Glaucoma today remains the main cause of visual disability in teh USA and accounts for more than a third of cases of all newly recognized disabled people.
Primary open-angle glaucoma (POAG) is considered one of the main factors leading to vision loss.
The prevalence of this dangerous disease increases with age. So, at the age of 40-45 years, 1% of the population suffers from POAG, at 50-60 – 1.5-2.0%, at 75 years and older – more than 18%.
Local conservative antihypertensive therapy occupies a leading place in the complex of therapeutic measures. Prostaglandin preparations have proven to be highly effective modern agents for the treatment of patients with glaucoma, capable of maintaining a low level of intraocular pressure (IOP) with slight fluctuations during the day, maintaining hypotensive activity for a long time, and having a convenient and simple dosing regimen. The main mechanism of action of this series of drugs is an increase in uveoscleral outflow due to interaction with specific receptors, the transition of inactive matrix proteases of the ciliary muscle into an active form, the destruction of collagen fibrils of the extracellular matrix by proteases, a decrease in the thickness of the ciliary muscle and resistance to the outflow of aqueous humor.
The group of prostaglandins/prostamides currently includes such drugs as bimatoprost and latanoprost. The use of drugs from the group of prostaglandin analogues has a pronounced clinical efficacy. The proportion of starting monotherapy with prostaglandins represented by latanoprost and bimatoprost is 51-57%, depending on the stage of the disease.
What is the difference between latanoprost and bimatoprost?
Bimatoprost (Lumigan) is a representative of the class of prostaglandin analogues, is a synthetic analogue of prostamides and structurally differs from latanoprost (Xalatan) and travoprost by the absence of a carboxylic acid group in the molecule. A number of studies have suggested the presence of prostamide-sensitive receptors that differ from receptors for other prostaglandin analogues. After instillation, a significant amount of bimatoprost was found in the ciliary body, as well as the product of its hydrolysis in the form of free acid – in the intraocular fluid (AHF), which suggested an additional mechanism for passing through the cornea as a prodrug.
Bimatoprost, like other drugs in its class, primarily has a therapeutic effect by increasing uveoscleral outflow. However, some studies have also shown improvement in trabecular outflow. The effect on efflux is thought to be through remodeling of the extracellular matrix in tissues. A number of studies also indicate the possibility of the drug’s effect on increasing the permeability of the sclera.
Latanoprost is a synthetic analogue of prostaglandin F2α, is a selective FP receptor agonist, synthesized in 1996 specifically to reduce IOP in glaucoma and ophthalmohypertension. The hypotensive effect is provided by an increase in uveoscleral outflow. Currently, more than 100 generic latanoprost monopreparations are registered on the international pharmaceutical market.
Bimatoprost (Lumigan) and latanoprost (Xalatan) are among the most effective drugs in the treatment of POAG, but the distinctive features in the hydrodynamic parameters of the eye of patients with long-term use are interesting: for example, the secretion of intraocular fluid (F) in patients who instill latanoprost for a long time increases, while with bimatoprost it decreases. Side effects of drug instillations are more pronounced in bimatoprost. Given the distinctive features of these drugs, the study of the hypotensive effect, hydrodynamics, tolerability is becoming an interesting and quite relevant issue at the present time.
Bimatoprost (Lumigan) vs Latanoprost (Xalatan) for glaucoma and eyelash growth
- Bimatoprost 0.03% (Lumigan) has a pronounced hypotensive effect in patients with newly diagnosed stage I and II open-angle glaucoma, which proves a decrease in IOP from 17.2±3.1 to 13.9±1.8 mm Hg. . mainly due to an increase in the ease of outflow (C) from 0.081±0.042 to 0.198±0.044 mm3/min/mm Hg. Latanoprost 0.005% (Xalatan) also has a pronounced hypotensive effect, which proves a decrease in IOP from 21.5±2.3 to 18.4±1.7 mm Hg. mainly by increasing the ease of outflow. However, in the implementation of the high hypotensive effect of bimatoprost, not only an increase in the ease of outflow is involved, but also a significant decrease in the production of aqueous humor.
- Individual IOP on the background of monotherapy of both drugs was achieved in 123 patients (246 eyes) – 100% of cases.
- The drugs are well tolerated, since the side effects that occurred in 10 patients (17.4% of 46 patients) did not require additional treatment and were not critical and weighty reasons for discontinuing or replacing the drug. However, a higher number was observed with bimatoprost (8 cases) than with latanoprost.
- Lumigan and Xalatan have similar prices – Lumigan costs $65.17 per bittle, and Xalatan costs $64.80 per bottle.
- Bimatoprost 0.03% (Lumigan) and latanoprost 0.005% (Xalatan) are convenient to use, which was noted by patients.
- When first diagnosed primary open-angle glaucoma in advanced and terminal stages, the doctor should think in favor of surgical treatment of glaucoma, as this is the most reliable way to reduce IOP.