People living with diabetes make an estimated 180 more health-related decisions each day than those without the condition – yet the ocular surface isn’t always front of mind. Dr Amira Howari explains how dry eye develops in these patients and why proactive management is essential.
As both a clinical optometrist and a person living with diabetes, Dr Amira Howari has come to understand first-hand how this systemic disease can affect the eyes in ways that aren’t always obvious.
Coincidentally, it was during a lecture with Scientia Professor Fiona Stapleton – a global dry eye authority involved in the landmark TFOS DEWS reports – that she began noticing unexplained blurry vision. Immediately after, in the UNSW optometry clinic, she learned she had significantly reduced corneal sensitivity – a subtle but important sign of ocular surface disease.
“I had chronic dry eyes, but I didn’t have the symptoms to go by,” Dr Howari recalls. “That’s the challenge with diabetes: reduced corneal sensitivity means the typical signs patients would describe – gritty, sandy, burning eyes – aren’t always there. Instead, it presents more as a vision-related issue.”
For Dr Howari, who works in interdisciplinary diabetes care and as a diabetes healthcare ambassador across several key organisations, it was a revealing moment. Diagnosed with type 1 diabetes around the age of nine and later a practising eyecare professional, she had long been aware of its risks due to diabetic retinopathy (DR) – a condition she was eventually diagnosed with during pregnancy (that’s another story).
But she hadn’t properly considered how the disease could be silently affecting her ocular surface – and the broader implications of that.
“Six years ago, I underwent a double transplant (kidney-pancreas) due to secondary kidney failure. Looking back, the reduced corneal sensitivity was an early marker of wider nerve damage – forecasting a 10-year trajectory toward peripheral neuropathy and nephropathy. A high-risk pregnancy with gestational hypertension also put extra strain on my kidneys.”
As is often the case, the eye provides a window into deeper systemic issues. And while retinal conditions take centre stage, the ocular surface can be just as debilitating. Dry eye impacts visual function, ocular surface health homeostasis, and overall quality-of-life, yet it can fly under the radar in diabetes care.
This disconnect between signs and symptoms is a key challenge. Reduced corneal sensitivity means patients may not present with the classic complaints. Combined with the competing demands of other systemic complications, dry eye can become less of a priority until it becomes a major problem.
But Dr Howari warns that it should be top of mind for optometrists. Studies suggest people with diabetes experience significantly higher rates of dry eye disease, with prevalence reported up to 54.3%.1 Many face a dual challenge of aqueous deficiency and meibomian gland dysfunction.
This mixed form of dry eye can make management even more complex.
“With hyperglycaemia – when blood glucose levels are high – we see problems with aqueous production,” Dr Howari explains.
“At the same time, diabetes-related inflammation disrupts lipid function, both in quantity and quality. So patients often face issues on both fronts, resulting in the need to tackle dry eye from both angles.”
Dr Howari points to sodium hyaluronate and perfluorohexyloctane as two therapies that can work alone, or in tandem, when patients with diabetes have ocular surface disease.
In the case of high-molecular-weight sodium hyaluronate, she says this plays a key role in replenishing and stabilising the aqueous layer. Its ability to bind significant volumes of water – it “carries roughly 1,000 times its molecular weight in water” – gives long-lasting hydration without the blur associated with gels or ointments.
Complementing this, perfluorohexyloctane – a unique, water-free, lipid-based agent – directly restores the tear film’s outer layer. By reducing evaporation and replenishing lipids, it can address meibomian gland dysfunction that is so common in patients with diabetes.
Both are available as preservative-free formulations through AFT Pharmaceuticals (Hylo-Forte and NovaTears, respectively), which helps minimise ocular toxicity with chronic use.
“This is critical in patients with diabetes,” Dr Howari adds.
And when combined with plant-derived omega-3 fatty acids (NovaTears + Omega-3), the formulation adds an anti-inflammatory benefit, tackling the chronic inflammation that underpins much of the disease process, Dr Howari says.
“There is limited benefit in increasing the aqueous [with sodium hyaluronate] if we don’t have the lipid layer to protect it [with perfluorohexyloctane].”
She also cautions that it’s not about prescribing an eye drop and wishing the patient well.
“It’s about the complete management plan in its entirety. We need to unblock and clear the meibomian glands first, then replenish it with the right oils to restore the cycle.”
Dr Howari hopes her lived experience and years of experience managing patients with diabetes can serve as an important reminder for her optometry colleagues.
That diabetes-related eye disease goes beyond the retinal plane.
“Every ocular structure – the cornea, conjunctiva, lids and margins – is affected,” she says. “Dry eye disease is chronic and debilitating, impacting both visual function and ocular health. As clinicians, we need to manage it holistically, starting from the surface and working back. One structure at a time.”
References:
1. Yoo TK, Oh E. Diabetes mellitus is associated with dry eye syndrome: a meta-analysis. Int Ophthalmol. 2019 Nov;39(11):2611-2620. doi: 10.1007/s10792-019-01110-y.
