Preliminary results from the use of the novel Interactive binocular treatment (I-BiT) system, in the treatment of strabismic and anisometropic amblyopia.

BACKGROUND: We have developed a novel application of adapted virtual reality (VR) technology, for the binocular treatment of amblyopia. We describe the use of the system in six children. METHODS: Subjects consisted of three conventional treatment 'failures' and three conventional treatment 'refusers', with a mean age of 6.25 years (5.42-7.75 years). Treatment consisted of watching video clips and playing interactive games with specifically designed software to allow streamed binocular image presentation. RESULTS: Initial vision in the amblyopic eye ranged from 6/12 to 6/120 and post-treatment 6/7.5 to 6/24-1. Total treatment time was a mean of 4.4 h. Five out of six children have shown an improvement in their vision (average increase of 10 letters), including those who had previously failed to comply with conventional occlusion. CONCLUSIONS: Improvements in vision were demonstrable within a short period of time, in some children after 1 h of treatment. This system is an exciting and promising application of VR technology as a new treatment for amblyopia.

Modified virtual reality technology for treatment of amblyopia.

PURPOSE: The conventional patching/occlusion treatment for amblyopia sometimes gives disappointing results for a number of reasons: it is unpopular, prolonged, frequently resulting in poor or noncompliance, and also disrupts fusion. The aim of this research was to develop a novel virtual-reality (VR)-based display system that facilitates the treatment of amblyopia with both eyes stimulated simultaneously. METHODS: We have adopted a multidisciplinary approach, combining VR expertise with a team of ophthalmologists and orthoptists to develop the Interactive Binocular Treatment (I-BiT) system. This system incorporates adapted VR technology and specially written software providing interactive 2D and 3D games and videos to the patient via a stereo (binocular) display, and a control screen for the clinician. RESULTS: We developed a prototype research system designed for treatment of amblyopia in children. CONCLUSIONS: The result is a novel way to treat amblyopia, which allows binocular treatment. It is interactive, and as it is partially software based, can be adapted to suit the age/ability, and needs of the patient. This means that the treatment can be made captivating and enjoyable. Further research is on-going to determine the efficacy of this new modality in the treatment of amblyopia.

The effects of vigabatrin on electrophysiology and visual fields in epileptics: a controlled study with a discussion of possible mechanisms.

PURPOSE: To compare the visual electrophysiology and visual fields of patients taking vigabatrin to those of a control group of epileptics on other anti-epileptic drugs (AEDs). METHODS: Fourteen epileptics treated with vigabatrin and 10 control patients treated with other AEDs underwent ERG and EOG. Goldmann visual fields were performed and analysed using standard software to measure areas contained within I4e isopters. RESULTS: The cone and rod b-waves of the ERG, the oscillatory potential amplitudes and Arden indices were reduced in vigabatrin-treated subjects and the oscillatory potentials delayed. The Arden indices were reduced due to an increased dark trough. The areas contained within the I4e isopter of vigabatrin treated subjects were reduced compared to the control group and these areas correlated well with oscillatory potential amplitudes and b-wave amplitudes in the vigabatrin group only. CONCLUSIONS: The use of vigabatrin is associated with a reduction of the ERG cone b-wave amplitude and oscillatory potentials which correlates with visual field loss. The Arden ratio is reduced in subjects taking vigabatrin but may recover after cessation. However, visual loss may persist in the presence of a recovered EOG. These findings suggest further effects of the drug than those mediated by GABA receptors, and support the contention that the cause of the field loss may be at least in part due to retinal effects. Possible mechanisms are discussed.

Epithelial ingrowth: causes, prevention, and treatment in 5 cases.

PURPOSE: To examine the clinical course, treatment, and outcome in 5 cases of epithelial ingrowth following laser in situ keratomileusis (LASIK). SETTING: The Eye Institute, Sydney, Australia. METHODS: Five patients with adequate follow-up were selected. Each patient had developed epithelial ingrowth as a consequence of LASIK, and each represented a different clinical course in terms of severity, time, and treatment of the epithelial ingrowth. RESULTS: Treatment ranged from observation, lifting and manual removal, phototherapeutic keratectomy, alcohol application, removal of the corneal cap, and penetrating keratoplasty (PKP). Outcomes ranging from retention of preoperative best corrected visual acuity to the need for PKP reflect the wide disparity in the severity of this complication and the therapeutic interventions required. CONCLUSION: Epithelial ingrowth is a relatively uncommon complication following LASIK. Suggestions for prevention and treatment are made.

Recutting the cornea versus lifting the flap: comparison of two enhancement techniques following laser in situ keratomileusis.

PURPOSE: To evaluate enhancement techniques following laser in situ keratomileusis (LASIK). METHODS: Recutting was performed on 263 eyes and the flap was lifted in 55 eyes that had LASIK for simple myopia or myopic astigmatism. The time interval between LASIK and retreatment was 340+/-46 days (range, 270 to 892 days) in the recutting group and 215+/-36 days (range, 53 to 617 days) in the flap lifting group. Mean spherical equivalent refraction, refractive cylinder, uncorrected and best spectacle-corrected visual acuity were examined prior to, and 1, 3, and 6 months after retreatment. RESULTS: Seventeen eyes were lost to follow-up in the lifting group and 53 eyes in the recutting group. In the recutting group, mean spherical equivalent refraction improved from -1.48+/-1.25 D to -0.49+/-0.88 D at 6 months. In the flap lifting group, mean spherical equivalent refraction improved from -1.05+/-1.49 D to -0.45+/-0.39 D at 6 months. Refractive cylinder did not change significantly in either group (P = .2). There was a significant increase in uncorrected visual acuity (UCVA) of 6/6 in each group. In the recutting group, UCVA of 6/6 increased from 3.8% to 65.2% at 6 months, and in the lifting group from 3.6% to 71.1% at 6 months. In the recutting group, seven free flaps and three macerated flaps that required removal occurred. One eye in the recutting group and two in the lifting group developed significant epithelial ingrowth. No patient lost more than one line of best spectacle-corrected visual acuity (BSCVA). CONCLUSION: Both procedures were safe, effective, and highly predictable for enhancements, but flap complications may be more likely with recutting.