Characteristics of retinal-binding proteins from the honeybee retina

Spectrophotometric studies were performed on two water soluble retinal-binding proteins isolated from honeybee retina. Both pigments, B and C, absorb maximally at about 440 nm. Pigment B is bleached by light to a photoproduct with λ_max at about 370 nm. This pigment reacts with hydroxylamine in the dark to form a product with an absorbance maximum at 360 nm, whereas with cyanoborohydride it reacts only in the light forming a product with λ_max at about 330 nm. Irradiation of pigment C also leads to the formation of a photoproduct with λ_max at about 370 nm but, in contrast to that of pigment B, it reconverts to its 440 nm-form during the following dark period. The results obtained by changing the pH of the extracts support the hypothesis that all-trans retinal binds to each protein via a Schiff base linkage (pK of 8.4). The data are discussed with relation to the physiological role pigment B could play in the visual cycle of honeybees.     

Update on the ophthalmic management of facial paralysis

Bell's palsy is the most common neurologic condition affecting the cranial nerves. Lagophthalmos, exposure keratopathy, and corneal ulceration are potential complications. In this review, we evaluate various causes of facial paralysis as well as the level 1 evidence supporting the use of a short course of oral steroids for idiopathic Bell's palsy to improve functional outcomes. Various surgical and nonsurgical techniques are also discussed for the management of residual facial dysfunction.     

Early receptor potentials and comparison of the electrical properties of median and lateral photoreceptors of the barnacle

Extracellular recordings of the early receptor potential (ERP) from Balanus eburneus revealed that the response of the median photoreceptor is faster by a factor of two than that of the lateral photoreceptor. This difference is similar to that shown for late receptor potentials (LRP) from both types of photoreceptor. A model for the photoreceptors is given which takes the electrical properties of the microvillar and perikaryon membrane areas as determining the time courses of the ERP responses. The perikaryon areas emerge with a specific membrane resistance of 1000 Ωcm², a value commonly found for nerve membranes, and as the dominant cell resistance. The microvillar areas have a specific membrane resistance of about 25 kΩ cm², and their large surface areas determine the large capacities of the cells. A specific capacitance of about 1 μF/cm² was measured for both types of membrane in median and lateral photoreceptors. The difference in ERP time course of the two types of photoreceptors is attributed to different proportioning of microvillar and perikaryon areas. Good agreement between calculated and observed ERP responses was found.     

Evaluating the efficacy of an educational ergonomics module for improving slit lamp positioning in ophthalmology residents

Objective

To characterize changes in body positioning while performing a standardized slit lamp examination after exposure to an educational module on ergonomics.

Phosphorylation of H2O2-treated lens Na+, K+-ATPase

It has been previously shown that H₂O₂ inhibits lens ⁸⁶Rb influx and results in modification of Na⁺,K⁺-ATPase with respect to ATP hydrolysis. The effect of H₂O₂ on ATP hydrolysis was further investigated using [γ-³²P]-ATP to examine the Na⁺,K⁺-ATPase phosphorylated intermediate. A Na⁺-dependent phosphorylated polypeptide with an apparent molecular weight of approximately 100 000 was detected in all lens preparations, irrespective of H₂O₂ treatment. Similar results were observed for partially purified Na⁺,K⁺-ATPase from bovine kidney, porcine brain and canine kidney.     

眼睑全层裂伤122例的临床特点及手术方法

目的 探索眼睑全层裂伤的临床特点及急诊手术方法.方法 2008年1月至2010年12月我院接受治疗的眼睑全层裂伤122例.回顾分析其损伤的原因、合并外伤及治疗效果.结果 122例的148处眼睑全层裂伤,经急诊一期缝合整复术后,伤口全部Ⅰ期愈合,愈合率为100％.术后并发症发生率为13.9％.对于所有并发症均给予二期手术处理,二期手术后随访1年,外观及功能均恢复良好.结论 全层裂伤的主要损伤原因为车祸,多合并其他眼组织损伤,及时准确的进行Ⅰ期修复,可获得较好的治疗效果.     

Reproducibility of minimum rim width and retinal nerve fibre layer thickness using the Anatomic Positioning System in glaucoma patients

ObjectiveTo determine the test?retest repeatability of minimum rim width and retinal nerve fibre layer thickness measurements obtained by spectral-domain optical coherence tomography using the Anatomic Positioning System protocol in glaucoma patients and controls. Also, to assess the ability of the minimum rim width and retinal nerve fibre layer thickness to diagnose glaucoma in 2 circular peripapillary locations.MethodsSpectral domain optical coherence tomography scans of the optic nerve head were obtained twice during the same visit using the Anatomic Positioning System eye-tracking protocol. The minimum rim width and retinal nerve fibre layer thickness were measured at 3 circular diameters (3.5 mm, 4.1 mm, and 4.7 mm). Intraclass correlation coefficients and area under the receiver operating characteristic were calculated for these parameters.ResultsA total of 36 glaucomatous eyes and 59 control eyes were included in the analysis. The intraclass correlation coefficients of minimum rim width and retinal nerve fibre layer thickness global measurement for 3.5 mm and 4.1 mm circles ranged between 0.98 and 1.00 and for 4.7 mm circle was between 0.76 and 1.00. The minimum rim width had an area under the receiver operating characteristic of 0.97, while the retinal nerve fibre layer thickness measurements had an area under the receiver operating characteristic of 0.95, 0.95, and 0.96 for the 3.5 mm, 4.1 mm, and 4.7 mm circles, respectively.ConclusionsThe minimum rim width and retinal nerve fibre layer thickness measurements using the Anatomic Positioning System protocol had overall excellent reproducibility and diagnostic performance. Using this protocol and the novel minimum rim width parameter may be useful in more accurate diagnosis and follow-up of patients with glaucoma.