Risk of aphakic glaucoma after pars plana-lensectomy with and without removal of the peripheral lens capsule.

BACKGROUND: The etiology of aphakic glaucoma is unclear. It has been suggested that remaining lens epithelium releases cytokines transducing trabecular meshwork cells. Therefore, we compared two cohorts of children undergoing lensectomy. In cohort 1, the entire lens including its capsule was removed, in cohort 2 the peripheral lens capsule was left intact, also to facilitate secondary intraocular lens implantation later on. METHODS: We included children with uni- or bilateral congenital cataract who underwent lensectomy during the first year of life with subsequent contact lenses fitting. Group 1 comprised 41 eyes, group 2 comprised 33 eyes. In group 1, the median age at surgery was 4.0 months in unilateral and 3.0 months in bilateral cases 1, in group 2, 8.1 months and 2.4 months, respectively. The mean follow-up was 12.8 years in group 1 and 9.3 years in group 2. All cases were analyzed for the prevalence of aphakic glaucoma, for visual acuity and for compliance in visual rehabilitation (contact lens/occlusion therapy). RESULTS: We found no significant difference in glaucoma prevalence between group 1 and group 2 (p = 0.68). The overall glaucoma rate was 26% after the mean follow-up of 11 years in both groups. In unilateral cases, the median visual acuity was logMAR 0.7 in both groups. In bilateral cases it was logMAR 0.4 in group 1 and logMAR 0.2 in group 2 (p = 0.05). CONCLUSIONS: Leaving the peripheral lens capsule intact had no negative effect on the incidence of glaucoma and on resulting visual acuity.

A randomised comparison of bilateral recession versus unilateral recession-resection as surgery for infantile esotropia.

OBJECTIVE: Infantile esotropia, a common form of strabismus, is treated either by bilateral recession (BR) or by unilateral recession-resection (RR). Differences in degree of alignment achieved by these two procedures have not previously been examined in a randomised controlled trial. DESIGN: Controlled, randomised multicentre trial. SETTING: 12 university clinics. PARTICIPANTS AND INTERVENTION: 124 patients were randomly assigned to either BR or RR. Standardised protocol prescribed that the total relocation of the muscles, in millimetres, was calculated by dividing the preoperative latent angle of strabismus at distance, in degrees, by 1.6. MAIN OUTCOME MEASURE: Alignment assessed as the variation of the postoperative angle of strabismus during alternating cover. RESULTS: The mean preoperative latent angle of strabismus at distance fixation was +17.2 degrees (SD 4.4) for BR and +17.5 degrees (4.0) for RR. The mean postoperative angle of strabismus at distance was +2.3 degrees (5.1) for BR and +2.9 degrees (3.5) for RR (p = 0.46 for reduction in the angle and p = 0.22 for the within-group variation). The mean reduction in the angle of strabismus was 1.41 degrees (0.45) per millimetre of muscle relocation for RR and 1.47 (0.50) for BR (p = 0.50 for reduction in the angle). Alignment was associated with postoperative binocular vision (p = 0.001) in both groups. CONCLUSIONS: No statistically significant difference was found between BR and RR as surgery for infantile esotropia.

Asymmetry of motion VEP in infantile strabismus and in central vestibular nystagmus.

Norcia et al. [1] found a nasal-temporal asymmetry of visually evoked potentials (VEP) elicited by motion stimuli in patients with infantile strabismus. Patients with infantile strabismus typically present with an asymmetry of the monocular optokinetic nystagmus (OKN). We here address the question whether the asymmetry of the motion VEP indicates a sensory defect in the afferent visual pathway that could explain the OKN asymmetry. We recorded the VEP to a horizontally oscillating vertical sinusoidal grating in 20 patients with infantile strabismus (esotropia, asymmetry of the monocular optokinetic nystagmus, latent nystagmus) and in 10 normal controls. No asymmetry occurred in the 10 controls. Eight of the 20 patients with infantile strabismus showed a clear difference between the VEPs evoked by back and forth movements with a mirror-like asymmetry between the two eyes (phase shift 180 +/- 20 degrees). However, there was no significant correlation between the degree of VEP and OKN asymmetries. Therefore, we assume that the VEP asymmetry does not reflect the primary cause of the OKN asymmetry. Rather, the OKN asymmetry may be due to a sensory-motor defect in the efferent subcortical pathway, and the VEP asymmetry could be an epiphenomenon. Some of the VEP asymmetry may be a consequence of the latent nystagmus typically released under monocular stimulation, leading to adaptation of the afferent retino-cortical pathway. This suggestion is supported by a marked VEP asymmetry that we found in two patients with an acquired central vestibular nystagmus, an abnormality most likely not combined with a primary defect of the retino-cortical pathway.

[Congenital nystagmus and intermittent exotropia. Suppression of nystagmus by fusional convergence]. / Kongenitaler Nystagmus und intermittierende Exotropie. Nystagmushemmung durch fusionale Konvergenz.

We report on a patient with a combination of congenital nystagmus and intermittent exotropia. When the exotropia became manifest, a gross nystagmus appeared. When, however, the exotropia was overcome by fusinal convergence, the nystagmus was largely suppressed. The angle of squint was surgically reduced by such an amount that the exodeviation was just compensated, and the fusional convergence required to overcome the remaining angle sufficed to suppress the nystagmus.