Why are cataracts possible?

A cataract is a clouding of the lens, obstructing the light to the retina.

Worldwide, cataracts are the number one cause of preventable blindness. https://eyesurgeryguide.org/global-cataract-surgeries-20-million-annually/ The World Health Organization estimates that cataracts cause distance vision impairment in 94 million people. https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment A cataract is a clouding of the lens, obstructing the light to the retina at the back of the eye. If the condition is left untreated, the resulting hazy vision can progress to blindness. https://eyesurgeryguide.org/global-cataract-surgeries-20-million-annually/ Cataracts can develop gradually and painlessly, so vision and lifestyle can be affected without a person realizing it. https://eyewiki.org/Cataract No established and widely accepted medical treatment is yet available to prevent the development or progression of cataracts. https://eyewiki.org/Cataract

Initially, cataracts can be addressed with prescription glasses. When cataracts progress beyond what glasses can correct, the only option is surgical: modern cataract surgery is the only definitive treatment for cataracts. https://eyewiki.org/Cataract The procedure replaces the cloudy lens with a clear intraocular lens (IOL). https://eyewiki.org/Cataract Cataract surgery is the most effective and most common procedure performed in all of medicine, and has an overall success rate of 97 percent or higher when performed in controlled settings. https://eyewiki.org/Cataract

What causes a cataract?

A cataract at its most fundamental level is an accumulation of protein in the lens. Lens have the highest concentration of protein of any tissue in the body. https://www.sciencedirect.com/topics/neuroscience/lens-protein This protein is long-lived, provides refractive accuracy and regulates water content. https://www.sciencedirect.com/topics/neuroscience/lens-protein However, its protein-rich composition can make the lens prone to protein aggregation and -- whether eventually or suddenly -- that extra protein forms cataracts. https://www.sciencedirect.com/topics/neuroscience/lens-protein There are several types of cataract including age-related, traumatic, and metabolic.

Age-related cataracts

“Age is the biggest risk factor for cataracts,” notes Dr. Jason M Dettori, a volunteer ophthalmologist with Cure Blindness Project. “Aging is the number one cause, as it's a normal process for all of us.”

Signs of age-related cataracts are a gradual decline in vision, blurry vision, difficulty reading in dim light, poor vision at night, glare and halos around lights, and occasionally double vision. https://eyewiki.org/Cataract The prescription in glasses may change more frequently and people might acquire a new ability to read without reading glasses once they reach their mid-50s. https://eyewiki.org/Cataract

“Sometimes the vision may look really good on the chart so it's not just about the vision according to the chart, but about the type of cataract,” comments Dr. Ashiyana Nariani, Senior Technical Advisor on Ophthalmic Training and Research for Cure Blindness Project. “Some patients also experience color desaturation where colors like reds and blues are not as vibrant as they used to be.”

Traumatic cataracts

A traumatic cataract can occur after injury, electrocution, chemical burns, and exposure to radiation. https://eyewiki.org/Cataract

“Any concussive force trauma to the eyeball itself or to the head and neck area can be enough to cause a cataract to form,” Dettori observes. “What’s unique about traumatic cataracts is that a cataract can form quickly, in the matter of months, whereas normal age-related cataracts progress slowly over years and years.”

The good news is that eyesight can be restored after trauma. “Traumatic cataracts can be corrected long after the trauma, provided the rest of the eye—the retina, the optic nerve—remains healthy,” Dettori explains. Even years after the injury, sight can be restored when the cataract is surgically removed.  If the trauma damages the optic nerve or the retina, however, there might be a smaller time frame in which to treat the eye and bring back visual acuity.

Metabolic cataracts

Metabolic cataracts occur in uncontrolled diabetics, patients with galactosemia, and those with Wilson disease. https://eyewiki.org/Cataract Nariani adds other conditions: atopic dermatitis and myotonic dystrophy Type 2. “Both result in specific design patterns,” she reports. “Myotonic dystrophy will have something called a Christmas tree cataract, a pattern resembling a sparkling Christmas tree with ornaments.”

Cataract surgery is effective

Modern cataract surgery removes the cataract-affected lens and replaces it with an intraocular lens (IOL), each with a specified IOL power. 

Cataract surgery is known for its safety record; complications are rare. Approximately 97% of the surgeries are successful and vision is improved. https://my.clevelandclinic.org/health/treatments/21472-cataract-surger

Surgical approaches can vary: manual small incision, phacoemulsification, and femtosecond laser-assisted are available and each has its advantages. Traditional cataract surgery, manual small incision, has proven to be very effective. It involves small tools and no electricity so manual small incision cataract surgery (SICS) is extremely portable and ideal for reaching rural patients. Phacoemulsification employs ultrasound lasers to break up the cataract, remove them, and place an IOL; the procedure has a faster healing time for patients and is also extremely effective. Femtosecond laser-assisted cataract surgery (FLACS) is the most modern, with a reduced surgery time and recovery rate, https://www.optometrists.org/general-practice-optometry/guide-to-eye-conditions/guide-to-cataracts/cataract-surgery-what-to-expect/femtosecond-lasers-for-cataract-surgery/ although its high cost is a drawback. https://www.healthline.com/health/laser-surgery-for-cataracts

All intraocular lenses (IOLs) are intended to improve vision and limit the need for glasses or contact lenses. https://eyewiki.org/Cataract Types of IOLs used in modern cataract surgery include monofocal, multifocal, accommodative, light-adjustable, and astigmatism-correcting lenses. https://eyewiki.org/Cataract

The IOL is matched to the patient. “The power of the intraocular implant is determined based on the axial length of the eye—the front-to-back diameter of the eye—as well as the curvature of the cornea,” comments Dr. Jason Cheung, volunteer ophthalmologist with Cure Blindness Project.

If we are to live in a world free of avoidable blindness, cataract surgeries must be accessible to everyone around the globe. We at Cure Blindness Project serve in these remote areas. Dr. Ashiyana Nariani, Senior Technical Advisor on Ophthalmic Training and Research for Cure Blindness Project.

Cataract Operations in Low and Middle Income Countries

Only 17% of people with vision impairment or blindness due to cataracts have access to quality surgery. https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment Lack of healthcare access is perhaps the biggest hurdle to providing cataract surgeries in low- and middle-income countries.

Even though cataract surgery is one of the most common surgical procedures, it is not prevalent in rural villages where overall access to care is lacking, Nariani points out. “If we are to live in a world free of avoidable blindness, cataract surgeries must be accessible to everyone around the globe. We at Cure Blindness Project serve in these remote areas.”

Dr. Michael Brush, volunteer ophthalmologist with Cure Blindness Project, sees the problem of doctor distribution in Ghana. “The number of ophthalmologists in Ghana is still relatively small for the population.” However, Brush is optimistic, “I think over the next couple of decades, that number is going to increase through the training processes. We are addressing the significant need by getting surgeons trained.”

Eye surgeons, including Brush, Cheung, Dettori, and Nariani, provide training for fellows and practicing ophthalmologists in countries where Cure Blindness Project serves. The traveling ophthalmic surgeons of Cure Blindness Project offer local ophthalmologists guidance and hands-on experience to get more comfortable with technology. “The last four or five years, I have worked with many doctors to get them comfortable with independently operating and adding [phacoemulsification] to their skill set,” states Brush. 

Dettori spoke for the Cure Blindness Project doctors when he explained how inspiring the doctors-in-training were to him in Ghana. “Their skill set is amazing. For example, most of the doctors we worked with were competent in manual small incision cataract surgery and were learning phaco. A lot of them had taken on [additional fellowship trainings] in subspecialties like oculoplastics or retina.” 

As a trainer of ophthalmologists in India, Nariani points out that in the country’s government municipal hospital settings: “We get patients from all across India who couldn't afford care. Their bill would be pretty minimal except for buying their own supplies. They would not have to pay for a surgeon, diagnostic testing, tools, instruments, operation theaters, or admissions. It is basically at cost.” The accessibility of high-quality eye care in India is a goal for the rest of the globe, especially in low- and middle-income countries.

How Cure Blindness Project Ends Cataracts

Approximately 43 million people in the world are blind. Cataract surgeries are crucial surgeries in the global treatment of avoidable blindness. Cure Blindness Project, a global non-profit organization, helps to provide cataract surgeries to cure treatable or preventable blindness in underserved communities in 30 nations across sub-Saharan Africa, South Asia and South America.

Cure Blindness Project’s model begins with bringing high quality care to those who need it and offers cataract surgeries through its volunteer ophthalmologists and building well-trained local capacity. Cure Blindness Project ophthalmologists with partners have performed approximately 1.6 million sight restoring surgeries. For early detection of eye disease, including cataracts, Cure Blindness Project has conducted more than 16.5 million eye screenings for the last three decades. 

Brush with Cure Blindness Project explains how the organization’s efforts have a powerful effect. “One motivation that, I think, drives the work that we do at Cure Blindness Project is knowing how much of an impact this surgery—one that, in very skilled hands, can be done very quickly and very effectively with low risk and low complications—can improve a patient's quality of life so dramatically.”