Phacoemulsification cataract surgery and unplanned anterior vitrectomy--is it bad news?

PURPOSE: The aim of this study was to determine the final visual outcome of patients who undergo complicated phacoemulsification cataract surgery in which the posterior capsule is compromised and vitrectomy was required. METHODS: Data were collected for patients operated on over an 18-month period from the 1st of January till the 24th of June 1999 at the Department of Ophthalmology, Leicester Royal Infirmary. All grades of surgeons were included and patients were identified from the theatre logbook. A standard proforma was completed and the data evaluated. RESULTS: A total of 2538 phacoemulsification cataract operations were performed over this duration. Of these, 2446 (96.4%) had uncomplicated phacoemulsification cataract surgery while 92 (3.6%) required anterior vitrectomy. In order to allow for a more accurate interpretation of the visual outcome, patients were divided into two groups, depending on whether or not there was pre-existing eye disease at initial listing.Sixty-five patients did not have pre-existing eye disease. From this, notes were available for 57 patients, whereby the best-corrected visual acuity (BCVA) was obtained postoperatively. Vision of 6/12 or better was used to define acceptable postoperative vision. This group consisted of 49 patients (86%): five had visual acuities of 6/12, 26 = 6/9, one = 6/7.5 and 17 = 6/6. There were eight (14%) patients with poor visual outcome, largely represented by patients with cystoid macular oedema (8.8%). The most frequent stage of vitreous loss was during primary phacoemulsification in 46 (50%). Irrigation and aspiration, which resulted in 21 (23%) instances, followed this. The rate of posterior capsule rupture and anterior vitrectomy during phacoemulsification cataract surgery is 2% when performed by consultants, 4% by specialist registrars and staff grades and 10% by senior house officers. CONCLUSION: This study looks at the final visual outcome of patients who underwent unplanned anterior vitrectomy during routine phacoemulsification cataract surgery, in a university teaching hospital in the United Kingdom. It includes all levels of surgeons with varying experience. The rate of vitreous loss in this study for phacoemulsification cataract surgery is 3.6%. Patients who undergo complicated phacoemulsification cataract surgery do comparatively well.

What is the prevalence of visual impairment in the general and diabetic populations: are there ethnic and gender differences?

AIMS: To estimate the prevalence of blindness and partial sight in the general and diabetic populations and to measure the impact of ethnicity and gender on these rates. METHODS: Data on visual impairment in the population to be studied was obtained from the Royal Leicestershire Rutland and Wycliffe Society for the Blind (RLRWSB). Using the validated technique of capture-mark-recapture (CMR), a census day was set and data from four sources collected: hospital admissions data, GP returns, wards, and mass media. Computer cross-linkage to Leicestershire Health Authority data ensured patients were alive and resident in Leicestershire at the census date. Estimates of diabetes, ethnicity and gender prevalence were calculated using the 1991 census. RESULTS: CMR calculations revealed that there was under ascertainment of visual impairment in the RLRWSB data. The CMR calculations with direct age standardization estimate the prevalence of blindness and partial sight in the general and diabetic populations to be 51.8/10 000 (CI 50.6-53.0) and 148.8/10 000 (CI 122.1-175.5), respectively. In the diabetic population there was a higher proportion of visually impaired females than males (P < 0.05), with no overall ethnic differences; however, rates were lower than expected in female Indo-Asians. In the general population there was a higher proportion of visually impaired Indo-Asian people (P < 0.01). CONCLUSIONS: Our study has shown the prevalence of visual impairment in both the general and diabetic populations and has demonstrated both ethnic and gender differences. CMR allows the calculation of prevalence of blindness and partial sight from existing data. When comparing the prevalence of visual impairment, whether from diabetes or other causes, it is important to know the gender and ethnicity of the 'at risk' population, as well as the rates in the background population.