Effects of topical prostaglandin drops on angiogenesis in an in ovo chick chorioallantoic membrane model

Comparison of peripapillary vascular density as measured by optical coherence tomography angiography between various types of open-angle glaucoma

PURPOSE

The purpose of this study is to compare the peripapillary vascular density in patients with various types of open-angle glaucoma (primary open-angle glaucoma, pseudoexfoliative glaucoma and pigmentary glaucoma) with healthy subjects by optic coherence tomography angiography (OCTA).

METHODS

Twenty-seven eyes with diagnosed POAG, thirty-four eyes with diagnosed PXG, twenty eyes with diagnosed PG and thirty eyes of healthy individuals were included in our study. Peripapillary vessel density measurements were performed with all images; (AI-DD), intra-disc (ID-DD) and peripapillary (PP-DD); measurement of vascular density in the radial peripapillary capillary network was performed by OCTA. The Kruskal-Wallis test and post-hoc test were performed for statistical analysis.

RESULTS

AI-DD was 50.76±2.07% in the healthy group, 47.12±2.57% in POAG, 39.71±6.64% in PXG, and 43.37±1.55% in PG. ID-DD was 50.49±3.74% in the healthy group, 49.51±6.83% in POAG, 38.42±13.46% in PXG, and 40.9±4.45% in PG. PP-DD was 51.26±3.12% in the healthy group, 50.13±3.04% in POAG, 42.31±7.31% in PXG, and 47.6±1.40% in PG. While it was found that all image and intra-disc vascular density measurements were statistically significantly lower in the PG and PXG group compared to the healthy group and the POAG (P<0.001), there was no significant difference between PXG and PG or between the control group and POAG.

CONCLUSIONS

The lower radial peripapillary capillary density in PXG and PG compared to the POAG and healthy groups suggests that the blood flow around the optic disc is negatively affected in these patients.

Acquisition of Immune Privilege in GBM Tumors: Role of Prostaglandins and Bile Salts

Based on the postulate that glioblastoma (GBM) tumors generate anti-inflammatory prostaglandins and bile salts to gain immune privilege, we analyzed 712 tumors in-silico from three GBM transcriptome databases for prostaglandin and bile synthesis/signaling enzyme-transcript markers. A pan-database correlation analysis was performed to identify cell-specific signal generation and downstream effects. The tumors were stratified by their ability to generate prostaglandins, their competency in bile salt synthesis, and the presence of bile acid receptors nuclear receptor subfamily 1, group H, member 4 (NR1H4) and G protein-coupled bile acid receptor 1 (GPBAR1). The survival analysis indicates that tumors capable of prostaglandin and/or bile salt synthesis are linked to poor outcomes. Tumor prostaglandin D₂ and F₂ syntheses are derived from infiltrating microglia, whereas prostaglandin E₂ synthesis is derived from neutrophils. GBMs drive the microglial synthesis of PGD₂/F₂ by releasing/activating complement system component C3a. GBM expression of sperm-associated heat-shock proteins appears to stimulate neutrophilic PGE₂ synthesis. The tumors that generate bile and express high levels of bile receptor NR1H4 have a fetal liver phenotype and a RORC-Treg infiltration signature. The bile-generating tumors that express high levels of GPBAR1 are infiltrated with immunosuppressive microglia/macrophage/myeloid-derived suppressor cells. These findings provide insight into how GBMs generate immune privilege and may explain the failure of checkpoint inhibitor therapy and provide novel targets for treatment.

The Effect of Intraocular Pressure-Lowering Medication on Metastatic Uveal Melanomas

Simple Summary

The most lethal tumor in the eye is metastatic uveal melanomas, while the most common cause of irreversible blindness is glaucoma. Glaucoma is treated by prescribing intraocular pressure-lowering drugs. Theoretically, these drugs may affect the risk of metastasis of intraocular tumors (uveal melanomas). Using data of a long-running and ongoing study on uveal melanomas, we found that eye drops that lower the intraocular pressure by stimulating outflow of fluid (aqueous humor) may increase the risk of metastasis, and subsequent mortality. Therefore, in patients at risk or suspect for uveal melanoma, we recommend choosing ophthalmic drugs with a working mechanism that is not based on the increase of outflow of aqueous humor from the eye.

Abstract

Background: There has been speculation that IOP-lowering medication, which increases aqueous humor outflow, increases the risk of metastatic uveal melanoma (UM). This hypothesis has not been studied previously but is relevant for UM patients who use IOP-lowering medication. The aim of the current study is to assess the association between the use of intraocular pressure (IOP)-lowering medication and the risk of metastatic UM, and mortality. Methods: A retrospective cohort study, in which patients from the Rotterdam Ocular Melanoma Study were included from 1986 onwards. Medical records were evaluated for use of IOP-lowering medication at baseline (i.e., before diagnosis). For each IOP-lowering medication, we divided patients into two groups for comparison (e.g., patients with alpha2-agonist use and patients without alpha2-agonist use). All patients underwent regular ophthalmic examinations and routine screening for metastasis. Survival analyses were initiated to compare groups in each IOP-lowering medication group. In addition, secondary analyses were performed to examine the association between IOP and the development of metastatic UM, and mortality. Results: A total of 707 patients were included of whom 13 patients used prostaglandin or pilocarpine at baseline. For alpha2-agonist, beta-blocker, carbonic anhydrase inhibitor, and oral IOP-lowering medication these were 4, 14, 11, and 12 patients, respectively. The risk of metastatic UM (choroid and ciliary body melanoma) among the prostaglandin/pilocarpine users was significantly higher than controls (HR [95% CI]: 4.840 [1.452–16.133]). Mortality did not differ significantly among the IOP-lowering medications groups, except for the prostaglandin or pilocarpine group (HR [95% CI]: 7.528 [1.836–30.867]). If we combined all IOP-lowering medication that increase aqueous humor outflow, the risk (HR [95% CI]) of metastatic UM and mortality was 6.344 (1.615–24.918) and 9.743 (2.475–38.353), respectively. There was an association between IOP and mortality, but not for the onset of metastatic UM. Conclusion: The use of topical prostaglandin or pilocarpine may increase the risk of metastatic UM and mortality compared to patients without prostaglandin or pilocarpine use. Therefore, use of IOP-lowering medication which increases aqueous humor outflow, should be avoided in patients with (presumed) UM.