Purpose: Primary angle-closure glaucoma is a common cause of blindness where angle closure is a fundamental pathologic process. Van Herick technique is one of the commonest tests used in clinical settings for iridocorneal angle estimation, but training is required. With the development of imaging devices for the anterior segment of the eye, such as multi-diagnostic platform VX120 (Visionix), objective quantification of the angle can be obtained. The purpose of this study is to compare the angle estimation of Van Herick (with the aid of image processing software) with that obtained by objective VX120 platform. Material and methods: 49 subjects were enrolled in the study among patients attending the Optometry Clinic of the Optometry Faculty (USC). All of them were assessed with multi-diagnostic platform VX120 (Visionix) in order to obtain the Anterior Chamber Depth (ACD) and temporal iridocorneal angle (TA) parameters. Then, an image of the temporal optic section of the cornea (following the requirements of Van Herick technique) was obtained from each subject by using a camera attached to a slit-lamp. Finally, Van Herick’s temporal angle was determined as a ratio between the peripheral anterior chamber depth and corneal thickness (AC/SC ratio) by using ImageJ software. Results: Van Herick´s AC/SC ratio showed a significant correlation with both TA (r=0.389, p=0.006) and ACD (r=0.370, p=0.009). As expected, both VX120 parameters (ACD and TA) showed a significant correlation between them (r=0.863, p<0.001). Conclusions: Van Herick´s AC/SC by using ImageJ software supposes a valuable parameter for iridocorneal angle estimation.
Purpose: Vital staining is one of the most widely test used to evaluate the corneal damage. The aim of this study was to assess the relationship of the corneal damage with tear meniscus height (TMH) and dry eye symptomatology. Material and methods: 530 subjects were recruited among patients of the Optometry Clinic (USC). Previously, all of them completed an OSDI questionnaire. Two videos of the ocular surface were recorded from each patient by a digital camera attached to a slit-lamp. Firstly, a video of central tear meniscus under 40x with the Tearscope device illumination was recorded. From those videos, a masked observer extracted one image and TMH was measured by using the ImageJ software. Secondly, after fluorescein instillation, the corneal surface was recorded by another experienced masked observer, who assigned a category to the corneal damaged based on the Oxford Scheme. The evaluation was stratified by corneal zones based on the CCLRU grading scales (central, superior, inferior, nasal and temporal). Results: When the sample was grouped by the corneal staining Oxford Grade, there was found a statistical difference between groups in OSDI and TMH value (ANOVA: both p≤0.006). There was found a difference in OSDI value when corneal damage was in nasal or inferior areas (t-test; both p≤0.015), and a difference in TMH value arises when damage was in the central, nasal or inferior areas (t-test; all p≤0.013). Conclusions: There is a relationship between corneal damage grade and corneal zones with dry eye symptomatology and tear film volume.
Purpose: Tranaglyphs and Vectograms are visual therapy material based on red/green or polarized targets respectively that used similar but slightly different images for each eye to train fusion and vergence skills. This study aimed to analyse the relationship of three accommodative parameters (the Negative Relative Accommodation [NRA], the Positive Relative Accommodation [PRA] and the Accommodative Amplitude [AA]) with the results of four different visual therapy vectograms/tranaglyphs. Material and methods: 45 subjects free of any accommodative or binocular problem were recruited among students attending the Optometry Clinic of the Optometry Faculty (USC). In a first session, the accommodative tests were performed according to their standard protocols. In a second session, following manufacturer’s instructions, the subjects performed in a random order four different calibrated vectograms/tranaglyphs: two red/green Variable Demand Anaglyphs (one based on circles [VDA-C] and one on draws [VDA-D]), one red/green Fixed Demand Anaglyph [FDA], and one polarized with Variable Demand [VDP]. Subjects were asked to indicate the maximum value both base-out (BO) and base-in (BI), where the image fusion was lost. Results: NRA showed a negative correlation with the BO results of the VDP (p = 0.040, r = -0.270). PRA showed a negative correlation with the BO results of the VDA-C, the VDA-D and the VDP (all p ≤0.017, r ≥ -0.323). AA showed a positive correlation with the BI results of the VDA-D, the FDA, and the VDP (all p ≤0.013, r ≥0.341). Conclusion: Accommodation seems to have some influence on the visual therapy training with vectograms and tranaglyphs.
In this study we use the Functional Vision Screening Questionnaire (FVSQ) to identify functional indicators of visual problems among a sample of older people living in nursing homes. An important proportion of residents under study have difficulties on the performance of distance and near vision tasks. We have found a high proportion of blanks in several items of the FVSQ that seems to suggest the need to adapt the functional indicators of FVSQ to the vision-dependent daily activities of our residents.
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