24-h versus daytime IOP phasing

Moodie et al determined the value of daytime and 24 h phasing in patients treated for progressive POAG despite apparently adequate IOP control. They performed a retrospective analysis of a cohort of patients (76) that had undergone IOP measurement in the clinic and daytime (08:00–18:00) or 24-h phasing. There was no significant difference between mean IOP values measured in clinic and daytime phasing or between clinic values and nighttime phasing. Although the mean daytime phasing IOP was significantly higher than the mean nighttime phasing IOP, there was no significant difference in the impact on management that occurred as a result of phasing between the daytime and 24-h groups. The authors conclude that 24-h phasing offers little advantage over daytime phasing in the identification of IOP fluctuations. See page 999

Myopia in Singapore Chinese preschool children

Wilson et al investigated the risk factors for myopia, including near work and outdoor activity, in a cross-sectional study of 3009 Singapore Chinese preschool children. Children with two myopic parents were more likely to be myopic (adjusted OR 1.91; 95% CI 1.38 to 2.63) and to have a more myopic spherical equivalent refraction. For each 1 cm taller height, the spherical equivalent refraction was more myopic by 0.01 dioptre. Neither near work nor outdoor activity was associated with preschool myopia. The family history of myopia was the strongest factor associated with preschool myopia suggesting that genetic factors may play a more substantial role than key environmental factors in the development of early-onset myopia. See page 1012

Electrophysiology and visual outcome in optic nerve hypoplasia

McCulloch et al assessed the prognostic value of ERG and VEP in 85 young children with ONH. The initial measures (prior to age 3 y) were compared with visual acuity outcomes at 5 years of age in the better-seeing eye. Visual outcomes ranged from normal to no light perception. Amplitude of the flash VEP, the threshold category of stimulus (flash or cheque size) that elicited a VEP, amplitude of the N95 component of the PERG, optic nerve size, and co-existing pallor were of prognostic value. Stepwise regression analysis composed a best prediction model from VEP threshold category, optic nerve size and optic disc pallor. See page 1017

Bevacizumab as the primary treatment for retinal vein occlusion

Figueroa et al evaluated the efficacy of intravitreal bevacizumab as the primary treatment of macular oedema (300 μm central retinal thickness) due to central or branch retinal vein occlusion. Eighteen eyes with CRVO and 28 eyes with BRVO with visual acuity of less than 20/40 were recruited. After an initial intravitreal injection of bevacizumab, re-treatment was performed if intraretinal or subretinal fluid with distortion of the foveal depression was found in optical coherence tomography. After 6 months, mean logMAR visual acuity improved significantly to 0.44 with reduction in mean macular thickness to 268.2 μm. The authors conclude that intravitreal bevacizumab seems to be an effective primary treatment option for macular oedema due to retinal vein occlusions. The main drawback of this approach is that multiple injections are necessary to maintain visual and anatomic improvements. See page 1052

Diagnostic accuracy of microbial keratitis with in vivo scanning laser confocal microscopy

Hau et al determined the accuracy of diagnosing microbial keratitis by masked medical and non-medical observers using the Heidelberg Retina Tomograph II/Rostock

Cornea Module in vivo confocal microscope in 62 eyes with culture- or biopsy-proven infections. The cases comprised 26 Acanthamoeba, 12 fungus, three Microsporidia, two Nocardia and 19 bacterial infections (controls). The reference standard for comparison was a positive tissue diagnosis. The images were assessed on two separate occasions by four observers who were masked to the tissue diagnosis. The highest sensitivity and specificity values were 55.8% and 84.2%, respectively, and the lowest sensitivity and specificity values were 27.9% and 42.1%, respectively. The correct diagnosis was associated with duration of disease for Acanthamoeba keratitis. The authors conclude that the diagnostic accuracy of microbial keratitis by confocal microscopy is dependent on observer experience. Difficulty in distinguishing host cells from pathogenic organisms limits the value of confocal microscopy as a stand-alone tool in diagnosing microbial keratitis. See page 982

Accelerated corneal graft rejection in baby rats

Schwartzkopff et al performed allogeneic keratoplasty between Lewis and Fisher rats. The recipients' ages were 10 and 3 weeks, respectively. Fisher donor buttons (2.5 mm) were used. Median graft survival times were 15 days in old recipients and 9 days in young recipients (p<0.01). There were fewer infiltrating cells in the younger rats than in the older ones on the day of rejection. There were more NK cells in young recipients at all time points after transplantation when compared to old recipients. The dominance of infiltrating NK cells suggests an involvement of the innate immunity. See page 1062