Factors Related to Prostaglandin-Associated Periorbitopathy in Glaucoma Patients

Clinical Staging of Prostaglandin-Associated Periorbitopathy Syndrome in Glaucoma: A Review from Asia

PURPOSE

Topical prostaglandin analogues are commonly used to treat patients with glaucoma, but may cause periocular and periorbital complications known as prostaglandin-associated periorbitopathy syndrome (PAPS).

METHODS

A literature review was conducted on PAPS. Given the lack of consensus on grading PAPS, glaucoma specialists from Asia convened to evaluate current PAPS grading systems and propose additional considerations in grading PAPS.

RESULTS

Existing grading systems are limited by the lack of specificity in defining grades and consideration for patients' subjective perception of symptoms. Patient-reported symptoms (e.g., via a self-assessment tool) and additional clinical assessments (e.g., exophthalmometry, lid laxity, differences between tonometry results, baseline measurements, and external ocular photographs) would be beneficial for grading PAPS systematically.

CONCLUSIONS

Effective management of PAPS could be facilitated by a common clinical grading system to consistently and accurately diagnose and characterise symptoms. Further research is required to validate specific recommendations and approaches to stage and monitor PAPS.

Prostaglandin-associated periorbitopathy syndrome (PAPS): Addressing an unmet clinical need

BACKGROUND

Topical prostaglandin analogs (PGAs) are widely approved and preferred first-line options for glaucoma and elevated intraocular pressure (IOP). However, prostaglandin-associated periorbitopathy syndrome (PAPS) is now a well-recognized clinical and cosmetic concern for patients receiving PGAs, especially during long-term and unilateral therapy. PGA-associated periocular changes occur in a substantial proportion of patients, with older patients (>60 years) at greater risk of clinical presentation. PAPS may hinder long-term management of glaucoma, including treatment adherence, ophthalmic surgery outcomes, and reliable IOP measurements.

RECOMMENDATION

New therapeutic approaches may address this unmet clinical need. Omidenepag isopropyl (OMDI) is a novel, non-prostaglandin, selective EP₂ receptor agonist in ongoing development, which provides a unique pharmacological mechanism of action. OMDI appears to provide IOP reductions comparable to PGAs, but without PAPS-related undesirable effects. OMDI may offer a suitable long-term option for patients who demonstrate decreased efficacy, or failure, of PGAs, plus patients with significant PAPS, while fulfilling international guidelines.

Proposal of a simple grading system integrating cosmetic and tonometric aspects of prostaglandin-associated periorbitopathy

The distribution of prostaglandin-associated periorbitopathy (PAP) graded using the Shimane University PAP Grading System (SU-PAP) among glaucoma/ocular hypertension subjects using a topical FP or EP2 receptor agonist was reported. A 460 consecutive 460 Japanese subjects (211 men, 249 women; mean age ± standard deviation, 69.9 ± 14.5 years) who had used either a FP agonist (0.005% latanoprost, 0.0015% tafluprost, 0.004% travoprost, 0.03% bimatoprost, or fixed combinations of these) or EP2-agonist (0.002% omidenepag isopropyl) for more than 3 months in at least 1 eye were retrospectively enrolled. Age, sex, prostaglandin, intraocular pressure (IOP) measured by Goldmann applanation tonometry (IOPGAT) and iCare rebound tonometry (IOPRBT), difference between IOPGAT and IOPRBT (IOPGAT-RBT), PAP grade, and PAP grading items were compared among groups stratified by PAP grade or prostaglandins. Of the study patients, 114 (25%) had grade 0 (no PAP), 174 (38%) grade 1 (superficial cosmetic PAP), 141 (31%) grade 2 (deep cosmetic PAP), and 31 (7%) grade 3 (tonometric PAP). The IOPGAT was significantly higher in grade 3 (17.5 ± 5.4 mm Hg) than grades 0 (15.0 ± 5.1 mm Hg, P = .032) and 1 (14.5 ± 4.2 mm Hg, P = .008), and the IOPGAT-RBT was significantly higher in grade 3 (5.8 ± 3.2 mm Hg) than the other 3 grades (1.3-1.9 mm Hg, P < .001 for all comparisons); the IOPRBT was equivalent among the 4 grades. The PAP grade was significantly higher associated with travoprost (2.0 ± 0.8) and bimatoprost (2.0 ± 0.7) than latanoprost (1.0 ± 0.8, P < .001 for both comparisons) and tafluprost (1.0 ± 0.7, P < .001 for both comparisons), but significantly lower associated with omidenepag (0.0 ± 0.0, P < .001 for all comparisons) than the other 4 prostaglandins. Multivariate analyses showed older age (standard β = 0.11), travoprost (0.53, referenced by latanoprost) and bimatoprost (0.65) were associated with higher PAP grades, while tafluprost (-0.18) and omidenepag (-0.73) were associated with lower PAP grades. The PAP graded using SU-PAP reflects the degree of overestimation of the IOPGAT and different severities of PAP among the different prostaglandins. SU-PAP, the grade system constructed based on the underlining mechanisms of PAP, is a simple grading system for PAP that is feasible for use in a real-world clinical situation.

New considerations for the clinical efficacy of old and new topical glaucoma medications

Glaucoma is the most common form of irreversible blindness in the world. Lowering intraocular pressure (IOP) remains the only clinically established method of treatment to slow the progression of glaucoma. Primary open angle glaucoma is a disease of the optic nerve head and often is associated with changes to the trabecular meshwork that cause a reduction to aqueous humour outflow and an increase in intraocular pressure. Until recently, topical IOP lowering medication has been limited to the mechanisms of action of decreasing aqueous production and/or redirecting outflow to the unconventional uveoscleral outflow pathway. Both of these mechanisms neglect to treat or act on tissue that becomes altered from glaucoma. Latanoprostene-bunod 0.024%, a nitric-oxide donating prostanoid, netarsudil 0.02%, a potent Rho-associated protein kinase (ROCK) inhibitor and norepinephrine transporter inhibitor, and a once daily dosed fixed combination medication with netarsudil 0.02% and latanoprost 0.005% have recently come on the market. This paper will discuss and review the limitations to traditional IOP lowering glaucoma medications as well as the mechanism of actions and clinical efficacy of the new glaucoma medications. It will also discuss how the new class of glaucoma medications might help to overcome some known limitations in treatment and barriers to patient adherence.

Effects of the Selective EP2 Receptor Agonist Omidenepag on Adipocyte Differentiation in 3T3-L1 Cells

Purpose: We aimed at comparing the effects of omidenepag (OMD) with those of prostaglandin F (FP) receptor agonists (FP agonists) on adipogenesis in mouse 3T3-L1 cells. Methods: To evaluate the agonistic activities of OMD against the mouse EP2 (mEP2) receptor, we determined cAMP contents in mEP2 receptor-expressing CHO cells by using radioimmunoassays. Overall, 3T3-L1 cells were cultured in differentiation medium for 10 days and adipocyte differentiation was assessed according to Oil Red O-stained cell areas. Changes in expression levels of the adipogenic transcription factors Pparg, Cebpa, and Cebpb were determined by using real-time polymerase chain reaction (PCR). OMD at 0.1, 1, 10, and 40 μmol/L, latanoprost free acid (LAT-A) at 0.1 μmol/L, or prostaglandin F_2α (PGF_2α), at 0.1 μmol/L were added to cell culture media during adipogenesis. Oil Red O-stained areas and expression patterns of transcription factor targets of OMD or FP agonists were compared with those of untreated controls. Results: The 50% effective concentration (EC₅₀) of OMD against the mEP2 receptor was 3.9 nmol/L. Accumulations of Oil Red O-stained lipid droplets were observed inside control cells on day 10. LAT-A and PGF_2α significantly inhibited the accumulation of lipid droplets; however, OMD had no effect on this process even at concentrations up to 40 μmol/L. LAT-A and PGF_2α significantly suppressed Pparg, Cebpa, and Cebpb gene expression levels during adipocyte differentiation. Conversely, OMD had no obvious effects on the expression levels of these genes. Conclusions: A selective EP2 receptor agonist, OMD, did not affect the adipocyte differentiation in 3T3-L1 cells, whereas FP agonists significantly inhibited this process.

In Vivo Analysis of Prostaglandins-induced Ocular Surface and Periocular Adnexa Modifications in Patients with Glaucoma

BACKGROUND/AIM

Prostaglandin analogues (PGAs) are a first-line medical treatment for glaucoma because of their powerful intraocular pressure (IOP) lowering effect, few systemic side-effects (SEs), and the once daily administration. Despite the high systemic safety profile, the chronic use of PGAs may induce periocular and ocular surface (OS)-related side effects, which affect a significant proportion of glaucomatous patients. In this review, we summarize the current knowledge about SEs of PGAs on periocular structures and OS, and their implications in clinical practice.

MATERIALS AND METHODS

A comprehensive literature search on the PubMed platform was performed. Two hundred fifty articles fulfilling key words were identified, of which 180 were excluded since they did not concern the effects of PGAs on the periocular tissues and OS, or because of their limited relevance. The following key words were used and combined, to narrow-down the literature: "prostaglandin" and "ocular surface," which identified 184 unique publications, of which 68 were selected; "prostaglandin" and "periocular" which identified 46 unique publications, of which 11 were selected. An additional search was conducted using "prostaglandin" and "Meibomian glands (MGs)", which identified twenty unique publications, of which 8 were selected. Thus, a total of 70 articles were chosen based on their relevance and were included in this review.

RESULTS

Prostaglandin-associated peri-orbitopathy, skin pigmentation and hypertrichosis, eyelash growth, and MGs dysfunction are the most frequent modifications of periocular tissues. They are induced by the tissue accumulation of PGAs, and FP receptor stimulation. Without preservatives, PGAs act as stimulators of conjunctival goblet cells, which are the main source of ocular surface mucoproteins, and seem to increase conjunctival epithelium microcysts proposed as in vivo hallmark of the trans-scleral aqueous humour outflow. Additional PGA-induced modifications can be recognized in the cornea, corneo-scleral limbus, conjunctival stroma and, conjunctiva-associated lymphoid tissue, mainly appearing as inflammatory changes. OS epithelia desquamation, chemosis, apoptosis, dendritic cell activation, conjunctival or episcleral vasodilation, and sub-basal nerve plexus disruption were also described in patients receiving preserved PGAs.

CONCLUSION

PGAs induce several modifications of the OS structures and adnexa; nonetheless, none of them significantly reduces the local safety profile of this class of drugs. Moreover, the OS changes do not affect the IOP lowering efficacy of PGAs. On these bases, local SEs of PGAs should not discourage clinicians in using this class of medications because of their efficacy, the systemic safety profile, and the better adherence.