Neurons in the posterior interposed nucleus of the cerebellum related to vergence and accommodation. I. Steady-state characteristics

The present study used single-unit recording and electrical microstimulation techniques in alert, trained rhesus monkeys to examine the involvement of the posterior interposed nucleus (IP) of the cerebellum in vergence and accommodative eye movements. Neurons related to vergence and ocular accommodation were encountered within a circumscribed region of the IP and their activity during changes in viewing distance was characterized. The activity of these neurons increased with decreases in vergence angle and accommodation (the far-response) but none showed changes in activity during changes in conjugate eye position and we therefore term them "far-response neurons." Far-response neurons were found within a restricted region of the IP that extended approximately 1 mm rostrocaudally and mediolaterally and 2 mm dorsal to the fourth ventricle. Microstimulation of this far-response region of the IP with low currents (<30 microA) often elicited divergence and accommodation for far. The behavior of 37 IP far-response neurons was examined during normal binocular viewing, during monocular viewing (blur cue alone), and during binocular viewing with accommodation open-loop (disparity cue alone). The activity of all cells was modulated under all three conditions. However, the change in activity of some of these neurons was significantly different under these three viewing conditions. The behavior of 70 IP far-response neurons was compared during normal binocular viewing and during viewing in which the accommodative response was significantly dissociated from the vergence response. The data from these two conditions was pooled and multiple regression analyses for each neuron generated two coefficients expressing the activity of the neuron relative to the vergence and to accommodative response respectively. On the basis of these coefficients, the overall activity of the neurons were classified as follows: 34 positively correlated with divergence, 11 positively correlated with far accommodation, 14 positively correlated with divergence and far accommodation, 9 positively correlated with divergence and accommodation, and 2 positively correlated with convergence and far accommodation. The results of this study demonstrate the involvement of a specific region of the posterior interposed nucleus of the cerebellum in vergence and accommodation. IP far-response neurons are active for vergence and accommodation irrespective of whether or not these eye movements are elicited by blur or disparity cues. The data in the present study strongly suggest that this cerebellar region is a far-response region that is involved in vergence as well as accommodative eye movements.     

Differential induction of apoptosis by Fas-Fas ligand interactions in human monocytes and macrophages

PURPOSE: To evaluate the differences in accommodative function between subjects with emmetropia and those with late-onset myopia (LOM). METHODS: This study suggests a modified model of static accommodation, in which an accommodative sensory gain as a linear operator is added to simulate the sensory part of the system. Results derived from the model show that the sensory part not only affects the slope of the accommodative response function but also increases the system's effective threshold (ET) to the blur signal. This method expands the utility of using the control model to evaluate accommodation behavior. Thirteen emmetropic and 10 LOM subjects participated in this study. The subject's accommodative responses to one-, two-, three-, and four-diopter stimuli were measured by the Canon R-1 optometer, and the differences in dark focus, the slope of the accommodative response function, and the ET were compared between the emmetropic and the LOM subjects. RESULTS: The results show that although the dark-focus values and the slopes of the accommodative response function are not significantly different in emmetropia and LOM, the ETs are significantly different. CONCLUSIONS: The higher ET found among subjects with LOM suggests that either the blur (or the error) signal is degraded significantly in the sensory part of the system, the dead space as an internal threshold of the system is high, or both factors are important. On the basis of further analysis of the data, we speculate that the sensory system in LOM subjects was less sensitive to blur than that of the emmetropic subjects.     

Gain changes in the accommodative convergence cross-link

The output of the accommodative vergence cross-link, the AC/A ratio, was measured before and after subjects viewed through a telestereoscope which increased their interocular separation (pd) approximately fourfold. The initial paradigm was designed to force an increase in the AC/A ratio in that subjects alternately fixated targets set at differing distances. In this paradigm, the varying vergence demands could not be met by a constant increase in phasic or tonic vergence responses. In a second paradigm, only one target was viewed at a fixed position from the eye. Now the constant vergence demand could be met by a set increase in phasic and/or tonic vergence. A significant increase in the AC/A ratio was found in the two-target study but not in the single-target study. Increases in the accommodative vergence gain did show considerable individual differences. Tonic vergence changes were interpolated from the data. This parameter increased significantly in both cases but more so when two targets were alternately fixated. This finding is consistent with current near triad models which predict that accommodative convergence input acts along with disparity vergence input to increase tonic levels of convergence. When AC/A ratios were calculated using clinical measures of the phoria at 6 and 0.4 m, increases were found in the two-target study and to a lesser degree in the single-target study. This clinical method of AC/A measure appears to have been confounded by changes in tonic vergence.     

The effect of dapiprazole on accommodative amplitude in eyes dilated with 0.5 percent tropicamide

BACKGROUND: Dapiprazole 0.5 percent (REV-EYES) eyedrops have recently become commercially available in the U.S. to reverse the diagnostic mydriasis produced by various concentrations and combinations of tropicamide and phenylephrine. Although a previous study has shown that dapiprazole increased accommodative amplitude after the administration of tropicamide, no attempt was made to control for differences in pupil size. METHODS: In the present single masked study, the accommodative amplitudes of forty-eight age-matched subjects previously dilated with 0.5% tropicamide were measured through a 3 millimeter artificial pupil following random instillation of dapiprazole in one eye and a placebo drop in the other eye. RESULTS: Area under the curve analysis determined that the magnitude of accommodative response to dapiprazole was significant at p < 0.001 (paired t-test). The McNemar test also showed that the accommodative amplitude was greater in eyes treated with dapiprazole at all observation points (p < 0.005), beginning at 15 mins after the instillation of the test drug. CONCLUSIONS: The results demonstrate that dapiprazole accelerates the return of accommodation independent of pupil size.     

Primary localization of malignant lymphoma in the urinary bladder?

The characteristics of post-task regression of accommodation to pre-task tonic accommodation (TA) levels have been examined in a number of studies to clarify the nature of the within-task facility for accommodative adaptation. Of special interest is the recent observation that significant attenuation of post-task regression occurs in late-onset myopes (LOMs) when compared with emmetropes (EMMs). These findings have led to speculation that such attenuation may reflect a deficit in inhibitory sympathetic innervation to ciliary smooth muscle in late-onset myopia and hence a predisposition to sustained accommodative adaptation which then acts as a precursor to the induced myopia. A consequence of this study was that post-task regression may have some value in predicting those individuals who may be susceptible to post-task accommodative hysteresis. A pre-requisite for such a predictive value is that for a given individual the variation in inter-trial regression patterns is not significant. The aim of this study is principally to investigate the inter-trial variability of post-task regression for individual subjects following a sustained near vision task, and to confirm further differences that have been reported between EMMs and LOMs with respect to the time course of post-task regressions. A modified Canon R1 infrared optometer was used to measure accommodation objectively throughout a near task and for 2 min post-task. Accommodative level was measured following 3 min fixation of a high contrast photopic Maltese cross target placed 3 D above the subject's baseline TA. Repeatability of post-task regression in 10 EMMs and 10 LOMs was assessed by taking measurements on three separate occasions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Strabismus in children with cerebral palsy

In 48 children with cerebral palsy the characteristics of the squint and amblyopia were analyzed, also with respect to the features of cerebral palsy and to birth weight. Strabismus of congenital esotropia type was found to be common, as was also exotropia of early onset. Spontaneous alternation or an accommodative component of the squint was present only in a few cases. There was no evidence of an accumulation of any strabismus type in the different subgroups of cerebral palsy, whereas amblyopia or an obvious risk for amblyopia was found in the great majority of the cases. Some kind of amblyopia treatment was given to 34. Most of them showed improvement of the visual capacity which encourages treatment of amblyopia, even in children with cerebral palsy.     

Static aspects of accommodation: age and presbyopia

Although the progressive reduction in accommodative amplitude with increased age is well documented, little is known about several other aspects of static or steady-state accommodation to provide a comprehensive assessment of changes related to age and presbyopia. Static components of accommodation (tonic accommodation, depth-of-focus, slope of the stimulus/response function, and accommodative controller gain) were assessed objectively using an infrared (IR) optometer in 30 human subjects aged 21-50 years; depth-of-focus was also determined psychophysically as was accommodative amplitude. Tonic accommodation and the amplitude of accommodation decreased with increased age, whereas the subjective depth-of-focus increased; the other parameters remained unchanged. The decrease in tonic accommodation and amplitude of accommodation was attributed to biomechanical factors, whereas the increase in subjective depth-of-focus was believed to result from increased tolerance to defocus related to the gradual onset of presbyopia. Constancy of the objective depth-of-focus suggested absence of age effects on the neurologic control of reflex accommodation, whereas the lack of systematic change in slope and controller gain provided support for the Hess-Gullstrand theory of accommodation and presbyopia.     

Controlled evaluation of a bandage contact lens and a topical nonsteroidal anti-inflammatory drug in treating traumatic corneal abrasions

BACKGROUND: Treating traumatic corneal abrasions is a common problem for the ophthalmologist. Traditional management has been the use of a pressure patch. Three different therapeutic modalities were evaluated for their efficacy in treating traumatic corneal abrasions. METHODS: Forty-seven consecutive patients with traumatic corneal abrasions were randomized prospectively in a single-masked, controlled clinical trial which compared the efficacy of (1) pressure patching, (2) a bandage contact lens, and (3) a bandage contact lens with a topical nonsteroidal anti-inflammatory drug (0.5% ketorolac tromethamine). RESULTS: There was no significant difference in the healing time of the three groups. However, psychometric analysis showed a significant decrease in pain in the group that received a bandage contact lens with a topical nonsteroidal anti-inflammatory drug. There was a significant difference in the ability to return to normal activities in both contact lens groups compared with the pressure-patch group. There was no significant difference among the three groups with respect to photophobia, redness, ocular irritation, headache, or tearing. CONCLUSION: Use of a bandage contact lens significantly shortens the time required for a patient to return to normal activities. Moreover, addition of a nonsteroidal anti-inflammatory drug to a treatment regimen significantly decreases the pain associated with traumatic corneal abrasions. Use of a bandage contact lens with a topical nonsteroidal anti-inflammatory may prove to be an effective adjunct in treating traumatic corneal abrasions.     

Management of intermittent esotropia

Management of patients with intermittent esotropia having either normal or high accommodative convergence to accomodation (AC:A) ratios is discussed. Treatment should be based on liberal use of miotics to build up fusional reserves and use of hyperopic corrections or bifocals or both whenever specifically indicated. Divergent fusional reserve training is time-consuming and the cost/benefit ratio so low that most patients and doctors prefer the former treatment.     

Prevalence of vision and ocular disease conditions in a clinical pediatric population

BACKGROUND: The purpose of this study was to fill a significant void in the ophthalmic literature by performing a large scale, comprehensive, prospective study of the prevalence of vision disorders and ocular pathology in a clinical pediatric population using well-defined diagnostic criteria. METHODS: A prospective study was performed on 2,023 consecutive patients between the ages of 6 months and 18 years presenting for an initial comprehensive examination at the Eye Institute of The Pennsylvania College of Optometry. There were 373 subjects between 6 months and 5 years, 11 months of age, and 1,650 subjects between 6 years and 18 years of age. RESULTS: The most important finding from this study is that other than refractive anomalies, the most common conditions optometrists are likely to encounter in a pediatric population are binocular vision and accommodative disorders. The prevalence of accommodative and binocular (strabismic and non-strabismic) vision disorders is 9.7 times greater than the prevalence of ocular disease in children 6 months to 5 years of age, and 8.5 times greater than the prevalence of ocular disease in children 6 to 18 years of age. CONCLUSIONS: The data from this study has great significance for clinicians, optometric educational institutions, health care planners, and administrators. This data suggests that other than refractive anomalies, the most prevalent conditions in the clinical pediatric population are binocular and accommodative disorders. Clinicians should use a minimum data base that includes assessments of accommodation and binocular vision that will allow them to detect conditions with the highest prevalence.     

Effect of systemic versus topical nonsteroidal anti-inflammatory drugs on postexercise jaw-muscle soreness: a placebo-controlled study

Certain types of jaw-muscle pain may be managed with pharmacologic treatment. This study evaluated the effect of topical and systemic nonsteroidal anti-inflammatory drugs on acute postexercise jaw-muscle soreness. Ten men without temporomandibular disorders performed six 5-minute bouts of submaximal eccentric jaw exercise. The outcome variables were pressure pain thresholds and pain tolerance thresholds at the masseter muscles, and maximum voluntary occlusal force. Surface electromyography from the masseter muscles was used to assess the development of muscle fatigue during the exercise period. Three treatment modalities were tested in a placebo-controlled, double-blind approach: (A) placebo gel and placebo tablets; (B) nonsteroidal anti-inflammatory drug gel (2 g, 5% ibuprofen) and placebo tablets; and (C) placebo gel and nonsteroidal anti-inflammatory drug tablets (400 mg ibuprofen). The subjects used their medication 3 times a day for 3 days in the postexercise period. In the exercise period, the mean power frequency of the electromyography signal, pressure pain threshold, pain tolerance threshold, and maximum voluntary occlusal force decreased significantly (analysis of variance, P < .01). In the postexercise period, the effect of treatment on pressure pain thresholds was significant (F[2,9] = 4.41, P = .02). On day 3, treatment with topical nonsteroidal anti-inflammatory drugs was associated with significantly higher pressure pain thresholds as compared to treatment with systemic nonsteroidal anti-inflammatory drugs (P < .05) and placebo (P < .05). Treatment effects on pain tolerance thresholds and on maximum voluntary occlusal force were nonsignificant. The results demonstrated that repeated eccentric jaw exercise caused muscle fatigue and low levels of postexercise pain and soreness. Topical nonsteroidal anti-inflammatory drugs seem to have some advantages over systemic nonsteroidal anti-inflammatory drugs for management of exercise-induced jaw-muscle pain.     

Are anti-oxidant and anti-inflammatory treatments effective in different subgroups of COPD? A hypothesis

The treatment of chronic obstructive pulmonary disease (COPD) with inhaled corticosteroids or anti-oxidants is still under debate and the identification of sub-groups of COPD patients who may benefit from either anti-inflammatory or anti-oxidant treatment is needed. We re-analysed data from an earlier study of inhaled beclomethasone therapy in COPD (n = 28) and asthma (n = 28) patients in order to determine patient characteristics that predict a favourable inhaled steroid treatment effect. A higher bronchodilatory response, a faster decline of FEV1 prior to the treatment period and a lower Tiffeneau index were significantly related to more beneficial treatment effects. Increased smoking tended to be related to less steroid treatment benefits, though it was not statistically significant. In this paper these findings are presented in light of the available literature on anti-inflammatory and anti-oxidant COPD treatment. On this basis the hypothesis is presented that anti-oxidant treatment might be relatively more effective among those COPD patients who respond less well to inhaled steroids (low reversibility and heavy smoking).     

Accommodative esotropia during the first year of life

Two infants developed accommodative esotropia during their first six months of life. One infant, whose age at onset was 4 1/2 months, had 4.50 diopters of hyperopia. The second infant, whose age at onset was 5 months, had 3.50 diopters of hyperopia. In both infants, the eyes completely aligned with hyperopic correction. Two points are stressed. First, when the amount of hyperopia exceeds +3.00, consideration should be given to an accommodative element as the cause of the esotropia, even if the child is only 4 to 6 months old. Second, even with small angles of esotropia, an accommodative element should be considered, if there is a substantial amount of hyperopia.     

Physical and chemical properties of DMP 504, a polyalkylammonium-based bile acid sequestrant

In an open, controlled, multi-centre clinical field trial, seven 'naturally occurring' outbreaks of acute febrile (rectal temperature > or = 39.5 degrees C) respiratory disease in housed calves were treated with a single antimicrobial agent, and either the non-steroidal anti-inflammatory drug (NSAID) carprofen (n = 95) or flunixin meglumine (n = 92) on an alternate basis. Carprofen was administered as a single subcutaneous injection at a mean dosage of 1.4 mg kg-1 (range 1.2 to 1.9 mg kg-1) body weight on the first day and flunixin meglumine by intravenous injection at a mean dosage of 2.0 mg kg-1 (range 1.2 to 2.6 mg kg-1) body weight on the first 3 consecutive days. All calves were examined clinically immediately prior to initial treatment and on three occasions up to 1 week after the end of treatment. There were no statically significant differences between NSAID groups in reduction of clinical parameters between examinations, or in overall efficacy. This trial demonstrated that a single dose of carprofen was equally effective as three daily doses of flunixin meglumine as adjunctive therapy to antimicrobial treatment in acute respiratory disease in calves.     

Wet Lay-Up Manufactured FRPs for Concrete and Masonry Repair: Influence of Water on the Properties of Composites and on Their Epoxy Components

The assessment of durability of fiber-reinforced polymers (FRPs), used to strengthen masonry or concrete structures, if subjected to weathering is a knotty problem. Environmental factors can have a significant effect on their performance in service. In order to investigate on this aspect, the mechanical behavior of two commercial composites, reinforced with unidirectional carbon and glass fibers, was analyzed after a long-term immersion in distilled water. For comparison purposes, three different commercial epoxy resins, used as primer, putty, or adhesive to manufacture and apply the composites through the wet lay-up technique to the surfaces to strengthen, were subjected to the same treatment. In order to take into account the peculiarities of the three cold-curing epoxy resins, a novel procedure to dry the specimens before the immersion treatment was used. The mechanical tests, performed on the composites before and after their immersion in water, evidenced that this agent has a limited effect only on the in-plane tensile strength of wet lay-up manufactured glass FRP, while the mechanical properties of carbon FRP are substantially unaffected by water. On the other hand, the effect of water on the thermal and mechanical characteristics of the three epoxy resins is quite severe, with significant reductions in the glass transition temperature, stiffness, and strength.     

Recovery from 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced immunosuppression in A/J mice by treatment with nonsteroidal anti-inflammatory drugs

BACKGROUND: We have previously reported that nonsteroidal anti-inflammatory drugs inhibit lung tumorigenesis induced by the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in mice. PURPOSE: The aims of this study were to determine if NNK suppresses humoral (i.e., antibody) and cellular immune responses in mice and if nonsteroidal anti-inflammatory drugs could attenuate these immune responses. METHODS: Female A/J mice (7-8 weeks old) were fed nonsteroidal anti-inflammatory drugs starting 2 weeks before the beginning of NNK treatment (9.1 mg per mouse in total) and continuing through the 7 weeks of NNK treatment. Eight groups (two control groups and six experimental groups) of 10 mice each were used per experiment. Animals in the two control groups received the same diet and water as animals in the six experimental groups; one control group received no nonsteroidal anti-inflammatory drugs or NNK and the other control group received only NNK. The primary humoral and cellular immune responses to the various treatments were assayed by the plaque-forming cell technique and by measurement of natural killer cell cytotoxic activity, respectively. At the end of each experiment, the animals were killed, blood was collected, plasma was prepared, and levels of the immune system modulator prostaglandin E2 were measured. RESULTS: NNK treatment inhibited the plaque-forming cell response by approximately 50%; this inhibition was attenuated by treatment with sulindac or acetylsalicylic acid (P = .0001 for both). In contrast, treatment with naproxen, which had no chemopreventive (i.e., tumor inhibitory) efficacy, further increased by 26% (P = .05) the immunosuppressive effect of NNK. The cytotoxic activity of splenic natural killer cells against YAC-1 cells was reduced by 60% (P = .002); treatment with acetylsalicylic acid (254 mg/kg of diet) reduced the NNK-induced natural killer cell cytotoxicity inhibition by 50% (P = .02), whereas the administration of the specific cyclooxygenase-2 inhibitor NS-398 (7 mg/kg of diet) resulted in an almost complete recovery (approximately 95%, P = .04) of natural killer cell activity. The prostaglandin E2 plasma concentration was approximately 100% greater in NNK-treated mice than in untreated mice. Treatment of the mice with nonsteroidal anti-inflammatory drugs attenuated this elevation (from approximately 25% to 100%), and NS-398 (7 mg/kg of diet) was the most effective (100%). CONCLUSIONS AND IMPLICATIONS: The ability of various nonsteroidal anti-inflammatory drugs to inhibit NNK-induced carcinogenesis appears to be directly related to the ability of these drugs to inhibit NNK-induced immunosuppression. Our results suggest that the chemopreventive effect of nonsteroidal anti-inflammatory drugs may be mediated through the modulation of prostaglandin E2 synthesis.     

The role of viscosupplementation with hylan G-F 20 (Synvisc) in the treatment of osteoarthritis of the knee: a Canadian multicenter trial comparing hylan G-F 20 alone, hylan G-F 20 with non-steroidal anti-inflammatory drugs (NSAIDs) and NSAIDs alone

To determine the safety and efficacy of viscosupplementation with hylan G-F 20, a cross-linked hyaluronan preparation, used either alone or in combination with continuous non-steroidal anti-inflammatory drug (NSAID) therapy, a randomized, controlled, multicenter clinical trial, assessed by a blinded assessor, was conducted in 102 patients with osteoarthritis (OA) of the knee. All patients were on continuous NSAID therapy for at least 30 days prior to entering the study. Patients were randomized into three parallel groups: (1) NSAID continuation plus three control arthrocenteses at weekly intervals; (2) NSAID discontinuation but with three weekly intra-articular injections of hylan G-F 20; and (3) NSAID continuation plus three injections, one every week, intra-articular injections of hylan G-F 20. Outcome measures of pain and joint function were evaluated by both the patients and an evaluator at baseline and weeks 1, 2, 3, 7 and 12, with a follow-up telephone evaluation at 26 weeks. At 12 weeks all groups showed statistically significant improvements from baseline, but did not differ from each other. A statistical test for the equivalence, the q-statistic, demonstrated that viscosupplementation with hylan G-F 20 was at least as good or better than continuous NSAID therapy for all outcome measurements except activity restriction. At 26 weeks both groups receiving hylan G-F 20 were significantly better than the group receiving NSAIDs alone. A transient local reaction was observed in three patients after hylan G-F 20 injection; only one patient withdrew from the study as a result and all recovered without any sequela. Hylan G-F 20 is a safe and effective treatment for OA of the knee and can be used either as a replacement for or an adjunct to NSAID therapy.     

Treatment of hepatic venocclusive disease with recombinant human tissue plasminogen activator and heparin in 42 marrow transplant patients

The purpose of this report is to review the Fred Hutchinson Cancer Research Center experience of treating patients with venocclusive disease of the liver (VOD) after marrow transplantation using recombinant human tissue plasminogen activator (rh-tPA) and heparin. The charts of 42 patients who had received rh-tPA and heparin for the treatment of VOD between February 1991 and December 1995 were reviewed. Response to rh-tPA and heparin was defined as a reduction in total serum bilirubin by 50% within 10 days of starting treatment. Total serum bilirubin, percent weight gain, and serum creatinine before, after, and at the start of rh-tPA and heparin were examined to determine whether these laboratory values distinguished patients who responded to treatment from those who did not. We also evaluated whether evidence of multiorgan failure (requirement for supplemental oxygen, requirement for hemodialysis, requirement for mechanical ventilation) or whether the calculated probability of a fatal outcome from VOD could discriminate responders from nonresponders. In addition, the incidence and outcome of bleeding as a major complication of thrombolytic therapy was examined. Twelve patients responded to rh-tPA and heparin and 30 patients did not. There were no statistically significant differences between responders and nonresponders in the day treatment was started, dose of rh-tPA, total serum billirubin, and percent weight gain before, after, or at the start of treatment, or the calculated probability of dying from VOD on the day treatment with rh-tPA and heparin was begun. More nonresponding patients required dialysis or mechanical ventilation (11 of 30) before or at the start of rh-tPA and heparin than responding patients (0 of 12), P = .0183. Serum creatinine was greater at the start of treatment in nonresponding patients (1.9 +/- 1.3 mg/dL) than in responding patients (1.1 +/- 0.4 mg/dL), P = .0794. Ten patients had severe bleeding episodes, which resulted in death in three patients and may have contributed to death in an additional three patients. Treatment for VOD using rh-tPA and heparin was successful in 29% of patients but was associated with a significant risk of life-threatening hemorrhage. Requirement for supplemental oxygen, dialysis, or mechanical ventilation before the start of treatment were prognostic indicators of no response to thrombolytic therapy. We do not recommend treatment using tPA and heparin in patients with severe VOD who have already developed multiorgan dysfunction.     

Accuracy of asthma treatment in schoolchildren in NSW, Australia

Insufficient use of anti-inflammatory drugs, such as inhaled corticosteroids and cromoglycate, may contribute to the disease burden associated with asthma. Conversely, aggressive treatment of mild disease may result in avoidable costs and/or adverse drug effects. The aim of this study was to determine the relationship between asthma severity and inhaled corticosteroid/cromoglycate use in a large (n=4,909) random sample of children, aged 8-11 yrs, in NSW, Australia. Asthma and its treatment were assessed by questionnaire responses. Asthma, defined as diagnosis plus current wheeze, was present in 901 children (18% of the sample), of whom 225 (5%) had moderate asthma, defined as asthma plus additional symptoms (sleep disturbance), utilization (hospital, casualty), or disability (reduced activity, school absence). Use of inhaled corticosteroid/cromoglycate was reported by 636 children (13% of the sample). Determinants of use included: asthma diagnosis, current wheeze, and troublesome dry nocturnal cough. There was also a strong relationship between anti-inflammatory treatment and a multicomponent asthma severity score constructed for each child. Inhaled corticosteroids and/or cromoglycate were used by 56% of the children with asthma (24% daily) and by 76% of children with moderate asthma (42% daily). Undertreatment, defined as less than daily inhaled corticosteroids/cromoglycate in moderate asthma, was identified in 130 children (14% of those with asthma or 3% of the sample). Conversely, apparently aggressive treatment, defined as inhaled corticosteroid/cromoglycate use in children with persistent minimal symptoms (asthma severity score of less than 3) was identified in 101 children (2% of the sample). Although there were significant differences between regions in the choice of anti-inflammatory drugs and in the prevalence both of undertreatment and apparently aggressive treatment, there was no clear relationship to regional utilization of emergency and hospital services for asthma. Nevertheless, the frequency of undertreatment suggests an opportunity to reduce asthma morbidity by more consistent application of current therapeutic guidelines.