Childhood cataracts.

OBJECTIVE: The aim of this study was to determine the surgical outcome of childhood cataracts. METHOD: Between 1990 and 1997, 137 patients less than 10 years of age (181 eyes) underwent cataract surgery at the Royal Alexandra Hospital for Children/New Children's Hospital. Data were collected retrospectively from medical records and supplemented with data from referrng ophthalmologists. RESULTS: In the majority of patients (53.0%), the cause of cataract was unknown. Sixty-two patients (45.3%) had bilateral and 75 patents (54.7%) had unilateral cataracts. In 84 patients (107 eyes: 59.1%), the onset of visually significant cataract was estimated to be before the age of 2 years. Reliable postoperatve visual acuity (VA) was obtained in 150 eyes from 116 patients. The mean LogMAR VA was 0.71 +/- 0.55 in bilateral cataracts and 1.17 +/- 0.68 in unilateral cataracts. Visual acuity was poor (LogMARVA > 1.0) in 71.8% of unilateral cataracts (compared to 27.9% in bilateral cataracts, P < 0.0001), and in 64.9% when onset was ess than 2 years (compared to 22.4% in later onset cataract, P < 0.0001). Posterior capsular opacity requiring laser or surgical removal was noted in 40 patients (44 eyes; 24.4%). Other complications included raised intraocular pressure in six patients (seven eyes: 3.7%), displaced intraocular lens or iris capture in 11 patients (12 eyes; 6.6%), ectopic pupil in five patients (five eyes; 2.7%), and severe inflammation in eight patients (12 eyes; 6.6%). There was cosmetically significant esotropia or exotropia in 24 patients (23 eyes; 12.7%). CONCLUSION: The prognosis for vision was significantly poorer in unilateral and earlier onset cataract. The importance of early diagnosis, prompt treatment and vigilant postoperative follow up in this subgroup cannot be overemphasized.

Evaluation of oculokinetic perimetry.

BACKGROUND AND METHOD: Oculokinetic perimetry (OKP) was performed on 98 patients (187 eyes) using the Damato 26-point glaucoma screening chart. Results were compared with those obtained from a 24-2 full threshold test on a Humphrey Field Analyser (HFA). RESULTS: In its ability to detect pathology in individual eyes, OKP had a sensitivity of 75.0% and a specificity of 71.4%. To detect glaucoma, OKP demonstrated a sensitivity of 86.0% and a specificity of 56.1%. The number of OKP defects detected increased with increasing HFA mean defect and corrected pattern standard deviation. Whereas moderate and severe field defects were almost always detected, smaller and shallower glaucoma defects were often missed. CONCLUSION: The fall in sensitivity and specificity of the OKP chart in identifying milder glaucomatous field defects diminishes its value as a screening test. However, its introduction into wider use in the community may increase awareness of glaucoma amongst general practitioners and members of the public, and help to detect previously undiagnosed glaucoma with moderate to severe damage. A normal OKP finding does not exclude the presence of early glaucoma. Combined with ophthalmoscopy, OKP may improve glaucoma detection rates amongst non-ophthalmologists.

Can the current oculokinetic perimetry chart be improved?

BACKGROUND/METHOD: Several studies have been performed to determine the effectiveness of oculokinetic perimetry (OKP) as a glaucoma screening test. In a previous study, we noted that OKP sensitivity and specificity was lower in mildly defective fields compared with moderately or severely, defective fields. In this study, we looked at visual fields with 'glaucomatous' defects. The visual field was divided into zones and points. The frequency of glaucomatous defects and visual sensitivity levels in these areas was recorded. The sensitivity and specificity of OKP to detect these defects were analysed. RESULTS: Ninety-six glaucomatous fields from 57 subjects were assessed. An OKP chart testing the 8 to 16 degrees of eccentricity, and an extended nasal region, would cover all the defective fields present in this study. The 12-16 degree eccentricity zone has the best sensitivity (75%) and specificity (65%). Points within the nasal, inferior temporal and 8-12 degree eccentricity might be less sensitive, but 11 (11.5%) fields had defects only in these areas. Zonal and point sensitivities and specificities were very similar suggesting that fewer points could be used in each zone with similar results. Many of the eyes with false-negative OKP results had Humphrey Field Analyser visual sensitivity levels in the 10-18 dB range (i.e. associated with a mild or moderate defect). Decreasing the target stimulus might increase the detection rate of these milder defects; however, it might also increase overall false-positive rates. Our proposed experimental chart consists of two to four test points in each quadrant within the 12-16 degree of eccentricity, five within the 8-12 degree zone and two in the nasal region, and a central 1 or 1.5 mm black target. CONCLUSION: Analysis of results with modifications of the testing device may permit the OKP chart to achieve its full potential.

Comparison of extracapsular and phaco-emulsification cataract extraction techniques when combined with intra-ocular lens placement and trabeculectomy: short-term results.

UNLABELLED: BACKGROUND METHODS: Fifty patients who had undergone combined extracapsular cataract extraction (ECCE), intra-ocular lens (IOL) placement and trabeculectomy (ECCE-trab) and 50 who had undergone combined cataract phaco-emulsification, IOL placement and trabeculectomy (phaco-trab) were reviewed over a period of 12 months. RESULTS: Postoperatively, intra-ocular pressure (IOP) in both eyes fell significantly (P < 0.005). Initially, IOP fell to roughly equal degrees (mean IOP being 14 mmHg at 3 months; P = 0.84). At 12 months, IOP in the phacotrab group was slightly lower than that in the ECCE-trab group (13.4+/-4.3 vs 15.4+/-4.4 mmHg, respectively; P = 0.0312). The number of pre-operative medications did not appear to affect outcome (P = 0.124). Visual recovery was approximately 3 months faster in the phaco-trab group. By 12 months there was little difference in visual acuity, with an average improvement of two Snellen lines (P = 0.68). The mean change in astigmatism was significantly less in the phaco-trab group (0.61+/-1.25 vs 1.39+/-1.46 D, respectively, P = 0.0063). Transient hypotony (IOP < 5 mmHg) was more frequent in the phaco-trab group (66 vs 32%, respectively; P < 0.002). The frequency of other complications was not significantly different between the two groups. CONCLUSION: Both ECCE-trab and phaco-trab procedures are safe and effective. However, the phaco-trab procedure may have slightly improved IOP control, earlier visual recovery and less astigmatism.

The need for second-generation antihepatitis C virus testing in uremic patients on continuous ambulatory peritoneal dialysis.

OBJECTIVE: To assess the prevalence and clinical relevance of a hepatitis C virus (HCV) infection in continuous ambulatory peritoneal dialysis (CAPD) patients by first- (Ortho) and second-generation (Abbott and UBI) HCV antibody enzyme immunoassays. DESIGN: Thirty-two serum samples tested by first-generation HCV antibody enzyme immunoassays (EIA's) were reevaluated using two second-generation HCV antibody EIA's. Basic demographic data, history of blood transfusions, and duration of hemodialysis and CAPD were reviewed. Results were analyzed by chi square analysis, Wilcoxon rank sum, and the paired t-test. SETTING: The medical college's affiliated teaching hospital. RESULTS: The prevalence of the antibody anti-HCV increases with the duration of previous hemodialysis, but not with the duration of CAPD. The positive detection of anti-HCV by second-generation HCV antibody EIA's was higher than first-generation EIA's (25% and 34.4% vs 12.5%). CONCLUSION: The prevalence and clinical relevance of HCV infection can be more accurately studied using the second-generation assays in uremic patients.