The use of Ahmed glaucoma valve in the management of pediatric glaucoma.

PURPOSE: To assess the intraocular pressure control (IOP), changes in visual acuity, complications, reoperation rates and risk factors for failure following Ahmed glaucoma valve implantation in pediatric eyes with glaucoma. METHODS: The medical records of consecutive patients with glaucoma who underwent Ahmed glaucoma valve implantation from January 2000 to December 2009) were retrospectively reviewed. Only one eye of each patient was included. Subgroup analysis was performed in three groups; group 1 included phakic eyes with primary congenital glaucoma, juvenile open-angle glaucoma, or glaucoma associated with ocular anomalies; group 2 included eyes with glaucoma in aphakia or pseudophakia; group 3 included eyes with other diagnoses. A successful outcome was defined as final IOP between 6 mm Hg and 18 mm Hg without loss of light perception or reoperation for glaucoma. RESULTS: A total of 71 eyes in 71 patients: 15 (21%) in group 1, 47 (66%) in group 2, and 9 (13%) in group 3 were included Successful IOP control was achieved in 44 eyes of 44 patients (62%). Cumulative probabilities of success by Kaplan-Meier analysis at 12 and 24 months was 97% and 80% for the entire group, 100% and 82% for group 1, 95% and 86% for group 2, and 90% and 42% for group 3. Reoperation was necessary for 18 patients (25%), either for tube-related complications or for IOP control. The only significant risk factor for failure was the category of diagnosis (P = 0.029). CONCLUSIONS: Ahmed glaucoma valve implantation is an option in the management of pediatric glaucoma; however, reoperations for tube related complications or for persistent elevated IOP is frequently needed.

Fear of failure: are we doing too many trials of instrumental delivery in theatre?

OBJECTIVES: Cesarean section has largely replaced the role of difficult midcavity instrumental deliveries. The aim of this study was to determine the trend in trials of instrumental delivery as well as the maternal and fetal factors associated with successful and failed trial of instrumental deliveries. SETTING: North Middlesex University Hospital, a teaching hospital in London. STUDY DESIGN: A retrospective review of trials of instrumental delivery in theatre involving singleton term pregnancies between 2000 and 2005. RESULTS: Of the 114 trials, 82 (40 forceps and 42 vacuum extraction) were successful. Women who had successful trials were similar in age (27.8+/-5.9 vs. 27.1+/-5.4 yrs), gestation (40.5+/-2.1 vs. 40.5+/-1.1 wks) and parity (0.4+/-1.2 vs. 0.3+/-1.6) when compared to those who were unsuccessful (p>0.05). The two groups also had similar birth weight (3.6+/-0.7 vs. 3.7+/-0.4 kg) and duration of second stage (164.9+/-12.0 vs. 162.8+/-16.0 min) (p>0.05). Babies born following failed trial of instrumental deliveries were more likely to be acidotic (p=0.014) but admission to Special Care Baby Unit was similar in both groups. Women who had failed trials of instrumental delivery were more likely to have post-partum hemorrhage (802.7+/-100.0 vs. 425.4+/-120.0 ml) and pyrexia (15.6% vs. 6.1%) (p<0.05). Trial of instrumental delivery was twice as likely to fail if occipito-posterior and three times more likely to succeed if the presenting part was visible (p<0.05). However, 25% of babies had presenting parts well below the ischial spines but still had instrumental deliveries in theatre and 80% of this subgroup were delivered by junior trainees. Although 71.9% of trials of instrumental delivery were successful, many were relatively uncomplicated and did not necessarily require delivery in theatre. CONCLUSION: Unsuccessful trials are associated with maternal rather than neonatal morbidity. The shortening of duration training as well as reduction of working hours in the United Kingdom has led to obstetric trainees being less experienced in conducting instrumental deliveries. Thus, many junior trainees may prefer to conduct relatively uncomplicated instrumental deliveries in theatre. Appropriate training and senior staff input would help reduce this.