Biomedical subjects

Mohamed Abdolell

Publications and source records attributed to Mohamed Abdolell.

At least 19 recordsLinked to original sources

PubMed2006

Parental understanding of the role of trainees in the ophthalmic care of their children.

OBJECTIVE: To examine parental knowledge and expectations regarding the roles of trainees involved in their child's ophthalmic care. DESIGN: Prospective survey. PARTICIPANTS: Parents of 128 children attending outpatient pediatric ophthalmology clinics at The Hospital for Sick Children in Toronto. METHODS: A questionnaire was given prospectively to parents (and 1 custodial grandparent). They were asked to identify, using a checklist, the roles and responsibilities of medical students, residents, and fellows and to explore their expectations regarding trainee participation using a multiple choice questionnaire. MAIN OUTCOME MEASURES: Parental knowledge and expectations regarding the roles and participation of medical trainees in the ophthalmic care of their children as measured by survey questionnaire. RESULTS: Parental knowledge about the roles of trainees was very limited with one exception: more than 95% knew that medical students are learning to be doctors and most had a good knowledge of the medical student role. More than 76% wanted to be asked specifically if they would allow trainees involved in their child's care. Seventy-five percent were happy to have capable trainees involved, provided that the trainees discuss all decisions with the responsible staff doctor. Parents wanted health care providers to identify themselves by name (77%) and position (86%). Only 3% did not want trainees involved in any part of their child's care. CONCLUSIONS: Although parental knowledge regarding the relative roles of trainees is poor, parents generally are willing to have trainees involved in their child's medical and surgical care, provided they are adequately supervised and that the parent is aware of their participation.

Adolescent↗

PubMed2005

12-hour versus 24-hour creatinine clearance in critically ill pediatric patients.

Measurement of renal function is important to optimize drug dosing in critically ill pediatric patients and to prevent dose-related toxicities caused by medications that are eliminated or metabolized by the kidney. In clinical practice, the 24-h creatinine clearance (CrCl) is used as a surrogate marker of renal function. However, a 24-h urine collection period delays the availability of the result and increases the potential for collection errors. This prospective, observational study was performed to determine whether a 12-h CrCl is comparable to the traditional 24-h CrCl and to assess whether CrCl could be reliably predicted by the Schwartz equation, which mathematically estimates a child's GFR. A 24-h urine sample was collected in two 12-h aliquots from 60 catheterized critically ill children (age 2 d to 18 y). CrCl and Schwartz glomerular filtration rate (GFR) estimates were determined for each 12- and 24-h period. Agreement between 12- and 24-h CrCl and between CrCl and Schwartz GFR estimates was assessed using intraclass correlation coefficients (ICCs). An ICC > or =0.8 was considered to indicate excellent agreement. The ICC between the first 12-h CrCl and 24-h CrCl was 0.9605. The ICC between the second 12-h CrCl and 24-h CrCl was 0.9602. The ICC between the 24-h CrCl and Schwartz GFR was only 0.7046. All comparisons of 12- and 24-h CrCl indicated excellent agreement. In summary, the Schwartz equation was not a reliable estimate of renal function in critically ill children, and a 12-h CrCl is just as accurate as the standard 24-h CrCl to assess renal function and guide drug dosing.

Adolescent↗

PubMed2005

Ophthalmologic findings in the Cornelia de Lange Syndrome.

BACKGROUND: Cornelia de Lange Syndrome (CdLS) is a disorder caused in many patients by a mutation in the NIPBL gene with a dominant pattern of inheritance characterized by mental retardation, prenatal and postnatal growth retardation, upper-limb abnormalities, and characteristic facies. Few data exist concerning the ophthalmic findings in this syndrome. METHODS: One hundred twenty individuals with CdLS underwent ophthalmic examination to ascertain the relative frequencies of oculofacial and ophthalmic abnormalities. RESULTS: We confirmed the frequent findings of synophrys (99%), long lashes (99%), hypertrichosis of the brows (96%), ptosis (44%), epiphora (22%), nasolacrimal duct obstruction (16%), blepharitis (25%), and myopia (58%). In addition, we found peripapillary pigment (83%), and microcornea (21%), which have infrequently been mentioned in the literature. CONCLUSION: Patients with CdLS can have multiple eye problems. Many of these problems can be readily treated, including myopia, blepharitis, nasolacrimal duct obstruction, and ptosis. Early examination is recommended for all children known or suspected to have CdLS.

Adolescent↗

PubMed2005

Gene-expression analysis after alcohol exposure in the developing mouse.

Exposure to alcohol in the embryonic mouse can lead to structural and neurophysiologic changes. The cause of these changes is poorly understood, but they are likely the result of numerous mechanisms. Here we investigate ethanol-induced alterations in gene expression in the fetal brain. Using complementary-DNA microarrays, we identified 25 genes that were down-regulated by prenatal ethanol exposure on days 7 and 9 of gestation. None were found to be up-regulated. Of those that were repressed, 6 (Timp4, Bmp15, Rnf25, Akt1, Tulp4, Dexras1) have been identified, and they are discussed here in the context of the developing fetus. The identified genes have been shown to be involved in cell proliferation, differentiation, and apoptosis, and they contribute to tissue growth and remodeling, as well as neuronal growth and survival. Microarray studies may be useful in the identification of a genetic marker for fetal alcohol syndrome, the discovery of novel pathways that may be involved in its origin, or both.

Animals↗

PubMed2005

Outcome of penetrating keratoplasty performed by cornea fellows compared with that of an experienced staff surgeon.

PURPOSE: To compare the outcome of penetrating keratoplasty performed by supervised cornea fellows and an experienced staff surgeon. METHODS: Retrospective review of cases of penetrating keratoplasty performed over a 4-year period with corneal topography performed on a clear graft. Overall, 202 cases from 184 patients were included: 108 performed by an experienced staff surgeon and 94 cases by 9 cornea fellows. Charts were reviewed for topographic astigmatism, other topographic indices, refractive astigmatism and best-corrected visual acuity (BCVA), all recorded after removal of the 10-0 sutures while the 11-0 suture remained in place. Graft clarity was assessed at final follow-up. RESULTS: Mean postoperative topographic astigmatism was 4.60 +/- 2.7 diopters in the fellow group and 4.08 +/- 2.41 diopters in the staff group. The mean postoperative time at which corneal topography was obtained was 9.53 +/- 4.4 months in the fellow group and 9.22 +/- 4.6 months in the staff group. Mean refractive astigmatism was 3.77 +/- 1.97 diopters (fellows) and 3.49 +/- 1.93 diopters (staff). Mean surface asymmetry index (SAI) was 1.89 +/- 1.42 (fellows) and 1.61 +/- 1.08 (staff). Mean surface regularity index (SRI) was 1.43 +/- 0.72 (fellows) and 1.45 +/- 0.61 (staff). Mean BCVA was 0.49 logMAR (20/61) +/- 4.3 lines (fellows) and 0.47 logMAR (20/59) +/- 3.9 lines (staff). In the fellow group, 85 (90%) cases remained clear over a mean follow-up of 32 months and in the staff group 100 (93%) grafts remained clear over a mean follow-up of 38 months. Simple and multiple regression analyses indicated no difference between the 2 groups in all outcome measures. CONCLUSIONS: Properly supervised cornea fellows in training achieved favorable penetrating keratoplasty results that were comparable to those of an experienced staff surgeon.

Adult↗

PubMed2005

Computerized corneal topography in a paediatric population with Down syndrome.

PURPOSE: To characterize abnormal corneal topographic changes using corneal computerized videokeratography (CVK) in a paediatric population with Down syndrome, and in their parents. METHODS: Prospective, non-randomized clinical trial. Twenty-one children with Down syndrome (mean age 6.9 years) recruited from The Hospital for Sick Children, 18 of their parents, and a paediatric control group of 60 otherwise well children (mean age 9 years), underwent complete ocular examination and CVK using the EyeSys system. Corneal topographic maps were assessed subjectively, and three objective parameters analysed: central corneal power (CP), difference in central corneal power between the two eyes (DCP), and inferior-superior steepening asymmetry (I-S). RESULTS: Corneal curvature in children with Down syndrome was significantly steeper than in the paediatric control population (CP 46.66 vs 42.60 D, P <0.0001), but changes with age paralleled that of the control population. DCP and I-S values were also significantly different from the control population (P <0.0001). 39% of the parents of children with Down syndrome had at least one abnormal parameter. CONCLUSIONS: This study demonstrates that CVK is a useful tool in the ocular assessment of patients with Down syndrome. The findings suggest that this patient population have abnormalities of corneal shape even in the absence of clinical evidence of keratoconus. A greater than expected incidence of abnormal topographic changes was observed in the parents of these patients.

Adolescent↗

PubMed2005

Color visual evoked potentials in children with type 1 diabetes: relationship to metabolic control.

PURPOSE: To examine the association between metabolic control (HbA(1c)) and the chromatic mechanisms of children with type 1 diabetes (T1D), by using the color visual evoked potential (VEP). METHODS: Fifty children with T1D (age range, 6-12.9 years) and 33 age-matched control subjects were tested. VEPs were recorded by placing five electrodes on the scalp according to the International 10/20 System of Electrode Placement. Active electrodes O1, O2, and Oz were placed over the visual cortex. Short-wavelength (S), and long- and medium-wavelength (LM) color stimuli consisted of vertical, photometric isoluminant (1 cyc/deg) gratings presented in a pattern onset (100 ms)-offset (400 ms) mode. Achromatic vertical gratings were presented at 3 cyc/deg. Primary outcome measure was VEP latency. The relationship between S, LM, and achromatic VEP latency, and HbA(1c) was determined by ANCOVA regression. RESULTS: S-, LM-, achromatic VEP latencies were not associated significantly with HbA(1c). Pubertal status, however, was associated significantly (P = 0.0114) and selectively with S-VEP latency. Pubertal children with T1D had delayed (mean delay, 9.5 ms) S-VEP latencies when compared with the prepubertal children with T1D. However, there was no statistically significant difference (P = 0.1573) in the effect of pubertal status on S-VEP latency between the T1D and control groups. CONCLUSIONS: Pubertal status rather than HbA(1c) appears to affect selectively the S-VEP latency of preteen children with T1D. Further study is warranted to determine whether the delay in S-VEP latency in pubertal children with T1D changes over time and whether this change could be a predictive marker for future development of background diabetic retinopathy.

Blood Glucose↗

PubMed2004

Ototoxicity following pediatric hematopoietic stem cell transplantation: a prospective cohort study.

BACKGROUND: Our objectives were to describe the frequency and determine risk factors for hearing deterioration following pediatric stem cell transplantation (SCT). METHODS: In this prospective cohort study, we performed pure tone audiometry and measured otoacoustic emissions (OAE) prior to and following SCT. Worse hearing was considered deterioration in either audiometry or OAE. RESULTS: Between October 2000 and November 2002, 45 informative audiometry or OAE results were obtained. Hearing deteriorated following SCT in 20/45 (44%) of these children. Those with worse hearing following SCT were more likely to have neuroblastoma (odds ratio [OR] 16.0 [95% CI 1.8, 143.2; P = 0.003]), receive carboplatin conditioning (OR 7.7 [95% CI 1.4, 41.9; P = 0.01]), have abnormal baseline hearing (OR 5.1 [95% CI 1.3, 19.5; P = 0.02]), and have higher baseline serum creatinine (OR for every increase of 5 micromol/L of serum creatinine of 1.5 [95% CI 1.03, 2.1; P = 0.03]). CONCLUSION: Many children who undergo SCT will have deterioration in hearing following SCT. A high-risk group of children can be delineated who may benefit from more intensive audiological monitoring following SCT.

Audiometry↗

PubMed2004

Early postoperative refractive outcomes of pediatric intraocular lens implantation.

PURPOSE: To evaluate the refractive outcome using 5 intraocular lens (IOL) calculation formulas to determine which best predicts refraction after pediatric cataract surgery. SETTING: The Hospital for Sick Children, Toronto, Ontario, Canada. METHODS: This study comprised a review of the charts of 158 consecutive patients aged 2 to 17 years old who were operated on by 1 of 2 staff surgeons between May 1992 and April 2000. The surgeons performed a total of 206 cataract extractions with primary or secondary IOL implantation. The measured outcome was the actual refraction 2 to 6 months postoperatively versus the target refraction. Two regression formulas (SRK, SRK II) and 3 theoretical formulas (Holladay 1, Hoffer Q, SRK/T) were used to predict refractive outcome based on preoperative axial length, corneal curvature, IOL power, and the IOL A-constant provided by the manufacturer. RESULTS: Forty-nine patients (59 IOL implantations) with available data 2 to 6 months after surgery were studied. Also analyzed were data from a subset of 31 patients (34 IOL implantations) with available data 2 to 3 months after surgery. There was poor to moderate agreement between the predicted and actual postoperative refractions using the SRK formula (intraclass correlation coefficient [ICC] = 0.50/0.04 [2- to 3-month follow-up/2- to 6-month follow-up]) and good or fair agreement using the other formulas (ICC from 0.60/0.24 for SRK II to 0.67/0.37 for Hoffer Q). The mean difference between the predicted and actual postoperative refractions with all formulas ranged from 1.06 to 1.22 diopters (D)/1.35 to 1.79 D (median 0.81 to 0.99 D/0.94 to 1.40 D; range 3.03 to 5.57 D/6.75 to 9.21 D). Using Holladay 1 and SRK, 9% to 18%/23% to 39% eyes were more than +/-2.00 D off the target outcome refraction. CONCLUSIONS: All 5 IOL power calculation formulas were unsatisfactory in achieving the target refraction. This finding may have implications for predicting long-term outcomes, interpreting previous reports of refractive outcomes, and obtaining preoperative informed consent in a clinical setting.

Adolescent↗

PubMed2004

Nutrition risk factors for survival in the elderly living in Canadian long-term care facilities.

OBJECTIVES: To determine the role of nutritional parameters in influencing the risk of mortality in institutionalized elderly. DESIGN: A prospective cohort study in which subjects had several nutritional parameters measured at baseline and were followed for 19 months. Time to death and mortality were recorded starting immediately after enrollment. SETTING: Fourteen long-term care facilities (LTCFs). PARTICIPANTS: Four hundred eight elderly long-term care residents aged 60 and older who resided in the facility for more than 6 weeks. MEASUREMENTS: At baseline, knee height, weight, mid-arm circumference (MAC), skin-fold thickness, and fat-free mass using bioelectric impedance analysis were measured. Covariates included demographic factors, length of stay in the facility, functional status, and medical diagnoses. Cox proportional hazards regression analysis was used to identify independent predictors of mortality. Results are reported as mean+/-standard error of the mean (SEM). RESULTS: Overall, mortality rate was 28.4%. Univariate predictors included male sex, body mass index, MAC, and triceps skin fold. In multivariate analysis, male sex (hazard ratio (HR)=1.7, 95% confidence interval (CI)=1.2-2.7, P=.0096) and MAC less than 26 cm were significantly associated with increased risk of mortality (HR=4.8, 95% CI: 2.8-8.3, P<.0001). CONCLUSION: Among this elderly population living in LTCFs, MAC is the best nutritional predictor of mortality.

Aged↗

PubMed2004

Systemic thromboembolism in children. Data from the 1-800-NO-CLOTS Consultation Service.

Thromboembolism (TE) has recently been recognized as a clinical entity in children. Determining the clinical characteristics of pediatric TE is an important first step in dealing with this new disorder. The paper summarizes 1776 consecutive children with systemic TE referred to 1-800-NO-CLOTS telephone consultation service. 1-800-NO-CLOTS is a free consultation service for clinicians managing pediatric TE. Patient information was collected immediately using standardized forms. In children with systemic TE, infants under one year of age (47%) including neonates (26%) represented the largest distinct pediatric age group. Age-related differences were seen in TE locations, associated conditions, and risk factors. However, venous TE was the most frequent manifestation (74%). Neonates and children with cardiac disorders were more likely to have an arterial TE than a venous TE Beyond the neonatal period, venous TE associated with a central line is more likely to occur than arterial TE. Children with ALL were 5.7 times more likely to have a venous TE than an arterial TE. TE were infrequent in otherwise healthy children with 90% of children having at least one risk factor. Central catheters were the single most common risk factor associated with TE, present in 2/3 of children. Ultrasound was most frequently employed for diagnosis of TE. Finally, there was marked heterogeneity in treatment of children with TE. In children, neonates form the largest single group with TE. TE usually occur only in the presence of one or more risk factors with catheters being the single most important factor.

Adolescent↗

PubMed2004

Tobramycin pharmacokinetics in children with febrile neutropenia undergoing stem cell transplantation: once-daily versus thrice-daily administration.

STUDY OBJECTIVE: To describe the pharmacokinetic disposition of tobramycin in children undergoing stem cell transplantation (SCT) after intravenous administration either every 24 hours or every 8 hours, and to use this information to create initial dosing guidelines for administration every 24 hours in this patient population. DESIGN: Pharmacokinetic analysis of a randomized controlled trial. SETTING: The Hospital for Sick Children, Toronto, Ontario, Canada. PATIENTS: Sixty children (< 18 yrs) with febrile neutropenia undergoing stem cell transplantation. INTERVENTION: Patients were randomized to receive intravenous tobramycin either every 24 hours (29 patients) or every 8 hours (31 patients). Initially, they received either 2.5 mg/kg/dose every 8 hours or weight-based doses by age group (< 5 yrs, 9 mg/kg/dose; 5 to < 12 yrs, 8 mg/kg/dose; > or = 12 yrs, 7 mg/kg/dose) every 24 hours. MEASUREMENTS AND MAIN RESULTS: Serum tobramycin concentrations were obtained at 2 and 8 hours after the first dose. Initial guidelines for dosing every 24 hours were derived using the parameters from all patients to achieve a maximum serum concentration (Cmax) of 20-22.5 mg/L and a drug-free interval (time during dosing interval when the tobramycin concentration was < 1 mg/L) of at least 4 hours. After the first tobramycin dose, the elimination rate constant (kel) and volume of distribution (Vd) observed in the every-8-hour group (23 patients) were 0.34 +/- 0.09 hours(-1) and 0.48 +/- 0.21 L/kg, respectively. The kel and Vd in the every-24-hour group (22 patients) were 0.43 +/- 0.12 hr(-1) and 0.43 +/- 0.26 L/kg, respectively. Tobramycin Vd varied with age. Initial doses of tobramycin every 24 hours recommended to achieve the target parameters are 10 mg/kg/dose for patients aged 6 months to less than 9 years, 8 mg/kg/dose for those aged 9 to less than 12 years, and 6 mg/kg/dose for those aged 12 years or older. CONCLUSION: Children undergoing SCT who receive tobramycin every 24 hours should receive an initial dose based on age. Further validation of the proposed dosing guidelines is required.

Adolescent↗

PubMed2003

Randomized controlled trial of once- versus thrice-daily tobramycin in febrile neutropenic children undergoing stem cell transplantation.

BACKGROUND: The benefits of aminoglycoside antibiotics, such as tobramycin, administered as a once-daily dose to manage febrile neutropenia, have been demonstrated in many patient populations. However, toxicity and safety data are lacking for pediatric stem cell transplant recipients, who are at especially high risk for aminoglycoside-related toxicity and infectious morbidity. In particular, the relative nephrotoxicity and efficacy of tobramycin administered as a single daily dose or as three daily doses among this patient population is not known. METHODS: We conducted a randomized, double-blind controlled study of tobramycin dosing among children 18 years or younger who had fever and neutropenia while undergoing stem cell transplantation. From October 2000 through November 2002, 60 children were randomly assigned to receive intravenous tobramycin, as either a single daily dose (n = 29) or every 8 hours (n = 31), in combination with either piperacillin or ceftazidime (intravenous). Tobramycin doses were adjusted to achieve pharmacokinetic targets. The primary outcome was nephrotoxicity, as represented by the maximal percent increase in serum creatinine concentration throughout the episode of febrile neutropenia relative to the baseline serum creatinine concentration. Efficacy was a secondary outcome and was defined as survival of the episode without modification of the antibacterial regimen. All statistical tests were two-sided. RESULTS: In a modified intent-to-treat analysis, the mean maximal percent increase in serum creatinine concentration was 32% (N = 26) in the once daily dose group and 51% (N = 28) in the every 8 hours dose group (difference = 19%, 95% confidence interval [CI] = 0% to 38%; P =.054). Among patients evaluable for efficacy, 12 (46%) of 26 patients in the once daily dose group and five (19%) of 27 patients in the every 8 hours dose group survived the episode of febrile neutropenia without requiring antibacterial treatment modification (difference = 27%, 95% CI = 4% to 52%; P =.03). There was one death in each group. CONCLUSIONS: In febrile neutropenic children undergoing stem cell transplantation, tobramycin may be less nephrotoxic and more efficacious when administered as a once daily dose than when administered every 8 hours.

Adolescent↗

PubMed2003

A cross-sectional study evaluating post-thrombotic syndrome in children.

BACKGROUND: Post-thrombotic syndrome (PTS) in adults, characterized by swelling, skin pigmentation, pain, and ulceration of the limb, is secondary to deep vein thrombosis (DVT). In contrast to the extensive documentation on PTS in adults, little is known about the risk of PTS in children. OBJECTIVE: To determine the incidence, clinical characteristics, and predictors of PTS in children. METHODS: A cross-sectional study in 153 nonselected children with objectively confirmed DVT. All children were assessed for PTS using a standardized score. As per the PTS score, severity was classified as: absent, mild, moderate, or severe. RESULTS: Post-thrombotic syndrome was present in 96/153 children (63%), in which 80 (83%) were mild and 16 (17%) were moderate. Swelling was the most frequently recorded subjective symptom (43%) while increased limb circumference (71%) and presence of collateral circulation (53%) were the most frequently recorded objective symptoms. Risk factors for development of PTS were: lack of resolution of the DVT by radiographic assessment (OR 3.96, 95% CI 1.68-9.30), number of vessels involved in the initial DVT (OR 2.05, 95% CI 1.52-2.77), and length of follow-up (OR 1.22, 95% CI 1.08-1.39). CONCLUSIONS: These findings demonstrate that PTS is a clinically significant disease in children with previous DVT.

Adolescent↗

PubMed2003

Complications in infants undergoing surgery for congenital cataract in the first 12 weeks of life: is early surgery better?

PURPOSE: To determine if there is an association between the timing of surgical intervention for congenital cataract within the first 12 weeks of life and the prevalence of postoperative complications. METHODS: We performed a retrospective review of records from 1990 to 2000 of infants who underwent surgery for congenital cataract within the first 12 weeks of life. Eighty eyes in 55 children were involved with a minimum follow up of 6 months. Bilateral cataracts were present in 25 and monocular cataracts in 30 infants. A limbal approach lensectomy-vitrectomy was performed in all infants. Children with aphakia were rehabilitated with contact lens or glasses. Operative and postoperative complications-including glaucoma, nystagmus, strabismus, retinal detachment, and posterior capsule opacification/secondary membranes-were recorded. Ocular and systemic associations were noted. Statistical analysis was carried out with classification and regression trees (CART). RESULTS: The mean age at the time of surgery was 31.5 +/- 23.3 days (median, 26.5; range, 2 to 84). Mean follow up from the time of surgery was 2.85 +/-1.9 years (median, 2; range, 0.5 to 8). Persistent fetal vasculature (persistent hyperplastic primary vitreous) was present in 14 eyes. One infant with bilateral persistent fetal vasculature had bilateral retinal dysplasia and was excluded from the analysis. Glaucoma developed in 12 infants (22%); nystagmus was present in 18 infants (33%); strabismus developed in 28 infants (52%); and secondary membranes developed in 7 eyes (13%). CART analysis suggests that glaucoma is more prevalent in infants when the surgery was performed between 13.5 and 43 days of life (CART = 0.370); nystagmus when surgery is performed between 48 and 84 days of life (CART = 0.500); strabismus when surgery is performed between 55.5 and 84 days of life (CART = 0.600); and secondary membranes when surgery is performed between 26.5 and 40 days of life (CART = 0.4). CONCLUSIONS: Our data suggest that the first 2 weeks of life comprise the most favorable time for decreasing postoperative complications resulting from surgical intervention for infants presenting with cataracts within the first 12 weeks of life.

Cataract↗

PubMed2003

The Ahmed drainage implant in the treatment of pediatric glaucoma.

PURPOSE: To report the safety and efficacy of Ahmed Glaucoma Valve (New World Medical, Inc., Rancho Cucamonga, California, USA) implantation for the management of pediatric glaucoma in the early and intermediate follow-up period. DESIGN: Consecutive interventional case series. METHOD: A retrospective chart review was conducted on 60 eyes (44 patients, age range at surgery 1.5 months to 16 years, average 6 +/- 4.9 years), with pediatric glaucoma that underwent Ahmed Glaucoma Valve implantation for medically uncontrolled intraocular pressure (IOP) between the years 1995 and 2000. Outcome measures were control of IOP below 21 mm Hg, the need for antiglaucoma medications after surgery, and loss of 2 or more lines of Snellen acuity. Complications were monitored. RESULTS: The postoperative follow-up period for each eye averaged 24.3 +/- 16 months (range, 3 to 60 months). At last follow-up, IOP was controlled in 44 eyes (73%), 11 of which did not need antiglaucoma therapy. Kaplan-Meier life-table analysis showed probability of success with or without medications of 93% (95% confidence interval [CI], 86%-100%), 86% (95% CI, 77%-96%), 71% (95% CI, 59%-87%), and 45% (95% CI, 28%-80%) after 12, 24, 36, and 48 months of follow-up. Average IOP decreased from 32.8 +/- 6.2 before surgery to 16.6 +/- 8.0 postoperatively (P <.0001). The average number of medications used decreased from 4.4 +/- 1.97 to 2.0 +/- 2.0 (P <.0001). Kaplan-Meier survival analysis did not reveal any difference in survival profiles related to specific diagnosis of glaucoma, age (above or below 18 months), or prior surgery. Complications occurred in 30 eyes (50%). Although most resolved or were treated successfully, four patients had severe visual loss during the follow-up. Uveitis was a significant risk factor for tube exposure (Fisher exact test, P =.006). CONCLUSIONS: Ahmed Glaucoma Valve implantation is an effective treatment for pediatric glaucoma, although patients frequently require antiglaucoma medications. However, a high rate of potentially sight-threatening postoperative complications warrants ongoing close follow-up.

Adolescent↗

PubMed2003

Longitudinal changes in photopic OPs occurring with vigabatrin treatment.

PURPOSE: Vigabatrin (gamma-vinyl-GABA) is an antiepileptic drug successful in the management of infantile spasms. Photopic ERGs were tested in children followed longitudinally before and during vigabatrin treatment. METHODS: Subjects were 26 infants (age range 1.5-24 months, median 7.6 months) on vigabatrin treatment who had been tested on multiple visits (two to four visits; mean, three visits). Eighteen of these were assessed initially before starting vigabatrin therapy and eight were assessed within 1 week of initiation of the drug. ERGs were recorded at 6-month intervals. Standard ISCEV protocol with Burian-Allen bipolar contact-lens electrodes (standard flash 2.0 cd.s/m2) was used. Although ISCEV standards were followed, a higher flash intensity (set at 3.6 cd.s/m2) was chosen for single-flash cone assessment to provide a better definition of OPs. Photopic OPs were divided into categories of early OPs and late OP (OP4). Responses were compared with age corrected limits extrapolated from our lab control database. RESULTS: Results showed differential effects of vigabatrin on the summed early OP amplitudes versus the late OP (OP4) and cone b-wave amplitude. The early OPs showed significant decrease (p = 0.0005, repeated measures analysis of variance) after 6 months and remained decreased for the duration of treatment. There was no significant change seen in the late OP. The cone b-wave amplitude showed initial increase (p = 0.04) after 6 months, followed by a decrease after 18 months; a trend similar to that of the late OP. CONCLUSION: Early photopic OPs were disrupted more than the late OP, suggesting relative deficit in the ON (depolarizing) retinal pathways.

Anticonvulsants↗

PubMed2003

Visual acuity assessment: a comparison of two tests for measuring children's vision.

PURPOSE: To compare the Kay Picture Test and the logMAR Crowded Test. METHODS: Monocular visual acuity measurement was attempted on 103 paediatric subjects (aged between 2.5 and 16 years) attending eye clinics, using each of the visual acuity tests. RESULTS: The results obtained with the two tests were found to be comparable as confirmed with the Intra-class Correlation Coefficient, which revealed good agreement between the two tests. There was significant correlation between the visual acuity results measured and high conformity in the results from the weaker eye. There was a statistical difference in acuity scores between the tests; the Kay Picture Test gave a lower logMAR score with a mean difference of 0.08 logMAR. This 0.08 difference represents an actual difference of less than one line of acuity measure which can be considered to be clinically insignificant. There was a significant difference in the ability to perform each of the tests under binocular conditions, with more of the 50 children, aged 5 and under, able to perform the Kay Picture Test than the logMAR Crowded Test. CONCLUSIONS: The results obtained with the two tests are comparable. Both tests can be considered to be appropriate for amblyopia detection and the use of picture-based logMAR tests should be considered for younger children.

Adolescent↗