[Papillary retinal nerve fiber layer thickness measurement using optical coherence tomography in children with ocular hypertension and juvenile glaucoma]. / Mesure de l'épaisseur de la couche des fibres nerveuses rétinienne péripapillaires par tomographie à cohérence optique chez les enfants hypertones et glaucomateux.

PURPOSE: To compare retinal nerve fiber layer (RNFL) measurements taken with OCT in normal, ocular hypertensive, and glaucomatous eyes of children 4-18 years old. MATERIALS AND METHODS: The study included 181 eyes: 106 normal, 37 with ocular hypertension, and 38 with juvenile glaucoma. Diagnostic groups were classified based on intraocular pressure, optic nerve head appearance, visual field examination, and central corneal thickness measurement. RNFL measurements were taken using the Zeiss Stratus OCT. RESULTS: The RNLF average thickness was 94.2 + or -13.2 microm in glaucomatous eyes, 105.4 + or - 6.8 microm in ocular hypertensive eyes, and 104.8 + or - 10.3 microm in normal eyes. RNFL average thickness, inferior thickness, and superior thickness showed statistically significant differences between normal and glaucomatous eyes (p<0.01) and between glaucomatous [corrected] and ocular hypertensive eyes (p<0.01). There was no difference found between normal and ocular hypertensive eye. CONCLUSION: OCT has already shown its diagnostic efficiency in adult glaucoma. This study shows that OCT is useful in childhood glaucoma diagnosis, helping to differentiate between ocular hypertension and beginning juvenile glaucoma.

[Central corneal thickness and endothelial cell density in congenital glaucoma]. / Pachymétrie centrale et comptage cellulaire endothélial dans le glaucome congénital.

PURPOSE: The aim of this study was to compare endothelial cell density and central corneal thickness between eyes with congenital glaucoma and normal eyes. MATERIALS AND METHODS: We conducted a prospective study of pediatric patients between 3 and 18 years of age. Group A comprised 401 normal eyes and group B 69 glaucoma eyes, categorized into three subgroups: 3-4, 5-9, and 10 or more years of age. Measurements were taken using the Topcon SP 2000 specular microscope. RESULTS: The mean pachymetry in group B (519+/-34 microm) was significantly thinner than in group A (529+/-32 microm) (p<0.05). There was a significant positive correlation with age in the two groups (p<0.05 ANOVA) until the 5- to 9-year-old subgroup. The mean endothelial cell density in group B (2,922+/-553 cells/mm2) was lower than in group A (3,470+/-357 cells/mm2) (p<0.01). There was a significant negative correlation with age in group A (p<0.01 ANOVA). DISCUSSION: Corneal distension attributable to intraocular hypertony may explain the thinner pachymetry. In congenital glaucoma, a thinner cornea may tend to lower tonometrically recorded intraocular pressure. Glaucoma seems to be the main factor of the endothelial cell loss. CONCLUSION: Central corneal thickness and endothelial cell density should be taken into account when managing congenital glaucoma to avoid undertreatment and to measure endothelial damage.

[Deep sclerectomy in congenital glaucoma: results of a study lasting more than 3 years]. / Glaucome congénital et sclérectomie profonde: résultats d'une étude sur plus de 3 années.

PURPOSE: To assess the outcome of deep sclerectomy surgery with intraoperative antimitotic application in children with primary and secondary congenital glaucomas. PATIENTS AND METHODS: Thirty-seven eyes of 22 children aged from 1 day to 14 years were included in this study; 30 eyes had primary congenital glaucoma and were divided into two groups according to the management delay. Eighteen eyes were managed early (group 1) and 12 eyes were diagnosed late (group 2). Finally, seven eyes had a more complex dysgenic glaucoma (group 3). All the eyes had a deep sclerectomy with antimitotic intraoperative application (5 FU). Pre- and postoperative intraocular pressures, success rate, preoperative corneal transparency, corneal diameter, and surgical complications were assessed. Total success was defined by final postoperative intraocular pressure lower than 16 mmHG without combined medical treatment; partial success was defined by lower than 16 mmHG with a combined medical treatment. RESULTS: The mean follow-up was 38.2 months. Total success was 34% and partial was 82%: 56% and 89%, respectively, for group 1, 33% and 100% for group 2, and 14% and 57% for group 3. No severe complications occurred after surgery. CONCLUSION: The probability of success was significantly lower for secondary congenital glaucomas and for primary congenital glaucomas with late management. Management delay and the type of glaucoma seem to be capital in the prognosis of high intraocular pressure. Deep sclerectomy with antimitotic application (5 FU) is a good alternative to trabeculectomy in primary glaucomas.

[Central corneal thickness in a pediatric population using a noncontact specular microscope: a study of 405 cases]. / Pachymétrie cornéenne centrale dans la population pédiatrique par microscopie spéculaire non-contact: à propos de 405 cas.

AIM: Central corneal thickness has become very important in the interpretation of intraocular pressure. The aim of this study was to correlate pachymetry values in a pediatric population with age, sex, and refraction. To our knowledge, the scientific literature has not reported such information. PATIENTS AND METHOD: This prospective study was conducted from May 2005 to November 2006 and included 405 eyes (186 eyes in boys and 219 eyes in girls) in children undergoing a general pediatric ophthalmologic visit. Patient age ranged from 3 to 16 years; three age groups were formed: 3-4 years, 5-9 years, 10-16 years. Objective refraction with cycloplegic was measured using a Nidek ARK 700 A autorefractometer and three refraction groups were formed. Pachymetry measures were taken using the Topcon SP 2000P specular microscopy. Exclusion criteria were a history of ocular surgery, lens wearers, and any disease that could alter the cornea. RESULTS: The mean age was 8.21 +/- 3.55 years, the mean refraction was +1.24 +/- 4.02 D. The mean central pachymetry was 529 +/- 32 microm: 534 +/- 31 microm in the male group and 524+/-31 microm in the female group, establishing a difference in pachymetry with no differences in refraction or age between the two groups. In the refraction groups, we found a significant difference in pachymetry between emmetropic (523+/-33 microm) and hyperopic (533 +/- 31 microm) groups and between hyperopic and myopic groups (520 +/- 32 microm) (p=0.005). There was no difference between emmetropic and myopic groups (p=0.902), nor in pachymetry between age groups (p=0.086). DISCUSSION: Except for differences found in refraction groups, the results reported herein were similar to those found with the ultrasonic method (the reference method), but they had been obtained under general anesthesia in most studies. CONCLUSION: Even though this is not the reference method of pachymetry measures, it seems more appropriate for children, because it is reliable, the measurements are taken quickly, they are noninvasive, and they do not cause the child undue stress (noncontact method).

Stimulus features affecting psychophysical detection thresholds for electrical stimulation of the cochlea. III. Pulse polarity.

Effects of initial-phase polarity on psychophysical detection thresholds for electrical stimulation of the cochlea were examined in four nonhuman primates using trains of biphasic and triphasic charge-balanced pulses. Initial-phase polarity had small but consistent effects on the levels and slopes of threshold versus phase duration functions. These effects were consistent with the hypothesis that the initial-phase polarity affects the site of action potential initiation. Thresholds for biphasic pulses were lower than those for triphasic pulses, suggesting that the system is responsive to both positive and negative phases of the stimulus. Interactions between initial-phase polarity, pulse waveform, and phase duration were observed.