Preservatives in topical glaucoma eye drops
Topical drops contain preservatives to prolong their shelf-life by preventing bacterial contamination. Preservatives are known to damage the ocular surface. The toxicity of benzalkonium chloride (BAK) and its effect on the precorneal tear film was described as long ago as 1975. Benzalkonium chloride (BAK) has been used in ophthalmology since the 1940s. Most deleterious effects of BAK occur at a subclinical level initially and are largely unrecognised and not directly attributed to the drug excipients including BAK.
Ocular melanoma review
Ocular melanoma is a rare form of non-cutaneous melanoma accounting for only 5.3% of reported melanomas. 85% originate from the uveal tract with the remainder originating from the conjunctiva, orbit, lacrimal gland, cornea and other structures. The uveal tract is a vascular pigmented coat of the eye consisting of the iris, ciliary body, and choroid. In the posterior segment, the uveal tissue lies between the sclera and the retina. Uveal melanoma is the most common primary intraocular tumour with most tumours arising posteriorly from the choroid and the ciliary body. In a review of 8033 uveal melanoma cases, 90% of the cases originated from the choroid.
Infective uveitis
Uveal tissue is susceptible to infection with viral, parasitic, bacterial and fungal organisms. Infective uveitis is common, accounting for up to 35% of uveitis in tertiary referral centres and especially prevalent in a 3rd world setting. Infective uveitis is potentially visually devastating, particularly with posterior segment involvement.
Attempts allowed: 2
70% pass rate