BJO at a glance
LIMBAL EPITHELIAL CRYPTS
Most self renewing tissues are served by stem cells. Stem cells are usually confined to their “niche,” a specific location within the organ where the microenvironment supports and maintains these cells. Dua and co-workers have re-evaluated the microanatomy of the corneal limbus and describe an anatomical structure that they termed the limbal epithelial crypt which appears to be a stem cell niche. See p 529
ANTI-TNF-α THERAPY FOR SIGHT THREATENING UVEITIS
In patients with uveitis and Behçet’s disease, tumour necrosis factor alpha (TNF-α) levels are raised in serum and aqueous humour. The cytokine TNF-α is an important factor in the pathogenesis of uveitis. Lindstedt and co-workers describe 13 patients with serious sight threatening uveitis treated with anti-TNF-α therapy. They conclude that this treatment may be of value and that a controlled masked study is warranted. See p 533
SMOKING AND AGE RELATED MACULAR DEGENERATION
Previous studies have identified smoking as a risk factor for age related macular degeneration. Evans and co-workers describe a population based cross sectional analytic study of 49 practices selected to be representative of the population of Britain. After controlling for potentially confounding factors, current smokers were twice as likely to have age related macular degeneration than non-smokers. People who stopped smoking more than 20 years previously were not an increased risk for age related macular degeneration. See p 550
RADIAL OPTIC NEUROTOMY FOR CENTRAL VEIN OCCLUSION
It has been suggested that radial optic neurotomy is beneficial in the treatment of central vein occlusion. Martinez-Jardón and co-workers describe a study of 10 patients with ischaemic retinal vein occlusion who underwent radial optic neurotomy. In this study no improvement in visual function or visual acuity occurred. Some improvement in macular thickness was measured. The authors suggest that the efficacy and safety in radial optic neurotomy is still in question. See p 558
STRAINING FOR HYDROXYCHLOROQUINE TOXICITY
Retinal toxicity is a well recognised complication of hydroxychloroquine therapy. Controversy surrounds the appropriate and most sensitive means to screen for this complication. Almony and co-workers describe the use of threshold Amsler grid as a screening tool. They conclude that by decreasing the perceived luminance of suprathreshold Amsler grid testing it provides a means of detecting shallow scotomas and areas of depressed retinal activity. It would be of interest to compare its sensitivity to focal electroretinography in detecting this problem. See p 569
INFECTIOUS KERATITIS IN OLDER PATIENTS
Butler and co-workers describe a retrospective study of patients 60 years of age and over with infectious keratitis. They conclude that in this age group infectious keratitis is associated with a high complication and surgical intervention rate and a poor visual outcome compared to younger patients. The microbiological spectrum is similar to younger age groups except that herpes simplex virus is more common and there may be increased risk of severe corneal thinning and perforations. Most bacterial isolates were sensitive to currently available antibiotic preparations. See p 591
ORIGINS OF POLYPOIDAL CHOROIDAL VASCULOPATHY
Polypoidal choroidal vasculopathy consists of a branching vascular network with polypoidal lesions at its edges under the retinal pigment epithelium. There are two theories as to its pathogenesis. One mechanism involves choroidal neovascularisation and another development of choroidal vascular abnormalities. Yuzawa and co-workers report the findings of high speed indocyanine green angiography and confocal scanning laser ophthalmoscopy in a series of 45 eyes with polypoidal choroidal vasculopathy. From their studies they conclude that the problem is caused by intrachoroidal vessel abnormalities not choroidal neovascularisation. See p 602
