BJO at a glance
RISK OF GLAUCOMA ASSOCIATED WITH ONCHOCERCIASIS
Onchocerciasis is a microfilarial disease that causes ocular disease and blindness. The question of whether it is associated with glaucoma remains contentious. Egbert and co-workers studied a group of patients in Ghana and found that glaucoma was seen in 10.6% of those with onchocerciasis and 2.6% of those with cataracts and no onchocerciasis evident. This association of glaucoma with onchocerciasis adds one more imperative to the move to eradicate onchocerciasis by continuation of vector control programmes and drug treatment with ivermectin. See p 796
RETINAL DAMAGE ASSOCIATED WITH SILICONE OIL
Silicone oil has been used in the management of complicated retinal detachment surgery. It provides prolonged intraocular tamponade. Unexplained visual loss is a complication following silicone oil removal that is infrequently reported. In a study by Cazabon and co-workers of three patients with unexplained visual loss following the removal of silicone oil multifocal electroretinography indicated selective damage to the central part of the macula especially the outer and middle layers. The exact mechanism for this retinal damage remains undefined. See p 799
METHOTREXATE IN UVEITIS IN CHILDREN
Juvenile idiopathic arthritis is the most common cause of uveitis in children. Heretofore, corticosteroids have been the mainstay of treatment but long term adverse effects of corticosteroids are well documented. The increasing use of methotrexate in the treatment of patients with juvenile idiopathic arthritis has been associated with a reduction in side effects compared to steroid therapy. Malik and Pavesio report the results of 10 children treated with methotrexate for chronic uveitis. This therapy appears to be effective and safe for chronic anterior and intermediate uveitis in children. See p 806
THE CONTRALATERAL EYE PRESSURE REDUCTION PHENOMENON
In 1924 Weekers described the effect of intraocular pressure in contralateral eyes being treated for glaucoma and coined the term “ophthalmotonic consensual reaction.” Many studies have reported that when a fall in intraocular pressure occurs in one eye the other eye has a fall as well. This has been reported in association with ocular compression, tonography, trauma, cauterisation of the sclera, paracentesis, laser trabeculoplasty as well as fistulising surgery. Vysniauskiene and co-workers report their finding in a study of 24 consecutive patients who underwent trabeculectomy with mitomycin C. In this study the mean intraocular pressure in the contralateral eye decreased independent of whether these contralateral eyes were undergoing topical ocular hypotensive therapy or not. See p 809
WHO IS WILLING TO BE A CORNEAL DONOR?
Corneal transplantation is a sight saving procedure with a very high success rate. Nevertheless, in many parts of the world a shortage of donor tissue is a major obstacle to providing this surgical therapy. Yew and co-workers studied 675 housing units in Singapore to assess the knowledge and willingness of Singapore adults for corneal donation. In Singapore, awareness of corneal donation is high and a significant proportion of participants are willing to donate their corneas but specific knowledge should be increased among this adult patient population. See p 835
EPIKERATOPLASTY FOR KERATOCONUS
Epikeratoplasty is a form of lamellar refractive corneal surgery. This surgical procedure was first used to correct aphakia but has been adapted for treatment of myopia. Nakamura and co-workers studied 12 penetrating keratoplasty specimens from patients with keratoconus who had already undergone epikeratoplasty. In nine of the 12 lenticules keratoconus-like disruptions were found in Bowman’s layer. Peripheral and posterior keratocyte repopulation of the lenticules was observed in all cases. The authors suggest that epithelial cells in keratocytes repopulated in the lenticules retained keratoconus-like biochemical abnormalities such as upregulation Sp1 and downregulation of α1-P1 and α2M. The authors speculate that both keratocytes and corneal epithelium may participate in the development of keratoconus. See p 841
“LIGHT” V CLASSIC” LASER TREATMENT FOR DIABETIC MACULAR OEDEMA
Macular oedema is the most common cause of visual loss in patients with diabetic retinopathy. Its prevalence in the diabetic population has increased fivefold over the past 10 years. Laser treatment has been shown to be effective in reducing the risk of moderate visual loss in eyes with clinically significant macular oedema. Bandello and co-workers completed a prospective randomised pilot clinical trial in which 29 eyes of 24 diabetics with mild to moderate non-proliferative diabetic retinopathy and clinically significant macular oedema were randomised to either classic or light laser therapy. In this study there was no statistical difference in the outcome between the two groups. The authors suggest that “light” photocoagulation for clinically significant macular oedema may be as effective as classic laser treatment. They suggest that a larger equivalence trial should be completed. See p 864
