Pediatric cataract, myopic astigmatism, familial exudative vitreoretinopathy and primary open-angle glaucoma co-segregating in a family.

PURPOSE: To describe an Australian pedigree of European descent with a variable autosomal dominant phenotype of: pediatric cortical cataract (CC), asymmetric myopia with astigmatism, familial exudative vitreoretinopathy (FEVR), and primary open-angle glaucoma (POAG). METHODS: Probands with CC, FEVR, and POAG were enrolled in three independent genetic eye studies in Tasmania. Genealogy confirmed these individuals were closely related and subsequent examination revealed 11 other family members with some or all of the associated disorders. RESULTS: Twelve individuals had CC thought to be of childhood onset, with one child demonstrating progressive lenticular opacification. One individual had severe retinal detachment while five others had dragged retinal vessels. Seven individuals had POAG. Seven individuals had myopia in at least one eye ≤-3 Diopters. DNA testing excluded mutations in myocilin, trabecular meshwork inducible glucocorticoid response (MYOC) and tetraspanin 12 (TSPAN12). Haplotype analysis excluded frizzled family receptor 4 (FZD4) and low density lipoprotein receptor-related protein 5 (LRP5), but only partly excluded EVR3. Multipoint linkage analysis revealed multiple chromosomal single-nucleotide polymorphisms (SNPs) of interest, but no statistically significant focal localization. CONCLUSIONS: This unusual clustering of ophthalmic diseases suggests a possible single genetic cause for an apparently new cataract syndrome. This family's clinical ocular features may reflect the interplay between retinal disease with lenticular changes and axial length in the development of myopia and glaucoma.

Vitreous haemorrhage without obvious cause: national survey of management practices.

AIM: We undertook a national survey to establish the management of dense vitreous haemorrhage without obvious cause. METHODS DESIGN: Cross-sectional anonymous self-reporting survey of ophthalmic practitioners within three target groups: vitreoretinal specialists (VRS), nonvitreoretinal specialists (NVRS), and associate specialists (AS). INTERVENTION: Presentation of the hypothetical scenario of a patient presenting with recent onset (fresh) vitreous haemorrhage with no retinal view and no apparent cause on history taken at presentation. OUTCOME MEASURES: The relative importance assigned by respondents to eight examination techniques at presentation. The proportion of respondents stating that they would review patients and perform B-scan examination at or prior to 2 weeks after presentation. The stated time to surgical intervention by VRS, and the time to referral by NVRS and AS. RESULTS: VRS ranked B-scan examination higher than AS (P<0.001). A total of 98.1% of VRS indicated that they would next review patients within 2 weeks of presentation, this figure fell to 86.5% for NVRS and 47% for AS (P<0.001). A 98.1% of VRS indicated that they would next perform B-scan ultrasound within 2 weeks of presentation, this figure fell to 88.9% for NVRS and 70.6% for AS (P<0.001). The mean time to surgical intervention by VRS was 9.5 weeks without retinal tear demonstrated on B-scan, 1.7 weeks with retinal tear demonstrated on B-scan and 1 week with retinal detachment demonstrated on B-scan. The mean time to referral by NVRS was 6.7 weeks and by AS was 11.9 weeks. CONCLUSIONS: Vitreoretinal specialists considered B-scan the most important examination tool, and typically perform B-scan early and frequently after presentation. Non-VR ophthalmologists (particularly associate specialists) review patients and perform B-scan ultrasound later and less often than vitreoretinal specialists. We recommend early referral to VR specialists, as reported referral even in uncomplicated cases would often be outside the timeframe within which VR specialists would typically choose to operate.

The evaluation of a humidifying device for vitreoretinal surgery.

AIM: To study the feasibility of humidifying air during vitreoretinal surgery and measure the water content of air before and after intraocular transit. METHODS: The absolute water content of air was measured in a series of six eyes undergoing fluid-air exchange during macular hole surgery. Infrared absorption spectroscopy was used to determine the water content of the air infusing and exiting each eye. After baseline measurements for each eye were recorded, a second fluid-air exchange was performed and the effect of humidifying the air infusion was documented. The humidifying device used in this study was a prototype adapted from a commercially available respiratory humidifier and enables humidified air to be delivered at a controlled temperature. RESULTS: The water content of air increased following intraocular transit, implying dehydration occurs from the intraocular surfaces. For a standard airline infusion the mean increase in water content of air egressing from an eye was 13.4 mg/l. Humidifying the air reduced the rate of water loss by nearly 90%. CONCLUSIONS: Significant water losses can occur from eyes undergoing fluid-air exchange. Humidifying the infused air can substantially reduce the dehydrating effect during an air exchange. This outcome may have a beneficial effect in reducing cataract formation and visual field defects associated with macular hole surgery.

Retinal dialysis: are we missing diagnostic opportunities?

AIMS: To review medical records of those patients managed by our department for retinal dialysis, and establish whether the initial assessment had been adequate to make the diagnosis. That is, to establish if an adequate initial assessment had been performed that would reasonably exclude the likelihood of retinal dialysis and other trauma-related sequelae such as angle recession. METHODS: A retrospective review was made of all patients managed for retinal dialysis at Sussex Eye Hospital between 20 March 1997 and 20 September 2002 (66 months). In addition to general demographic data, surgical management and outcome, patient files were reviewed for history of trauma, prior ophthalmic review, and whether such review included documentation of peripheral retinal examination and gonioscopy. RESULTS: A total of 580 primary procedures were performed for retinal detachment during the review period, of which 32 eyes of 29 patients underwent surgery for retinal dialysis (6%). There were 21 male and eight female patients, with a history of trauma obtained in 55% (17 eyes, 16 patients). Of the 16 patients with prior trauma, nine had undergone prior ophthalmic review at the time or soon after their trauma; however, only 2 (22%) had documented evidence of indented peripheral retinal examination. Only one (3%) patient in the whole series had documented gonioscopy. CONCLUSIONS: Patients with history of trauma often present at the time or soon after their injury (eg hyphaema, orbital fractures). Thus, an opportunity exists to screen patients for known sequelae of trauma such as retinal dialysis and angle recession. It was disappointing to learn that this opportunity was not always being utilized, with some patients consequently developing macula-off retinal detachments and potential for reduced visual outcome.

Humidity devices in vitreoretinal surgery.

PURPOSE: To assess a humidity device used in vitreoretinal surgery. METHODS: Infrared absorption spectroscopy analysis of absolute water content (absolute humidity) was determined for a typical vitreoretinal air infusion line with and without the humidifying device. A variety of experimental laboratory conditions were utilized and designed to mimic those found in the operating room. The effect on physical parameters, such as flow rates and resistance to flow, were also determined. RESULTS: While large bore infusion (LBI) lines had a negligible effect on flow rate and resistance to flow (reduction in infusion pressure), the standard 20 G infusion line (SI) reduced flow rate and infusion pressure by approximately 25%. When used together, the humidifying device and SI reduced flow rate and infusion pressure by one third. The humidifying device was found to add 6.5 mg/L water content to the air infusion line system. Typical operating room (OR) air contains 9.5 mg/L water content, and 43.876 mg/L water content is required to saturate air at body temperature. CONCLUSION: To eliminate dehydration as a cause of intraocular morbidity, one must first saturate the infused air. If the visual field defects and other complications are eliminated, this would be good evidence for saturating infused air. As infusion pressure (flow rate) influences dehydration rate, unless saturated air is used, infusion pressure cannot be considered an independent variable in the analysis of field defects.

Anti-inflammatory fibrosis suppression in threatened trabeculectomy bleb failure produces good long term control of intraocular pressure without risk of sight threatening complications.

AIMS: To determine the long term outcome of systemic anti-inflammatory fibrosis suppression in cases of threatened trabeculectomy bleb failure in open angle glaucoma. METHODS: This prospective non-comparative case series followed 77 eyes of 63 patients which showed signs of threatened early bleb failure and were treated with oral anti-inflammatory fibrosis suppression of prednisone, a non-steroidal anti-inflammatory agent, and colchicine taken for a mean period of 6 weeks, in addition to standard postoperative topical treatment, for a mean follow up of 6 years. RESULTS: Trabeculectomy with anti-inflammatory fibrosis suppression controlled the IOP at < or =21 mm Hg with a probability of 0.91 (95% CI: 0.81 to 1.0) at 8 years and 0.89 (95% CI: 0.56 to 1.1) at 12 years. There were no reported cases of endophthalmitis, hypotonous maculopathy, late bleb leak, or serious systemic side effects. CONCLUSION: Anti-inflammatory fibrosis suppression provided good control of bleb fibrosis without risk of sight threatening complications in a patient group at high risk of bleb failure.

X-ray turns a blind eye to ferrous metal.

The case is reported of a 31-year-old man with a retained metallic intraocular foreign body (IOFB) in the left eye who underwent magnetic resonance imaging (MRI) for investigation of a subsequent unrelated brachial plexus injury Despite the patient providing good history of IOFB, the decision to proceed with MRI was based on screening orbit X-ray which was reported as normal. A review of published reports regarding screening recommendations for MRI for patients with IOFB is provided. A minimum recommendation is for prescreening questionnaire; belief of the patient history is critical. If there is any doubt after history and examination by an ophthalmologist, then computed tomography imaging of the orbits is recommended. Whether screening by plain X-ray imaging is worthwhile is debatable as the sensitivity and specificity of this modality is poor.

Upside-down orbitopathy: unilateral orbital dependent-tissue oedema causing total visual loss.

The case is reported of a 24-year-old man who was involved in a road traffic accident and became trapped upside down with the right side of his face being the most dependent part of his body. Marked hemifacial tissue oedema was associated with right acute compressive orbitopathy and vascular compromise. Acute dysfunction of al orbital nerves was found on examination. Such neuropathy is usually related to the consequences of direct trauma, fractures or haemorrhage; however, computed tomography scanning demonstrated no evidence of orbital fracture or haemorrhage. Immediate anterior surgical orbital decompression was performed in the emergency room in addition to high dose intravenous steroids. Dependent orbtal tissue oedema is proposed as a mechanism of compressive orbitopathy with consequent ischaemic damage to all orbital nerves, total visual loss and complete ophthalmoparesis. Good recovery of other orbital nerves has occurred and the globe has reperfused. Despite intervention, no visual function has returned.

Undergraduate ophthalmology education survey of New Zealand ophthalmologists, general practitioners and optometrists.

AIM: To determine what New Zealand ophthalmologists, general practitioners and optometrists consider important ophthalmic topic areas requiring emphasis in the medical undergraduate curriculum. METHOD: A total of 793 questionnaires related to the content and teaching of undergraduate ophthalmology were sent to ophthalmologists, general practitioners and optometrists. Results were analysed separately for the three respondent groups and as a whole. RESULTS: Four hundred and fourteen questionnaires were returned (52% return rate). Overall responses of the three participant groups were similar and agreed favourably with the current curriculum. The ability to measure visual acuity (97%) and pupillary reflexes (93%), perform ophthalmoscopy (92%), and assess visual fields (68%) were regarded as 'important or essential' by the majority of respondents. Only 53% of respondents consider the ability to diagnose chronic open angle glaucoma as important. The respondents stressed the importance of the diagnosis of predominantly anterior segment disease contrasting with the traditional bias towards the teaching of ophthalmoscopy and posterior segment disease. The majority of respondents stressed the importance of graduating medical students being able to treat bacterial and allergic conjunctivitis, styes, blepharitis, corneal abrasion, and corneal and conjunctival foreign bodies, areas present but not normally emphasized in current curricula. CONCLUSION: The findings of this study provided additional data to facilitate curriculum design and illustrated the value of an integrated problem-based learning approach in ophthalmology undergraduate teaching.

Cyanoacrylate glue for corneal perforations: a description of a surgical technique and a review of the literature.

The effective early application of a cyanoacrylate glue corneal patch can aid in the management of small corneal perforations, corneal melts and wound leaks. Their use gives improved visual outcomes with reduced enucleation rates (6% vs 19%). It may also avoid the need for tectonic penetrating keratoplasty. Cyanoacrylate glue prevents re-epithelialization into the zone of damaged and naked stroma and prevents the development of the critical setting for collagenase production that leads to stromal melting. Cyanoacrylates also have significant bacteriostatic activity against gram-positive organisms. We describe a simple and easily reproducible method of cyanoacrylate corneal patch application, with neglible risk of inadvertent glue complications. It has the further advantage of a smooth corneal surface rather than an irregular surface as often occurs with direct application methods. With corneal application, the major concern is toxicity of cyanoacrylates through direct contact with the corneal endothelium and lens. Fibrin glues may be less toxic; however, they are not as readily available. The longer alkyl chains of currently available cyanoacrylate glues (e.g. Histoacryl) slows degradation significantly, limiting accumulation of histotoxic by-products to amounts that can be effectively eliminated by tissues. Vigilance in monitoring for infection/corneal infiltrate is necessary at all times, especially when the glue has been present for more than 6 weeks. Corneal patching with cyanoacrylate glue is a temporizing procedure only, buying time to allow healing secondary to medical treatment of the underlying condition, or allowing surgery to be elective and under more optimal conditions once inflammation has been reduced and the integrity of the globe restored.