The Cataract National Dataset electronic multicentre audit of 55,567 operations: when should IOLMaster biometric measurements be rechecked?

PURPOSE: Calculation of intraocular lens (IOL) power for implantation during cataract surgery depends on ocular biometric measurements. The aim of this study was to characterise the normal range of intra- and interindividual variation in axial length (AL) and corneal power (K) when IOLMaster measurements were possible and to derive recommendations as to which outlying measurements merit verification before acceptance. METHODS: The Medisoft electronic patient database contains prospectively collected data conforming to the United Kingdom (UK) Cataract National Dataset on 55,567 cataract operations. From this AL and K information on the 32,556 eyes (14,016 paired) of patients older than 25 years, without corneal pathology, history of intraocular surgery and who had all biometric measurements taken with the Zeiss IOLMaster (Carl Zeiss Meditec) were extracted. R 2.8.1 (R Foundation for Statistical Computing) was used for statistical analysis. RESULTS: Mean age was 76.4 years and 62.0% were female. Mean (95% confidence interval) values for AL, mean K and corneal astigmatism were 23.40 (21.27-26.59) mm, 43.90 (40.94-47.01) D and 1.04 (<2.50) D. Nearly all astigmatism was either with or against the rule. Differences between paired eyes were not statistically significant. 95% individuals had asymmetry of AL and mean K<0.70 mm and 0.92 D, respectively. CONCLUSIONS: On the basis of approximation of the 95% CI above, it is suggested that AL, mean K and keratometric astigmatism measurements outside the ranges 21.30-26.60 mm, 41.00-47.00 D and >2.50 D, respectively, and intraindividual asymmetry of AL >0.70 mm or mean K>0.90 D should be verified before acceptance.

The Cataract National Dataset electronic multi-centre audit of 55,567 operations: updating benchmark standards of care in the United Kingdom and internationally.

AIMS: To pilot the use of the Cataract National Dataset (CND) using multi-centre data from Electronic Patient Record (EPR) systems and to demonstrate the ability of the CND to deliver certain of its intended benefits, including detailed preoperative profiling of cataract surgery patients and updating of benchmark standards of care in the NHS and beyond. METHODS: NHS departments using EPR systems to collect a minimum preoperative, anaesthetic, operative and postoperative data set, the CND, were invited to submit data, which were remotely extracted, anonymised, assessed for conformity and completeness, and analysed. RESULTS: Four-hundred and six surgeons from 12 NHS Trusts submitted data on 55,567 cataract operations between November 2001 and July 2006 (86% from January 2004). Mean age (SD) was 75.4 (10.4) years, 62.0% female. Surgery was for first eyes in 58.5%, under local anaesthesia in 95.5% and by phacoemulsification in 99.7%. Trainees performed 33.9% of operations. Preoperative visual acuity (VA) was 6/12 or better in 42.9% eyes overall, in 35.3% first eyes and in 55.3% second eyes. Complication rates included the following: posterior capsule rupture and/or vitreous loss of 1.92%, simple zonule dialysis of 0.46% and retained lens fragments of 0.18%. Postoperative VA of 6/12 or better (and 6/6 or better) was achieved for 91.0% (45.9%) of all eyes, 94.7% (51.0%) of eyes with no co-pathologies and 79.9% (30.2%) of eyes with one or more co-pathologies respectively. CONCLUSIONS: The CND is fit for purpose, is able to deliver useful benefits and can be collected as part of routine clinical care via EPR systems. This survey confirms shifts in practice since the 1997-1998 UK National Survey with full conversion to phacoemulsification, better preoperative acuity, a halving of the surgical 'index' benchmark complication of posterior capsule rupture and/or vitreous loss, and improved VA outcomes.

The Cataract National Dataset electronic multicentre audit of 55,567 operations: antiplatelet and anticoagulant medications.

AIMS: This study aims to establish the prevalence of aspirin, dipyridamole, clopidogrel, and warfarin use in patients undergoing cataract surgery, and to compare local anaesthetic and intraoperative complication rates between users and non-users. METHODS: The Cataract National Dataset was remotely extracted and anonymised on 55,567 operations at 12 NHS Trusts using electronic patient records (EPRs) between 2001 and 2006. RESULTS: This report analyses 48,862 of the 55,567 operations from the eight centres, which routinely recorded a drug history. In all, 28.1% of the 48,862 patients were taking aspirin, 5.1% warfarin, 1.9% clopidogrel, and 1.0% dipyridamole. The recording of any complication of a sharp needle or subtenon's cannula local anaesthetic block was increased in patients taking clopidogrel, 8.0% (P<0.0001) or warfarin, 6.2% (P=0.0026) vs non-users, 4.3%, but no increase in potentially sight-threatening complications was identified. The incidence of subconjunctival haemorrhage was increased in patients taking clopidogrel, 4.4% (P<0.0001) or warfarin, 3.7% (P<0.0001) vs non-users, 1.7%. The recording of any operative complication was increased in those taking clopidogrel, 7.3% (P=0.0002) vs non-users, 4.4%, but the haemorrhagic operative complications of choroidal/suprachoroidal haemorrhage and hyphaema were not significantly increased. The non-haemorrhagic complication of posterior capsular rupture (PCR) was increased in those taking clopidogrel, 3.23% (P=0.0057) vs non-users, 1.77%. CONCLUSIONS: Clopidogrel or warfarin use was associated with a significant increase in minor complications of sharp needle and subtenon's cannula local anaesthesia but was not associated with a significant increase in potentially sight-threatening local anaesthetic or operative haemorrhagic complications.

The Cataract National Dataset electronic multicentre audit of 55,567 operations: risk stratification for posterior capsule rupture and vitreous loss.

AIMS: To identify and quantify risk factors for posterior capsule rupture or vitreous loss or both (PCR or VL or both) during cataract surgery and provide a method of composite risk assessment for individual operations. METHODS: The Cataract National Dataset was extracted on 55,567 operations from 12 National Health Service (NHS) Trusts using an electronic patient record (EPR) system between November 2001 and July 2006. Risk indicators for variations in the rate of 'PCR or VL or both' were identified by univariate and multivariate analyses. Adjusted odds ratios (ORs) were used to formulate a composite 'bespoke' risk for individual cases. RESULTS: Overall 'PCR or VL or both' rate was 1.92% (95% CI=1.81-2.04%). Risk indicators for this complication were increasing age, male gender, presence of glaucoma, diabetic retinopathy, brunescent/white cataract, no fundal view/vitreous opacities, pseudo-exfoliation/phacodonesis, reducing pupil size, axial length > or = 26.0 mm, the use of the alpha-blocker doxazosin, inability to lie flat and trainee surgeons performing operations. Adjusted ORs for these variables are used to estimate overall composite risk across multiple risk indicators in the form of a predicted probability of PCR or VL or both. Predicted probability for this complication ranged from less than 0.75% to more than 75%, depending on risk profile of individual operations. CONCLUSIONS: Higher-risk cases can be predicted, thus better informing the consent process and allowing surgeons to take appropriate precautions. Case-mix is a major determinant of the probability of an intraoperative complication. A simple composite risk estimation system has been developed.

The Cataract National Dataset Electronic Multi-centre Audit of 55,567 operations: anaesthetic techniques and complications.

PURPOSE: The primary aim of this study was to detail anaesthetic techniques and complications for cataract surgery in the UK. METHODS: The Cataract National Dataset was extracted from 12 National Health Service Trusts that used the same electronic patient record system between November 2001 and July 2006 on a total of 55,567 cataract operations. RESULTS: Anaesthesia was administered by an ophthalmologist in 56.7% of the cases, a career anaesthetist in 42.1% of the cases, a clinical assistant anaesthetist in 0.3% of the cases, and staff were not recorded in 0.9% of the cases. Local anaesthesia (LA) was used in 95.5%, with topical anaesthesia alone in 22.3% (range by site, 0-99.8%), topical and intracameral in 4.7% (range, 0-24.1%), subtenons in 46.9% (range, 0-81.8%), peribulbar in 19.5% (range, 0-63.4%), and retrobulbar in 0.5% (range, 0-5.3%). One or more minor complications occurred in 4.3% of 38,058 local blocks administered by either sharp needle or subtenons (blunt) cannula. Minor complications were 2.3 times more common with subtenons blocks (P<0.001). Serious complications, defined as sight or life threatening occurred in 25 eyes, 0.066%, undergoing sharp needle or subtenons cannula blocks. Sharp needle techniques had a 2.5-fold increased risk of serious complications compared with subtenons cannula techniques (P=0.026). CONCLUSION: Subtenons anaesthesia was the most widely used anaesthetic technique for cataract surgery but wide variation existed by site. There was a low rate of reported LA complications. There was a statistically significant increased risk of serious complications with sharp needle anaesthesia compared with subtenons technique.

Outcomes of macular hole surgery: implications for surgical management and clinical governance.

PURPOSE: The optimal method and timing of the surgical treatment for idiopathic macular holes remains unknown. The aim of this retrospective study was to identify factors associated with anatomical and visual success in macular hole surgery. METHODS: Case records of 55 patients undergoing macular hole surgery at three units in the 2-year period up to July 2002 were reviewed to identify factors associated with anatomical and visual success. The following potential prognosticators were evaluated: patient age, hole stage, hole latency prior to surgery, preoperative acuity, simultaneous phacoemulsification, and intraocular lens implantation, internal limiting membrane peeling with and/or without indocyanine green, and postoperative posturing. RESULTS: The duration of preoperative symptoms, indocyanine green-assisted internal limiting membrane peeling, hole stage, and better preoperative visual acuity were associated with both anatomical success and regaining a postoperative visual acuity of 6/12 or better. DISCUSSION: The closure rate in patients undergoing surgery within 1 year of onset was 94.0%, and in those waiting 1 year or more it was 47.4%. Clinical governance and quality issues should dictate that NHS macular hole surgery is available to all within 1 year of onset. This study showed no adverse effect of ICG dye retinal staining. The results support the use of a 'patient-friendly' approach of simultaneous cataract surgery with no prone postoperative posturing.

A pilot study of pars plana vitrectomy, intraocular gas, and radial neurotomy in ischaemic central retinal vein occlusion.

BACKGROUND/AIMS: There is no effective treatment for ischaemic central retinal vein occlusion (CRVO). The two major negative outcomes are neovascular glaucoma (NVG) and severe central visual loss. In this study pars plana vitrectomy (PPV), mild panretinal photocoagulation, and intraocular gas injection were employed to prevent NVG. The potential role of incision of the lamina cribrosa (radial neurotomy) for visual recovery was examined. METHODS: Eight eyes of seven patients with ischaemic CRVO had PPV, mild panretinal photocoagulation, and intraocular perfluoropropane gas injection. Four eyes had radial neurotomies performed. The patients were examined by fundus photography, fundus fluorescein angiography, optical coherence tomography, and Goldmann visual field analysis. RESULTS: No patients suffered from neovascular glaucoma. Visual recovery was seen in patients with and without neurotomy but some patients had cataract extraction to allow visualisation for PPV. Fundus photography demonstrated reduced engorgement of retinal veins in two of the patients with neurotomy and one with PPV alone. Optical coherence tomography demonstrated macular oedema in three patients with neurotomy and all patients with PPV alone. Segmental visual field loss was seen in one patient with neurotomy suggesting damage to the optic nerve head. CONCLUSIONS: PPV is safe in ischaemic CRVO. Combined with mild PRP and intraocular gas injection the risk of neovascular glaucoma is low. Neurotomy can be added to try to improve the chances of recovery of central vision but may cause additional peripheral visual field loss.

Rectus muscle trauma complicating sub-Tenon's local anaesthesia.

PURPOSE: To describe three cases of rectus muscle trauma in patients undergoing phacoemulsification cataract extraction and intraocular lens implantation under sub-Tenon's local anaesthesia via the inferonasal quadrant. METHODS: Retrospective review was carried out of 3 cases from 1080 patients who underwent phacoemulsification cataract extraction and intraocular lens implantation under sub-Tenon's local anaesthesia in our unit over a 3 year period up to April 2000. RESULTS: Two patients complained postoperatively of vertical diplopia and were shown to have restriction of elevation of the eye, which was found at surgical exploration to be due to inferior rectus muscle restriction. One patient had post-operative horizontal diplopia due restriction of abduction and exploration of the medial rectus muscle was planned. CONCLUSION: Rectus muscle trauma is proposed as a complication of sub-Tenon's local anaesthesia and caution is advised to operators to clearly identify the sub-Tenon's space for injection of local anaesthetic.