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Biomedical subjects

N Strong

Publications and source records attributed to N Strong.

12 recordsLinked to original sources
PubMed1999

Use of animal testing for evaluating glycoconjugate vaccine immunogenicity.

Most animal species respond with high antibody levels to polysaccharide antigens after they have been covalently linked to a protein carrier, converting a T-cell independent to a T-cell dependent antigen. This chemical modification has enabled the development of glycoconjugate vaccines for Haemophilus influenzae type b, Neisseria meningitidis, and multivalent Streptococcus pneumoniae. This new generation of vaccines can be well characterized physically and chemically to ensure consistent vaccine manufacture. Such analytical tests provide an alternative to animal models for Quality Control Laboratories; biological models can be difficult and costly to develop and use on a routine basis. If animal tests are used, they need to be refined, defined, and validated for their intended purpose.

Animal Testing Alternatives↗
PubMed1993

Retrobulbar phenol injection in blind painful eyes.

Retrobulbar phenol injection was used as a neurolytic to manage blind chronically painful eyes in ten patients. The cause of the blind painful eye was absolute glaucoma in eight of the ten eyes. We used 1.5mL of 1:15 (6.7%) aqueous phenol solution in each case. None of the patients experienced any pain from the injection. Seven patients obtained complete pain relief after the procedure, and one patient had some improvement. We found a range of duration of pain relief of 4.5 to 48 months (mean, 15 months), which compares favorably with retrobulbar alcohol injection. We believe retrobulbar phenol injection is preferable to alcohol. It has the advantage of being less painful during injection because of its local anesthetic properties.

Adult↗
PubMed1992

Interferometer assessment of potential visual acuity before YAG capsulotomy: relative performance of three instruments.

The accuracy of white light and laser interferometers in predicting visual acuity after YAG laser capsulotomy was compared. 42 eyes of 41 patients were tested with both a Haag-Streit (Lotmar) white light interferometer and a Rodenstock laser interferometer, and 14 were also tested with a Site white light machine. The laser interferometer predicted a final visual acuity to within one line of that actually achieved in 93%, and to within two lines in 98%, whereas for the Haag-Streit these figures were 64% and 81%, and for the Site 77% and 92%. In patients with poor initial visual acuity, the difference in the relative performance of the two instruments was increased further. When interferometry was repeated after capsulotomy, the values obtained with all instruments agreed closely with Snellen acuity. This difference in predictive accuracy shows that capsular thickening causes a greater degree of optical degradation of the image produced by a white light interferometer than occurs when a laser interferometer is employed.

Adult↗
PubMed1992

Occlusion for amblyopia: a comprehensive survey of outcome.

The results of a long term follow up of all patients from a single health district started on occlusion for amblyopia in 1983 are reported. Three hundred and sixty-eight patients started treatment, their average age was four years seven months, the average amount of daily occlusion was 1.5 hours and the average length of follow up was 31 months. 37% of cases achieved a final visual acuity of 6/9 or better and another 33% a visual acuity of 6/12 or 6/18.23% did not achieve 6/18 and treatment of these patients was regarded as failure. Data for the remainder (7%) were incomplete. The success rate of occlusion treatment varied little with the age of starting treatment. The group with combined strabismus and anisometropia responded least well to treatment.

Age Factors↗
PubMed1992

Ophthalmic day case surgery: the role of a dedicated day case unit.

A study was undertaken to examine all cases admitted to a new ophthalmic surgical day case unit during its first six months of operation. This paper describes the experience gained in establishing the unit, including operational management, and outlines the factors contributing to the unit's success. A quarter of the patients usually admitted as inpatients have been treated in the day unit, and day case surgery rarely results in unplanned inpatient admission, or subsequent readmission. Provided strict admission criteria are followed, the results show that this facility can accommodate a wide range of common ophthalmological procedures, and that general anaesthesia is compatible with day case management.

Ambulatory Surgical Procedures↗
PubMed1991

The incidence and prevalence of amblyopia detected in childhood.

We present incidence estimates for amblyopia using data from a study of a cohort of 364 children from a single English county who were referred during 1983 for occlusion therapy. Using a criterion of a visual acuity of 6/12 or worse to define amblyopia, we estimate that 3.0% of the county's children develop the condition. Successful treatment of some of these children means that 1.9% will remain amblyopic as adults.

Adolescent↗
PubMed1991

Colour contrast sensitivity changes caused by peripheral retinal laser photocoagulation.

Macular phototoxicity is known to occur with laser use, and there is evidence that the wavelength of the light used influences this effect. In this study, a computer based colour contrast sensitivity test was used to assess the immediate macular effects of photocoagulation of peripheral flat retinal holes in otherwise normal retinas, using blue-green (488 and 514 nm), yellow (577 nm), orange (595 nm) or red (647 nm) laser light. The laser aiming beam was not allowed to traverse the macula at any stage during treatment. No protan or deutan axis threshold changes were noted in the 17 patients tested irrespective of the laser wavelength used. Tritan axis sensitivity was significantly reduced one hour after treatment with the blue-green laser, but no tritan axis change was found after treatment with longer wavelength lasers. The effect was no longer present the day after treatment in the subjects tested. The results show that even peripheral retinal treatment with blue-green laser can cause acute macular phototoxicity.

Color Perception↗
PubMed1990

[Color vision disturbance in laser operators and patients: comparison of argon and dye lasers].

Color contrast sensitivity was measured in laser operators before and after laser sessions. The tritan threshold was elevated after the sessions in all laser operators who had used argon (blue-green) lasers. No change was observed when lasers with longer wave-lengths were used. Elevation of the tritan threshold to above-normal levels was observed even before laser sessions. The thresholds remained increased even when the laser operator did not use a laser for 3 weeks. Thus, it appears that the damage caused by the argon blue-green laser is cumulative. Elevated tritan thresholds were also observed in patients with peripheral retinal breaks who were treated with an argon (blue-green) laser.

Adolescent↗
PubMed1989

Using argon laser blue light reduces ophthalmologists' color contrast sensitivity. Argon blue and surgeons' vision.

Color contrast sensitivity was measured in laser operators before and after laser use. After argon blue-green laser treatment sessions, sensitivity was reduced for colors lying along a tritan color-confusion line for several hours. This acute effect is due to specular "flash-backs" from the aiming beam off the surface of the contact lens. It is caused only by argon 488-nm light, when the aiming beam intensity is high. In addition, a correlation has been demonstrated between the number of years of laser experience and a chronic reduction in tritan color contrast sensitivity. It is suggested that repeated acute changes caused by the argon lasers may cause cumulative effects and produce a chronic threshold elevation. A simple method of eliminating the acute effect is documented.

Adult↗
PubMed1988

The acute red eye.

Explore the source record for details and available documents.

Acute Disease↗
PubMed1981

Analysis of monocular optokinetic nystagmus in normal and visually deprived kittens.

The asymmetry of monocular OKN was assessed in normal, monocularly deprived (non-deprived eye) and strabismic cats. No significant differences were observed between the responses of these 3 groups. In young kittens, the gain of OKN for nasalward stimulus movement was larger than that for temporalward. This asymmetry declined to a low residual level by about one year of age. Neurophysiological recordings indicated that the symmetry of OKN is not related to cortical binocularity.

Aging↗