Alice Z. Chuang

Caudal block in children: ropivacaine compared with bupivacaine.

BACKGROUND Bupivacaine provides reliable, long-lasting anesthesia and analgesia when given via the caudal route. Ropivacaine is a newer, long-acting local anesthetic that (at a concentration providing similar pain relief) has less motor nerve blockade and may have less cardiotoxicity than bupivacaine. METHODS In a double-blind trial, 81 healthy children, undergoing ambulatory surgical procedures, were randomly allocated to receive caudal analgesia with either bupivacaine or ropivacaine, 0.25%, 1 mVkg. All blocks were placed by an attending anesthesiologist or an anesthesia fellow after induction of general anesthesia. RESULTS Data were available for 75 children. There were no significant differences between the two groups in baseline characteristics or in anesthesia, surgery, recovery room, or day surgery unit durations. The quality and duration of postoperative pain relief did not differ. Motor and sensory effects were similar. Time to first micturition did not differ. CONCLUSION Ropivacaine (0.25%, 1 ml/kg) provided adequate postoperative analgesia with no difference from bupivacaine (0.25%, 1 ml/kg) in quality and duration of pain relief, motor and sensory effects, or time to first micturition in our study children.

Refractive Outcomes Following Bevacizumab Monotherapy Compared With Conventional Laser Treatment A Randomized Clinical Trial

IMPORTANCE Children born prematurely who develop retinopathy of prematurity (ROP) often develop myopia, and those who require laser treatment may develop very high myopia, which has considerable clinical consequences. OBJECTIVE To report refractive outcomes in preterm infants who developed ROP in zone I or zone II posterior as stage 3+ ROP or aggressive posterior ROP (APROP). DESIGN, SETTING, AND PARTICIPANTS All infants received intravitreal bevacizumab or laser therapy in a prospective, stratified, randomized, controlled, masked, multicenter clinical trial, Bevacizumab Eliminates the Angiogenic Threat for ROP (BEAT-ROP). Children who received intravitreal bevacizumab or laser in the BEAT-ROP clinical trial, with treatment randomized by infant, underwent cycloplegic retinoscopic refraction at a mean age of 2½ years. Fifteen centers with both pediatric and vitreoretinal ophthalmologists participating in level 3 neonatal intensive care units in academic centers with institutional review board approval were included in the trial. Of the originally enrolled 150 infants (300 eyes) in the BEAT-ROP clinical trial, 13 infants (26 eyes) died (6 received intravitreal bevacizumab; 7 received laser) and 19 eyes had intraocular surgery (6 infants bilaterally). Thus, 45 eyes (19 infants bilaterally) were excluded, leaving 131 infants (255 eyes, including 21 eyes that received a successful second treatment for recurrence). INTERVENTIONS Follow-up of the BEAT-ROP cohort. MAIN OUTCOMES AND MEASURES Spherical equivalent refractive outcomes and their distribution by ROP zone and treatment. RESULTS Refractions were available for 109 of 131 eligible infants (83.2%) and 211 of 255 eyes (82.7%). Mean (SD) spherical equivalent refractions were as follows: zone I, -1.51 (3.42) diopters (D) in 52 eyes that received intravitreal bevacizumab and -8.44 (7.57) D in 35 eyes that received laser treatment (P < .001); and zone II posterior, -0.58 (2.53) D in 58 eyes that received intravitreal bevacizumab and -5.83 (5.87) D in 66 eyes that received laser treatment (P < .001). Very high myopia (≥-8.00 D) occurred in zone I in 2 of 52 (3.8%) eyes that received intravitreal bevacizumab and in 18 of 35 (51.4%) eyes that received laser treatment (P < .001). Very high myopia occurred in zone II posterior in 1 of 58 (1.7%) eyes that received intravitreal bevacizumab and in 24 of 66 (36.4%) eyes that received laser treatment (P < .001). CONCLUSIONS AND RELEVANCE More very high myopia was found in eyes that received laser treatment than in eyes that received intravitreal bevacizumab. This difference is possibly related to anterior segment development that is present with intravitreal bevacizumab but minimal or absent following laser treatment. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00622726.

Photoreceptor Coupling Is Controlled by Connexin 35 Phosphorylation in Zebrafish Retina

Electrical coupling of neurons is widespread throughout the CNS and is observed among retinal photoreceptors from essentially all vertebrates. Coupling dampens voltage noise in photoreceptors and rod–cone coupling provides a means for rod signals to enter the cone pathway, extending the dynamic range of rod-mediated vision. This coupling is dynamically regulated by a circadian rhythm and light adaptation. We examined the molecular mechanism that controls photoreceptor coupling in zebrafish retina. Connexin 35 (homologous to Cx36 of mammals) was found at both cone–cone and rod–cone gap junctions. Photoreceptors showed strong Neurobiotin tracer coupling at night, extensively labeling the network of cones. Tracer coupling was significantly reduced in the daytime, showing a 20-fold lower diffusion coefficient for Neurobiotin transfer. The phosphorylation state of Cx35 at two regulatory phosphorylation sites, Ser110 and Ser276, was directly related to tracer coupling. Phosphorylation was high at night and low during the day. Protein kinase A (PKA) activity directly controlled both phosphorylation state and tracer coupling. Both were significantly increased in the day by pharmacological activation of PKA and significantly reduced at night by inhibition of PKA. The data are consistent with direct phosphorylation of Cx35 by PKA. We conclude that the magnitude of photoreceptor coupling is controlled by the dynamic phosphorylation and dephosphorylation of Cx35. Furthermore, the nighttime state is characterized by extensive coupling that results in a well connected cone network.

Ondansetron/promethazine combination or promethazine alone reduces nausea and vomiting after middle ear surgery

STUDY OBJECTIVES To determine the incidence of postoperative nausea and vomiting when a combination of ondansetron and promethazine is given prophylactically, and to ascertain the effect of postoperative nausea and vomiting on recovery room duration and patient satisfaction. DESIGN Prospective, randomized, placebo-controlled, double-blind study. SETTING University-affiliated tertiary-care hospital. PATIENTS 87 ASA physical status I and II adult patients scheduled for middle ear surgery. INTERVENTIONS Patients were randomly assigned to receive one of the following interventions intravenously: ondansetron 4 mg (Group 1), promethazine 25 mg (Group 2), ondansetron 2 mg plus promethazine 12.5 mg (Group 3, combination), or placebo (Group 4). MEASUREMENTS AND MAIN RESULTS Independent, study blinded observers recorded complaints of nausea and number of episodes of vomiting for 24 hours following the patients first response to commands. All patients were contacted the day after discharge to inquire about nausea and vomiting. The awakening time, postanesthesia care unit and day surgery unit durations, opioid use, and side effects were recorded. At the end of the 24-hour period, the study blinded observers asked patients for an overall assessment of their global anesthesia experience using an 11-point scale. During the 24-hour period, the incidence of postoperative nausea and vomiting was reduced from 74% (placebo) to 39% (promethazine; p = 0.03) and 29% (combination; p = 0.003). Compared with placebo, the severity of vomiting was significantly less in the combination group (p = 0.04). The number of very satisfied patients correlated negatively with the incidence of postoperative nausea and vomiting (p < 0.0001) and with the severity of vomiting (p = 0.003). CONCLUSION The prophylactic use of an antiemetic with middle ear surgery may reduce postoperative nausea and vomiting over 24 hours, and the ondansetron/promethazine combination or promethazine alone are cost-effective choices. Finally, the combination reduced significantly the severity of vomiting.

Ocular Integrity after Refractive Procedures

PURPOSE The purpose of the study was to determine the integrity of human eyes after refractive procedures. METHODS Whole human globes underwent either radial keratotomy (RK) with eight incisions, automated lamellar keratoplasty (ALK), photorefractive keratectomy (PRK), or excimer laser assisted in situ keratomileusis (LASIK). Eyes then were subjected to quantitatively increasing levels of trauma until rupture occurred. RESULTS All eyes operated on required less energy to rupture as compared with that of control eyes. The mean number of trials required for rupture is as follows (energy doubled with each successive trial): normal, 4.29; LASIK, 3.80; ALK, 3.67; PRK, 3.60; and RK, 2.83. The level of energy required to rupture normal, ALK, PRK, and LASIK eyes was not significantly different. All RK eyes ruptured at incisions. Most ALK, PRK, and LASIK eyes ruptured near the flap edge or limbus. Most normal eyes ruptured with both corneal and scleral involvement. Age of tissue donors at the time of death and time elapsed between death and procedure were not significantly different between groups (P = 0.88 and 0.79, respectively). CONCLUSIONS The energy required to rupture ALK, PRK, and LASIK eyes is not significantly different from that for normal eyes. The RK eyes ruptured with significantly less energy than did normal eyes. All RK eyes ruptured at incision sites.

Laser epithelial keratomileusis for myopia with the autonomous laser

PURPOSE To describe the refractive outcome, objective clinical data, and subjective patient experiences after laser epithelial keratomileusis (LASEK) at 1, 3, and 6 months after surgery. METHODS This was a retrospective, nonrandomized, comparative study of 58 LASEK-treated eyes (36 patients) with myopia (with and without astigmatism) between -1.50 and -14.75 D (mean -7.80 +/- 2.90 D, median -7.90 D). Refractive surgery was performed using the Alcon Summit Autonomous LADAR Vision excimer laser. Manifest refraction, best-spectacle and uncorrected Snellen visual acuity, stability of refraction, and corneal haze were evaluated before surgery and up to 6 months after surgery. A group of randomly selected LASIK-treated eyes were compared at each time point. RESULTS Patients who opted for monovision (n=12) were excluded. In the emmetropia targeted eyes (n=46), 45%, 83%, 85%, and 89% achieved 20/40 or better uncorrected Snellen visual acuity (UCVA) at 1 day, 1 week, 2 weeks, and 1 month respectively. At 6 months, 73% (n=28) of eyes treated achieved UCVA 20/20 with 97% achieving 20/40 or better (mean, -0.51 D). At 3 and 6 months, 71% (n=46) and 68% (n=28) were within +/- 0.50 D of emmetropia. The percentage of eyes that achieved UCVA 20/40 or better at 6 months was 97% (n=28). Visually significant corneal haze was evident in two LASEK-treated patients (four eyes) at 6 months. No eyes lost two or more lines of best spectacle-corrected Snellen visual acuity. CONCLUSIONS Preliminary data suggest that LASEK appears to be a safe, effective, and comparable alternative to LASIK, even for higher amounts of myopia. A prospective, randomized clinical trial is needed to better define the role of LASEK as it compares to other refractive procedures, specifically LASIK and PRK.

Prediction of corneal haze using an ablation depth/corneal thickness ratio after laser epithelial keratomileusis

PURPOSE To investigate the usefulness of ablation depth/corneal thickness (AD/CT) ratio to predict corneal haze after laser epithelial keratomileusis (LASEK) using a retrospective, comparative, interventional case series. METHODS Fifty patients (90 eyes; mean age 40.9 years) with myopia, hyperopia, and/or astigmatism underwent bilateral or unilateral LASEK for correction of refractive error. After epithelial flaps were created using an 18% alcohol solution, bilateral or unilateral LASEK was performed using the Alcon Autonomous LADARVision 4000 excimer laser. Visual acuity (best spectacle-corrected and uncorrected) and refractive error were measured before and after LASEK. Corneas were assessed by two independent evaluators under a slit-lamp biomicroscope with broad tangential illumination. The relative haze scale was quantitated: 0 (clear), 0.5+ (trace), 1+ (mild), 2+ (moderate), 3+ (marked), and 4+ (severe). RESULTS Mean preoperative spherical equivalent refraction was -5.46 +/- 3.74 D (range -12.375 to +5.00 D), mean ablation depth was 93.04 +/- 45.03 microm (range 21.2 to 207.2 microm), and mean AD/CT ratio was 0.18 +/- 0.09 (range 0.04 to 0.41). Of 90 eyes, 40 eyes had a higher ablation depth (AD/CT ratio > 0.18) and 50 eyes had a lower ablation depth (AD/CT ratio < 0.18); 92.5% of eyes in the higher ratio group developed clinically significant haze (1+ or greater). In the lower ratio group, 94% of eyes developed no more than 1+ corneal haze, if any. CONCLUSION The ablation depth/corneal thickness ratio is useful for predicting corneal haze after LASEK. An AD/CT ratio of 0.18 or more suggests that patients have a high risk of developing clinically significant haze (1+ or more) after LASEK.

A Randomized Double-Masked Trial Comparing Ketorolac Tromethamine 0.5%, Diclofenac Sodium 0.1%, and Prednisolone Acetate 1% in Reducing Post-Phacoemulsification Flare and Cells

BACKGROUND AND OBJECTIVE To compare the efficacy of ketorolac tromethamine 0.5%, diclofenac sodium 0.1%, and prednisolone acetate 1% in reducing flare and cells following cataract surgery. PATIENTS AND METHODS Fifty-eight patients undergoing phacoemulsification with posterior chamber intraocular lens implantation were randomly selected to receive either ketorolac tromethamine 0.5%, diclofenac sodium 0.1%, or prednisolone acetate 1% following surgery. The treatment regimen was 1 drop 4 times a day for 1 week, then twice a day for the next 3 weeks. Flare, cells, and intraocular pressures (IOPs) were measured preoperatively and on postoperative days 1, 7, and 28. RESULTS No statistically significant differences in either actual flare or cell counts or in change in flare or cell counts from baseline were detected among the three groups. No statistically significant differences in IOP or in change of IOP from preoperative measurements were detected. No medication-related complications were noted at any time. CONCLUSION Ketorolac tromethamine 0.5% and diclofenac sodium 0.1% may be as effective and as safe as prednisolone acetate 1% in controlling inflammation following cataract extraction.

Autologous conjunctival resurfacing of leaking filtering blebs.

PURPOSE To present a case series of a new technique to repair late bleb leaks. DESIGN Retrospective, noncomparative, consecutive case series. PARTICIPANTS Forty-seven autologous conjunctival resurfacings of late bleb leaks were performed by four surgeons at two institutions. METHODS Autologous conjunctival grafts were placed over existing de-epithelialized leaking blebs. MAIN OUTCOME MEASURES Leak-free, Seidel-negative blebs and controlled glaucoma. RESULTS After a mean follow-up of 14 +/- 12 months, one patient continued to have bleb leak at the last follow-up, and one frank leak resolved with aqueous suppression. Intraocular pressure increased from 6.6 +/- 4.4 mmHg (0.13 glaucoma medications) to 11.9 +/- 4.1 mmHg (0.41 glaucoma medications). CONCLUSIONS Conjunctival resurfacing with autologous tissue is an effective technique to repair late bleb leaks.

Epithelial heating rates with topical ciprofloxacin, ofloxacin, and ofloxacin with artificial tears after photorefractive keratectomy

Abstract Purpose To determine whether corneal epithelial healing differs after the use of topical ciprofloxacin alone, topical ofloxacin alone, or topical ofloxacin with artificial tears in patients having photorefractive keratectomy (PRK). Setting Department of Ophthalmology and Visual Science, The University of Texas Health Science Center at Houston, Houston, Texas, USA. Methods Eighteen patients (6 women, 12 men) with moderate myopia (−1.50 to −6.00 diopters [D]) had standardized PRK. Patient age ranged from 25 to 62 years. The 28 eyes (16 right, 12 left) were randomized into 3 treatment groups: ofloxacin alone, n=9 eyes; ciprofloxacin, n=9 eyes; and ofloxacin with Refresh Plus®, n=10 eyes. The drugs were administered immediately after surgery and then every 6 hours. Video recordings of the corneal wounds stained with fluorescein were performed at 8:00 am and 4:00 pm using a video slitlamp camera with a cobalt-blue light until the wound completely healed. The videotaped images were recorded and analyzed by a computer planimetry program. Wound areas were recorded and compared among the 3 drugs. The square-root transformation was applied to the wound area to obtain a constant healing rate. Statistical comparisons were analyzed using an analysis of variance test. Results Mean recovery time was 82.67 hours ± 14.42 (SD) in the ofloxacin eyes, 120.89 ± 34.05 hours in the ciprofloxacin eyes, and 76.80 ± 19.30 hours in the ofloxacin with Refresh Plus eyes. Mean healing rate was 0.66 ± 0.17 hours, 0.54 ± 0.16 hours, and 0.67 ± 0.15 hours, respectively. The healing rate was significantly higher in the ofloxacin with Refresh Plus eyes than in the ciprofloxacin eyes ( P P = .42). Conclusion Ofloxacin with Refresh Plus and ofloxacin alone had a more positive effect on epithelial healing than ciprofloxacin. The ciprofloxacin eyes were significantly more prone to impaired or delayed wound healing and to the development of corneal haze.