Left: Reduced Demodex after a year of treatment. Right: Finally resolved.
Alan Saks has embarked on a new stage of his eye care journey, gaining a fresh appreciation for what it means to sit on the other side of the slit lamp.
Around two years ago I started developing increasing symptoms of dry eye, with crusty eyelids and irritation. This was particularly bad in the evenings and on wakening. As a long-term sufferer of allergies and atopia – along with my forme fruste keratoconus (FFKC) – I could tell that this was not the typical itching that often made me want to rub my eyes.
I went to see a local optometric colleague in Forster NSW who, once I described the symptoms, had a good look with the slit lamp and exclaimed (almost joyfully), “You’ve got Demodex!” She showed me the images. I was devastated.
Despite having dealt with such eyelid and ocular surface conditions and much else over my practising career, this was not the kind of news I wanted to hear as a patient. I felt dirty. But at least I knew why my dry eye had spiralled.
Human Demodex colonisation becomes extremely common with age. It’s oft cited as affecting nearly 100% of people aged around 70 and older, but is still common in younger people. Exact estimates vary by diagnostic method and study population, but you get the picture.
Eyelid Demodex presence is defined by the prevalence of collarettes on the eyelashes. Although a diagnosis can be made, it does not mean patients are symptomatic. Many patients remain happily oblivious and symptom free. As with many conditions, treatment is often dependent on symptoms.
I embarked on a long and varied treatment program. I eventually beat the Demodex into submission, an interesting journey I will share at some stage.
Human Demodex colonisation becomes extremely common with age. It’s oft cited as affecting nearly 100% of people aged around 70 and older, but is still common in younger people.
Patient Change
To add to my patient journey, I started experiencing increasing light scatter and starbursts, especially at night from headlights and other light sources. Of course, I knew what was likely causing this, having heard it for decades from many patients: I am developing cataracts and have booked in to see an expert cataract surgeon in Sydney.
What with my FFKC and early Fuchs’ dystrophy (which I also only recently learned I had developed), along with a maternal history of geographic atrophy, most surgeons agree to go for maximum distance vision, targeting plano distance with monofocal intraocular lenses (IOLs). Low pressure phaco and femtosecond laser-assisted cataract surgery (FLACS) are also on the cards, to minimise any impact on my already compromised endothelium. I’m happy to continue with progressive/occupational glasses over IOLs for most of my waking hours, as I do now, with no issues.
The other consideration is that I have had significant floaters most of my life (probably from a concussion after landing on my head in a bike accident and/or falling on my head out of a tree). The floaters don’t bug me, and I am not that keen on having ports shoved through my sclera and undergoing a vitrectomy. I will probably delay cataract surgery until my aided vision starts dropping toward 6/9 or 6/12.
For now, I’m coping and don’t drive much at night, so it’s not an issue really.
An Irritated Patient
My history of atopia and allergies since childhood is likely linked to my FFKC. My colleagues and mates would often scold me when they’d see me rubbing my eyes in the wee hours on a pool night. I am, of course, fully aware of eye rubbing and its link to keratoconus.
Most of us should be familiar with the good work of Professor Charles McMonnies. Along with many papers on the subject, Prof McMonnies publishes an excellent hand-out on eye rubbing and keratoconus, in collaboration with the Brien Holden Vision Institute. You can download or share it with patients and their families via the Keratoconus Australia website.1
You may be less familiar with the work of French ophthalmologist Professor Damien Gatinel.2 He has published many papers on eye rubbing and goes further than Prof McMonnies in stating “No rub, no cone”. He theorises that a genetic predisposition for the disease will come to nothing without excessive eye rubbing and that eye rubbing is an essential factor in the development of keratoconus. He also states that sleeping on one side, with forces applied to that eye, is a likely cause of keratoconus. As others have hypothesised, the cone may be worse on the side of the dominant hand that rubs harder. Some of this is detailed in an excellent article in Ophthalmology Times by Dr Lisa Stewart,3 which includes an interesting debate between Prof Gatinel and colleagues.
For the past few decades, I have tried to avoid rubbing pressure on my FFKC corneas and only ‘knuckle’ my inner canthus. But a colleague once reprimanded me on that technique, stating that canthal knuckling is likely to release histamines from mast cell degranulation.
Bottom line is, I try to treat any symptoms of itching and allergies immediately, by using eye drops to avoid that desire to rub the itch.
Olopatadine worked well for me, but it’s very expensive in Australia, costing around AU$50 a bottle, whereas very effective dexamethasone is much less expensive. One is covered by the Pharmaceutical Benefits Scheme (PBS); the other not. Obviously, we cannot use dexamethasone on any kind of regular basis for allergy, but I use a few drops of prescription dexamethasone a year, when I have an extreme follicular conjunctivitis.
It works fast. No wonder people abuse it.
Strangely enough, generic olopatadine is available for next to nothing in New Zealand as a Pharmac subsidised drop. A friend gets three bottles for free every few months.
Now that helps compliance.
It’s way overdue for the PBS to approve generic olopatadine.
With my dry eyes also much improved after beating the Demodex, my eyes are feeling the best they have in years.
Patience
Not long ago, someone mentioned azelastine as a good antihistamine eye drop. I’d never heard of it but have used it occasionally ever since. It’s worked very well over the past months and quickly suppresses the itch. I’ve thus also avoided any desire to put in a drop of dexamethasone.
My only issue is that azelastine drops are preserved with benzalkonium chloride (BAK), a preservative I prefer to avoid. Azelastine drops are also not on the PBS, nor available in single dose, but as I only tend to use it occasionally, I am living with occasional BAK for now. It is also a third of the price of olopatadine and probably more suited to occasional use and faster relief.
With my dry eyes also much improved after beating the Demodex, my eyes are feeling the best they have in years.
Winner winner, chicken dinner.
My point is that every treatment has its place. Patients should, of course, be seen by their optometrist or ophthalmologist and a prescription obtained where indicated.
But the take-home message from all of this is that sometimes we need to wear our patients’ shoes and be empathetic. It’s a very different experience sitting on the other side of a slit lamp and being told you have Demodex, Fuchs, cataracts, FFKC, allergies, drusen or whatever the ‘bad’ news is that you may have for your patient.
Be kind and understanding. Take the time to explain and counsel.
References
- McMonnies C. Abnormal eye rubbing: what families need to know. Available at: keratoconus.org.au/wp-content/uploads/2020/02/Abnormal-Rubbing-Guide-2015-2.pdf [accessed Aug 2026].
- Gatinel D. What’s the rub? Cataract Refract Surg Today Eur. 2017 Apr:30-3. Available at: defeatkeratoconus.com/wp-content/uploads/2017/09/Keratoconus-Whats-the-rub-D-Gatinel-CRST-Europe-April-2017.pdf [accessed Aug 2026].
- Stewart L. The pathophysiology and pathomorphology of corneal ectasia: keratoconus will not develop without eye rubbing. Ophthalmol Times Eur. 2022 May 30;18(5). Available at: ophthalmologytimes.com/view/the-pathophysiology-and-pathomorphology-of-corneal-ectasia-keratoconus-will-not-develop-without-eye-rubbing [accessed Aug 2026].
