Incidence and risk factors for intraocular pressure rise after transconjunctival vitrectomy

Cannabinoids as Multitarget Drugs for the Treatment of Autoimmunity in Glaucoma

Diseases of multifactorial origin like neurodegenerative and autoimmune diseases require a multitargeted approach. The discovery of the role of autoimmunity in glaucoma and retinal ganglionic cell (RGC) death has led to a paradigm shift in our understanding of the etiopathology of glaucoma. Glaucoma can cause irreversible vision loss that affects up to an estimated 3% of the population over 40 years of age. The current pharmacotherapy primarily aims to manage only intraocular pressure (IOP), a modifiable risk factor in the glaucomatous neurodegeneration of RGCs. However, neurodegeneration continues to happen in normotensive patients (where the IOP is below a reference value), and the silent nature of the disease can cause significant visual impairment and take a massive toll on the healthcare system. Cannabinoids, although known to reduce IOP since the 1970s, have received renewed interest due to their neuroprotective, anti-inflammatory, and immunosuppressive effects on autoimmunity. Additionally, the role of the gut-retina axis and abnormal Wnt signaling in glaucoma makes cannabinoids even more relevant because of their action on multiple targets, all converging in the pathogenesis of glaucomatous neurodegeneration. Cannabinoids also cause epigenetic changes in immune cells associated with autoimmunity. In this Review, we are proposing the use of cannabinoids as a multitargeted approach for treating autoimmunity associated with glaucomatous neurodegeneration, especially for the silent nature of glaucomatous neurodegeneration in normotensive patients.

Effect of Intravenous Mannitol on Intraocular Pressure Changes in Vitrectomized and Non-Vitrectomized Eyes: A Systematic Review and Meta-Analysis

PURPOSE

Intraocular pressure (IOP) control is paramount during ophthalmic surgeries to ensure successful outcomes and prevent complications. Intravenous mannitol has been explored for its ability to manage IOP fluctuations in both vitrectomized and non-vitrectomized eyes. This meta-analysis aimed to assess the efficacy of mannitol in controlling IOP across these patient groups.

DESIGN

Systematic review and meta-analysis.

METHODS

A literature search was conducted across PubMed, EMBASE, Scopus, and Web of Science from inception up to March 1, 2024, focusing on studies investigating mannitol's impact on IOP in vitrectomized and non-vitrectomized eyes. Randomized controlled trials, cohort studies, and case-control studies were included, while case reports and review articles were excluded. The primary outcome was the change in IOP following mannitol administration. Meta-analysis was performed using a random-effects model. R software (V 4.3) was used for statistical analysis.

RESULTS

Our search included five studies of both vitrectomized (145 eyes) and non-vitrectomized eyes (91 eyes). The meta-analysis demonstrated significant IOP reductions following mannitol administration across multiple time points. Three studies were included at 30 min and 2 studies at all other time points in the analysis. In vitrectomized eyes, notable decreases were observed: at 30 min, the Ratio of Means (ROM) was 0.81 (95% CI: 0.53; 1.24), indicating a 19% reduction; at 60 min, the ROM of 0.833 (95% CI: 0.77; 0.89) showed a 16.7% reduction; at 90 min, the ROM of 0.757 (95% CI: 0.755; 0.758) corresponded to a 24.3% reduction; at 2 h, the ROM of 0.726 (95% CI: 0.642; 0.820) reflected a 27.4% reduction; at 3 h, the ROM of 0.692 (95% CI: 0.600; 0.797) resulted in a 30.8% reduction; and at 4 h, the ROM of 0.700 (95% CI: 0.363; 1.350) indicated a 30% reduction. No significant changes were observed on IOP with mannitol administration when comparing vitrectomized versus non- vitrectomized eyes.

CONCLUSION

Intravenous mannitol effectively reduces IOP in both vitrectomized and non-vitrectomized eyes, demonstrating its utility in the acute management of elevated IOP during and after ophthalmic surgeries. These findings support the integration of mannitol into perioperative care protocols. However, further research, particularly randomized controlled trials and studies with broader demographic representation, is needed to optimize mannitol's usage and fully understand its long-term safety and efficacy.

Risk Factors and Management of Intraocular Pressure Elevation After Vitrectomy Combined with Silicone Oil Tamponade

Silicone oil has emerged as the common option for intraocular tamponade during complicated retina vitrectomy. However, the postoperative elevation of intraocular pressure (IOP), influenced by numerous factors, remains a significant and frequently encountered complication that poses a potential threat to vision. Extensive research has been conducted to investigate the risk factors associated with elevated IOP following silicone oil tamponade, including silicone oil viscosity, preoperative high IOP, diabetes, and lens status. This comprehensive review aims to gather and summarize the current research findings regarding the risk factors contributing to IOP elevation following silicone oil tamponade, as well as the optimal management strategies for secondary glaucoma. The analysis includes the physicochemical properties of silicone oil, preoperative and intraoperative risk factors, and the effective management of secondary glaucoma. Enhancing our understanding of the primary factors associated with silicone oil-induced IOP elevation will facilitate the guidance of timely and appropriate interventions.

Prediction model for elevated intraocular pressure risk after silicone oil filling based on clinical features

Background

To evaluate risk factors and further develop prediction models for intraocular pressure elevation (IOP) after vitreoretinal surgery with silicone oil tamponade to support clinical management.

Methods

A retrospective study analyzed 1,061 eyes of 1,061 consecutive patients that presented to the Jiangsu Province Hospital between December 2015 and December 2020, the IOP was measured from the preoperative visit and at the 1-week, 1-month, 3-month, and 6-month visits, and the final postoperative visit before silicone oil removal. Four machine learning methods were used to carried out the prediction of IOP elevation: Decision Tree, Logistic Regression, Random Forest, and Gradient-Boosted Decision Trees (GBDT) based on features including demographic and clinical characteristics, preoperative factors and surgical factors. Predictors were selected based on the p-value of the univariate analysis.

Results

Elevated intraocular pressure developed in 26.01% of the eyes postoperatively. Elevated intraocular pressure primarily occurred within 1-2 weeks after surgery. Additionally, the majority of IOP values were distributed around 25-40 mmHg. GBDT utilizing features with p-values less than 0.5 from the hypothesis testing demonstrated the best predictive performance for 0.7944 in accuracy. The analysis revealed that age, sex, hypertension, diabetes, myopia, retinal detachment, lens status and biological parameters have predictive value.

Conclusion

Age, sex, hypertension, diabetes, myopia, retinal detachment, lens status and biological parameters have influence on postoperative intraocular pressure elevation for patients with silicone oil tamponade after pars plana vitrectomy. The prediction model showed promising accuracy for the occurrence of IOP elevation. This may have some reference significance for reducing the incidence of high intraocular pressure after pars plana vitrectomy combined with silicone oil filling.

Efficacy of Continuous-Wave Transscleral Cyclophotocoagulation Post-Pars Plana Vitrectomy in Glaucoma Patients: A Retrospective Study from Poland

BACKGROUND Glaucoma, a vision-threatening condition, results from optic nerve damage and affects millions of people worldwide. Often asymptomatic, it is hereditary, with risk factors like hypertension, diabetes, and steroid use. Despite its link with intraocular pressure (IOP), not everyone with high IOP develops glaucoma. After pars plana vitrectomy (PPV), patients face increased IOP risks. Traditional treatment includes pharmacotherapy, and, when ineffective, surgical interventions. Continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) is an alternative for refractory glaucoma but can have complications. Our study compares the efficacy and safety of CW-TSCPC after PPV. MATERIAL AND METHODS The study group consisted of 18 patients diagnosed with glaucoma who underwent the CW-TSCP procedure as the first-choice therapy after conservative treatment of glaucoma proved ineffective. The comparison group consisted of 12 patients who underwent the CW-TSCP procedure after conservative drug treatment and in whom surgical treatment of glaucoma had been unsuccessful. All patients had inadequate control of IOP after PPV. RESULTS Study and comparison group patients showed a decrease in IOP during the follow-up, independent of the type of endotamponade used (P<0.05). When the indication for PPV was retinal detachment hemorrhage into the vitreous chamber, a significant decrease in IOP between 0 days and 180 days was only found in the study group (P<0.05). In contrast, when the indication for PPV was the state after uveitis or proliferative diabetic retinopathy, a significant decrease in IOP was found at 180 days in the study and comparison groups (P<0.05). CONCLUSIONS The analysis showed that the CW-TSCPC procedure can be recommended as the first-choice invasive treatment in patients with increased IOP after PPV.

Outcomes and Adverse Effects of Voretigene Neparvovec Treatment for Biallelic RPE65-Mediated Inherited Retinal Dystrophies in a Cohort of Patients from a Single Center

Our study evaluated the morphological and functional outcomes, and the side effects, of voretigene neparvovec (VN) gene therapy for RPE65-mediated inherited retinal dystrophies (IRDs) in 12 eyes (six patients) at the Oxford Eye Hospital with a mean follow-up duration of 8.2 (range 1-12) months. All patients reported a subjective vision improvement 1 month after gene therapy. Best-corrected visual acuity (BCVA) remained stable (baseline: 1.28 (±0.71) vs. last follow-up: 1.46 (±0.60); p = 0.25). Average white Full-Field Stimulus Testing (FST) showed a trend towards improvement (baseline: -4.41 (±10.62) dB vs. last follow-up: -11.98 (±13.83) dB; p = 0.18). No changes in central retinal thickness or macular volume were observed. The side effects included mild intraocular inflammation (two eyes) and cataracts (four eyes). Retinal atrophy occurred in 10 eyes (eight mild, two severe) but did not impact FST measurements during the follow-up period. Increased intraocular pressure (IOP) was noted in three patients (six eyes); four eyes (two patients) required glaucoma surgery. The overall safety and effectiveness of VN treatment in our cohort align with previous VN clinical trials, except for the higher occurrence of retinal atrophy and increased IOP in our cohort. This suggests that raised IOP and retinal atrophy may be more common than previously reported.

Early influence of endotamponade on corneal biomechanical parameters, central corneal thickness and accuracy of intraocular pressure measurement

To define the influence of air, SF6 gas and silicon oil 1000cs tamponade injection and oil tamponade removal on corneal biomechanics, central corneal thickness and intraocular pressure. 77 eyes referred to vitrectomy were divided into 4 groups: 19 to air tamponade, 21 to SF6 tamponade, 19 to oil tamponade, 18 to oil tamponade removal. Pre- and postoperative corneal hysteresis, corneal resistance factor, corneal thickness, Goldman intraocular pressure (GAT) and corneal compensated intraocular pressure (IOPcc) were analysed. GAT and IOPcc did not change after the air or SF6 tamponade. The oil tamponade injection caused increase in GAT and IOPcc, while the oil removal caused reduction in those parameters. In all groups, preoperative and postoperative values of GAT and IOPcc did not differ. There was no change in corneal thickness and biomechanics after air, SF6 or oil tamponade while after removal of oil those parameters are decreased. The air, SF6 and oil tamponade does not change the corneal thickness and corneal biomechanics. The removal of oil causes decrease in corneal thickness and biomechanics which can lead to bias in intraocular pressure measurement. GAT and IOPcc did not differ in eyes pre- and post-vitrectomy, being similarly reliable measure.