The idea of using eye drops to cure cataracts is compelling, but the direct answer is no, not yet. Currently, no commercially available eye drop can dissolve or reverse the clouding of the eye’s natural lens that defines a cataract. While this medical reality is disappointing, researchers are making significant progress toward a non-surgical solution. A cataract occurs when the normally clear lens, positioned behind the iris, becomes opaque, causing light to scatter and resulting in blurred vision.
Understanding Cataracts: The Clouded Lens
The eye’s lens maintains transparency through specialized structural proteins called crystallins. These proteins are tightly packed and arranged to allow light to pass through the lens without obstruction. Unlike most proteins in the body, crystallins are never replaced, meaning they must remain stable and soluble for a lifetime.
Over decades, damage from factors like oxidation and ultraviolet (UV) light can cause these proteins to misfold. When crystallins lose their correct structure, they begin to aggregate, or clump together, forming clusters. Once these protein clumps reach a size comparable to the wavelength of visible light, they scatter the light entering the eye, leading to the cloudy vision of a cataract.
The Current Status of Eye Drop Treatments
Existing commercial eye drops, such as those used to manage dry eye or reduce inflammation, address symptoms but do not affect the underlying cataract. These drops cannot penetrate the lens capsule to reach the aggregated crystallin proteins and reverse the clumping. For an eye drop to cure a cataract, it must contain a pharmacological agent capable of breaking down these protein clumps and restoring the lens’s transparency.
The most promising research focuses on molecules that can act as “chemical chaperones” to stabilize or resolubilize the damaged proteins. One compound that generated excitement is lanosterol, a naturally occurring sterol involved in cholesterol synthesis. In a 2015 study, lanosterol eye drops reduced the severity of cataracts and increased lens transparency in laboratory tests using rabbits and dogs.
Lanosterol appears to work by reversing the protein aggregation process, possibly by stabilizing healthy crystallins or dissolving existing clumps. Scientists have also investigated other sterols and compounds, such as “Compound 29,” which show similar potential in preventing or reversing protein aggregation in laboratory settings. Despite these promising animal results, a major challenge remains in formulating a drop that can effectively pass through the protective layers of the human eye and reach the lens at a sufficient concentration. These treatments are not yet approved or available for human use.
Surgical Correction: The Definitive Treatment
While researchers continue to explore pharmaceutical cures, the only definitive method to eliminate a cataract and restore clear vision is surgical intervention. This procedure is one of the most common and successful operations performed worldwide. The standard surgical technique is called phacoemulsification, typically performed on an outpatient basis.
During the procedure, the surgeon makes a tiny incision in the cornea. A small ultrasonic probe is inserted through this opening and uses high-frequency vibrations to break the cloudy lens into microscopic fragments. These fragments are then suctioned out of the eye. Once the clouded lens is removed, it is replaced with a clear, artificial intraocular lens (IOL). The IOL is folded and inserted through the same small incision, where it unfolds and is positioned to function as the new lens. The incision is often self-sealing and rarely requires stitches, allowing for a quick recovery, with the entire procedure typically taking less than 30 minutes.
Steps to Slow Cataract Progression
Given that a non-surgical cure is not yet available, focusing on preventative lifestyle measures is the most effective way to slow the progression of cataracts. Protecting the eyes from ultraviolet (UV) radiation is recommended, as UV light contributes to the oxidative damage that causes protein aggregation. Wearing sunglasses that block 100% of both UVA and UVB rays is an effective step, even on cloudy days.
Dietary choices also play a role in eye health. Consuming a diet rich in antioxidants, such as Vitamin C, Vitamin E, lutein, and zeaxanthin, found in leafy green vegetables and colorful fruits, may help protect the lens proteins from damage. Quitting smoking is important, as smoking can double the risk of cataract development. Managing chronic health conditions, particularly diabetes, is crucial, as high blood sugar levels are associated with accelerated cataract formation.