Changes of olfactory processing in childhood and adolescence.

OBJECTIVES: Olfactory event-related potentials (OERPs) are widely used to study central odor processing. Only a few studies used this method in children and adolescents. Aim of the current study therefore was to measure OERP and the possible influences of age and sex on central odor processing in this age group. METHODS: A total of 81 children between 6 and 17 years of age were included in this study. OERP in response to a rose-like odor were measured from three recording positions (Fz, Cz, Pz) according to the 10-20 system. Stimuli were presented by means of a computer-controlled olfactometer. RESULTS: Age had a significant influence on the amplitudes of the late positivity with younger children showing larger amplitudes. Although age did not significantly affect the latencies of OERP, interactions of recording positions and latencies between younger and older children and between girls and boys were found. CONCLUSIONS: OERP can be used to study central odor processing in children older than 6 years of age. Central odor processing changes from childhood to adolescents possibly reflecting maturation of the brain.

Wound healing following excimer laser radial keratotomy.

A pulsed excimer laser was used to produce radial keratotomy in vivo in human corneas and the wound healing process was studied. Fluences of 370 mJ/cm2 at a repetition rate of 20 Hz were effective and atraumatic. The wound healing process was remarkably uneventful without an inflammatory or immune reaction apparent at 21 days. Consistent flattening of the cornea was obtained by shallower cuts than with conventional radial keratotomy techniques.

Corneal wound healing after excimer laser keratotomy in a human eye.

A pulsed excimer argon-fluorine laser was used to produce corneal incisions in vivo in a human cornea. Fourteen days after the laser surgery, the incisions were examined by light and transmission electron microscopy. There was good initial healing, with no inflammatory or immune reactions in the incisions.

Pathology and physics of YAG-laser intraocular lens damage.

Polymethylmethacrylate and silicone intraocular lenses were subjected to controlled Nd:YAG laser irradiation. Following damage, each lens was examined by scanning electron microscopy. Highly specific morphologic patterns, believed to be pathognomonic for each material, were observed. The physics of damage mechanisms and clinical correlation of damage morphology are discussed.

Complications from anterior chamber lenses: report of cases.

This is a report of cases of complications from anterior intraocular lenses. Problems discussed include dislocated, misfit, or malpositioned implants and methods of surgical correction. The importance of accurate anterior chamber diameter measurement, flexible anterior chamber lenses, and stability of lens fixation for successful anterior chamber surgery is stressed.

Results of monovision correction in bilateral pseudophakes.

We performed a retrospective study of the postoperative use of glasses in 100 patients with bilateral posterior chamber implants. Patients' vision had been corrected with one emmetropic eye and one myopic eye for simultaneous distance and near vision without glasses. The number of patients wearing bifocals preoperatively declined by half with this technique. Postoperatively, 11% of patients wore glasses out of habit, even though their visual acuities were equivalent to those of the 14% who subjectively needed no correction after surgery. The results of the study and the advantages of this monovision method of optical correction in bilateral pseudophakes are discussed.

Examination of YAG laser marks on intraocular lenses.

A lathe-cut intraocular lens was hit with the mode-locked YAG laser. The resulting marks (dinks) were examined with scanning electron microscopy and are described.

Control of astigmatism by wound placement.

We performed a clinical surgical study of extracapsular extraction/phacoemulsification and lens implantation to determine the effectiveness of posterior wound placement in reducing immediate astigmatism. One hundred three cases, one half with anterior wounds and one half with posterior wounds, were analyzed for cylinder, axis, and astigmatism at six days and six weeks. We found little change in the amount of preexistent astigmatism with posteriorly placed wounds. The change was much greater with anteriorly placed wounds.

Electron microscopy for the diagnosis of ocular viral infections.

Tear samples obtained from patients with suspected viral conjunctivitis were examined by virus culture and by the pseudoreplica method for electron microscopy (EM). Adenoviruses were isolated in 13 of the 34 cases (38%) clinically diagnosed as adenovirus conjunctivitis. Characteristic adenoviral particles were demonstrated by electron microscopy in seven of the culture-positive, and two of the culture-negative samples. In cases of herpes simplex virus ocular infection, tears were virus positive by culture in one-third of the patients; two-thirds of the culture positive specimens were also positive by EM. This study demonstrates the potential of electron microscopy as a rapid, specific, and relatively inexpensive method for the laboratory diagnosis of ocular viral infections.