Evaluation of a family-based substance abuse prevention program targeted for the middle school years.

A family-based substance abuse prevention program was evaluated which emphasizes family cohesion, school and peer attachment, self-esteem, and attitudes about adolescent use of alcohol and tobacco. The program was implemented in rural communities and targeted families with students entering middle or junior high school. Baseline surveys were conducted with students and parents in four schools and were readministered one year later. Because the program was voluntary, a quasi-experimental design was used to compare participants (29 students and 28 parents) and nonparticipants (268 students and 134 parents). Analyses of covariance indicated that student participants, as compared to nonparticipants, had higher family cohesion, less family fighting, greater school attachment, higher self-esteem, and believed that alcohol should be consumed at an older age at the one year follow-up. There were fewer significant results for parent participants. Strategies for involving parents in prevention programs are discussed.

[Ocular hemoglobinometry--physiological variations]. / Die unblutige Hämoglobinmessung am Auge--ihre physiologische Variation.

BACKGROUND: To explore the relationship between ocular (fundus) hemoglobin and that sampled and measured conventionally. To look for differences in hemoglobin density determined by both methods when the body hemoglobin is acutely (blood donation) or pathologically e.g. anemia altered. PATIENTS AND METHODS: Conventional (capillary and antecubital) and ocular fundus (papillary and choroidal) determinations of hemoglobin density in 14 females and 23 males, aged 25 to 30 years were compared. Application of the ocular method before and after blood donation in 21 females and 12 males, aged 20 to 68 years was performed. All these subjects were ophthalmologically and systemically healthy. Five male and 5 female anemia patients, aged 27 to 90 years, were also measured as above. RESULTS: Good correlation between fundus hemoglobin density and capillary (r = 0.81) and venous (r = 0.61) hemoglobin was observed in healthy persons. Differences in hemoglobin density according to gender were obvious at all fundus sites measured. Following blood donation, papillary hemoglobin density in males moreover increased, while that in females decreased (F = 7.53), suggesting a gender-specific difference in the ocular blood regulation, an effect also noted in the anemia patients. CONCLUSIONS: Comparison of conventional and ocular determination of hemoglobin reveals good correlation in healthy people. However, in acute or chronic blood loss the papillary hemoglobin level differs from that measured peripherally. A gender-related regulatory capacity of the ocular tissues under low-level conditions can be shown: Male persons maintain ocular hemoglobin at a normal level even when peripheral hemoglobin falls to low values, whereas female persons show a decrease in ocular hemoglobin parallel to the venous levels. Hence, under such extreme conditions,--and only in males--the ocular method yields values other than those from the conventional method, because ocular regulatory mechanisms, otherwise undetected, are exquisitely revealed.

[Velocity model for Heidelberg retinal flowmetry]. / Geschwindigkeitsmodell für Heidelberg Retina Flowmetrie.

BACKGROUND: An application of scanning-laser ophthalmoscopic flowmetry, Heidelberg Retina Flowmetry (HRF) is reported to faithfully quantify retinal perfusion. Indeed, without convincing regard for the fact that the method produces numerical values for such so-called "VELOCITY" (and subsequently "calculates" "FLOW", and "VOLUME") with no physical units or proven real-life meaning, current clinical drug studies and patient care are being based on this method. To test the physical "fidelity" of the HRF method, the author hence devised a simple, reliable mechanical model to generate known velocities of movement of a test surface. MATERIALS AND METHODS: Movement of the circumferential surface of an 89 mm (3 1/2-inch) Ø cylinder, belt-driven by a brass spindle with segments of increasing diameter, was "analyzed" with the HRF method. The true velocities (mm/sec) with which the surface passed the HRF's focal point were then determined using a stopwatch. A 10 degrees x 2.5 degrees measuring field and a 20 x 20-pixel analysis window were used. Measurements were made for horizontal, diagonal (45 degrees and 135 degrees), and vertical motion at all velocity settings of the model. RESULTS: The relationship between real velocities of cylinder-surface motion and the corresponding HRF-"VELOCITY" values was nonlinear, an effect which increased significantly for diagonal and vertical motion. CONCLUSIONS: Considering the dependency on orientation of motion and the non-linearity of the relationship between HRF results and true velocity, as well as several other weaknesses discussed herein, the question arises whether the validity of the HRF method should be reconsidered.

Modulation of Heidelberg Retinal Flowmeter parameter flow at the papilla of healthy subjects: effect of carbogen, oxygen, high intraocular pressure, and beta-blockers.

The Heidelberg Retina Flowmeter (HRF) is intended to assess ocular blood flow by scanning laser doppler flowmetry. In the retina and possibly in the optic nerve head, carbogen increases blood flow, whereas pure oxygen or high intraocular pressure (IOP) decrease it. This study addresses whether at the papilla of healthy volunteers, the HRF parameter flow, is modulated by breathing 5% carbogen (5% carbon dioxide + 95% oxygen) for 7 minutes, breathing 100% oxygen for 7 minutes, increasing IOP to 50 mm Hg with a suction cup, or decreasing IOP with a single topical ocular instillation of the beta-blockers 0.5% betaxolol (betoptic) or 0.5% timolol (timoptic). At the papilla (20 degrees x 5 degrees, 256 X 64 pixels), values of HRF parameter, flow (50 X 50) pixels, increased after carbogen (N = 5, P < 0.05), but decreased after oxygen (N = 5, P < 0.05) or IOP increase (N = 5, P < 0.01). Although IOP values were significantly reduced by betaxolol (N = 9, P < 0.05) and timolol (N = 9, P < 0.01), HRF values were only significantly decreased (N = 9, P < 0.05) after timolol. In conclusion, at the papilla of healthy volunteers, a positive correlation exists between changes in values of the HRF-parameter, flow, and stimuli considered to modulate retinal and ONH blood flow. Furthermore, although of unkown clinical relevance, it appears that in contrast to betaxolol, values of the HRF parameter, flow, at the papilla of healthy volunteers are significantly decreased after a single instillation of timolol.

[Mechanical model of ocular pulsatile flow for evaluating the ocular blood flow device with known pressure pulsations]. / Mechanisches Modell für Okular-Pulsatilfluss zur Prüfung des 'Ocular Blood Flow' (OBF)-Gerätes mit bekannten Druckpulsationen.

BACKGROUND: Ocular perfusion consists of steady-state and pulsatile components of flow. The latter can be measured clinically by means of the 'Ocular Blood Flow' (OBF)-device (O.B.F. Ltd, Crowshearst, GB). METHODS: 1) Mechanical 'eye': To mechanically simulate the effect of pulsatile flow in the eye, a mechanical 'eye' model was built: A brass chamber (9 cm3) was machined and fitted with in- and outflow connections. The front opening was covered with a taughtly fixed rubber membrane (COSANO, no. 5203.106, Migros AG, Zurich) which, as mechanical 'cornea', pulsated with changes in pressure within the mechanical chamber. 2) Mechanical 'heart': To mechanically simulate pulsatile flow (i.e. pulsations in pressure like those within the human eye), two reservoirs were constructed of acrylic plastic and mounted on an upright optical bench with a millimeter scale. The reservoirs were constantly filled to overflowing with perfusate (tap water) and were connected by rubber tubing to the 'eye'-chamber. A computer-guided valve alternated between the 'systolic' and 'diastolic' columns of different, independently adjustable elevation. Frequency and duration of each pressure phase could also be independently adjusted via dialog with the computer. Input pressure levels were measured just outside the input using a transducer. The OBF-device measured the chamber pressure at the center of the rubber 'cornea'. RESULTS: Even the slightest alterations in the parameters (frequency, amplitude, and pressure) were precisely detected by the OBF-device, both graphically and numerically. CONCLUSIONS: Challenged by the mechanical model, the OBF-device demonstrated high sensitivity and fidelity of reproduction of any and all pulsations in intra- "ocular" -pressure.

[The mechanical fundus perfusion model: blood flow velocity determined by ICG angiography and Heidelberg retina flowmetry]. / Mechanisches Fundusperfusions-Modell: Blutflussgeschwindigkeiten ermittelt durch ICG-Angiographie und Heidelberg Retina Flowmetry.

BACKGROUND: Heidelberg Retina Flowmetry (HRF) is now popularly, perhaps even indiscriminately applied in eye research, without apparent concern for the fact that the results are given numerically, but without physical units. METHODS: 1) HRF: To challenge the HRF-device with known values of blood-flow velocity, a perfusion chamber with input and output connections was constructed of acrylic plastic. Three serial segments were milled to provide cross-sectional areas (1.93 mm2, 3.33 mm2, and 5.08 mm2) and accordingly decreasing, true, clinically representative flow-velocity values. Under a constant perfusion setting of a calibrated clinical infusion pump (Perfusor Secura FT, B. Braun Medical AG, Sempach, CH), heparinized human blood (P. H.) was pumped through the chamber, and the HRF-parameter, "VELOCITY" was measured within one image encompassing the three chamber segments, using a 20 degrees x 5 degrees-field and a 20 x 20-pixel measuring "window". 2) HRA: Immediately thereafter, our perfusion model was placed in front of the Heidelberg Retina Angiography device, the infusion pump started at the same constant level, and a 1 cc bolus of ICG dye was added to the blood. Digital ICG-angiography was then conducted, and the images analyzed on-screen. RESULTS: In the three segments of the perfusion chamber, flow velocities determined ICG-angiographically were 11.5 mm/s, 6.7 mm/s, and 4.4 mm/s, respectively. The corresponding values for HRF- "VELOCITY" were 5.3, 4.2, and 3.4, respectively (no units). CONCLUSIONS: Under identical perfusion conditions, the phenomenologically (ICG-angiographically) determined values of flow velocity in the 3 perfusion chamber segments ran similar to (but not numerically coincidental with) those determined for HRF-parameter "VELOCITY". Extrapolation of HRF-values to true physical units is, thus, feasible.

Telemetry monitoring in acute and critical care.

With the expansion of higher acuity patients in noncritical care areas, the perceived need for arrhythmia monitoring has also escalated. For institutions pursuing this expansion, many factors must be kept in mind, including patient criteria for telemetry initiation and discontinuation, staff competency of ECG interpretation, safety, technology required, usability, and cost effectiveness. All of these issues must be addressed according to the individual institution's needs and the needs of the patient populations they serve.

Heidelberg retina flowmeter parameters at the papilla in healthy subjects.

PURPOSE: To assess the Heidelberg Retina Flowmeter (HRF) parameters "volume", "flow", and "velocity", at the papilla in healthy subjects. METHODS: HRF measurements were taken at the papilla (5 degrees x 20 degrees), superficially at level of the retina and at the bottom of the excavation. The effect of increasing frame size (1 x 1 to 50 x 50 pixels) on HRF values was assessed in ten subjects. HRF parameters were calculated (50 x 50 pixels) for 150 eyes of 150 subjects. To assess short-term reliability, measurements were repeated five times in ten subjects. RESULTS: With 50 x 50 pixels the location of the frame had no influence on HRF values. Reliability was > 90%. Values were significantly higher (p < 0.001) in the superficial than in the deeper papillary layers. The correlation between HRF parameters was good (r2 > 0.85). CONCLUSIONS: A low magnification (5 degrees x 20 degrees) and a 50 x 50 frame allows a global assessment of HRF parameters at the papilla with high reliability. In healthy eyes, the HRF values are influenced by the level where measurements are made at the papilla. This might be of importance in glaucoma patients with excavated papilla.

Effect of carbogen, oxygen and intraocular pressure on Heidelberg retina flowmeter parameter 'flow' measured at the papilla.

The aim of the study was to evaluate whether the Heidelberg retina flowmeter (HRF), a new device for retinal and anterior optic nerve blood flow assessment, can gauge, at least semiquantitatively, a known effect such as an increase in optic nerve blood flow by hypercapnia or a decrease in optic nerve blood flow by hyperoxia or high intraocular pressure (IOP). Measurements with the HRF were obtained at the papilla of three groups of 5 young healthy subjects (1) at baseline and after breathing 5% carbogen, (2) at baseline and after breathing 100% oxygen and (3) at baseline and after increasing IOP to 20 and 50 mm Hg. The changes in the value of the HRF parameter 'flow' were analyzed by means of a paired Student's t test. Breathing 100% oxygen for 7 min resulted in a statistically significant decrease of 34.7+/-2.5% (mean+/-SEM) in HR parameter 'flow' (p < 0.01) at the papilla. Breathing 5% carbogen for 7 min resulted in a statistically significant increase of 18.3+/-2.6% in HRF parameter 'flow' (p = 0.024). Increasing IOP to 20 mm Hg did not result in a statistically significant change in HRF parameter 'flow' (-9.6+/-7.4%; p = 0.13). Increasing IOP from 20 to 50 mm Hg, however, resulted in a statistically significant decrease of 40.1+/-6.6% in HRF parameter 'flow' (p = 0.003). With the applied stimuli, the HRF parameter 'flow' changed in the expected direction, i.e. an increase with hypercapnia and a decrease with hyperoxia or high IOP. The simplicity of use of the HRF instrument suggests that it might be well suited for a non-invasive, at least semiquantitative, assessment of changes in blood flow at the papilla.

Measurement of intraocular pressure with a modern noncontact tonometer.

PURPOSE: To evaluate the intraocular pressure (IOP) in a population without known glaucoma as measured by means of a noncontact tonometer (NCT). METHODS: IOP values of 842 persons, measured by means of a Pulsair 2000 NCT (Keeler Instruments, Inc., Broomhall, Pennsylvania) by 5 investigators were evaluated. Three consecutive measurements were taken first on the right eye and then on the left eye in each subject. Topical anesthesia was not used. RESULTS: The distribution of the measured IOP values was significantly different from a normal distribution. The median IOP was 15.0 mmHg (lower quartile/ upper quartile 12.5/17.2). There were no differences in IOP values between male and female subjects or between right and left eyes. There was no correlation between age and IOP values. Ninety percent of the subjects had an IOP within a range of 9-24 mmHg in both eyes. Among the examined subjects, the IOP was above 24 and 21 mmHg in 4,6 and 11%, respectively, in at least one eye. The median range of consecutive IOP measurements in one eye was 3 mmHg (lower quartile/upper quartile 2.0/4.0). The median interocular IOP difference was 1.7 mmHg (0.7/2.7). The median individual coefficient of variation (CV) values were 10.0% for the right eyes, -10.8% for the left eyes. Among the 5 different examiners, the IOP values, range of 3 consecutive IOP readings in one eye, interocular asymmetry and CV values were statistically comparable. CONCLUSION: The Pulsair 2000 NCT is very simple to use and its handling is mostly independent of the operator. The results of the present investigation might be of some value for future screening programs.

Interaction between silicone oil and silicone intraocular lenses: an in vitro study.

The objective of this study was to examine the interaction between silicone oil and silicone intraocular lenses (IOLs) in vitro. Six types of silicone IOLs were placed in silicone oil (1000 or 5000 centistokes) for 1 minute, 7 days, and 420 days. Slit-lamp examination, target photographs, and opacity measurements were performed. Optical measurements were repeated in a balanced salt solution after removal from the oil. The IOL surface was examined through scanning electron microscopy, and surface irregularities underwent x-ray spectroscopy. No changes were observed while the IOLs were stored in silicone oil, but in the balanced salt solution, the IOLs were observed to have a layer of silicone oil droplets that reduced the optical quality. Scanning electron microscopy showed that oil-coated foreign body particles were simulating IOL surface defects. After ultrasonic cleaning with ethanol, the oil layer was broken, and no damage to the IOL surface could be detected. The length of exposure to silicone oil, the type of oil, and the type of IOL were found to have no bearing on the interaction between silicone oil and silicone IOLs. Although no surface damage is incurred by silicone IOLs from silicone oil, the reduction in optical quality and fundus view due to remnant oil droplets seems to indicate that complex cases requiring silicone oil injection may contraindicate IOLs made of silicone.

Evaluation of the Brusini glaucoma staging system for follow-up in glaucoma.

BACKGROUND: Brusini developed a new interpretation system for Octopus and Humphrey automated perimeters that is based on mean defect (MD) and corrected loss variance (CLV) or corrected pattern standard deviation (CPSD). This study tested the performance of Brusini's glaucoma staging system (GSS) in staging and follow-up. METHODS: Retrospectively, 610 visual fields of 64 eyes of open-angle glaucoma patients were analyzed with Brusini GSS and compared with Aulhorn-Karmeyer stages and by PeriData 7.0 trend analysis. RESULTS: Follow-up was comparable to PeriData 7.0 trend analysis in 97%. Change was observed in 41% of eyes, i.e., initial improvement (19% eyes), deterioration (16%), and after an initial improvement, either deterioration (11%) or a stable period (5%). No change was seen in 59% of the eyes, of which 30% showed small and 19% high long-term fluctuation (LF) due to fatigue effect, poor cooperation of patient, impaired reliability, or short-term fluctuation (SF) greater than 1.7 dB. However, for 8% of the eyes there was no apparent reason for high LF. CONCLUSIONS: Brusini GSS is useful for staging and recommended for follow-up evaluation of visual fields in glaucoma.

Regression of rubeosis iridis after trabeculectomy combined with mitomycin-C.

The authors report two cases in which severe rubeosis iridis regressed after trabeculectomy with intraoperative application of mitomycin-C. Several days after the operation, the vessels were no longer perfused. Only white, empty, "ghost" vessels were visible. This phenomenon was observed in one case with well-controlled intraocular pressure (IOP) after surgery, as well as in a case in which IOP rose again to high preoperative values. The authors conclude that the regression of the rubeosis may be caused by a local, intraocular pharmacologic side effect of mitomycin-C, not by the drop in IOP alone.

Physiological influence on ocular photometry. A review.

During the development of the ocular photometer (OPM) since 1983, we have considered several physical and physiological factors that could potentially influence the measurement and its results. Attention has been given to respiratory, circulatory, and intraocular pressure provocations, and numerous publications document the influences or lack thereof. Most recently, the authors conducted a simple reproducibility study with only 1 observer and 1 subject. Measurement of the same 2 retinal sites during a 3-week period yielded no statistically significant differences, even under relatively extreme temperature conditions. Thus, changes in readings with the OPM may be considered due to variations within the eye, such as cataract. Thus, increase in lens density may be directly and correctly expressed by dual-site measurement of retinal brightness, resulting in the contrast transfer ratio.

Visaline in the treatment of age-related macular degeneration: a pilot study.

Age-related macular degeneration (AMD) is the main cause of a reduction in visual acuity in patients over the age of 65 years. A positive influence of medical treatment (i.e. with vitamins and trace minerals) has been suggested but remains unproven. In this randomized, double-blind study, 20 patients in an early stage of AMD were included. Over a period of 6 months, 9 patients were treated with Visaline and 11 with a placebo. The effect of the treatment was not statistically different between the two groups, admittedly small in number, in terms of visual and retinal acuity, color vision, and contrast sensitivity. Despite the lack of such measureable differences, the patients' own subjective assessments, however, were much better in the Visaline-treated group. Due to the short duration of the observation time, we can not comment on a possible long-term effect.

Intraocular pressure decrease after local ocular cooling is underestimated by applanation tonometry.

BACKGROUND: The effects of intense systemic or local cooling on aqueous humor dynamics in animals are an increased total outflow facility and a decreased aqueous flow. Few studies suggest that only vasoconstriction of arteriolar segments of the episcleral vasculature may be the cause for a decrease in intraocular pressure after local cooling in humans. Because corneal changes may have influenced such studies, the effect of local cooling was assessed in normal subjects. METHODS: Intraocular pressure and corneal thickness were measured in 18 healthy human subjects before and after exposure of the right eye to both, an air stream at 20 degrees C, and an air stream at 0 degrees C. RESULTS: No significant changes in IOP or corneal thickness occurred under 20 degrees C conditions. After local cooling, the mean corneal thickness increased from 0.52 +/- 0.01 mm to 0.57 +/- 0.02 mm (p < 0.001). Mean intraocular pressure decreased from 13.8 +/- 2.9 mmHg to 12.9 +/- 3.1 mmHg (p < 0.026). The observed decrease in IOP correlated significantly but negatively (R = -0.53; p = 0.024) with the increase in corneal thickness, indicating that the cooling effect on IOP may be rather underestimated. CONCLUSION: The eye is very sensitive to local cooling effects, which may, however, partially be masked by changes in corneal thickness.

Anterior chamber depth and pigment dispersion syndrome.

Pigment dispersion syndrome is thought to be the result of iris pigment abrasion by zonular packets. This condition primarily affects young males with myopia, perhaps because of deeper anterior chambers that make such pigment abrasion more likely. Males have been described to have larger eyes and deeper anterior chambers. This constellation, however, does not explain conclusively the predominance of males who have pigment dispersion syndrome. We, therefore, studied whether anterior chambers in males are deeper than those in females, not only in absolute measures but also relative to the axial length. Our results of 60 patients disclosed that men had not only significantly deeper mean absolute anterior chambers (men, 3.22 +/- 0.42 mm; women, 2.88 +/- 0.38 mm; P = .002) but also deeper mean relative anterior chambers (men, 13.54% +/- 1.66%; women, 12.45% +/- 1.2%; P = .013). No significant differences existed between genders with regard to lens thickness, extent of ametropia, and visual acuity. Thus, normal developmental differences between genders may predispose males for deeper anterior chambers and, consequently, for pigment dispersion syndrome.

Longterm visual field follow-up of glaucoma patients treated with beta-blockers.

In a prospective, randomized, double-masked study, 44 patients with primary open-angle glaucoma were treated either with 0.5% betaxolol or 0.5% timolol in both eyes twice daily. Twenty-nine patients could be followed up for 48 months. Seventeen of these patients were treated with betaxolol and 12 with timolol. Each examination included visual field measurements with an Octopus automated perimeter 201 (Program G1), intraocular pressure measurement, funduscopy, as well as pulse and arterial blood pressure measurements. Both drugs lowered in the intraocular pressure. This reduction was slightly but not statistically significantly higher in the timolol-treated group. However, the visual fields improved more in the betaxolol group. Patients treated with betaxolol had significantly smaller averaged mean defects (p < 0.05) and higher averaged mean sensitivities (p < 0.05, Wilcoxon rank score text) than did timolol-treated patients at months 3, 6, 12, and 18. Thereafter, the difference between the two groups was not statistically significant in this relatively small sample size. For betaxolol patients the cumulative area-under-the-curve analysis for the worse eye yielded significantly larger mean sensitivities beyond month 12 (exception: month 30; p < 0.05) and significantly smaller mean defects beyond month 6 (p < 0.05).

High-resolution perimetry of the central visual field.

The Octopus Program M1 was designed for the detection/follow-up of central or paracentral visual field defects in patients with neurological disorders or with macular or perimacular diseases. Within the central 25 degrees visual field, 59 test locations provide a resolution of < or = 1.4 degrees. The differential light sensitivity is measured with 'Octopus normal strategy', i.e. a 4/2/1 staircase procedure. The Program M2X has 81 test locations in the central 10 degrees, giving even higher resolution (< or = 0.7 degrees) of the central visual field. Both programs have 2 phases, the second being a re-test. Program M2X's phases are divided into 4 stages and allow interruption anytime.