Introduction
The most common cause of visual impairment in the world, cataracts, are caused by aberrant lens protein aggregation. More than 40 percent of incidents of blindness, according to the World Health Organization, are caused by cataracts. The frequency of cataracts will rise quickly as the population ages. Although cataract surgery is beneficial, it still has difficulties, is expensive, and cannot keep up with the rising demand for surgeries.
As a result, patients have a more affordable and accessible choice of pharmaceutical therapy for cataracts. As a result, cataracts may benefit from the therapeutic effects of antioxidants and ROS scavengers. Upregulating GSH and GSH production enzymes might prevent cataract development. Glutathione (GSH), abundant in the lens, is critical in reducing oxidative stress. Therefore, pharmacological therapy, which has a smaller financial burden and is more widely available, is the best option for cataract prevention and treatment.
What Is Cataract?
A cataract is a clouding of the eye lens that happens over time and impairs vision. It is brought on by the lens's proteins being clumped together, which scatter light and significantly lower retinal transmission. Millions of individuals worldwide lose their vision from cataracts and become blind.
The most common cause of vision loss is cataracts, seen as an opacity of the lens. Cataracts can be classified into two categories based on etiology: congenital and acquired. The former is mostly connected to genetic inclinations. The latter is linked to aging, genetics, illnesses, medicines, smoking, UV exposure, and frequent risk factors for cataracts.
What Is the Importance of Endogenous Antioxidants in Cataracts?
The cornea, trabecular meshwork, and lens, which comprise the anterior part of the eye, are predominately composed of two endogenous antioxidants, ascorbic acid, and glutathione. These tissues are avascular and prone to oxidative deterioration throughout their lifespan. Fundamentally, these two antioxidants are essential for scavenging and repairing any harm caused by reactive oxygen and free radical species.
The corneal epithelium is thought to have the highest levels of ascorbic acid (vitamin C), whereas the lens has the highest levels of GSH. Due to a deficiency of the enzyme L-gluconolactone oxidase, humans cannot produce ascorbic acid on their own and must thus obtain it from other sources. The lens's ascorbic acid guards the lens' cation pumps and inhibits membrane lipid peroxidation. The transfer of ascorbic acid from the aqueous humor to the lens may be mediated by aquaporin 0, according to recent research.
What Is the Pharmacological Treatment of Cataracts?
Pharmacological therapy's primary goals are to postpone lens opacification while lowering morbidity and medical expenses. A decade's delay at the beginning of the age-induced cataract will likely reduce the operation and accompanying expenditures by half.
Following are the primary characteristics of several pharmacological therapy groups that could show potential for postponing or reversing age-related cataracts.
1. Aspirin is the most effective medication for preventing cataract development, although aspirin-similar medications like Paracetamol and Ibuprofen also showed promising benefits.
2. Aspirin and aspirin-like medications may exert their protective benefits via a number of different processes; these mechanisms may function in concert to provide the desired results.
Some of these mechanisms include:
-
Increasing blood flow results in more nutrients being delivered, allowing for the passage of antioxidants into the aqueous humor and, ultimately, into the lens.
-
Defending the lens proteins from post-translational modification by acetylating free amino group residues and terminal amino groups.
-
Acetylating free amino group residues and terminal amino groups protect the lens proteins from post-translational modification.
-
Reducing blood glucose levels and preventing the production of prostaglandins reduces the generation of malondialdehyde.
-
Potentially having an antioxidant effect because Aspirin therapy was linked to a decrease in free radical stress by lowering lipid peroxidation and GSSG levels.
The primary disadvantage of this pharmacological therapy is the need for high oral dosages (about 1500 mg/day) of Aspirin and Aspirin-like medications to provide cataract prevention for at least 4 to 6 months. Non-steroidal anti-inflammatory medicines (NSAIDs) are widely used after cataract surgery to minimize postoperative symptoms and reduce cystoid macular edema associated with cataract surgery. NSAIDS have shown several promising therapeutic uses in ophthalmology.
3. Depending on whether they are insoluble (lipophilic) or water-soluble (hydrophilic), the antioxidants are divided into two broad categories. GSH, cysteine, cysteine prodrug L-2-oxothiazolidine-4-carboxylic acid (OTZ), N-acetyl carnosine, N-acetylcysteine, and N-acetylcysteine amide are a few notable examples of water-soluble antioxidants, thiol antioxidants, and their chemical derivatives that have recently been highlighted as anti-cataractogenic agents.
4. Curcumin, quercetin, and diosmin are a few examples of natural flavonoids, and -carotene, lutein, and lycopene are a few examples of natural carotenoids. These compounds have strong antioxidant activity; studies have shown they may effectively prevent cataracts.
5. Some researchers have noted a beneficial impact on lens transparency at a dosage of 500 mg orally three times daily with Bendazac lysine. This AR inhibitor has an anti-denaturant action on proteins and has been used for decades to avoid early cataracts.
Conclusion
The most common cause of vision recession around the globe is cataracts. Despite the fast advancements in cataract surgery technology, the procedure is still expensive and popular, particularly in poorer nations. Therefore, pharmacologic treatment may effectively lessen the disease burden, lower medical expenses, and assist patients in rural regions. Numerous studies have been conducted in the past several decades on using antioxidants, AR inhibitors, and sulfhydryl combinations of quinoid substance inhibitors as pharmacological treatments for delaying the development of cataracts. To know more, consult the doctor online.
