Does head tilt influence facial appearance more than head turn?

Purpose: To evaluate the frequency of facial asymmetry parameters in patients with head tilt versus those with head turn. Methods: This cross-sectional comparative study was performed on 155 cases, including 58 patients with congenital pure head turn due to Duane retraction syndrome (DRS), 33 patients with congenital pure head tilt due to upshoot in adduction or DRS, and 64 orthotropic subjects as the control group. The facial appearance was evaluated by computerized analysis of digital photographs of patients' faces. Relative facial size (the ratio of the distance between the external canthus and the corner of the lips of both face sides) and facial angle (the angular difference between a line that connects two external canthi and another line that connects the two corners of the lips) measured as quantitative facial parameters. Qualitative parameters were evaluated by the presence of one-sided face, cheek, and nostril compression; and columella deviation. Results: The facial asymmetry frequency in patients with head tilt, head turn, and orthotropic subjects was observed in 32 (97%), 50 (86.2%), and 22 (34.3%), respectively (P < 0.001). In patients with head tilt and head turn, the mean facial angle was 1.78º ± 1.01º and 1.19º ± 0.84º, respectively (P = 0.004) and the mean relative facial size was 1.027 ± 0.018 and 1.018 ± 0.014, respectively (P = 0.018). The frequencies of one-sided nostril compression, cheek compression, face compression, and columella deviation in patients with pure head tilt were found in 19 (58%), 21 (64%), 19 (58%), and 19 (58%) patients, respectively, and in patients with pure head turn the frequencies were observed in 42 (72%), 37 (63%), 27 (47%), and 43 (74%), respectively. All quantitative and qualitative facial asymmetry parameters and facial asymmetry frequencies were significantly higher in head tilt and head turn patients as compared to the control group (P < 0.001). Conclusion: All facial asymmetry parameters in patients with head tilt and head turn were significantly higher than orthotropic subjects. The quantitative parameters such as relative facial size and facial angle were significantly higher in patients with pure head tilt than pure head turn. The results revealed that pure head tilt was associated with a higher prevalence of facial asymmetry than pure head turn.

Comparison of an Italian chart with an Iranian chart in visual acuity measurement

Taking visual acuity is an important part of an eye routine examination. This study was conducted to compare visual acuity measured using an Iranian digital tumbling E chart with visual acuity measured using an Italian digital tumbling E chart as a familiar foreign chart. This study was carried out on 200 participants [400 eyes; healthy n=40, glaucoma n=40, retinal disorders n=40, post lasik n=40, corneal n=40] with mean age 44.28 years. Visual acuity of both eyes in half of the subjects [n=100, n=20 from each group] was first measured using the Italian digital chart and then measured using Iranian digital chart. Visual acuity of the rest of subjects [n=100, n=200 from each group] was first measured using the Iranian digital chart and then measured using the Italian digital chart. Measured visual acuities were recorded in logMAR notation. Mean of the Iranian and Italian Tumbling E chart is 0.280 +/- 0.012 and 0.277 +/- 0.012, respectively. Paired t-test used to evaluate the mean difference between two groups [p=0.721] indicated that there was no statistically significant difference between means of the two tests. Spearman correlation coefficient for the results of both tests was 0.942 [p<0.001], which was statistically significant and could be categorized as a strong positive correlation. The two digital Tumbling E charts acted similarly at different levels of acuity in different disorders. However, the Iranian chart requires a more accurate design for optotypes of the lower acuity lines in order to obtain more accurate measurement of visual acuities in healthy subjects

Comparison of Two Marketed Hydroxypropyl Methylcellulose Based Artificial Tear Drops in Young Patients with Dry Eye Syndrome

Background: Artificial tears have been among the first line of therapy in management of Dry Eye Syndrome [DES]. This study was conducted to compare a local artificial tear with an imported one in reduction of DES. This comparison would help to evaluate the cost and benefits of each drop in the proper management of DES.

Materials and Methods: In this double-blind randomized clinical trial study, a total 65 students meeting our inclusion criteria for DES entered the study. The OSDI questionnaire, TBUT, corneal and conjunctival staining and Schirmer test, were performed. The patients were divided into two groups by block randomization. Group 1 received first drop and group 2 received second drop. Both groups were instructed to use the drops 4 times a day for 14 days. The same tests were performed by the same examiner who was blind to the treatment type after two weeks. Repeated measured ANOVA was used to analyze the data.

Results: A total of 58 patients completed the study. In both groups, after the intervention, the OSDI scores [P<0.001], TBUT score [P=0.041], corneal [P<0.001] and conjunctival staining scores [P<0.001] showed improvement in compare to those before the intervention. However, the Schirmer test score did not show significantly difference before and after intervention. In comparing two groups the OSDI scores, the TBUT score, the corneal and conjunctival staining scores and the Schirmer scores did not show statistically significant difference.

Conclusion: The two artificial tears equally reduced the symptoms and signs of DES in two weeks.

Lower tear meniscus in computer reading task with and without soft contact lens

Dry eye is the major contributor to computer vision syndrome. The reductions in the blink rate and amplitude have been considered as the possible mechanisms leading to this condition. The purpose of this study is to evaluate the changes in the lower tear meniscus heights and areas in the computer reading task, in dry eye subjects, with and without soft contact lenses. In this quasi-experimental study, 39 subjects [with mean age of 21.2 +/- 2.4 years], with dry eye, were enrolled. The lower tear meniscus height and area [TMH, TMA] of the right eye was captured by Spectral Optical Coherence Tomography before and after 45 minutes of reading task behind desktop 17" Cathode Ray Tube monitors. The same procedure was performed after the insertion of the hydrogel soft contact lenses with 58% water content. The results of TMHs, TMAs were analyzed with a repeated measures analysis of variance [ANOVA] with two within-subject factors.: The mean +/- standard error of TMH and TMA pre and post computer tasks were 283.6+/- 25.4 micro m, 0.029+/-0.005 mm2, 297.6+/-20.7 micro m , 0.036 +/- 0.005 mm2 respectively. After contact lens insertion, the mean TMH and TMA pre and post computer task were 231.6 +/- 10.6 micro m, 0.020+/-0.0019 mm2, 213.0+/-9.0 micro m, 0.018 +/- 0.0011 mm2, respectively. Repeated measures analysis of variance showed that the changes in TMH [P=0.86] and TMA [P=0.37] after computer task, were not statistically significant, while the insertion of the soft contact lens had reduced the TMH and TMA significantly [P<0.001 for both]. After 45 minutes of reading task behind desktop monitors, the tear volume has not changed, with and without high water SCLs. A reduction in tear volume might be expected with longer duration of computer task or at late hours of the day. The creation of a more stable tear film should be considered in the management strategies for shorter duration of work behind desktop monitors