Validation of two scoring systems for the prediction of posterior capsule rupture during phacoemulsification surgery.

AIM: To attempt to validate two scoring systems for the prediction of intraoperative complication during phacoemulsification surgery. METHODS: The study population was patients attending Sunderland Eye Infirmary who underwent phacoemulsification surgery between 1 January 2001 and 31 December 2003. The authors applied each scoring system to a control group of 300 patients from this study population and extrapolated the results to give an estimate of the spread of scores for the entire population. They then applied the same scoring systems to all complicated cases from the same study population. Using these results they were able to calculate the risk of a complication for a particular score on each scoring system. CONCLUSION: The application of these systems in clinical practice would allow appropriate selection of phacoemulsification cases for trainee surgeons, more accurate consent from patients for their phacoemulsification surgery, and the unbiased comparison of surgical outcomes from surgeons with differing case mix difficulties.

The role of case mix in the relation of volume and outcome in phacoemulsification.

BACKGROUND/AIM: The authors previously demonstrated a decrease in complication rate with an increase in volume of cases performed by a surgeon. All studies of volume and outcome are potentially hampered by the issue of case mix, in that some lower volume surgeons may in fact do fewer cases because they have more complex patients. This study was designed to assess the influence of case mix on the volume-outcome relation in phacoemulsification surgery that had previously been demonstrated. METHODS: This study took place wholly in Sunderland Eye Infirmary. 667 cases from between 1996 and 2001 were randomly selected from the operative lists of the six surgeons involved in a previous study. The case complexity was assessed using a potential difficulty score (PDS) devised from preoperative data predictive of potential surgical difficulty. The PDS was validated by a retrospective analysis of a sample of 100 cases. RESULTS: 528 complete sets of notes were retrieved. The overall PDS scores ranged from 1 to 6. There was a difference between the proportions of patients with each PDS value (p=0.015) in the two groups, which suggested that the low volume surgeons were doing potentially more difficult cases. The median PDS for each volume group were the same (=1.0). Retrospective validation analysis of the PDS score revealed higher mean and median values in complicated cases compared to uncomplicated cases. CONCLUSION: This follow up study re-emphasises the importance of case mix adjustment in comparative assessment of healthcare quality. These results may explain in part the trend previously demonstrated of lower complication rates for higher volume surgeons.

The incidence of prescribing errors in an eye hospital.

BACKGROUND: Relatively little is known about the incidence of prescribing errors and there has been no work on this in a single specialty ophthalmic hospital. Knowing where and when errors are most likely to occur is generally felt to be the first step in trying to prevent these errors. This study is an attempt in, the setting of an eye hospital, to try to identify and attribute these medication errors. METHODS: The study setting was a single specialty eye hospital geographically separated from the main general hospital. Pharmacists prospectively recorded the number of errors of prescribing during a 4 week period at an eye hospital in UK. The errors were categorised as error of prescription writing or drug error. Potential significance of the errors was not addressed. RESULTS: Overall 144/1952 (8%) prescription sheets had errors. 7% of the total errors were errors of prescription writing while 1% were drug errors. The majority of errors were made by junior doctors and no drug errors were made by senior doctors. The outpatients department had by far the highest prevalence of errors. CONCLUSION: Certain areas within the hospital and certain grades of staff are more prone to drug errors. Further study is required to look at the reasons why this is so and what systems can be put in place to reduce these errors.

The relation of volume with outcome in phacoemulsification surgery.

BACKGROUND/AIMS: High case volume has been associated with better health outcomes for a variety of procedures and conditions including coronary angioplasty, carotid endarterectomy, colorectal surgery, and various types of cancer surgery. The association of volume and outcome has important implications for patient safety and healthcare delivery planning. The relation between surgical volume and outcome has not, as far as is known, been looked at for phacoemulsification alone. METHODS: All cataract surgery performed from 1996 to 2001 by six consultant surgeons was reviewed. Using theatre logbooks and cross checking with the hospital database, the total number of phacoemulsification procedures performed per surgeon per year was calculated. The total number of operations in which it was judged that significant intraoperative complications occurred was also counted. RESULTS: When the data were pooled for all the surgeons there was evidence that complication rate decreased over time (Spearman's rho = -0.319, p = 0.058). If the data were pooled from all the years and all the surgeons then there was strong evidence of a decrease in complication rate with an increase in the number of cases (Spearman's rho = -0.63, p<0.01). CONCLUSIONS: This study is the first to describe a possible relation between volume of surgery and the outcome (as measured by complication rates) for phacoemulsification. There are however some caveats in that the issue of case mix was not addressed and that the results are from a single unit and may not necessarily be generalisable

Indicators of patient suitability for topical anesthesia.

PURPOSE: To determine whether a patient's suitability for phacoemulsification under topical anesthesia can be predicted preoperatively by their performance during tonometry and A-scan. SETTING: Whipps Cross Hospital Ophthalmology Department, London, England. METHODS: Fifty consecutive patients who were considered suitable for phacoemulsification were selected for the study. Using a scoring system we devised, observers assessed the patients for the ease with which intraocular pressure and axial length were measured. These scores were compared with an assessment of how well they tolerated phacoemulsification under topical anesthesia. Correlation between the scores was measured with Spearman's rank correlation coefficient, Kendall's rank correlation coefficient, and the Goodman-Kruskal gamma statistic. RESULTS: Phacoemulsification and posterior chamber intraocular lens implantation were completed in all patients. Statistical analysis showed that tonometry and A-scan scores correlated highly with surgery scores. Age was also a significant variable in predicting the surgery score. A significant discrepancy between tonometry and A-scan and surgery scores was found in only one patient, and it was noted that he was one of the youngest patients in the study. CONCLUSION: How well a patient performs during tonometry and A-scan was a good predictor of how well he or she tolerated having phacoemulsification under topical anesthesia. The decision about type of anesthesia should, however, also involve other factors, including communication, cooperation, and the age of the patient.

Twelve year follow-up of unfenestrated polysulfone intracorneal lenses in human sighted eyes.

PURPOSE: To evaluate unfenestrated polysulfone intracorneal lenses (ICLs) in human sighted eyes 12 years after their implantation and to assess eyes that had the ICLs explanted. SETTING: A department of clinical ophthalmology at a general hospital and the Department of Pathology at the National Institute of Ophthalmology, London, Great Britain. METHODS: In this retrospective study, seven eyes were evaluated 12 to 14 years after ICL implantation. Case notes were scrutinized for preoperative ophthalmic history, and patients were interviewed and examined to establish outcome of the ICL implantation. Histopathological correlates were made for two study patients who had had ICL explantation and penetrating keratoplasty (PKP). RESULTS: Uncorrected visual acuity in eyes retaining the ICL ranged between hand motion and 20/40, improving to 20/32 with correction. Corneal clarity varied between complete lucency to extensive opacity on each ICL surface. No corneal vascularization, endothelial decompensation, or uveitis was seen in eyes with clear ICLs. Acuity in eyes in which the ICL was explanted was between 20/20 corrected and finger counting in cases of PKP and between 20/200 and hand motion in eyes after lamellar keratoplasty. CONCLUSION: Despite satisfactory surgical technique in some eyes, unfenestrated polysulfone appears to be associated with color change and varying degree of stromal opacity in eyes evaluated 12 years postoperatively and thus cannot be considered clinically acceptable.

Glaucoma prescribing trends in England 2000 to 2012.

PURPOSE: In 2009, the National Institute for Clinical Excellence (NICE) published guidance on the treatment of ocular hypertension and glaucoma. The aim of the present study was to describe the impact this guidance had on glaucoma prescribing and to describe recent prescribing trends in England. METHOD: Prescribing cost analysis data held by NHS Business Authority for the years 2000-2012 was analysed. RESULTS: The number of prescriptions dispensed increased by 67% from 4.76 million in 2000 to 7.96 million in 2012. Over the same time period, drug costs increased by 88% from £55.2 million to £103.7 million. Prescriptions for prostaglandin analogues increased fourfold, while there was a threefold decrease in the use of beta-blockers. The most commonly prescribed glaucoma medication was latanoprost. The introduction of generic latanoprost in 2012 more than halved the cost associated with this medication. NICE guidance appeared to have had no effect on the total number of prescriptions or the classes of medications prescribed. CONCLUSION: The introduction of the NICE guidelines did not change glaucoma prescribing practice, although it is not clear whether this represents non-adherence to the guidelines or whether the guidelines embodied pre-existing practice.

An observational study of laterality errors in a sample of clinical records.

BACKGROUND: Confusing left with right eyes can have a potentially serious adverse outcome. The most extreme occurrence is wrong site surgery but even potentially less serious errors can undermine patient confidence in their medical care. This study was designed to look into how often this could be detected in clinical notes. METHODS: An observational study conducted in an ophthalmic hospital. Hundred patients were randomly selected and their clinical notes retrieved. Notes were analysed for the number of left/right transpositions, which part of the notes they were found and whether they were corrected. RESULTS: Forty-four transposition errors were found in 32 sets on notes. The commonest error was drawing the eye on the wrong side of the page. The commonest place where errors were found was in the written outpatient notes. Nineteen of the errors had evidence of later correction. Three consent forms had the incorrect eye denoted and one patient was listed for surgery on the wrong side although this error was corrected before the operation. CONCLUSION: As far as we are aware, this study is the first to look at how often, in standard clinical notes, left/right transposition occurs. Although a direct link cannot made between their occurrence and later wrong side surgery, intuitively it would be reasonable to think it could increase the likelihood if other defences were to fail. We make a number of recommendations that might reduce this confusion and therefore more serious consequences.

Hospital Episode Statistics and changing trends in glaucoma surgery.

BACKGROUND: A number of authors have documented the decrease in the rate of glaucoma drainage surgery, felt to be owing to increased medical therapy options. There has also been an increase in cataract extraction. The aim of this study was, using the NHS Hospital Episode Statistics (HES), to attempt to confirm these trends and to examine the possibility that these trends are not necessarily independent. METHODS: The HES was accessed for the main glaucoma procedures between 1998 and 2004 and for cataract operations performed over the same time period. Diagnostic data were also extracted from the HES data for glaucoma. Figures for the changes in glaucoma medications were obtained from pharmaceutical data. RESULTS: Over the period that the data are available, trabeculectomy numbers have reduced by 51%, laser trabeculoplasty by 60%, and laser peripheral iridectomy (PI) by 30%. Cataract extractions have increased by 52%. Medical treatments, especially prostaglandin use, have increased. The number of admissions for acute glaucoma did not increase. CONCLUSIONS: The figures indicated a decrease in glaucoma drainage surgery and an increase in cataract extraction-consistent with other studies. More surprisingly, there was no increase in diagnosis of angle closure glaucoma or laser PIs within the figures and we suggest this may in part be related to the increase in cataract extraction. We speculate that this may also partly be responsible for the reduction in trabeculectomies. Although the HES data are a potentially rich source of information, there are potential inaccuracies in the data, which means interpretations must be made with caution.

The relation of volume and outcome in trabeculectomy.

BACKGROUND/AIMS: Higher case volume has been associated with improved outcomes for a number of procedures. This study was designed to investigate whether this relationship existed for trabeculectomy. METHODS: The study was retrospective and conducted at an ophthalmic unit in the UK. All patients who had unenhanced trabeculectomy between 1996 and 2000 were identified. From their notes, the surgeon who performed the trabeculectomy was ascertained as were any unplanned interventions (eg conjunctival suturing, anterior chamber reformation, repeated attendances) within the first month of surgery. RESULTS: Two hundred and eleven trabeculectomies were performed over the study period. Twenty nine had unplanned interventions within the first postoperative month. Analysis of the data indicated that surgeons who performed less than eight operations per year had more complications than those who performed more than 10 per annum. This difference was only significant (chi(2)=4.0, P=0.045) when the data were aggregated. When separated per year, although not significant, the complication rate of the lower volume group was always higher than the group performing more than 10 per year. CONCLUSIONS: The results suggest that trabeculectomy can be added to the list of procedures in which larger case volume is associated with fewer early complications and potentially a better outcome. The findings, if replicated, tend to strengthen the argument for subspecialisation in glaucoma with its implications for training and revalidation.

Viscogonioplasty: an effective procedure for lowering intraocular pressure in primary angle closure glaucoma.

PURPOSE: To evaluate the safety and intraocular pressure (IOP) lowering effect of combined phacoemulsification and viscogonioplasty (Phaco-VGP) in managing primary acute closed-angle glaucoma (ACAG) unresponsive to conventional therapy (patent PI). PATIENT AND METHODS: In all, 15 consecutive eyes of patients with refractory ACAG and greater than 270 degrees peripheral anterior synechiae (PAS) underwent VGP. The technique of VGP involved routine phacoemulsification with intraocular lens implantation (Phaco/IOL) under topical anaesthetic. Following IOL implantation a heavy viscoelastic was used to deepen the anterior chamber and then injected near the angle for 360 degrees (without touching the trabecular meshwork) to break the PAS. No surgical instrument was used to physically break the PAS. Upon completion of VGP, automated irrigation with balanced salt solution to remove the viscoelastic was performed. RESULTS: Mean IOP reduced from 52.1 to 14.1 mmHg by Phaco-VGP at 6-months review. 14/15 patients were free of glaucoma medications at 6-month review. All angles showed exposure of the trabecular meshwork over 360 degrees postoperatively without evidence of residual synechiae. No untoward complications were observed in any patient. CONCLUSION: VGP may have a role in controlling IOP effectively and safely in patients with refractory ACAG. It produces a large drop in the IOP and opening of the angle. It is a relatively simple technique to learn and we would recommend its use in the eyes of all patients who have had ACAG and are undergoing cataract extraction.

Intraocular caterpillar hairs (setae): clinical course and management.

Ophthalmia nodosa is a well-documented condition. We present a case in which a live caterpillar was rubbed into a patient's eye and, after relentless penetration of the hairs into the globe, vitrectomy was required. We discuss the differing clinical features of these injuries, the mode of penetration and the treatment options.

Misdiagnosis of acute angle closure glaucoma.

When acute glaucoma presents in its classical form, the diagnosis is fairly simple to make. However, atypical presentations are not uncommon and the diagnosis can be missed. This inevitably leads to a delay in treatment which can permanently compromise visual function. We have studied which doctors are most likely to make a misdiagnosis and calculated the resulting delay in treatment. All patients with acute glaucoma attending Whipps Cross eye unit between 1991 and 1994 were identified and their notes obtained. Thirty-eight patients were found to have a had diagnosis of acute closed angle glaucoma. In only 39.5% was the diagnosis correctly made by the referring practitioner and a misdiagnosis resulted in a mean delay of treatment of 5.8 days. General practitioners were the most likely group to have difficulty making the diagnosis, while casualty officers were most likely to make the correct diagnosis. Because acute glaucoma can present without its typical features, there needs to be a high index of suspicion for this diagnosis. This diagnosis does not require expensive equipment or a high level of training--all our patients had a significant reduction in vision. Any patient who has a red eye and a subjective reduction in vision should be referred to an ophthalmologist the same day.