Clinical News
MEDICAL AND PRODUCT UPDATES

LASIK COMPLICATIONS
Epithelial defects correlate to skin, eye, hair and age factors

• study recently conducted in Canada by Mounir Bashour, M.D., C.M., F.R.C.S.C., found that certain aspects of physical appearance correlate to the risk of epithelial defects following refractive surgery. Dr. Bashour followed 962 patients for 6 months after LASIK. Patients were treated using the same laser, nomogram settings, microkeratome and technique. Data showed:
• Light-skinned patients had a 12-fold greater risk of developing erosions.
• Patients who were older than 40 has a six-fold greater risk of defects.
• Patients with significant skin wrinkling had a nine-fold greater risk.
• Patients with any hair color other than brown or black when they were 3 years old had a three-fold greater risk.
• Patients with blue or green eyes had a 2.3-fold greater risk of defects.

"This means that a young, black patient undergoing this surgery is at little risk of developing such a defect," Dr. Bashour explained. "By contrast, an older person with fair skin, who has facial skin wrinkling, should be cautioned of the risk."

OPTICAL SIDE-EFFECTS
Drugs linked to eye problems

Several medications have recently been linked to unwanted side effects:

Topiramate linked to myopia and glaucoma. Johnson & Johnson's Ortho-McNeil Pharmaceuticals has issued a letter to healthcare professionals warning that its epilepsy drug Topamax (topiramate) has been linked to cases of severe myopia and secondary angle-closure glaucoma. Topamax is used as an adjunct to current seizure treatments for Lennox-Gastaut Syndrome, a debilitating, potentially fatal form of epilepsy. An estimated 825,000 patients have used Topamax worldwide.

Symptoms, including acute blurred vision and/or painful, red eyes, typically occur within a month of initiating therapy. (At least one patient presented with intraocular pressure in the mid 70s OU.)

The letter, distributed to almost half a million physicians, stated that there were 23 reported cases as of August 17, involving 22 adults and one child. (The company also acknowledged that most post-marketing adverse events are under-reported.)

The condition appears to be self-resolving once the medication is tapered off. (Note: Stopping the treatment suddenly can increase the risk of a seizure.)

Latanoprost linked to angina. The British Medical Journal reported that a 73-year-old patient repeatedly developed an exacerbation of angina whenever he used latanoprost to treat open-angle glaucoma. The patient suffered from peripheral vascular and ischaemic heart disease, for which he was taking glyceryl trinitrate, amlodipine, and clopidogrel.

Clinicians point out that systemic absorption of latanoprost applied topically can induce vasoconstriction in coronary vessels, especially in patients with unstable angina.

Doctors at the Royal Halifax Infirmary in England believe this is the first reported case of such a reaction.

Ocular abnormalities associated with use of isotretinoin. Researchers have identified 38 ocular abnormalities associated with the use of isotretinoin (Accutane), a compound used to treat severe acne and other skin conditions.

Eye problems that clinicians have labeled "strongly linked" to the drug include abnormal meibomian gland secretion, blepharoconjunctivitis, cor-neal opacities, decreased dark adaptation, decreased tolerance to contact lenses, and increased tear osmolarity.

Also "strongly linked" to use of isotretinoin: keratitis, meibomian gland atrophy, myopia, ocular discomfort, ocular sicca, photophobia, and teratogenic ocular abnormalities.

Conclusions were based on a review of 1,741 reports of ocular adverse events associated with isotretinoin use.

The study was reported in the September issue of the American Journal of Ophthalmology.

TRAUMATIC CORNEAL ABRASIONS
Eye patching isn't necessary

Differences in appearance might correlate with the risk of epithelial defect after LASIK.

Eye patching doesn't improve the healing rate or pain level of traumatic corneal abrasions treated with topical antibiotics, according to a report published in the August issue of the Annals of Emergency Medicine. Apparently, many previous studies supporting the use of patching were unblinded studies, based on a small sample of patients.

A new single-blind study conducted by Natalie Le Sage, M.D., and colleagues in Quebec, Canada, monitored 163 emergency room patients with traumatic corneal abrasions. Researchers found that corneal healing, as well as levels of pain and discomfort, were similar in patients whether or not they were treated using an occlusive eye patch.