Differential diagnoses in a daily disposable contact lens wearer

The question:

A 20-year-old male presents at your practice with sudden onset pain and blurred vision in both eyes. He is a daily disposable contact lens wearer, but removed his lenses when his symptoms started two days ago. He is otherwise in general good health, and is not taking any medication. How would you manage?

OT’s panel says...

Ceri Smith-Jaynes: I’m glad he has turned up for a check and he’s done the right thing by removing the lenses. There are numerous differential diagnoses for this, for example microbial keratitis, but in the absence of being able to hear his responses to my questioning, I’m going to start a discussion about contact lens associated red eye (CLARE).

Although bacteria are involved, this is more of an inflammatory condition than infection as such. The eye responds to the presence of bacterial endotoxins and reacts. It’s usually gram-negative bacteria that have colonised the lenses, and it often happens in hypoxia, so we’ll need to have a serious chat about contact lens use: sleeping in them and reusing them, as well as hand and lid hygiene. It could just be because he has had a cold – Haemophilus influenzae is a gram-negative bacterium that can cause conjunctivitis or CLARE as well as respiratory infections. I’ll need to see those lenses in his eyes later down the line to make sure they aren’t too tight at the end of a day’s wear.

I’ll be expecting to see diffuse bulbar and limbal redness, and maybe some peripheral infiltrates, but not a lot of staining. If there is a lot of staining, or there is an anterior chamber reaction, I’ll be monitoring more closely over the next few days.

The blurred vision bothers me a bit though. Is that just because of epiphora, or maybe some corneal oedema? It shouldn’t be very blurred after two days, should it? A visual acuity check is standard in any acute presentation, and I’ll have to look into that during the slit lamp exam, checking the posterior pole too.

My management might range from simply artificial tears, to antibiotic drops, to steroids, or combination, depending on the slit lamp findings. What antibiotic would you choose, Kevin and Ankur? Chloramphenicol is widely available and broad spectrum, and mentioned in the College of Optometrists guidance, but should we be thinking levofloxacin or similar? Sometimes, in community practice, I have to go with the choice that is available that day in pharmacies nearby.

We’ll need to have a serious chat about contact lens use: sleeping in them and reusing them, as well as hand and lid hygiene

Kevin Wallace: I am also glad that he removed his contact lenses and sought help. I always remind contact lens wearers that they need to have a low threshold for telling me something is wrong – you don’t want to struggle on for a few days with a worsening red eye – and particularly not to continue to wear the contact lenses.

The bilateral symptoms make me feel slightly better – I’d still want to look carefully, but he’d be quite unlucky to get something serious, like microbial keratitis, in both eyes.

I’d also want to know more about his recent general health, and if the symptoms are better after not wearing the contact lenses – they are perhaps just a red herring and he has developed a ‘regular’ eye infection, but if things are improving then something about the contact lenses would make sense as the cause.

I’d also want to know more about the contact lenses and what he’s been doing with them – it wouldn’t be the first time I’ve found that someone was rinsing and reusing them or had never had them fitted or was buying lenses I’d never heard of from overseas. That can be the cause of the issues, particularly if it’s not an appropriate solution for that purpose.

If I did decide to give him an antibiotic, I would tend to use ofloxacin for the reason Ceri states.

Like all these things, it starts off as what appears to be a simple external problem – but I’d want to check a few other things too. If the vision doesn’t improve with pinhole, the examination would need to be much broader to look for something internal. Depending on what his anterior chamber looks like, it could lead to an intraocular pressure assessment, which wouldn’t usually be something I’d do at this stage.

Ankur Trivedi: As stated, a thorough discussion covering the details of contact lenses, their modality, and any solutions and associated drops or artificial tears that are being used, needs to happen – especially if this is a new patient to you or to the practice.

Sudden onset bilateral pain and blurred vision makes me wonder what he was doing when the symptoms started. Is there an environmental factor? I find the reporting of pain can be very variable with patients. The patient may not have back-up spectacles, so may have been managing unaided for two days. Some of the persistent discomfort he is experiencing might be partially due to asthenopic symptoms, due to his vision being uncorrected.

If following a thorough clinical examination, as already outlined by Ceri and Kevin, an infection is the top of my list of differential diagnoses. I would also opt for a fluoroquinolone, due to the different microbiota found on the ocular surface of a contact lens wearer versus a non-contact lens wearer.

A recent study by Cai et al showed how lower severity contact lens associated keratitis was managed with empirical fluoroquinolone treatment. This was also covered by Optometry Today.

If you are unsure about how to manage a scenario in practice, contact the AOP’s regulation team by email.