Asymmetry of the macular structure is associated with ocular dominance

Evaluation of the Diagnostic Capability of Spectralis SD-OCT 8 × 8 Posterior Pole Software with the Grid Tilted at 7 Degrees and Horizontalized in Glaucoma

Background: The goal was to evaluate the diagnostic capability of different parameters obtained with the posterior pole (PP) software in Spectralis SD-OCT with the 8 × 8 grid tilted at 7° and horizontalized in glaucomatous eyes. Methods: A total of 299 eyes were included, comprising 136 healthy eyes and 163 with primary open-angle glaucoma (POAG). The following segmentations were evaluated: complete retina, retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), GCL and inner plexiform layer (GCLIPL), ganglion cell complex (GCC), outer plexiform layer and outer nuclear layer (OPLONL), inner retinal layer (IRL), and outer retinal layer (ORL). Different patterns of macular damage were represented using heatmaps for each studied layer, where the areas under the curve (AUROC) values and a retinal thickness cutoff point were defined to discriminate POAG patients. Results: There was not any difference in the diagnostic capability for detecting glaucoma between the grid tilted at 7° and horizontalized. The macular segmentations that offer the highest diagnostic ability in glaucoma discrimination were, in the following order, RNFL (AUROC = 0.796), GCC (AUROC = 0.785), GCL (AUROC = 0.784), GCLIPL (AUROC = 0.770), IRL (AUROC = 0.755), and the complete retina (AUROC = 0.752). In contrast, ORL and OPLONL do not appear to be helpful for discriminating POAG. Conclusions: Some results of PP software may be useful for discriminating POAG.

Digital Pupillometry and Centroid Shift Changes in Dominant and Nondominant Eyes

PURPOSE

To investigate the differences between dominant and nondominant eyes in a predominantly young patient population by analyzing the angle kappa, pupil size, and center position in dominant and nondominant eyes.

METHODS

A total of 126 young college students (252 eyes) with myopia who underwent femtosecond laser-combined LASIK were randomly selected. Ocular dominance was determined using the hole-in-card test. The WaveLight Allegro Topolyzer (WaveLight Laser Technologies AG, Erlangen, Germany) was used to measure the pupil size and center position. The offset between the pupil center and the coaxially sighted corneal light reflex (P-Dist) of the patients was recorded by the x- and y-axis eyeball tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system (Wavelight GmbH). The patient's vision (uncorrected distance visual acuity [UDVA], best-corrected visual acuity (BCVA), and refractive power (spherical equivalent, SE) were observed preoperatively, 1 week, 4 weeks, and 12 weeks postoperatively, and a quality of vision (QoV) questionnaire was completed.

RESULTS

Ocular dominance occurred predominantly in the right eye [right vs. left: (178) 70.63% vs. (74) 29.37%; p < 0.001]. The P-Dist was 0.202 ± 0.095 mm in the dominant eye and 0.215 ± 0.103 mm in the nondominant eye (p = 0.021). The horizontal pupil shift was - 0.07 ± 0.14 mm in dominant eyes and 0.01 ± 0.13 mm in nondominant eyes (p = 0.001) (the temporal displacement of the dominant eye under mesopic conditions). The SE was negatively correlated with the P-Dist (r = - 0.223, p = 0.012 for the dominant eye and r = - 0.199, p = 0.025 for the nondominant eye). At 12 weeks postoperatively, the safety index (postoperative BDVA/preoperative BDVA) of the dominant and nondominant eyes was 1.20 (1.00, 1.22) and 1.20 (1.00, 1.20), respectively, and the efficacy index (postoperative UDVA/preoperative BDVA) was 1.00 (1.00, 1.20) and 1.00 (1.00, 1.20), respectively; the proportion of residual SE within ± 0.50 D was 98 and 100%, respectively.

CONCLUSIONS

This study found that ocular dominance occurred predominantly in the right eye. The pupil size change was larger in the dominant eye. The angle kappa of the dominant eye was smaller than that of the nondominant eye and the pupil center of the dominant eye was slightly shifted to the temporal side under mesopic conditions. The correction of myopia in the dominant and nondominant eyes exhibits good safety, efficacy, and predictability in the short term after surgery, and has good subjective visual quality performance after correction. We suggest adjusting the angle kappa percentage in the dominant eye to be lower than that of the nondominant eye in individualized corneal refractive surgery in order to find the ablation center closest to the visual axis.

Comparative study of refractive and visual quality after wavefront-optimized FS-LASIK for angle kappa adjustment in dominant and nondominant eyes

PURPOSE

To investigate the differences between dominant and nondominant eyes in femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) with 50% angle kappa compensation on diopter and visual quality.

SETTING

University hospital.

DESIGN

Retrospective clinical study.

METHODS

109 patients (218 eyes, 100%) with myopia who underwent FS-LASIK were randomly selected. The preoperative pupil size, center position, and offset between the coaxially sighted corneal light reflex ( P-Dist ) of the patients was recorded. In preoperative and postoperative 6 months, an iTrace wavefront aberrometer was used to measure the corneal, internal optics, and total aberrations.

RESULTS

The 6 months postoperatively for corneal coma of the dominant eyes were 0.141 ± 0.055 μm and the nondominant eyes were 0.157 ± 0.033 μm, which was significantly greater than the dominant eyes ( P = .028). The postoperative corneal coma aberration changes were positively correlated with preoperative P-Dist , the dominant eyes ( r = 0.221, P = .023), and the nondominant eyes ( r = 0.251, P = .009).

CONCLUSIONS

Adjusting the angle kappa percentage in the nondominant eyes to be higher than that of the dominant eyes in individualized corneal refractive surgery may help find the ablation center closest to the visual axis.

Distractor-induced saccade trajectory curvature reveals visual contralateral bias with respect to the dominant eye

The functional consequences of the visual system lateralization referred to as "eye dominance" remain poorly understood. We previously reported shorter hand reaction times for targets appearing in the contralateral visual hemifield with respect to the dominant eye (DE). Here, we further explore this contralateral bias by studying the influence of laterally placed visual distractors on vertical saccade trajectories, a sensitive method to assess visual processing. In binocular conditions, saccade trajectory curvature was larger toward a distractor placed in the contralateral hemifield with respect to the DE (e.g., in the left visual hemifield for a participant with a right dominant eye) than toward one presented in the ipsilateral hemifield (in the right visual hemifield in our example). When two distractors were present at the same time, the vertical saccade showed curvature toward the contralateral side. In monocular conditions, when one distractor was presented, a similar larger influence of the contralateral distractor was observed only when the viewing eye was the DE. When the non dominant eye (NDE) was viewing, curvature was symmetric for both distractor sides. Interestingly, this curvature was as large as the one obtained for the contralateral distractor when the DE was viewing, suggesting that eye dominance consequences rely on inhibition mechanisms present when the DE is viewing. Overall, these results demonstrate that DE influences visual integration occurring around saccade production and support a DE-based contralateral visual bias.

Ocular Dominance in Open Angle Glaucoma: the shifting trend depending on stage of the disease

Purpose

To investigate the characteristics and distribution of ocular dominance in primary open-angle glaucoma eyes. In addition, we tried to catch any trend of ocular dominance according to the stage of disease.

Methods

Two hundred participants with bilateral open-angle glaucoma underwent ocular dominant testing by “the hole-in-a-card” test. Using optical coherence tomography, macular ganglion cell-inner plexiform layer, as well as circumpapillary retinal nerve fiber layer thickness were measured and compared according to ocular dominance. Of the two eyes of one subject, the eye with less glaucomatous damage based on mean deviation was considered to be the “better eye” in our study.

Results

Ocular dominance was in the right eye in 66% of the population and ocular dominance was positioned in the better eye in 70% of the population (p = 0.001 and p = 0.002, respectively). In conditional logistic regression analyses, right eye and better mean deviation were significantly associated with ocular dominance (p = 0.001 and p = 0.002, respectively). Ocular dominance tends to be present in the better eye and this trend was more apparent as the severity of glaucoma increased. Intereye comparison of visual field indices and retinal nerve fiber layer thickness between dominant versus nondominant eye become apparent in moderate and advanced glaucoma whereas it was not as apparent in early glaucoma.

Conclusions

In glaucomatous eyes, laterality and severity of glaucoma determined ocular dominance. Intereye difference between nondominant and dominant eyes increased with the severity of glaucoma. Our findings suggest the existence of potential reciprocal interactions between ocular dominance and glaucoma.

Impact of ocular dominance on circumpapillary and macular retinal nerve fibre layer thickness and ganglion cell layer thickness in a healthy pediatric population

OBJECTIVE

This study was designed to evaluate potential differences in circumpapillary retinal nerve fibre layer (cpRNFL) thickness and segmented macular retinal layers between dominant and nondominant eyes on spectral-domain optical coherence tomography in a pediatric population.

DESIGN

Cross-sectional study.

PARTICIPANTS

89 healthy children attending a general pediatric clinic.

METHODS

Participants underwent sighting dominant testing and macular and cpRNFL spectral-domain optical coherence tomography. Segmented macular layer thicknesses and cpRNFL thickness were compared for individual patients based on their ocular dominance.

RESULTS

Ocular dominance occurred particularly in the right eye (64.7%). Dominant and nondominant eyes did not differ significantly in axial length or spherical equivalent refraction; axial length: 22.99 ± 1.17 mm versus 22.98 ± 1.19 mm; p = 0.51 and spherical equivalent refraction: -0.09 ± 2.68 D versus 0.32 ± 2.93 D; p = 0.41. In the comparison of the macular ganglion layer the average thickness in the 1 mm central Early Treatment Diabetic Retinopathy Study area was significantly different between the dominant and nondominant eye (16.56 ± 6.02 μm vs 17.58 ± 8.32 μm; p = 0.02). However, when compensating with Bonferroni, this difference was no longer statistically significant. There were no differences in the analyses of average global and sectorial cpRNFL thickness in dominant and nondominant eyes.

CONCLUSION

Dominant eyes demonstrated no significantly thicker average macular retinal nerve fiber layer (mRNFL), Ganglion cell layer (GCL) thickness or cpRNFL thickness. No ocular characteristic was found to be associated with the relative dominance of an eye in eyes with low anisometropia.

The effect of ocular dominance on macular function: A pattern electroretinogram study

PURPOSE

To investigate the effect of ocular dominance on pattern electroretinogram (PERG) recordings in the participants who have no ophthalmic diseases.

METHODS

One hundred and twelve eyes of 56 participants (mean age 32.96 ± 10.82 years) were included in this prospective, cross-sectional study. After detailed ophthalmological examination and determination of the ocular dominance with hole-in-a-card test, the PERG was performed to determine implicit time and amplitudes of P50 and N95.

RESULTS

There were no significant interocular differences in visual acuity, refractive error, or intraocular pressure (p > 0.05 for all). Thirty-six (64.3%) of the participants had ocular dominance in the right eye. The dominant eyes had significantly higher P50 amplitude than in the fellow nondominant eyes (6.90 µV in dominant vs 5.87 µV in nondominant; p = 0.015; 95% confidence interval). There was no significant difference in N95 amplitude, N95/P50 ratio, and implicit times of P50 and N95 between the dominant and nondominant eyes of the participants (p = 0.090, p = 0.124 p = 0.817, p = 0.668; respectively).

CONCLUSION

The analysis revealed a significantly increased P50 amplitude of the PERG, which is known to be highly associated with macular function, in dominant eyes of the patients when compared to fellow nondominant eyes.

Hair Whorl Direction: The Association with Handedness, Footedness, and Eyedness

Hair whorl direction and handedness were stated to have a common genetic basis in the random recessive model. This study was carried out with a total of 317 healthy young males. The association between hair whorl swirling direction and handedness, footedness and eyedness were assessed. The direction of hair whorl was clockwise at a rate of 76.7%, and counter clock wise at a rate of 23.3%. There was no significant association between hair whorl direction and handedness, footedness, and eyedness (p > .05). The results indicate that hair whorl swirling direction is not an evident marker of functional laterality.