By Jamie Chang, Yong Loo Lin School of Medicine, National University of Singapore
Nowadays, many people wear contact lenses. However, contact lens complications can be asymptomatic which poses a great risk to contact lens wearers. Dr Wilfred Tang, Clinical Optometrist at Sir Charles Gairdner Hospital, Perth, Australia, discussed the detection, diagnosis and management of contact lens-related complications and the difference between corneal infiltrative keratitis and ulcers during the Singapore Primary Eye Care Symposium (SPECS) 2019 between 23-24 July 2019 at One Farrer Hotel, Singapore, during his lecture titled, “Optometrists Save Sight: Contact Lens-related Corneal Ulcers”.
Some symptoms and signs of contact lens complications include reduced visual acuity, dry eye sensation, itchiness and discharge, conjunctival redness, limbal injections, neovascularisation, anterior chamber reactions and corneal infiltrates. Practitioners are advised to either observe the progression of condition, address the condition or refer the patient to an ophthalmologist.
Dr Tang espoused the importance in having the ability to tell the difference between infiltrates and ulcers. Infiltrates in infiltrative keratitis are single or multiple aggregates of grey or white inflammatory cells which are diffuse whereas ulcers in microbial keratitis are excavated corneal defects with underlying inflammation. Ulcers are a result of epithelial damage which in worst case scenario cause an infection.
He also discussed the various characteristics of Contact Lens Peripheral Ulcer (CLPU) and Microbial Keratitis (MK). CLPU patients are usually asymptomatic. If not, single, circular, focal infiltrates and a positive fluorescein stain can be observed. Small, bulbar redness is typically noted near the limbus and patients may complain of a foreign body sensation. MK presents with significant excavated lesions with a diffuse infiltration and positive fluorescein staining. Patients may also have photophobia, swelling of the eyelid, foreign body sensation, tearing and discharge.
In order to manage CLPU, practitioners need to rule out bacterial, fungal and acanthamoeba infections from the lesion appearance – size and shape, and the consistency with the signs and symptoms. Practitioners should also advise patients against wearing contact lens and use chloramphenicol eye drops. Likewise, MK patients should not wear contact lens. Practitioners are highly recommended to do a corneal scraping and culture, to remove the necrotic tissues and use strong antibiotics such as fluoroquinolones and in stronger bacterial cases, ciprofloxacin, ofloxacin and gatifloxacin. Referrals are needed when the patient presents with a high risk of corneal scarring, a fungal and a protozoan infection.
If managed early, this reduces the risk of corneal scarring and reduced vision. Corneal grafts may hence not be needed. Therefore, it is of utmost importance to fully understand the detection, diagnosis and management of contact lens-related complications in order to treat them in a timely manner to avoid long term, irreversible effects. Dr Tang ended off with the encouragement that all empowered optometrists, if given the right motivation and training, can save sight.