular massage.
Results
1, postoperative anterior chamber formation: 4 cases of filtration port was blocked by neovascularized fibrous membrane, there was a little blood clot, the second day the anterior chamber was extremely shallow, 1/2CT in the middle axis, given local finger pressure, pressure pack double eyes, 20% mannitol sedation, the patient anterior chamber recovery, the fourth day the anterior chamber has returned to 2CT, without any exudation and other reactions.
2, Filtration vesicles: according to Kronfeld typing, 12 cases of type I, 11 cases of type II and 12 cases of type III.
3.Iris surface neovascularization regression: 30 cases of iris surface neovascularization regressed within 1 week, and all 35 cases of iris surface neovascularization regressed in 14 days.
4. Postoperative IOP and visual acuity: IOP decreased to normal range of 10-21 mmHg in 33 cases. 2 cases with postoperative IOP greater than 30 mmHg underwent 2 surgeries after 1 month, and mitomycin C infiltrated cotton tablets were dipped under the conjunctival capsule and scleral flap. 12 cases with visual acuity improved by 2 lines.
5. Complications: 4 cases of choroidal detachment and shallow anterior chamber recovered after 2 surgeries.
Discussion
Neovascular glaucoma is a refractory glaucoma secondary to retinal ischemic disease or inflammation such as retinal vein obstruction, diabetic retinopathy. The formation of neovascularization and connective tissue membranes on the iris surface and anterior chamber angle causes close adhesion of the iris and trabecular meshwork in the periphery, disrupting the normal structure of the atrial angle, resulting in poor drainage or anterior displacement of the crystalline iris diaphragm and closure of the atrial angle, causing increased intraocular pressure, ocular congestion, and severe pain. It is a type of refractory glaucoma. Diabetic retinopathy mostly develops in both eyes.
The disease is difficult to treat and most cases have a poor prognosis. Clinical medications are generally topical beta-blockers and ciliary paralytics that can relieve symptoms, but are difficult to control the disease. Early retinal photocoagulation is effective, but for eyes with corneal, lens, or vitreous opacities that cannot undergo retinal photocoagulation, the application of extensive retinal coagulation can degenerate the neovascularization. Retinal ischemia and capillary nonperfusion, and neovascularization factor production, are the root causes of iris neovascularization. Extensive retinal condensation destroys a large number of mitochondria in the photoreceptor cells, which consume much oxygen, and replaces them with collagen tissue, which consumes very little oxygen, thus improving retinal hypoxia, and the oxygen tension of the choroidal capillaries diffusing into the inner retinal layer is increased, resulting in retinal vasoconstriction and reduced blood flow, reducing vascular leakage and decreasing the incidence of neovascularization. Postoperative hypoxia in the intraocular tissues is improved resulting in a reduction in atrial angle iris neovascularization and a decrease in IOP. This procedure is different from ciliary condensation, which aims to disrupt the atrial aqueous production function of the ciliary body. Due to its indeterminate amount, the ciliary body is highly damaged, and postoperative reactive hypertension, severe uveitis, and eventually uncontrolled intraocular pressure or ocular atrophy often occur.
Conventional filtration surgery, because the atrial angle is closed and there is a large amount of neovascularization, intraoperative bleeding is extremely easy, and postoperative blockage of the filtration port by neovascularized fibrous membrane will occur, so intraoperative hemostasis should be adequate, especially at both corners of the scleral flap to avoid blood flow into the anterior chamber. Patients with persistent high intraocular pressure before surgery, make an incision at the anterior edge of the scleral flap, first cut 1 mm, slowly release the atrial fluid, and use the scleral flap to cover the posterior lip to control the flow of atrial fluid. It is also feasible to release fluid from the vitreous to reduce the posterior chamber pressure and prevent vitreous protrusion. Intraoperative mitomycin C use can inhibit fibroblast proliferation, reduce scar proliferation, prevent adhesions, and improve the success rate of surgery.