Safe eye surgery: non-technical aspects

The traditional training of surgeons focused exclusively on developing knowledge, clinical expertise, and technical (surgical) skills. However, analyses of the reasons for adverse events in surgery have revealed that many underlying causes originate from behavioural or non-technical aspects of performance (eg, poor communication among members of the surgical team) rather than from a lack of surgical (ie, technical) skills. Therefore, technical skills appear to be necessary but not sufficient to ensure patient safety. Paying attention to non-technical skills, such as team working, leadership, situation awareness, decision making, and communication, will increase the likelihood of maintaining high levels of error-free performance. Identification and training of non-technical skills has been developed for high-risk careers, such as civil aviation and nuclear power. Only recently, training in non-technical skills has been adopted by the surgical world and anaesthetists. Non-technical skills need to be tailored to the environment where they are used, and eye surgery has some substantial differences compared with other surgical areas, for example, high volume of surgery, use of local anaesthetics, and very sophisticated equipment. This review highlights the need for identification of the non-technical skills relevant to eye surgeons and promotion of their use in the training of eye surgeons.

Autologous scleral patch graft in tube shunt surgery

Purpose . To investigate alternative surgical method to cover subconjunctival portion of the tube in tube shunt surgery in glaucoma Methods. In thirteen eyes of twelve patients who underwent tube shunt surgery at WEH between July 1991 to November 1996 a "rotating" autologous scleral lamellar graft was created to cover the subconjuctival course of the tube. These patients were followed for clinical signs of conjuctival breakdown, graft melt, tube erosion, anterior staphylomas, graft related inflammation, infections or graft related complications. Results. The patients were followed up for a mean of 16 5 months( range 1-60 months). All eyes tolerated the autologous graft well without any clinical evidence of tube erosions, graft melting , graft related or intraocular inflammation Conclusions The use of autologous sciera, to cover the tube in a tube shunt procedure appears to be effective and without inappropriate short term risk. It offers the advantages of availability , lower cost, and eliminates the potential risk of transmission of infectious disease( i.e. slow-virus, HIV etc.).

Reversal of optic disc cupping after glaucoma surgery analyzed with a scanning laser tomograph

Objective: To detect and quantitate changes in optic nerve morphology after glaucoma surgery using the Heidelberg Retina Tomograph (HRT, Heidelberg Instruments, Heidelberg, Germany). Design: Nonconsecutive observational case series. Participants and Intervention: The authors prospectively enrolled 21 adult patients undergoing incisional glaucoma surgery for progressive glaucoma damage. Quantitative analysis of the optic nerve head by scanning laser tomography and automated perimetry were performed before and after glaucoma surgery. Main Outcome Measures: Changes in optic nerve parameters were subjected to linear regression analysis with respect to percent of postoperative reduction of intraocular pressure (IOP), as well as with respect to age, refraction, preoperative cup:disc ratio, and change in visual field parameters. Results: Seventeen patients had pre- and postoperative images suitable for analysis. Mean IOP at the time of image acquisition before surgery was 30.5 ± 12 mmHg, and after surgery 11.8 ± 5.2 mmHg (mean follow-up, 26 ± 7 weeks). Eleven of 13 (85%) patients having IOP reduction of greater than 40% showed improvement in optic disc parameters. All four patients with less than 25% reduction in IOP showed worsening of most parameters. Changes in optic disc parameters were highly correlated with percent IOP reduction and with age. The parameters in which change most strongly correlated with percent change of IOP were cup area, rim area, cup:disc ratio, and mean cup depth (each, P <0.005). The age of the patient correlated highly with change in maximum cup depth (P <0.005). Refraction and clinically determined cup:disc ratio correlated poorly with changes in measured optic disc parameters. Clinical improvement in visual fields was correlated with the degree of improvement of cup:disc ratio (P = 0.025). Conclusion: Most patients showing a 40% lowering of IOP after glaucoma surgery show improved optic nerve morphology as measured by the HRT. The amount of improvement correlated highly with the percent reduction of IOP.

Surgical checklist for cataract surgery:progress with the initiative by the Royal College of Ophthalmologists to improve patient safety

PurposeThe World Health Organisation (WHO) identified patient safety in surgery as an important public health matter and advised the adoption of a universal peri-operative surgical checklist. An adapted version of the WHO checklist has been mandatory in the National Health Service since 2010. Wrong intraocular lens (IOL) implantation is a particular safety concern in ophthalmology. The Royal College of Ophthalmologists launched a bespoke checklist for cataract surgery in 2010 to reduce the likelihood of preventable errors. We sought to ascertain the use of checklists in cataract surgery in 2012.Patients and methodsA survey of members of the Royal College of Ophthalmologists seeking views on the use of checklists in cataract surgery. Four hundred and sixty-nine completed responses were received (18% response rate).ResultsRespondents worked in England (75%), Scotland (11%), Wales (5%), Northern Ireland (2%), the Republic of Ireland (1%), and overseas (6%). Ninety-four per cent of respondents support the use of a checklist for cataract surgery and 85% say that they always use a checklist before cataract surgery. Sixty-seven per cent of cataract surgeons stated they undertake a pre-operative team brief. Thirty-six per cent use a cataract surgery checklist developed locally, 18% use the college's bespoke cataract surgery checklist, 39% use a generic surgical checklist, and 4% reported that they do not use a checklist.ConclusionNinety-three per cent of cataract surgeons responding to the questionnaire report using a surgical checklist and 67% use a team brief. However, only 54% use a checklist, which addresses the selection of the correct intraocular implant. We recommend wider adoption of checklists, which address risks relevant to cataract surgery, in particular the possibility of selection of an incorrect IOL.Eye advance online publication, 24 May 2013; doi:10.1038/eye.2013.101.

Relationship between socioeconomic deprivation or urban/rural residence and visual acuity before cataract surgery in Northern Scotland

Purpose: To evaluate the influence of socioeconomic factors on visual acuity before cataract surgery. ?Methods: The medical case notes of 240 consecutive patients listed for cataract surgery from January 1, 2010, at Grampian University Hospital, Aberdeen, were reviewed retrospectively. Patients with ocular comorbidity were excluded. Demographics, postal codes, and visual acuity were recorded. Scottish Index of Multiple Deprivation was used to determine the deprivation rank. Home location was classified as urban or rural. The effect of these parameters on preoperative visual acuity was investigated using chi-square tests or Fisher exact test as appropriate. ?Results: A total of 184 patients (mean 75 years) were included. A total of 127 (69%) patients had visual acuity of 6/12 or better. An association was found between affluence and preoperative visual acuity of 6/12 or better (?2trend = 4.97, p = 0.03), with a significant rising trend across quintile of deprivation. There was no evidence to suggest association between geographical region and preoperative visual acuity (p = 0.63). ?Conclusion: Affluence was associated with good visual acuity (6/12 or better) before cataract surgery. There was no difference in preoperative visual acuity between rural and urban populations.

Stereological estimation of Weibel-Palade bodies in the retinal vasculature of normal and diabetic dogs

The absolute volume of Weibel-Palade (WP) bodies, the storage organelles of von Willebrand factor (vWF), was estimated by a stereological method in a known volume of central retina from normal and 5-year diabetic dogs. The results showed that the volume of WP bodies present in the endothelium of the retinal vasculature varies with blood vessel type and in diabetes. In both diabetic and normal dogs the endothelium of the retinal veins contained a higher volume of WP bodies than that of the retinal arteries. In dogs which had been diabetic for a duration of 5 years the volume of WP bodies present in the endothelium of retinal veins was significantly greater than in the endothelium of veins from the control animals. However, there was no significant difference in the volume of WP bodies present in the endothelium of retinal arteries or capillaries between the two groups of animals.

Selective loss of vascular smooth muscle cells in the retinal microcirculation of diabetic dogs

This study was undertaken to further characterise the fine structural changes occurring in the retinal circulation in early diabetes. The eyes of eight alloxan/streptozotocin and three spontaneously diabetic dogs were examined by trypsin digest and electron microscopy after durations of diabetes of between 1 and 7 years. Basement membrane (BM) thickening in the retinal capillaries was the only obvious fine structural change identified during the first 3 years of diabetes and was established within 1 year of induction. Widespread pericyte loss was noted after 4 years of diabetes and was paralleled by loss of smooth muscle (SM) cells, in the retinal arterioles. SM cell loss was most obvious in the smaller arterioles of the central retina. No microaneurysms were noted in the experimental diabetic dogs with up to 5 years' duration of diabetes but were widespread in a spontaneously diabetic animal at 7 years. This study has shown that SM cell loss, a hitherto unrecognised feature of diabetic microangiopathy, accompanies pericyte loss in the retinal circulation of diabetic dogs.

Induction of alloxan/streptozotocin diabetes in dogs: a revised experimental technique

The diabetic dog represents an excellent model for use in many aspects of diabetic research. The present paper describes, in detail, a reproducible experimental protocol for the successful induction of chemical diabetes in beagles using a combination of the 2 pancreatic beta-cell cytoxic agents alloxan and streptozotocin.

Measurement of nasal patency in anesthetized and conscious dogs

Experiments were undertaken to characterize a noninvasive chronic, model of nasal congestion in which nasal patency is measured using acoustic rhinometry. Compound 48/80 was administered intranasally to elicit nasal congestion in five beagle dogs either by syringe (0.5 ml) in thiopental sodium-anesthetized animals or as a mist (0.25 ml) in the same animals in the conscious state. Effects of mast cell degranulation on nasal cavity volume as well as on minimal cross-sectional area (A(min)) and intranasal distance to A(min) (D(min)) were studied. Compound 48/80 caused a dose-related decrease in nasal cavity volume and A(min) together with a variable increase in D(min). Maximal responses were seen at 90-120 min. Compound 48/80 was less effective in producing nasal congestion in conscious animals, which also had significantly larger basal nasal cavity volumes. These results demonstrate the utility of using acoustic rhinometry to measure parameters of nasal patency in dogs and suggest that this model may prove useful in studies of the actions of decongestant drugs.

Endocrine Surgery: Principles and Practice:adrenal chapter

The paired adrenal (suprarenal) glands are flattened retroperitoneal endocrine glands closely applied to the medial aspect of the superior pole of each kidney. The internal structure of these pale yellow glands are incongruous in that the adrenal gland is composed of two discrete parts, namely an outer cortex enveloping a central medulla. The adrenal cortex and medulla contain distinct endocrine tissues that secrete different hormones and are regulated by separate control systems.