A Pilot Study Assessing Treatment Outcomes in Neovascular Glaucoma Using Ahmed Glaucoma Valve with and without Cyclophotocoagulation.

Purpose: The purpose of this retrospective pilot study was to examine the short-term effect of simultaneous Ahmed Glaucoma Valve implantation and cyclophotocoagulation on postoperative outcomes in patients with neovascular glaucoma. Methods and materials: Patient charts were selected for inclusion in this study if they carried a diagnosis of neovascular glaucoma and underwent Ahmed glaucoma valve implantation only, Ahmed glaucoma valve implantation with cyclophotocoagulation, or cyclophotocoagulation only. A total of 55 eyes of 54 patients were selected for data collection and analysis. Main outcome measures included 1-, 3-, and 6-month intraocular pressure and occurrence of the hypertensive phase. Other outcomes included visual acuity, surgical complication rate, and a number of 6-month postoperative ophthalmic medications. Results: A significantly lower intraocular pressure was seen in the group that received Ahmed glaucoma valve implantation + cyclophotocoagulation compared to the Ahmed glaucoma valve-only group at 3 and 6 months (p = 0.03 and <0.001, respectively). The difference in the occurrence of the hypertensive phase between the Ahmed glaucoma valve-only group and the Ahmed glaucoma valve + cyclophotocoagulation group approached but did not reach significance (p = 0.052). A significantly lower intraocular pressure was also seen in the cyclophotocoagulation-only group compared to the Ahmed glaucoma valve-only group at 3 months (p = 0.006). Conclusion: Simultaneous Ahmed glaucoma valve implantation and cyclophotocoagulation significantly lowered intraocular pressure at 3 and 6 months compared to Ahmed glaucoma valve implantation alone in patients with neovascular glaucoma. Clinical significance: Neovascular glaucoma is difficult to manage medically and surgically. When surgery is performed, intraocular pressure often remains elevated postoperatively despite aggressive medical management. This study examines a novel method to lower intraocular pressure after Ahmed glaucoma valve implantation in patients with neovascular glaucoma. How to cite this article: Ford RL, Knight ORJ, Klifto MR, et al. A Pilot Study Assessing Treatment Outcomes in Neovascular Glaucoma Using Ahmed Glaucoma Valve with and without Cyclophotocoagulation. J Curr Glaucoma Pract 2022;16(1):4-10.

Cerebrospinal fluid and ophthalmic disease.

PURPOSE OF REVIEW: The purpose of this review is to discuss the contemporary body of literature examining the relationship between cerebrospinal fluid (CSF) and ophthalmic disease. This review focuses on diseases that have a pathogenesis related to the translaminar pressure difference, defined as the pressure difference between the orbital subarachnoid space (OSAS) and the intraocular pressure. The diseases discussed include glaucoma, idiopathic intracranial hypertension, and spaceflight associated neuro-ocular syndrome. RECENT FINDINGS: The relationship between cerebrospinal and ophthalmic disease has been investigated for over 100 years. Recent research provides insight into the mechanisms that dictate CSF circulation in the OSAS and how alterations in these mechanism lead to disease. This review discusses these recent findings and their relationship to major ophthalmic diseases. SUMMARY: The recent findings provide insight into diseases that have pathogenic mechanisms that are not fully understood. This information will help physicians gain a clearer understanding of the relationship between CSF and ophthalmic disease and guide future research.

Thyroid Disruptors: Extrathyroidal Sites of Chemical Action and Neurodevelopmental Outcome-An Examination Using Triclosan and Perfluorohexane Sulfonate.

Many xenobiotics are identified as potential thyroid disruptors due to their action to reduce circulating levels of thyroid hormone, most notably thyroxine (T4). Developmental neurotoxicity is a primary concern for thyroid disrupting chemicals yet correlating the impact of chemically induced changes in serum T4 to perturbed brain development remains elusive. A number of thyroid-specific neurodevelopmental assays have been proposed, based largely on the model thyroid hormone synthesis inhibitor propylthiouracil (PTU). This study examined whether thyroid disrupting chemicals acting distinct from synthesis inhibition would result in the same alterations in brain as expected with PTU. The perfluoroalkyl substance perfluorohexane sulfonate (50 mg/kg/day) and the antimicrobial Triclosan (300 mg/kg/day) were administered to pregnant rats from gestational day 6 to postnatal day (PN) 21, and a number of PTU-defined assays for neurotoxicity evaluated. Both chemicals reduced serum T4 but did not increase thyroid stimulating hormone. Both chemicals increased expression of hepatic metabolism genes, while thyroid hormone-responsive genes in the liver, thyroid gland, and brain were largely unchanged. Brain tissue T4 was reduced in newborns, but despite persistent T4 reductions in serum, had recovered in the PN6 pup brain. Neither treatment resulted in a low dose PTU-like phenotype in either brain morphology or neurobehavior, raising questions for the interpretation of serum biomarkers in regulatory toxicology. They further suggest that reliance on serum hormones as prescriptive of specific neurodevelopmental outcomes may be too simplistic and to understand thyroid-mediated neurotoxicity we must expand our thinking beyond that which follows thyroid hormone synthesis inhibition.

Chronic Kidney Disease as a Predictor of Postoperative Choroidal Effusions After Glaucoma Surgery.

PRCIS: Patients with chronic kidney disease (CKD) are at increased risk for choroidal effusion development following glaucoma surgery. PURPOSE: Choroidal effusion is a postoperative complication of glaucoma surgery that results from a transudative fluid collection in the suprachoroidal space. Kidney disease alters bodily fluid dynamics through a variety of mechanisms. The relationship between CKD and choroidal effusion following glaucoma surgery has not previously been studied. The purpose of this study was to determine the relationship between CKD and choroidal effusion development after glaucoma surgery. PATIENTS AND METHODS: This retrospective cohort study consisted of 86 eyes from 86 patients who received glaucoma filtering surgery or transscleral cyclophotocoagulation within the study timeframe. Forty-three patients had CKD, and 43 patients did not have kidney disease. The main outcome of this study was the development of choroidal effusion measured by the Pearson χ2 test and multivariate analysis using a binomial regression with a log link. RESULTS: Ten patients (23.3%) in the CKD group developed choroidal effusion, while 2 patients (4.7%) in the no-kidney disease group developed choroidal effusion (relative risk, 5.0; 95% confidence interval: 1.16-21.5; P=0.013). The association between CKD and choroidal effusion showed mixed results in the multivariate analysis, with some analyses showing a significant association and others showing no significant association. CONCLUSIONS: In both the univariate and multivariate analyses, CKD was found to be significantly associated with choroidal effusion after glaucoma surgery.

A transient window of hypothyroidism alters neural progenitor cells and results in abnormal brain development.

Cortical heterotopias are clusters of ectopic neurons in the brain and are associated with neurodevelopmental disorders like epilepsy and learning disabilities. We have previously characterized the robust penetrance of a heterotopia in a rat model, induced by thyroid hormone (TH) disruption during gestation. However, the specific mechanism by which maternal TH insufficiency results in this birth defect remains unknown. Here we first determined the developmental window susceptible to endocrine disruption and describe a cellular mechanism responsible for heterotopia formation. We show that five days of maternal goitrogen treatment (10 ppm propylthiouracil) during the perinatal period (GD19-PN2) induces a periventricular heterotopia in 100% of the offspring. Beginning in the early postnatal brain, neurons begin to aggregate near the ventricles of treated animals. In parallel, transcriptional and architectural changes of this region were observed including decreased Sonic hedgehog (Shh) expression, abnormal cell adhesion, and altered radial glia morphology. As the ventricular epithelium is juxtaposed to two sources of brain THs, the cerebrospinal fluid and vasculature, this progenitor niche may be especially susceptible to TH disruption. This work highlights the spatiotemporal vulnerabilities of the developing brain and demonstrates that a transient period of TH perturbation is sufficient to induce a congenital abnormality.

Thyroid Hormone Disruption in the Fetal and Neonatal Rat: Predictive Hormone Measures and Bioindicators of Hormone Action in the Developing Cortex.

Adverse neurodevelopmental consequences remain a primary concern when evaluating the effects of thyroid hormone (TH) disrupting chemicals. Though the developing brain is a known target of TH insufficiency, the relationship between THs in the serum and the central nervous system is not well characterized. To address this issue, dose response experiments were performed in pregnant rats using the goitrogen propylthiouracil (PTU) (dose range 0.1-10 ppm). THs were quantified in the serum and brain of offspring at gestational day 20 (GD20) and postnatal day 14 (PN14), two developmental stages included in OECD and EPA regulatory guideline/guidance studies. From the dose response data, the quantitative relationships between THs in the serum and brain were determined. Next, targeted gene expression analyses were performed in the fetal and neonatal cortex to test the hypothesis that TH action in the developing brain is linked to changes in TH concentrations within the tissue. Results show a significant reduction of T4/T3 in the serum and brain of the GD20 fetus in response to low doses of PTU; interestingly, very few genes were significantly different at any dose tested. In the PN14 pup significant reductions of T4/T3 in the serum and brain were also detected; however, twelve transcriptional targets were identified in the neonatal cortex that correlated well with reduced brain THs. These results show that serum T4 is a good predictor of brain THs, and offer several target genes that could serve as pragmatic readouts of T4/T3 dysfunction within the PN14 cortex.