Contact lens use is the leading cause of corneal scarring in Bahrain, a local study has revealed.
Wearing contact lenses puts users at risk of several serious conditions including eye infections and corneal ulcers, unless they abide by a strict regime of care.
According to Bahraini ophthalmologist Dr Nada Al Yousif’s analysis, a bacterial infection in the eyes known as microbial keratitis, appears to be the main potentially vision-loss threats.
The retrospective study titled ‘Microbial Keratitis in the Kingdom of Bahrain: Clinical and Microbiology Study’, concluded that the majority of patients with this condition developed permanent scarring on the cornea.
The study involved 285 patients with keratitis who were admitted to the Salmaniya Medical Complex (SMC) between 2005 and 2007. Dr Al Yousif, an SMC consultant ophthalmologist, found that sleeping with contact lenses was a major risk factor.
“People who wear contact lenses, especially women and girls who wear coloured contact lenses, must be careful not to sleep with them in as it can lead to microbial keratitis,” said Dr Al Yousif, who is also an assistant professor at the Arabian Gulf University.
“It is a potentially vision-threatening condition all over the world. According to local studies, contact lenses are the leading cause of microbial keratitis corneal infection in Bahrain.”
Bacterial keratitis is an infection of the cornea which is the clear dome that covers the coloured part of the eye.
Symptoms of eye irritation or infection include discomfort, excess tearing or other discharge, unusual sensitivity to light, itching, burning, or gritty feelings, unusual redness, blurred vision, swelling and pain.
Prompt diagnosis and treatment is required to prevent devastating outcomes. Problems may be caused by bacteria, fungi, viruses or parasites that rarely occur in the normal eye because of the cornea’s natural resistance to infection.
However, predisposing factors such as trauma, contact lens wear, dry eyes, ocular surface disorders and immunosuppression may alter the defence mechanism of the outer eye, and permit bacteria to invade the cornea.
“Contact lens users, particularly teenagers and young adults, must exercise extreme caution when using lenses,” said Dr Al Yousif.
“They should use lubrication eye drops to keep their eyes from drying out and be mindful of the expiry dates of their contact lenses. Hands must be washed with soap before touching the lens; cleanliness is essential.”
The study also stated that understanding the risk factors and infectious substances can help in the control and prevention of this condition. Contact lens use, the presence of blepharitis (red and swollen eye), diabetes, lid abnormalities, dry eyes, keratoplasty (cornea transplant), and refractive surgery were all measured as predisposing risk factors.
According to the findings, contact lens wear was a risk factor for microbial keratitis in 40 per cent of the study population. Other risk factors identified included dry eyes in 24 cases (8pc), blepharitis in 10 cases (3pc), trauma in 22 cases (8pc), and abnormal lid position in 14 cases (5pc). Six patients (2pc) had keratitis in a graft (a corneal transplant complication), and three (1pc) had refractive surgery.
It also revealed that the most common causative organism identified was pseudomonas aeroginosa – a bacteria that causes most infections in humans, especially blood, lungs (pneumonia), or other parts of the body after surgery – 54pc, followed by streptococcus 12pc, staph 10pc, and other organisms 6pc.
The study shows that 95pc of contact lens wearers had pseudomonas aeruginosa of which the vast majority (92pc) healed with scarring. One pc needed therapeutic keratoplasty and 7pc lost to follow-up.
Risk factors in contact lens wearers were – 41 patients (36pc) slept with the contact lenses, 12 (8pc) had contact lens related trauma and eight (7pc) had poor hygiene.
Out of 285, 173 (61pc) were females and 112 (39pc) were males; 239 were Bahrainis (84pc) and 46 (16pc) were non-Bahrainis. The mean age was 51 and the mean age among contact lens wearers was 21.