In glaucoma, retinal ganglion cell (RGC) death is induced by many risk factors, including ocular hypertension. It has been proposed that glutamate-mediated oxidative stress may also contribute to this RGC death. Cannabinoids are known to possess therapeutic properties including ocular hypotension and antioxidation. In this study, we test the hypothesis that (–)Δ⁹-tetrahydrocannabinol (THC) lowers intraocular pressure (IOP) and prevents RGC death in a rat model of glaucoma. Arat model of experimental glaucoma with chronic, moderately elevated IOP was produced unilaterally by cauterization of episcleral vessels. Rats received weekly injections of THC at a level of 5 mg/kg or vehicle for 20 weeks. IOP of both eyes was measured weekly on anesthetized animals immediately before THC treatment. RGCs were labeled in a retrograde fashion and counted in whole-mounted retinas. IOP was elevated in all operated eyes 1 day after the operation and remained elevated in the vehicle-treated rats throughout 20 weeks. In THC-treated rats, IOP elevation in operated eyes was diminished 2 weeks after operation and remained reduced. IOP in the contralateral control eyes was not affected by THC. In the operated eyes of vehicle-treated animals, there was a loss of ∼50 and 40% of the RGCs in the peripheral and central retina, respectively. The RGC loss in the operated eyes of the THC-treated animals was reduced to 10–20%. These results demonstrate that THC is a neuroprotectant that preserves RGCs in an experimental model of glaucoma, possibly through a reduction in IOP.

Purpose-To evaluate the outcomes of 360-degree suture trabeculotomy in childhood glaucoma with poor prognosis.Subjects and Methods-A nonrandomized, retrospective chart review was performed on pediatric patients (under 18 years old) treated with a 360-degree suture trabeculotomy for glaucoma. The cases were categorized into the following groups: (1) primary congenital glaucoma with birth-onset presentation accompanied by corneal clouding noted at birth, (2) primary congenital glaucoma with onset or presentation after 1 year of age, (3) primary congenital glaucoma with prior failed goniotomy surgery, (4) infantile-onset glaucoma following congenital cataract surgery, and (5) infantile-onset glaucoma with associated ocular/systemic anomalies.Results-A total of 45 eyes of 33 patients were analyzed. The mean preoperative intraocular pressure (IOP) was 34.3 ± 6.7 mm Hg on an average of 1.5 medications. Median age at time of surgery was 7 months. Mean final IOP (median last follow-up or failure, 12 months) was 22.2 ± 7.1 mm Hg on an average of 1.5 medications. The probability of success according to time after surgery was 87% at 6 months, 63% at 1 year, and 58% at 2 years. Kaplan-Meier analysis of Groups 1-4 versus Group 5 failed to demonstrate a statistically significant difference (p = 0.13). Of 5 eyes with port wine mark-related glaucoma, 2 had a large (>50%), persistent postoperative hyphema and concurrent vitreous hemorrhage.Conclusions-Children with a wide range of ocular pathologies can be successfully treated with 360-degree suture trabeculotomy. Further evaluation of this surgical technique in primary congenital glaucoma and open-angle glaucoma following congenital cataract surgery is warranted.

It is postulated that the resultant complement activation with subsequent leukoembolization along with the combined effect of other variables led to microvascular damage resulting in bilateral central retinal artery occlusion.