Long-term surgical and visual outcomes in primary congenital glaucoma: 360 degrees trabeculotomy versus goniotomy.

PURPOSE: To compare the visual outcome and refractive status of children with primary congenital glaucoma who underwent 360 degrees trabeculotomy or goniotomy as an initial surgical procedure. METHODS: This retrospective study describes 24 eyes (15 patients) with primary congenital glaucoma that underwent 360 degrees trabeculotomy as the initial procedure and 40 eyes (23 patients) that underwent goniotomy as the initial procedure. Inclusion criteria were: (1) diagnosis of primary congenital glaucoma and initial angle surgery before 1 year of age, (2) no other ocular or systemic diseases, (3) 360 degrees trabeculotomy or goniotomy as the first surgical procedure, and (4) ability to obtain an Allen or Snellen visual acuity. A postoperative vision of 20/50 or better was considered good. Surgical success was defined as an intraocular pressure (IOP) less than 22 mm Hg with or without medication and without evidence of a progressive optic neuropathy. RESULTS: The IOP was successfully controlled in 92% of eyes in the trabeculotomy group and in 58% of eyes in the goniotomy group (P =.004). Of eyes in the trabeculotomy group, 79% had vision of 20/50 or better compared with 53% in the goniotomy group (P =.03). High myopia was more prevalent in the goniotomy group, but this difference was not statistically significant (P =.16). A poor visual outcome was associated with failure of the angle surgery or poor compliance with follow-up and amblyopia therapy. CONCLUSION: For primary congenital glaucoma, 360 degrees trabeculotomy is a highly effective procedure that results in excellent pressure control and is at least as successful as multiple standard procedures. In this study, 360 degrees trabeculotomy resulted in better vision than what is reported in the literature for standard angle procedures.

Brimonidine 0.2% versus dorzolamide 2% each given three times daily to reduce intraocular pressure.

PURPOSE: To evaluate the efficacy and safety of brimonidine compared with dorzolamide given three times daily as monotherapy in patients with primary open-angle glaucoma or ocular hypertension. METHODS: In a double-masked, multicenter, crossover comparison in 40 patients, qualified patients were washed out from their previous medication and randomized to dorzolamide 2% or brimonidine 0.2% for the first 6-week treatment period. Patients then were washed out for 2 weeks and started on the opposite medication for the second 6-week period. RESULTS: Baseline intraocular pressure for all 40 subjects (76 eyes) was 24.1 +/- 2.0 mm Hg. This study found that the 8:00 AM trough intraocular pressure after 6 weeks of therapy for dorzolamide was 20. 7 +/- 3.1 mm Hg and for brimonidine 20.8 +/- 3.2 mm Hg (P =.99). The peak intraocular pressure (2 hours after dosing) for dorzolamide was 18.6 +/- 3.4 mm Hg and for brimonidine 17.8 +/- 2.7 mm Hg (P =.10 ). Dorzolamide caused more stinging upon instillation (P <.01) and brimonidine more itching (P =.01). No statistical differences existed between groups for systemic adverse events. Six patients, all on brimonidine, were discontinued from a treatment period early. Of these, two were discontinued for inadequate pressure control, two with dizziness and fatigue, one with ocular pain, and one for lifestyle reasons (P =.07). CONCLUSIONS: This study found similar efficacy and safety between monotherapy treatment with dorzolamide or brimonidine when each was given three times daily to patients with ocular hypertension or primary open-angle glaucoma.

Vaccination of wildlife against rabies: successful use of a vectored vaccine obtained by recombinant technology.

The impact of recombinant technology in veterinary and human medicine can only be hypothesized at this time. The development of vaccines and other biological products that go beyond the abilities of conventional products demonstrates the benefits of this new technology. Raboral V-RG was developed as an alternative rabies vaccine with the novel attribute of being effective by the oral route. Within 10 years after its first application as an experimental vaccine in European, red foxes it developed into a useful tool and is being used to curtail rabies epizootics in three wildlife species in the United States. The use of this vaccine can be considered as monumental in contributing to the control of rabies in species that were at one time considered to be incapable of vaccination in large-scale campaigns.

The relationship and tensions between vertical integrated delivery systems and horizontal specialty networks.

UNLABELLED: This activity is designated for physicians, medical directors, and healthcare policy makers. GOAL: To clarify the issues involved with the integration of single-specialty networks into vertical integrated healthcare delivery systems. OBJECTIVES: 1. Recognize the advantages that single-specialty networks offer under capitated medical care. 2. Understand the self-interests and tensions involved in integrating these networks into vertical networks of primary care physicians, hospitals, and associated specialists. 3. Understand the rationale of "stacking" horizontal networks within a vertical system.

Asymmetric pigmentary glaucoma resulting from cataract formation.

Pigment dispersion syndrome usually manifests bilaterally, and asymmetric involvement is unusual. When asymmetry is present, the eye with greater involvement may have an additional exacerbating condition or the eye with less involvement may be protected. Analysis of such cases should further elucidate the mechanism of the disorder and its development and regression. We examined four patients in whom unilateral cataract formation or extraction was associated with reduced clinical signs of pigment dispersion syndrome in the affected eye. Cataract formation, by inducing relative pupillary block, appears to decrease or prevent the manifestation of pigment liberation.

The relationship between the type A behavior pattern and physiological responsivity: a quantitative review.

Researchers have attempted to specify the process linking Type A behavior to coronary artery disease. Increased cardiovascular and neuroendocrine reactivity in Type A individuals has been proposed as the intervening mechanism. There have been several previous reviews of the research relating Type A behavior to physiological reactivity. The authors' conclusions have been equivocal; some assert that Type A persons are more reactive, whereas others find no evidence for such a conclusion. In this report, meta-analysis, an alternative to the traditional narrative review, was employed to provide a quantitative evaluation of the relationship between Type A behavior and physiological reactivity. Results indicated that: 1) Type As respond to cognitive and psychomotor stimulus situations with greater heart rate and systolic blood pressure responses, 2) this relationship is not evident in females, 3) the relationship is more evident for some cognitive tasks than for others, and 4) the strength of the relationship depends upon the instrument used to assess Type A behavior.

The effects of low-level carbon monoxide exposure upon evoked cortical potentials in young and elderly men.

The neurophysiological effects of acute, low-level carbon monoxide (CO) exposure are not well known. This experiment investigated the effects of a 5% carboxyhemoglobin level upon two indices of neurophysiological function, reaction time and the late positive component of the visual evoked potential in young and elderly men. Results indicated (1) no effects of CO upon any of the neurophysiological indices and (2) greater absorption of CO by young than by elderly men. These results, along with those of other studies, indicate that acute, low-level CO exposure is probably not neurotoxic, in normal, healthy men.

Massive hemorrhage complicating age-related macular degeneration. Clinicopathologic correlation and role of anticoagulants.

Reported are 15 cases of age-related macular degeneration (AMD) complicated by massive subretinal and/or vitreous hemorrhage. Clinicopathologic correlation is presented in four of the seven cases studied histopathologically. Salient histologic findings include: subretinal and subretinal pigment epithelium (sub-RPE) fibrovascular scar in the posterior pole; discontinuities in Bruch's membrane with choroidal neovascularization; extensive hemorrhagic detachment of the RPE and sensory retina; and vitreous hemorrhage. In three cases, a choroidal artery, emerging from breaks in Bruch's membrane, had ruptured walls. The authors have reviewed the previously reported cases of AMD complicated by massive hemorrhage and found that 19% of the patients were taking Coumadin (warfarin) or aspirin treatment when the bleeding occurred. Forty percent had a positive history of systemic hypertension and cardiovascular diseases. Although the occurrence of hypertension is expected in the aged population with AMD, use of anticoagulants or antithrombotics by such patients may predispose them to serious ocular hemorrhagic complications.

The effects of age and attention upon reflex inhibition.

Previous research has suggested that reflex amplitude may be influenced by the direction of attention. The purpose of this investigation was to evaluate the effects of an attention-demanding visual reaction time task upon the elicitation of reflexes and modification of reflexes by an antecedent prestimulus in young and elderly adults. In young subjects, eyeblink inhibition was augmented by the task, yet there was no effect upon overall reflex amplitude. Elderly subjects showed no effect upon reflex inhibition while overall reflex amplitude was diminished by the task, independent of the amount of inhibition. In young subjects, the prestimulus also accentuated the initial decelerative component of a biphasic heart rate response. The reaction time task also served to augment this deceleration. The elderly heart rate response was not affected by the experimental conditions. These results provide evidence that reflex inhibition is modulated by attention. However, the relationship is complex, developmentally sensitive, and involves generalized attentive processes as well as selective attention toward specific stimuli or sensory modalities.

Postoperative suprachoroidal hemorrhage following filtration procedures.

We reviewed the charts of 500 patients who underwent filtration procedures and found ten patients who developed postoperative suprachoroidal hemorrhage (PSCH) following surgery. The incidence (2% overall) is especially high in those patients who were aphakic (6.6%) or who had high myopia (10%). Nine patients developed PSCH within the first four postoperative days. Pain, nausea, and vomiting were common presenting symptoms of PSCH although not invariably present. Postoperative suprachoroidal hemorrhage is related to prolonged hypotonia and inflammation; prevention centers on proper case selection and on avoiding a precipitous rise in postoperative intravascular pressure. Initial treatment consisted of anterior chamber reformation and drainage of suprachoroidal blood, often followed by vitrectomy and scleral buckling procedures. Four eyes (40%) obtained final visual acuities of 20/200 or better, four (40%) were reduced to counting fingers or hand motions, and two (20%) lost all light perception.

Relationships among age, sex, the type A behavior pattern, and cardiovascular reactivity.

Most investigations of Type A behavior and cardiovascular responsivity have used age-homogeneous, male samples. In this study, heart rate (HR) and blood pressure responses were obtained from men and women, age 27 to 70, during mental arithmetic and a visual discrimination task called the Matching Familiar Figures test (MFF). Both tasks produced HR deceleration in Type A women and acceleration in Type B women, responses that decreased with age. Men's responses were not related to Type A behavior or age. Systolic pressure decreased in response to the MFF. This response became larger with age in Type Bs and smaller in Type As. Diastolic pressure also decreased during the MFF. Response amplitude increased with age in Type Bs but was unrelated to age in Type As. The results of this study indicate that the relationship between cardiovascular responding and Type A behavior is complex and may be different for men and women and for persons of different ages.

The late positive component of the evoked cortical potential: application to neurotoxicity testing.

There is an urgent need for efficient, non-invasive measures of neurotoxic insult in humans. The late positive component (LPC) of the event-related cortical potential may be such a measure. The latency and amplitude of the LPC have been related to both memory and response speed, two aspects of behavior which are indicators of neurological status. The LPC has been found to be altered in cases of known neurophysiological insult, including Alzheimer's disease, cerebrovascular disease, Parkinson's disease, surgical and traumatic damage, hyperkinesis, chronic alcoholism, mental retardation, and in schizophrenia. Further development of the LPC as a possible indicator of both the cognitive impairment due to neurotoxic substances as well as the site of neurological damage is warranted.

Differences in the late components of the event-related potential due to age and to semantic and non-semantic tasks.

Recent work in event-related potentials (ERPs) has revealed differences between ERPs elicited during the performance of semantic and nonsemantic tasks. This experiment examined age differences in the late components of the ERP as a function of these tasks. Young and elderly males were presented with 5-word strings on each trial. The subject's task was to decide whether or not the fifth word matched the other four. In one condition, the first 4 words were identical to one another and the fifth word was either the same or different. In the other condition, the first 4 words were different from one another but were drawn from from the same semantic category. The fifth word was either from the category or from a different category. Matches occurred in 15% of the trials and mismatches in 85%. The ERP to the fifth word was analyzed. All ERPs evidenced a late positive component (LPC), the latency of which was greater for the Category task and for mismatches. LPC amplitude was greater in the Identity task. In addition, young subjects' LPC amplitudes were greater for matches than for mismatches, whereas the reverse was true for the elderly. In agreement with previous research, our results indicated that an N400 wave is evident only in response to semantic incongruity and that variables affecting late positive activity seem to be independent of those producing N400. The N400 wave was seen at a greater latency in the elderly. Our results extend previous work (e.g., Kutas and Hillyard 1980) by finding an N400 in a semantic context other than sentences, and in concluding that this component is relatively insensitive to stimulus frequency.

Corneal ulcer due to Achromobacter xylosoxidans.

We report a case of corneal ulcer caused by the opportunistic organism Achromobacter xylosoxidans which developed during chronic topical steroid treatment of an eye with neovascular glaucoma. A. xylosoxidans has probably been underreported as a cause of ocular infection because of confusion between this organism and other Gram-negative organisms, particularly pseudomonas. A. xylosoxidans is resistant to aminoglycosides and some cephalosporins but not carbenicillin. This difference in antibiotic sensitivity patterns between A. xylosoxidans and pseudomonas makes an accurate differentiation between the 2 organisms important. This case was successfully treated after substituting topical carbenicillin for topical gentamicin and amikacin.

Applanation-Schiøtz disparity after retinal detachment surgery utilizing cryopexy.

Previous reports of applanation-Schiøtz disparity following retinal detachment surgery involved patients whose detachments were treated with diathermy and scleral buckling. In 73 patients with retinal detachments treated by cryopexy and scleral buckling, applanation and Schiøtz pressures were measured before and after surgery. In the postoperative period, applanation tension values were significantly higher than Schiøtz values in the operated eyes only; the mean disparity was 6 mm Hg, with a range of 0 to 14 mm Hg. Sex, age, surgical aphakia, and length of time after surgery did not influence the data. Placement of the buckle, rather than extent of cryopexy, appeared to be the main factor in producing this disparity. Ophthalmologists who utilize the Schiøtz tonometer should be aware of the various conditions, including retinal detachment surgery, which produce low ocular rigidity.