Morphometric Effects of Long-term Exposure to Latanoprost

Phosphodiesterase inhibitors and prostaglandin analogues in dermatology: A comprehensive review

Due to immune-mediated nature, medicines with immunomodulatory and anti-inflammatory effects can used to treat many dermatologic diseases. Phosphodiesterase and prostaglandins are involved in many inflammatory pathways that cause cutaneous disorders. Phosphodiesterase inhibitors (PDEIs) and prostaglandin analogues are currently employed to treat several dermatologic disorders. Given the few comprehensive reviews in this context, focusing on the dermatologic applications and efficacy of these medicines appears valuable. The present comprehensive review was, therefore, performed on the applications of PDEIs and prostaglandin analogues in different cutaneous disorders. All the relevant articles were selected to perform this review by searching databases such as Medline, Google Scholar, Scopus, and Web of Science. Oral PDEIs, especially apremilast, is an effective medicine in psoriasis and a number of other cutaneous disorders such as vitiligo. Topical PDEIs, including crisaborole ointment 2%, is a safe and effective treatment in atopic dermatitis. Prostaglandin analogues, especially their topical forms such as latanoprost and bimatoprost, have different applications in cutaneous disorders, including pigmentary disorders, especially vitiligo and hair repigmentation; for instance, bimatoprost is used for eyelash repigmentation. Prostaglandin analogues are also used in alopecia, including androgenetic alopecia and alopecia areata. Oral (apremilast) and topical (crisaborole) PDEIs and topical prostaglandin analogues, including latanoprost and bimatoprost, were found safe and effective in different skin diseases. In terms of efficiency and safety, these medicines compete with other medications of similar use even with higher efficacy and fewer side effects that necessitate further studies.

Effects of 0.4% ripasudil hydrochloride hydrate on morphological changes in rabbit eyes

We evaluated the cellular structure changes after continuous use of ripasudil hydrochloride hydrate in rabbit eyes which might affect its own efficacy and adverse effects. Two pigmented Dutch rabbits and 1 Japanese white rabbit were instilled with 0.4% ripasudil hydrochloride hydrate to the left eye twice daily. The right eye was observed as the control. Both eyes of all 3 rabbits were then enucleated for histopathologic examination by light and electron microscope at 1mo in 1 of the pigmented Dutch rabbits, 3mo in the other pigmented Dutch rabbit, and in the Japanese white rabbit after instillation. Microscopic observations showed increase intercellular space in trabecular meshwork, ciliary body, and iris stoma, increase pigmented granule number and size in iris epithelial cells, and decrease actin filament in iris muscle fiber cells. Consequently, ripasudil hydrochloride hydrate decreases the intraocular pressure by improving the conventional outflow and may also facilitate the unconventional outflow via intercellular space widening without serious side effects.

Anterior Segment Optical Coherence Tomography Analysis of Iris Morphometric Changes Induced by Prostaglandin Analogues Treatment in Patients with Primary Open Angle Glaucoma or Ocular Hypertension

Background:

The study aimed to evaluate iris thickness changes in patients with Primary Open Angle Glaucoma (POAG) or Ocular Hypertension (OHT) under treatment with Prostaglandin Analogues (PG).

Objectives:

Primary outcome measures were iris thickness at the region of Dilator Muscle Region (DMR) and Sphincter Muscle Region (SMR). DMR/SMR ratio was also evaluated. The secondary outcome was the correlation between PG treatment length and iris parameters.

Methods:

The charts of patients with POAG or OHT who underwent Visante OCT were retrospectively selected. The patients were divided in a group using PG for at least 6 months and a group using hypotensive drops not including PG or alpha-adrenergic agonists. A third group included healthy subjects.

Result:

98 subjects were selected. Patients with POAG or OHT using PG eyedrops showed a significant iris thickness reduction at DMR compared to healthy subjects and to patients using hypotensive eyedrops not containing PG. Significantly higher SMR thickness values were found in PG group compared to both control groups. DMR/SMR ratio significantly reduced in PG group. No correlation was found between PG treatment length and iris parameters.

Conclusion:

The present data indicate that PG treatment induced DMR thickness reduction and an increase in SMR thickness. These changes were not related to the duration of PG exposure.

Periocular mexametric melanin and erythema indexes in adult glaucoma patients treated with topical prostaglandin analogs

CONTEXT

Although topical prostaglandin analogs (PGAs) have been previously associated with periocular skin hyperpigmentation, studies using objective clinical methods are lacking. Furthermore changes in periocular skin erythema indexes associated with topical PGAs have not been reported previously.

OBJECTIVE

The purpose of the present study was to evaluate periocular melanin and erythema indexes in patients treated with topical PGA using an objective clinical method - Mexameter.

METHODS

About 45 glaucoma patients treated with topical PGA therapy, and 30 age-, and sex-matched controls were enrolled in the study. Demographic data, medical history including duration of therapy, PGA type, involved eye (unilateral, bilateral) were noted, and skin phototypes were evaluated. Melanin and erythema indexes on medial and lateral upper and lower eyelids, and normal skin from the upper cheeks were measured using Mexameter MX-18. The index of difference for lower/upper eyelid was calculated. Reading results of patients and controls were compared.

RESULTS

Melanin and erythema indexes of upper/lower eyelids, and the index of differences for upper/lower eyelids were significantly higher in patients despite similar clinical findings (p < 0.05). Duration of therapy and type of PGA were not associated with skin changes (p > 0.05).

CONCLUSIONS

Both periocular melanin and erythema indexes increased in both upper and lower eyelids due to PGA therapy compared to controls, despite similar clinical findings. Mexametric evaluation is more sensitive than clinical evaluation, and may be used as an objective, sensitive clinical method to evaluate periocular skin changes, even smallest changes, in such patients.

Repigmentation of Hypopigmented Scars Using Combination of Fractionated Carbon Dioxide Laser with Topical Latanoprost Vs. Fractionated Carbon Dioxide Laser Alone

Background:

Fractionated carbon dioxide (CO₂) can treat hypopigmented scars. Latanoprost is a prostaglandin analog used to treat glaucoma. It can cause adverse effects, such as periocular hyperpigmentation. The aim of this study was to assess the efficacy and safety of latanoprost plus CO₂ laser on the repigmentation of hypopigmented scars.

Patients and Methods:

28 patients with hypopigmented scars were divided randomly into two groups. The patients in group A were treated in six sessions (1-month intervals) with 10600-nm fractional CO₂ laser plus latanoprost 0.005% and those of group B fractionated CO₂ laser plus placebo (distilled water). Digital photographs were taken at baseline and 3 months after the last treatment session. The blinded dermatologist compared the photographs and evaluated the efficacy of treatment in the hypopigmented scars using a 4-scale point (grade 1-4). Patient satisfaction was scored from 0 to 10 on a visual analog scale.

Results:

Follow-up results 12 weeks after the last treatment session demonstrated that 11 of the 14 patients in group A had more than 50% improvement in hypopigmentation The difference in improvement of the two groups was statistically significant (P = 0.027). The mean of the VAS scores of patients in group A was 6.50 ± 1.45 and in group B 4.57 ± 1.6. The difference in mean satisfaction of the two groups was statistically significant (P = 0.003). Side effects were mild and resolved within 1 to 5 days.

Conclusion:

The fractional CO₂ laser resurfacing plus topical latanoprost can be used as a safe and efficacious method to treat hypopigmented scars.

Therapeutic uses of prostaglandin F(2α) analogues in ocular disease and novel synthetic strategies

The pharmacological management of glaucoma and ocular hypertension has significantly changed over the last 18 years with the introduction of PGF2α analogues, more specifically latanoprost (6), travoprost (8), bimatoprost (10) and tafluprost (12). Prostanoids are currently the first-line medicines among ocular antihypertensive drugs in terms of efficacy, safety, patient compliance and medical economy. Their ability to effectively reduce intraocular pressure with once-per-day dosing, ocular tolerability comparable to timolol and general lack of systemic adverse effects have made them the mainstay of pharmacological therapy for glaucoma and ocular hypertension all over the world. The present review reports a novel, convergent and highly diastereoselective method for the synthesis of PGF2α analogues from the structurally advanced prostaglandin phenylsulfone (5Z)-(+)-15 and new ω-chain synthons. The biochemistry, clinical efficacy and side effects of four commercially available PGF2α analogues, currently used as first-line agents for reducing intraocular pressure in patients with glaucoma or ocular hypertension, are also discussed.

Do antiglaucomatous prostaglandins induce melanogenesis in human conjunctiva?: an impression cytology pilot study

PURPOSE

To determine the effect of antiglaucomatous prostaglandin analogs on conjunctival melanogenesis.

METHODS

For this pilot study, 30 glaucomatous patients treated with prostaglandin drops (alone and in association to beta-blockers) and 30 control subjects (15 healthy volunteers and 15 patients treated with beta-blockers) were included in this transversal, single masked, case-control, observational study. Skin complexion, eye color, conjunctival pigmentation, lacrimal tests, and corneal fluorescein staining were evaluated. Immunoreactivity for Tyrosinase was assayed on conjunctival imprints.

RESULTS

Twenty percent of patients treated with prostaglandins and 10% of the control subjects clinically manifested conjunctival pigmentation (P=0.279). Only 4% (8/198) of the conjunctival specimens were positive to Tyrosinase immunostaining, with no statistically significant difference among the groups (P=0.449). In all cases, the proportion of positive cells was below 4%. When compared with subjects having negative specimens, those with positive immunostains did not show any statistically significant difference in skin complexion, eye color or exposure to irritants, and ultraviolet (P>0.05).

CONCLUSIONS

According to our preliminary results, prostaglandin antiglaucomatous analogs do not significantly enhance pigmentation in the superficial layers of the conjunctiva. The existence of the Tyrosinase enzyme in the superficial layers of the conjunctiva suggests that basal melanocytes may transfer their melanogenic apparatus to superficial epithelial cells.

Side effects associated with prostaglandin analog therapy

Topical prostaglandin analogs, which have become first-line therapy in the medical management of glaucoma, have an excellent safety profile with regard to systemic side effects, but are associated with several ocular side effects. Some of these are common, with no apparent serious consequences other than cosmetic, whereas others are much less common but represent potentially sight-threatening side effects. The former group includes conjunctival hyperemia, elongation and darkening of eyelashes, induced iris darkening, and periocular skin pigmentation. The latter group of side effects, which are relatively rare and lack definitive causal relationship to prostaglandin analog therapy, includes iris cysts, cystoid macular edema, anterior uveitis, and reactivation of herpes simplex keratitis. Most of the literature regarding side effects associated with prostaglandin analogs involves the use of latanoprost, probably because it was the first to be studied. There is no evidence, however, aside from less conjunctival hyperemia with latanoprost, that the commercially available prostaglandin analogs differ significantly with regard to side effects.

A study of histopathological features of latanoprost-treated irides with or without darkening compared with non-latanoprost-treated irides

OBJECTIVES

To study the histopathological features of latanoprost-treated irides with or without darkening, compared with non-latanoprost-treated irides.

METHODS

Iridectomy specimens and patient history forms were independently examined by 3 ophthalmic pathologists in a masked fashion. Specimens were evaluated for premalignant changes and for differences in level of pigmentation and degrees of cellularity, inflammation, and vascular abnormalities.

RESULTS

The specimens consisted of 22 latanoprost-treated darkened irides, 35 latanoprost-treated irides without darkening, and 35 non-latanoprost-treated irides. There was a statistically significant decrease in the number of nuclear invaginations and prominent nucleoli in latanoprost-treated darkened irides compared with the other 2 groups (P = .004 and P = .005, respectively). The average thickness and pigmentation of the anterior border layer was greater in the latanoprost-treated darkened irides than in the other 2 groups (P = .03 and P = .02, respectively). The latanoprost-treated darkened irides had increased pigmentation of the stroma (P < .001), stromal fibroblasts (P < .001), melanocytes (P = .005), vascular endothelium (P = .02), and adventitia (P < .001) relative to the other 2 groups.

CONCLUSIONS

There is no histopathological evidence of premalignant changes in latanoprost-treated darkened irides. The latanoprost-induced iris color changes are due to a thickening of the anterior border layer and an increased amount of melanin in the anterior border layer and within the stromal melanocytes.

Monte Carlo simulation of latanoprost induced iris darkening

The aim of this study was to provide numerical evidence that latanoprost induced iris darkening (LIID) can be caused by changes to the melanin granule size distribution in the anterior segment of the iris. Iridectomies from two patients were used, where both had undergone unilateral treatment with latanoprost and had exhibited LIID. The untreated eye provided the comparative control. Micrographs from the iris samples were analysed to determine the number and size of the mature melanin granules. Monte Carlo (MC) simulation of light propagation in the iris was performed to examine the changes in reflectance and absorption with varying particle size and density. The reflected intensity of light was obtained as a function of wavelength. CIE colour theory was employed in order to estimate a perceived colour from the reflectance data. MC simulations showed that the reflectance was reduced for the LIID irises compared to the control irises for both subjects and for all wavelengths of light. The MC simulated colours were in good agreement with the in vivo photography of the eye colour. Hence, we have demonstrated that increases in melanin granule size causes iris darkening, and can explain LIID.