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Biomedical subjects

J J Saladin

Publications and source records attributed to J J Saladin.

At least 19 recordsLinked to original sources
PubMed1995

Effects of heterophoria on stereopsis.

The effects of horizontal heterophoria on Howard-Dolman stereopsis scores were investigated in a population of 1765 stereophotogrammetrists with no obvious impediment to binocular vision as determined in a vision screening. Exophoria over the 1 to 7 delta range showed no systematic and statistically valid effect on stereopsis but esophoria did show an effect. In a related population of 1339 stereophotogrammetrists, subjects with as little as 1 delta (+/- 0.5 delta) of vertical heterophoria exhibited a small but statistically significant decrease in stereopsis test scores compared to those with vertical orthophoria. Therefore, a heterophoria had different effects on stereoacuity depending on whether it was in the exo, eso, or vertical direction. An explanation for the difference is proposed using the known dependence of heterophoria and stereoacuity on fixation disparity.

Depth Perception↗
PubMed1988

Effect of vision therapy on stereophotogrammetric profiling--a controlled clinical trial.

A single, masked controlled clinical trial showed that vision therapy improved both the accuracy and repeatability of stereophotogrammetric performance on the profiling task with experienced, visually normal observers. The average fixation disparity measured under working conditions decreased and stereoscopic acuity as measured with a Howard-Dolman apparatus increased. The data suggest that vision therapy is most helpful for those profiling situations in which disparity stimuli are plentiful and stereopsis is the dominant depth cue.

Clinical Trials as Topic↗
PubMed1988

Interpretation of divergent oculomotor imbalance through control system analysis.

Control systems analysis is proposed as a method for understanding the pathophysiology of oculomotor imbalance, thereby permitting better differential diagnosis and more specific treatment. Clinical cases of nonstrabismic divergent deviations, with an emphasis on convergence insufficiency (CI) are presented and explained using conventional optometric diagnostic concepts and fixation disparity (FD) curves with control systems analysis as the central, unifying concept.

Adaptation, Ocular↗
PubMed1986

Convergence insufficiency, fixation disparity, and control systems analysis.

The diagnosis and management of convergence insufficiency (CI) is discussed through a control systems model of the combined accommodation and disparity vergence mechanisms. The emphasis is put on drawing definite clinical implications such that CI can be understood as a logical continuum from its etiology, through symptoms, signs, and finally through its treatment.

Adaptation, Ocular↗
PubMed1983

Fusion lock diameter and the forced vergence fixation disparity curve.

The effect of the diameter of the fusion lock on the forced vergence fixation disparity (FD) curve was investigated because of ambiguity in the results of previous investigations. Data gathered from 20 asymptomatic subjects with normal binocularity showed that the fusion lock diameter had no noticeable effect on the shape of the curve. Further investigations using symptomatic subjects showing large FDs or steep forced vergence FD curves showed that fusion lock diameter did have an effect on the curves of these subjects. The results are interpreted for their clinical implications through a control systems model of the accommodation-vergence interaction.

Adult↗
PubMed1982

Effect of orthoptic procedures on stereoscopic acuities.

Ten stereophotogrammetry students and three graduate photogrammetrists were given 7 weeks of nonspecific orthoptic exercises. The visual systems of these 13 experimental subjects were matched to those of 13 control subjects chosen from the students and staff of the Ferris State College of Optometry. Stereoscopic acuities were determined before and after the training period on both groups using a Wild Stereoplotter, a Howard-Dolman apparatus, and the Keystone Multi-Stereo Test. Stereoscopic acuities as determined on the stereoplotter and the Howard-Dolman apparatus were improved at better than a 0.05 significance level as computed on the Wilcoxon signed rank test and Student's t-test for the difference between two dependent means.

Adult↗
PubMed1980

The relation between night myopia and accommodative convergence.

Accommodation and convergence normally bear a tight relation to each other. To the extent that night myopia is due to an actual change in lens convexity, accommodation in night myopia should be accompanied by a commensurate change in convergence. This prediction was shown to be false because of variability in the convergence mechanism.

Accommodation, Ocular↗
PubMed1978

The effect of 2-hexanone and 2-hexanone metabolites on pupillomotor activity and growth.

Neurotoxic agents such as MBK (2-hexanone) and MBK metabolites were fed in drinking water to guinea pigs. Effects of these solvents on locomotor activity were studied. Dynamic pupillometry indicated that MBK, 2,5-hexanedione and 2-hexanol decreased pupillary response throughout the first five weeks; by the 24th week, all treatment groups showed a greatly impaired pupillary response. From biotransformation studies, it is possible that the 2-hexanol effect on pupillary response may be attributed to its conversion to MBK and/or 2,5-hexanedione. Each of the solvents increased body weight, but decreased locomotor activity. The pupillary changes reported here may serve as an index of solvent exposure in the work environment, if such measurements were to be conducted on workers.

Animals↗
PubMed1978

Association of symptoms with measures of oculomotor deficiencies.

Phoria, vergence, and fixation-disparity were measured at near working distances for a nonclinical sample of 3rd-yr optometry students. A questionnaire divided the sample into 33 symptomatic and 44 asymptomatic subjects. Discriminant analysis was used to determine which clinical measures best predicted the group to which each subject belonged. Sheard's criterion was a good discriminator for exo deviations, and a variant of Percival's criterion was good for eso deviations. Fixation-disparity variables proved to be valuable diagnostically. The best fixation-disparity measures were the curve slope, curve type, and amount of fixation disparity.

Asthenopia↗
PubMed1978

Population study of fixation disparity, heterophoria, and vergence.

Data on phorias, vergences, and fixation disparities were gathered for distant and near viewing conditions from a nonclinical, young adult population. Normative values were computed from the data for analysis and comparison. Our study revealed slightly less exophoria at far and near than Morgan's study, together with large base-out vergence readings. We found proportionately more esophores with exo fixation disparity who require base-in prism to neutralize the fixation disparity than Ogle's studies found.

Adult↗
PubMed1978

Television pupillometry via digital time processing.

A new modification of the dynamic, infrared recording pupillometer of the closed-circuit television type has been developed, utilizing recent developments in high speed electronic counters. The pupillometer is simple and reliable in operation, has excellent response characteristics, and can be used over a broad range of research and clinical applications.

Animals↗
PubMed1978

Gonioscopy using the Brandreth-Saladin goniochamber.

The Brandreth-Saladin Goniochamber is a new diagnostic instrument available to the optometric profession. In this paper, a description of the instrument and technique is given and the results obtainable with the Goniochamber are compared to those obtainable with existing gonioscopic instruments.

Eye Protective Devices↗
PubMed1977

Development of the modified Frostig Test.

We developed a screening version of Marianne Frostig's Developmental Test of Visual Perception, which we call the Modified Frostig Test. It was designed to guide optometrists educators, and psychologists in screening kindergarten or first grade children for possible visual perception problems.

Child↗
PubMed1977

Phoria, vergence, and fixation disparity in oculomotor problems.

Measures of horizontal phoria, vergence, and fixation disparity were obtained for 2 samples: 28 optometry students without symptoms and 32 orthoptic patients with symptoms associated with binocular oculomotor difficulties. Discriminant analysis was used to determine which tests or group of tests best discriminated between the 2 samples. Analysis was done for both samples and for exophoric and esophoric subsamples. Sheard's criterion was the best discriminator for the exophoric group, and amount of heterophoria was the best discriminator for the esophoric group. Fixation disparity was the next best discriminator for both groups.

Accommodation, Ocular↗
PubMed1977

Anaglyphic T.V. ping pong antisuppression trainer.

Orthoptic therapy often entails the repetitive usage of detailed and complicated training procedures. Amblyopia and antisuppression therapy in particular may require weeks or months of trainning. A multipurpose training device has been constructed from commercially available components and promises to maintain a high level of patient interest and cooperation throughout the training procedure.

Amblyopia↗
PubMed1975

Exophoria at near in presbyopia.

The exophoria at near working distances through a plus lens addition which exists in presbyopia was investigated in order to explain the paradoxical lack of asthenopic symptoms associated with this condition. Fixation disparity measurements indicate that the exophoria which is measured by the von Graefe technique does not exist under binocular conditions. Further analysis indicates that presbyopes may have unrestrained use of accommodative convergence.

Accommodation, Ocular↗