Aims-To evaluate the clinical features as well as the visual and anatomical outcome in eyes with magnetic posterior segment foreign bodies, to identify prognostic factors after removal using an electromagnet. Methods-The records of 40 patients with posterior segment foreign bodies were retrospectively reviewed for 6 years (1989-94). Post-traumatic cataracts and secondary retinal detachments were treated using conventional surgical techniques. Pars plana vitrectomy was used only for late complications. The mean follow up was 30 months (6-71). Clinical factors were studied using univariate analysis. Results-The most common findings before treatment of these 40 eyes were lens wound, hyphaema, vitreous haemorrhage, and retinal impairment. The foreign body was in the vitreous (85%) or minimally embedded in the retina (15%). Initial visual acuity was worse or equal to 20/40 in 70% of the cases. Subsequent to surgical treatment, a cataract was reported in 60% of the patients. Postoperative complications included retinal detachment (15%) and phthysis (5%). The prognosis was worse in cases with intraocular foreign body of largest diameter >3 mm, an initial visual acuity less than 20/200, or the presence of post-traumatic retinal detachment. Presence of initial intravitreous haemorrhage, hyphaema, or intraocular tissue prolapse did not appear to aVect the prognosis. Conclusion-The long term visual acuity results indicated that wound repair associated with conventional magnet extraction in an emergency is a viable treatment for posterior segment magnetic foreign bodies in this selected group. At the time of diagnosis, size of foreign body (<3 mm) and initial visual acuity >20/200 were predictors of good visual outcome after primary magnetic extraction. (Br J Ophthalmol 1998;82:801-806)

Purpose: To characterize the phenotype of retinal vessels using central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), tortuosity and fractal dimension (FD) in primary open-angle glaucoma (POAG) subjects. Methods: This prospective case-control multicentre study included 61 POAG subjects and 61 controls matched for age, systemic hypertension and body mass index. Fundus images of the right eye were acquired using a non-mydriatic camera. Central retinal artery equivalent (CRAE), CRVE, arteriole-to-venule ratio, FD and tortuosity of the vascular network were measured using VAMPIRE software (Vessel Assessment and Measurement Platform for Images of the Retina). Primary open-angle glaucoma (POAG) patients underwent 24.2 sita-standard visual field and peri-papillary optical coherence tomography (OCT) examinations. Data were expressed as median and interquartile range (75-25th percentiles).Results: The control group was comparable to the POAG group for sex ratio, refraction and intraocular pressure. The mean CRAE and the mean CRVE were significantly lower in the POAG group than in the control group [150.5 (137.9; 157.1) lm versus 161.3 (154.0; 168.4) lm and 204.8 (190.1; 218.1) lm versus 233.5 (222.3; 246.9) lm, respectively; p < 0.001] and for fractal parameters as well. No significant difference was found for tortuosity between the two groups. There was a significant correlation between CRAE and retinal nerve fibre layer (RNFL) thickness (r = 0.27; p = 0.03). VAMPIRE parameters were not correlated with visual field indices.Conclusion: Primary open-angle glaucoma (POAG) was associated with a narrowing of arterial and venous retinal vessels, a higher arteriole-to-venule ratio and lower values of FD. The relationship between CRAE and RNFL thickness needs further investigation.

We aimed to compare measurements from three of the most widely used software packages in the literature and to generate conversion algorithms for measurement of the central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) between SIVA and IVAN and between SIVA and VAMPIRE. We analyzed 223 retinal photographs from 133 human participants using both SIVA, VAMPIRE and IVAN independently for computing CRAE and CRVE. Agreement between measurements was assessed using Bland–Altman plots and intra-class correlation coefficients. A conversion algorithm between measurements was carried out using linear regression, and validated using bootstrapping and root-mean-square error. The agreement between VAMPIRE and IVAN was poor to moderate: The mean difference was 20.2 µm (95% limits of agreement, LOA, −12.2–52.6 µm) for CRAE and 21.0 µm (95% LOA, −17.5–59.5 µm) for CRVE. The agreement between VAMPIRE and SIVA was also poor to moderate: the mean difference was 36.6 µm (95% LOA, −12.8–60.4 µm) for CRAE, and 40.3 µm (95% LOA, 5.6–75.0 µm) for CRVE. The agreement between IVAN and SIVA was good to excellent: the mean difference was 16.4 µm (95% LOA, −4.25–37.0 µm) for CRAE, and 19.3 µm (95% LOA, 0.09–38.6 µm) for CRVE. We propose an algorithm converting IVAN and VAMPIRE measurements into SIVA-estimated measurements, which could be used to homogenize sets of vessel measurements obtained with different software packages.