Cataracts are one of the most widely encountered conditions in eye care, affecting most people directly or through someone close to them. Yet according to Sydney-based corneal and cataract surgeon Dr Tanya Trinh, the condition is still widely misunderstood, both in terms of who is at risk and what can be done about it.
Cataracts as a normal part of ageing
Dr Trinh describes cataracts in the same terms she uses for grey hair or wrinkles: an inevitable consequence of living long enough. A cataract develops when the lens inside the eye, which is normally clear, gradually becomes cloudy, eventually affecting vision. If a person is fortunate enough to have a long life, she says, they will also have the privilege of developing a cataract at some point. This framing matters, Dr Trinh notes, because cataracts are sometimes met with alarm when in fact they are one of the most predictable and treatable parts of ageing eyes.
Several factors can bring cataracts on earlier than expected
While age is the single biggest driver, a number of other factors can accelerate cataract formation, sometimes by decades. Diabetes is one of the most significant: elevated blood sugar impairs the lens's ability to clear free radicals as it grows, leading to earlier and more rapid cataract development in people with poorly controlled diabetes. Cumulative ultraviolet exposure is another major contributor, which is why cataract rates are disproportionately high in populations living near the equator. Long-term systemic steroid use, radiation exposure and prior trauma to the eye can all bring on cataracts prematurely as well. Dr Trinh notes that when a cataract appears in only one eye in a patient in their 40s or 50s, rather than the more typical age-related pattern affecting both eyes gradually, she will specifically ask about a history of eye injury, since a one-off trauma from years earlier, even a childhood accident, can be the underlying cause.
Diabetes can complicate treatment as well as cause it
Diabetes doesn't only bring cataracts on earlier — it can also complicate what happens after cataract surgery. Dr Trinh explains that when the retina at the back of the eye isn't receiving enough oxygen, a common feature of diabetic eye disease, it sends out chemical signals that prompt abnormal blood vessel growth. Removing a cataract can inadvertently make it easier for these signals to reach the front of the eye, potentially worsening complications there if the underlying diabetic eye disease isn't already well controlled. This is one of the reasons Dr Trinh takes a whole-eye view when planning cataract surgery in diabetic patients, rather than treating the cataract in isolation. She notes that management of these complications has improved substantially in recent years, with targeted eye injections now largely replacing the laser treatments once used to reduce this risk.
Left untreated, cataracts don't resolve on their own
Unlike some eye conditions that can plateau, Dr Trinh is clear that an untreated cataract will, given enough time, progress to complete opacity, regardless of its underlying cause. There is no equivalent of watchful waiting that leads to improvement. This is part of why she encourages patients not to delay assessment once symptoms start affecting daily life, even though cataracts themselves are rarely an emergency.
Cataract surgery remains one of the most common, and most effective, procedures in medicine
Cataract extraction is the most frequently performed surgery in the world, and Dr Trinh describes it as one of the most genuinely transformative procedures in her field, often restoring vision that has gradually declined over years without the patient fully realising how much they had adapted around it. She also points to emerging evidence linking cataract surgery to broader health outcomes, including in cognitive health, an area of growing research interest. For most patients, cataract surgery is a well-understood, low-risk procedure with a very high rate of success, and the outlook for anyone facing one is, in Dr Trinh's words, ultimately a positive one.
Source: Interview with Dr Tanya Trinh, conducted by Prof Hosen Kiat for the TAIK Health Community.
Dr Tanya Trinh, co-director of Australia's only Keratoprosthesis Service at Sydney Eye Hospital and founder of LUMIÈRE Vision, is a Clinical Collaborator with the TAIK Health Community.
