Etiology and Management of Referred Patients with Intraocular Pressure Elevation

PURPOSE: To investigate the underlying causes and clinical characteristics of patients referred with intraocular pressure (IOP) elevation. METHODS: We retrospectively reviewed the medical records of patients who were referred with IOP elevation from July 2016 to July 2017. Patients with baseline IOP ≥ 22 mmHg and those who were treated and followed up for 6 months were included. The prevalence rates of the underlying diseases that caused IOP elevation were evaluated and the clinical characteristics were compared between patients with primary and secondary glaucoma. RESULTS: A total of 127 patients were included (mean age, 59.3 ± 16.8 years; baseline IOP, 31.7 ± 10.5 mmHg). Among the study participants, 22.0%, 31.5%, and 46.5% had been diagnosed with ocular hypertension, primary glaucoma, and secondary glaucoma, respectively. Among the causes of IOP elevation, open-angle glaucoma (20.5%) had the highest prevalence rate among those with primary glaucoma and inflammation-related glaucoma (12.6%) was the most prevalent cause among those with secondary glaucoma. In a comparison between patients with primary and secondary glaucoma, the percentage of IOP reduction was not significantly different at 6 months after treatment (52.1% vs. 53.9%, p = 0.603). However, the rate of patients treated with drugs other than IOP lowering agents or who underwent surgery was significantly higher in the secondary glaucoma group compared with the primary glaucoma group (all p < 0.05). At 6-month follow-up, the secondary glaucoma group showed significantly higher improvement rates of visual acuity (p = 0.004), but had a larger proportion of patients with a visual acuity of less than or equal to finger count (p = 0.027). CONCLUSIONS: Treatment and visual outcome can vary depending on the underlying cause of IOP elevation. Therefore, a thorough examination for determining the cause of IOP elevation is recommended at the initial stage.

Study on the pathogenesis of transient intraocular pressure after laser iridectomy with Krypton laser combined with Q -switched Nd:YAG laser / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM:To study the pathogenesis of transient intraocular pressure ( IOP ) after laser iridectomy with Krypton laser combined with Q-switched Nd:YAG laser.· METHODS: Totally 42 healthy rabbits ( 84 eyes ) provided by the Animal Experimental Center of our hospital were selected, including 18 female rabbits, 24 male rabbits, average weight 2. 24±0. 31kg, and they were randomly divided into 6 groups, 7 rats in each group (14 eyes) . We observed the change of intraocular pressure after laser iridectomy surgery at 20min, 2, 6, 18, 24h and the nitric oxide ( NO ) , malondialdehyde ( MDA ) , superoxide dismutase ( SOD) , 6-keto-prostaglandin ( 6-keto-PGF1α) and nitric oxide synthase ( NOS) content in aqueous.· RESULTS: There was no significant difference in intraocular pressure, NO, NOS, SOD, MAD and 6-keto-PGF1α before operation ( P > 0. 05 ). The intraocular pressure increased after operation, and the difference was statistically significant (P<0. 05) at 20min, 2 and 6h after operation, and decreased at 18h after operation, 24h after operation (P>0. 05). The levels of NO, NOS and SOD in the aqueous humor of the two groups decreased 20min, 2 and 6h after the operation (P<0. 05), while increased after 6h, increased more at 18 and 24h. The difference with control group was no more significant (P>0. 05). The levels of MDA and 6-keto-prostaglandin in the aqueous humor increased after the operation, and the difference was statistically significant at 20min, 2 and 6h after operation (P<0. 05), while decreased at 18 and 24h and the difference with control group was not significant ( P>0. 05).· CONCLUSION: The increase of transient intraocular pressure after laser iridectomy may relate to the increase of malondialdehyde, 6-keto-prostaglandin content and the decrease of superoxide dismutase and nitric oxide in the aqueous humor after operation.

Risk Factors and Incidence of Elevated Intraocular Pressure after Dexamethasone Intravitreal Implant

PURPOSE: To report the incidence of intraocular pressure (IOP) elevation and identify the risk factors of IOP elevation after intravitreal dexamethasone 0.7 mg (Ozurdex®, Allergan, Irvine, CA, USA) implant. METHODS: A total of 86 eyes of 79 patients who underwent intravitreal dexamethasone implantation and who were followed for ≥ 3 months were included in the present study. IOP elevation was defined as a pressure > 21 mm Hg at some time during follow-up. RESULTS: Twenty-nine eyes (33.7%) had an IOP > 21 mm Hg after dexamethasone intravitreal implant. The incidence of IOP elevation increased rapidly at 2–3 months after dexamethasone intravitreal implant. The Kaplan-Meier estimated incidence of IOP elevation was 25.6 ± 4.7% (mean ± standard error) at 81 days. Cox multivariate analysis showed the significant risk factors of IOP elevation to be age < 55 years (p = 0.045), baseline IOP ≥ 15 mm Hg (p < 0.001), and history of intraocular surgery (p = 0.039). CONCLUSIONS: This study demonstrates the incidence of IOP elevation to be 33.7% and describes the risk factors associated with IOP elevation. Clinicians should be cautious regarding the possibility of IOP elevation after intravitreal dexamethasone implant, especially in the presence of identified risk factors.

The Effect of Experimental Ocular Hypertension on the Electroretinogram in Laser Treated Rabbit Eyes

The argon laser is widely used to coagulate the diabetic retina in order to inhibit the progression of diabetic retinopathy. To compare the electrophysiological changes of the photocoagulated retina according to the level of intraocular pressure(IOP), the right eyes of 24 pigmented rabbits underwent retinal photocoagulation with an argon laser. Retinal function was assessed electroretinographically at 4 weeks after retinal photocoagulation before treatment and under elevated IOP(40 mmHg, 60 mmHg, 80 mmHg) for 4 hours. In the 40 mmHg group, the amplitude of the a-, b-, oscillatory potentials(OPs) of the photocoagulated eyes showed a more rapid drop than the control eyes, and there was no recovery stage seen in the control eyes. In the 60 mmHg group the amplitude of the a-wave, b-wave, and OPs of photocoagulated eyes showed a rapid drop and were abolished after 3.5 hours, but that of the control eyes showed biphasic changes; first, a rapid drop with the same velocity as the photocoagulated eyes during the first 2 hours, then a steady stage for the last 1.5 hours. In the 80 mmHg group, electroretinogram was totally abolished within 20 minutes after elevation of IOP in both eyes. The above results showed that the photocoagulated eyes treated 4 weeks ago were more vulnerable to elevated IOP than the control, healthy eyes.