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.

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.

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.