Editor

We thank Konstantopoulos et al. for their interest in our paper and congratulate them for having conducted such a large study. It should be noted, however, that we did not actually conclude that older age was not associated with an increased risk of intraoperative complications, rather we stated that our data suggest that age alone may not be a major risk factor for any complication. Clearly absence of statistical evidence can never be equated to proof of no difference and we were careful to highlight that our numbers were small ( 9 patients older than 96, 111 greater than 88 years).

If we attempt to summarise data from our study, the Southampton Study and that by Berler to examine whether or not age greater than 88 is a risk factor for intra operative complications using meta analysis techniques, we find that there is significant inconsistency between the studies (test for heterogeneity Chi-square = 7.54, P = 0.02, I-squared = 73.5 %). It seems likely therefore that the different findings from our work and that of Southampton are not simply a reflection of varying study sizes but arise from other differences between the studies - for example the populations being operated on, or perhaps the techniques employed.

We would therefore agree with Konstantopoulos that further research into this interesting subject is needed.

References

1. Robbie SJ, Muhtaseb M, Qureshi K, Bunce C, Xing W, Ionides A. Introperative complications of cataract surgery in the very old. Br J Ophthalmol 2006; 90:1516-1518.

2. Berler DK. Intraoperative complications during cataract surgery in the very old. Trans Am Ophthalmol Soc. 2000; 98:127-30; discussion 130-2.

Dear Editor

We read with interest the article by Robbie et al titled ‘Intraoperative complications of cataract surgery in the very old’.[1] We agree with the authors that identification of risk factors for cataract surgery is important, as it has implications for patient care, surgical training, auditing and revalidation. The authors concluded that older age was not associated with an increased risk of intraoperative complications. Complication rates in patients >=88 years were not significantly different to patients <88 (4.5% vs. 6.3%, p=0.54). In patients >=96 years, although the complication rate was higher than in patients <96, this was not statistically significant (11.1% vs. 6.3%, p=0.45). However, the study included only 54 patients older than 90 years (number of patients older than 88 not stated) and 9 patients older than 96 years.

In a similar study, we identified all phacoemulsification cataract procedures carried out between 2001 and 2005 at the Southampton Eye Unit. Intraoperative complications, as classified in the National Cataract Surgery Survey,[2] were recorded on a computer database for each cataract procedure. We analysed the same data as the above study,[1] including age of patient, grade of surgeon and intraoperative complications (defined as abnormality in wound closure, posterior capsule tear, zonule dehiscence, anterior chamber haemorrhage, iris trauma or persistent iris prolapse).

Logistic regression analysis was carried out to examine whether age >=88 and age >=96 years were associated with an increased risk of complications. SPSS version 14 was used for statistical analysis; p<0.05 was considered statistically significant.

We identified 9367 consecutive phacoemulsification procedures. The mean patient age was 76.9 (SD 9.8) years. The overall complication rate was 3.1%. No significant difference was found between grades of surgeon and complication rates (trainee vs. consultant: 3.2% vs. 3.1%, p=0.90).

Interestingly, the complication rate in patients >=88 years (837 eyes) was 4.3% compared to 3.0% in patients <88 years (OR 1.4, 95% CI 1.005-2.049, p<0.05). In patients >=96 years (36 eyes) the complication rate was 8.3% vs. 3.1% in patients <96 years (OR 2.8, 95% CI 0.858-9.228, p=0.09).

Therefore, in contrast to the above study,[1] our results suggest that older age may be a risk factor for intraoperative complications during phacoemulsification surgery. We suggest that the rate of complications in cataract surgery in different age groups requires further study and that, in view of our results, experienced surgeons should preferentially operate on patients older than age 88.

References

1. Robbie SJ, Muhtaseb M, Qureshi K, Bunce C, Xing W, Ionides A. Introperative complications of cataract surgery in the very old. Br J Ophthalmol 2006;90:1516-1518.

2. Desai P, Minassian DC, Reidy A. National cataract surgery survey 1997- 8: a report of the results of the clinical outcomes. Br J Ophthalmol 1999;83:1336-1340.