Long-term success of argon laser peripheral iridoplasty in the management of plateau iris syndrome

OBJECTIVE: To document the long-term effect of argon laser peripheral iridoplasty (ALPI) in eyes with plateau iris syndrome. DESIGN: Retrospective, noncomparative, interventional case series. SETTING: New York Eye and Ear Infirmary. METHODS: The charts of all patients with plateau iris syndrome treated with ALPI from 1982 to 1991 and subsequently followed for 6 or more years were retrospectively reviewed. Patients with lens-related mechanisms contributing to angle closure (e.g., phacomorphic or malignant glaucoma) were excluded. MAIN OUTCOME MEASURES: Necessity for repeat ALPI and/or any additional means of intervention. RESULTS: A total of 26 ALPI procedures were performed in 23 eyes of 14 patients (4 men, 10 women). The mean age was 61+/-8.7 years. The mean follow-up was 78.9+/-8.0 months (range, 72-188 months). The angle in 20 of 23 (87.0%) eyes remained open throughout the entire follow-up period after only 1 treatment with ALPI. In 3 eyes, there was gradual reclosure of the angle 5 to 9 years after initial ALPI, but they were readily reopened and maintained open by a single repeat treatment. No filtration surgery was necessary in any eye during follow-up. CONCLUSIONS: ALPI is highly effective in eliminating residual appositional closure after laser iridotomy caused by plateau iris syndrome. The effect is maintained for years, although a small proportion of patients might require retreatment.     

Pressure phosphene self-tonometry: a comparison with goldmann tonometry in glaucoma patients

PURPOSE: To evaluate whether the pressure phosphene tonometer (PPT) is suitable for self-tonometry in patients with glaucoma or ocular hypertension. METHODS: This was a prospective comparative study of 102 eyes of 102 patients with chronic glaucoma or ocular hypertension. Intraocular pressure (IOP) measurements by the Goldmann tonometer (GT) were compared with self-measured readings with the PPT. Patients evaluated the ease of home use of the PPT. The last 15 patients were asked to stop their glaucoma medications, and the ability of the PPT to detect an elevated IOP during self-tonometry was studied. RESULTS: The mean +/- SD difference between PPT and GT readings was -0.24 +/- 1.57 mm Hg. Comparing the PPT with the GT, 86% of the readings were within +/- 2.0 mm Hg, and 91% were within +/- 3.0 mm Hg. Spearman's correlation coefficient was 0.91. A Bland-Altman plot showed that the 95% limits of agreement between the two methods lay between 2.90 and -3.38 mm Hg. Within-subject coefficients of variation for the GT and the PPT were 4.4% and 7.3%, respectively. In detecting an elevated IOP of more than 21 mm Hg, the sensitivity and the specificity of the PPT were 92.3% and 98.6% respectively. The mean satisfaction score for home use of the PPT was 87.4 +/- 16.3 (maximum 100). CONCLUSIONS: With proper training and technique, self-tonometry with the PPT appears to be accurate up to at least 25 mm Hg and is reproducible. The PPT was sensitive and specific in detecting an elevated IOP of more than 21 mm Hg. As patients were expected to seek ophthalmic care before the self-measured IOP reaches 25 mm Hg, the PPT may have a value for self-monitoring. Patients rated the PPT as satisfactory for home use. Because the PPT is portable and relatively inexpensive and requires no topical anesthesia or direct contact with the eyeball, it may have potential as an instrument for home self-tonometry.     

Vestibulo-oculomotor behaviour in rats following a transient unilateral vestibular loss induced by lidocaine

The effects of a transient vestibular nerve blockade, achieved by intra-tympanic instillation of lidocaine, were studied in rats by recording horizontal eye movements in darkness. Evaluation of the dose-response relationship showed that a maximal effect was attained with a concentration of 4% lidocaine. Within 15 min of lidocaine instillation, a vigorous spontaneous nystagmus was observed which reached maximal frequency and velocity of the slow phase after about 20 min. Subsequently, the nystagmus failed for approximately half an hour before it reappeared. This could be avoided by providing visual feedback in between the recordings in darkness or by a contralateral instillation of 2.5% lidocaine. It is suggested that the failure reflects an overload of the vestibulo-oculomotor circuits.

After recovery from the nerve blockade, when the gaze was stable, dynamic vestibular tests were performed. They revealed that a decrease of the slow phase velocity gain and the dominant time constant during, respectively, sinusoidal- and step stimulation toward the unanaesthetised side, had developed with the nerve blockade. These modulations were impaired by a nodulo-uvulectomy but not by bilateral flocculectomy, which is consistent with the concept of vestibular habituation.

A GABA_B receptor antagonist, CGP 56433A, given systemically during the nerve blockade, aggravated the vestibular asymmetry. The same effect has previously been demonstrated in both short- (days) and long-term (months) compensated rats, by antagonising the GABA_B receptor.

In summary, this study provides the first observations of vestibulo-oculomotor disturbances during the first hour after a rapid and transient unilateral vestibular loss in the rat. By using this method, it is possible to study immediate behavioural consequences and possible neural changes that might outlast the nerve blockade.     

New plasmid-borne antibiotic resistance gene cluster in Pasteurella multocida

A new antibiotic resistance gene cluster comprising genes for sulfonamide (sul2), streptomycin (strA-strB), and tetracycline [tetR-tet(H)] resistance was detected on plasmid pVM111 from Pasteurella multocida. The tetR-tet(H) gene region was inserted between sul2 and strA, possibly by illegitimate recombination. Two potential recombination sites of 18 and 25 bp were identified.     

Bilateral diffuse lamellar keratitis following bilateral simultaneous versus sequential laser in situ keratomileusis

AIM: To determine the difference in the incidence of bilateral diffuse lamellar keratitis (DLK) in patients undergoing simultaneous versus sequential laser in situ keratomileusis (LASIK) as an indication of intrinsic risk for inflammation. METHODS: A retrospective non-comparative case series of 1632 eyes that had undergone bilateral, simultaneous or sequential LASIK between April 1998 and February 2001 at a university based refractive centre by three surgeons. All cases that developed clinically evident DLK were identified and reviewed. In order to identify isolated cases and exclude those caused by environmental factors, when more than one patient in a given session developed DLK, the session was excluded. The main outcome measure was the incidence of unilateral and bilateral isolated, non-epidemic DLK. RESULTS: Of 1632 eyes, 126 eyes (7.7%) of 107 patients developed at least grade 1 DLK. In six operating sessions, DLK was observed in more than one patient per session, and on this basis 13 patients were excluded. 16 of the 94 remaining patients developed DLK in both eyes (17.0%). Six of 41 patients (14.6%) in the simultaneous group, versus 10 of 53 patients (18.9%) in the sequential group developed bilateral DLK (p >0.5). CONCLUSION: In isolated, non-epidemic bilateral DLK, a similar incidence was observed regardless of whether the surgery was simultaneous or sequential, suggesting an underlying intrinsic cause for DLK.     

Role of the alpha-chemokine stromal cell-derived factor (SDF-1) in the developing and mature central nervous system

alpha-chemokines, which control the activation and directed migration of leukocytes, participate in the inflammatory processes in host defense response. One of the alpha-chemokines, CXCL12 or stromal cell-derived factor 1 (SDF-1), not only regulates cell growth and migration of hematopoietic stem cells but may also play a central role in brain development as we discuss here. SDF-1 indeed activates the CXCR4 receptor expressed in a variety of neural cells, and this signaling results in diverse biological effects. It enhances migration and proliferation of cerebellar granule cells, chemoattracts microglia, and stimulates cytokine production and glutamate release by astrocytes. Moreover, it elicits postsynaptic currents in Purkinje cells, triggers migration of cortical neuron progenitors, and produces pain by directly exciting nociceptive neurons. By modulating cell signaling and survival during neuroinflammation, SDF-1 may also play a role in the pathogenesis of brain tumors, experimental allergic encephalitis, and the nervous system dysfunction associated with acquired immunodeficiency syndrome.     

筛查和诊断糖尿病的新观点

美国约有30％的糖尿病患者（约620万人）被漏诊。超过25％的新诊断糖尿病患者已经患有糖尿病视网膜病变或出现微量白蛋白尿，这意味着患者在2型糖尿病发病和确诊之间被“忽视”了7年。有时发现在糖尿病前期，即空腹血糖（FPG）略有偏高（IFG，空腹血糖受损）或口服葡萄糖耐量试验（OGTT）略有偏高，甚至已存在微血管和大血管并发症。     

青翘和老翘中连翘苷的含量测定

目的：测定青翘与老翘中连翘苷含量。方法：。双波和薄层扫描法。结果：表翘中连翘苷含量为０．０７６％;老翘中仅占０．０１２％,与报道的青翘中连翘酯苷含量高于老翘的实验结果相同,结论;本文结果与文献报道的就抗菌效价而言青翘优于老翘的结论吻合,目前市售药材青老翘混杂,有必要进行深入研究,确定合理的采收期。