Titmus Stereo Test Research Articles

Optical coherence tomography parameters as prognostic factors for stereopsis after vitrectomy for unilateral epiretinal membrane: a cohort study

This retrospective cohort study explored the relationship between monocular and interocular optical coherence tomography (OCT) parameters and stereopsis in 56 patients undergoing pars plana vitrectomy (PPV) for unilateral idiopathic epiretinal membrane (IERM). IERM impairs visual functions, with symptoms ranging from asymptomatic to severe impairment. Despite established surgical interventions, including PPV with membrane peeling, the impact on advanced three-dimensional visual functions such as stereopsis remains inadequately investigated. All subjects were assessed for stereopsis, visual acuity, and metamorphopsia, alongside spectral domain OCT parameters. These visual functions significantly improved 3-month postoperatively. Central retinal thickness at the fovea, parafovea, and perifovea (CFT, CRT-3 mm, and CRT-6 mm), ectopic inner foveal layer thickness, and retinal layer thickness notably decreased 1 week to 3 months after surgery. The interocular difference in OCT parameters between bilateral eyes was included as a parameter. Baseline CRT-3 mm difference and inner nuclear layer (INL) thickness were independently correlated with postoperative stereopsis on the Titmus Stereo Test, while baseline CRT-6 mm difference and INL thickness were independently related to stereopsis on the TNO stereotest. This study highlights the substantial enhancement in stereopsis post-IERM surgery, with both interocular and monocular OCT parameters independently influencing postoperative stereopsis. These findings underscore the importance of retinal microstructures in assessing and predicting stereopsis in IERM patients after vitrectomy.

A comparative study of stereopsis in term and preterm children with and without retinopathy of prematurity.

To evaluate stereopsis in term-born, preterm, and preterm children with and without retinopathy of prematurity (ROP) and its treatment. The cross-sectional study included 322 children between 3 and 11years of age born term or preterm, with or without ROP, and with or without treatment for ROP. The ROP treatments were laser therapy, intravitreal injection (IVI) of anti-vascular endothelial growth factor, or their combination. Stereoacuity was measured using the Titmus Stereo Test, and the results among various age groups were analyzed. Stereopsis was found to improve with increasing age at testing (P < 0.001) across the entire study population. The term group exhibited significantly better stereoacuity than the preterm group (P < 0.001). At 3-5years and 6-8years, the preterm children without ROP exhibited significantly better stereoacuity than did those with ROP (P < 0.001 and P = 0.02, respectively); however, at 9-11years, both groups exhibited similar stereoacuity (P = 0.34). The stereoacuity in the children with untreated ROP was similar to that of the children with treated ROP in all age groups (P > 0.05). No significant differences in stereopsis were identified between children with ROP treated with laser versus with IVI (P > 0.05). From multivariate analysis, younger age at testing (P = 0.001) and younger gestational age (P < 0.001) were associated with poorer stereopsis. Stereopsis development gradually improved with age in all groups. The children born preterm exhibited poorer stereoacuity than those born term. Children with ROP treated with laser photocoagulation versus IVI may exhibit similar levels of stereoacuity. Younger age at testing and gestational age were independent risk factors for poorer stereoacuity.

Correlation between Central Visual Field Defects and Stereopsis in Patients with Early-to-Moderate Visual Field Loss

To investigate the association between stereoacuity and the presence of central visual field defects (CVFDs) due to glaucoma. A prospective, cross-sectional cohort study. Participants with early-to-moderate glaucoma with a visual acuity better than 20/40, less than a 2-line difference in visual acuity between eyes, and 2 reliable Humphrey visual fields (VFs) (24-2 SITA standard) with mean deviation (MD) in the worse eye better than-12 dB. Stereoacuity was measured using the Titmus stereo test. Participants with a significant field defect (P<0.005) in any 1 of the central 4 points in the 24-2 SITA standard total deviation map in either eye were classified as having a CVFD. Vision-related quality of life (VR-QOL) was measured using 25-item National Eye Institute Visual Function Questionnaire scores. Logistic regression was used to determine the associations between the level of stereoacuity and age, sex, race, glaucoma type, presence of CVFDs, visual acuity, contrast sensitivity, and VF MD. Stereoacuity in the CVFD and non-CVFD groups. Sixty-five participants met the inclusion criteria. The mean age of the participants was 64.3±8.0 years, and 64.6% were women. The median stereoacuity was 60 arc seconds (interquartile range [IQR], 40-120 arc seconds). Forty-two (65%) patients had CVFDs, and 23 (35%) patients did not. The median stereoacuity of the CVFD group was worse than that of the non-CVFD group (60 arc seconds [IQR, 50-140 arc seconds] vs. 40 arc seconds [IQR, 40-80 arc seconds], respectively; P=0.001). The non-CVFD group had a higher percentage of participants with normal stereopsis than the non-CVFD group (61% vs. 21%, respectively; P=0.001). A multivariable analysis found that the presence of CVFDs was associated with worse stereopsis levels (odds ratio, 4.49; P=0.021). The CVFD group had a lower Visual Functioning Questionnaire-25 (VFQ-25) composite score (84.0 vs. 91.4; P=0.004) and lower VFQ-25 subscale scores for general vision, near activities, and mental health (P<0.05). Central visual field defects were associated with increased odds of poor stereoacuity in patients with early-to-moderate glaucomatous VF loss. Specifically, patients without CVFDs are more likely to have normal stereopsis and higher VR-QOL than those with CVFDs. Patients with CVFDs should be counseled regarding how depth perception difficulties may affect daily living. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Analysis of stereopsis and fusion in school-aged children with reduced visual acuity due to refractive error.

In patients with strabismus, the stereopsis and Worth 4-dot (W4d) tests have often been used to evaluate whether sensory fusion is achieved. However, if patients face difficulties undergoing the Titmus or W4d test because of poor visual acuity (VA) due to refractive error abnormalities, the results of these tests cannot be appropriately interpreted. Therefore, we evaluated the correlation between distance uncorrected VA (UCVA) and sensory status in children with reduced VA due to refractive error abnormalities to identify the effects of refractive errors on sensory test results. We retrospectively reviewed the medical records of 195 children with reduced VA with VA improvement ≥ 20/25, Titmus stereoacuity ≤ 50 arcsec, and fusion in the W4d result after refractive error correction with spectacles. We evaluated the correlation between distance UCVA in logMAR and sensory status measured by the near Titmus stereotest and distance W4d test. Additionally, the minimum required UCVA for interpreting Titmus or W4d results was assessed using a receiver operating characteristic (ROC) curve. The UCVA showed a marginal but non-significant correlation with Titmus stereoacuity (p = 0.053) and a significant correlation with fusion in W4d (p < 0.001). The ROC curve analysis showed an optimal cut-point value of VA required for interpreting the results of W4d test as 0.3 logMAR (20/40 in Snellen acuity). Correcting refractive error in advance may help appropriately interpret sensory status in school-aged children with reduced VA due to refractive error abnormalities.

Measurement of Aniseikonia Tolerance in Binocular Fusion.

The determination of aniseikonia tolerance may aid in developing optimal treatment plans for cataract surgery, refractive surgery, and refractive correction with glasses and contact lenses. This study aimed to measure aniseikonia tolerance. We included 33 patients (mean age ± standard deviation, 28.9 ± 6.4 years; male/female, 12:21) with anisometropia ≤1.0 D and best spectacle-corrected visual acuity of 20/20 or more in both eyes, with no ophthalmologic disease other than refractive errors and no history of ocular surgery. The exclusion criteria were anisometropia >1.0 D, axial length difference >0.5 mm, corneal refractive power difference >0.5 D, astigmatism >3.0 D, stereoacuity threshold >100 arcsec according to the Titmus Stereo Test, and >0% aniseikonia according to the New Aniseikonia Test. Aniseikonia tolerance was assessed using Eyemark Hello, a haploscope using gaze detection technology. Although the optotype of one eye was enlarged or reduced at a speed of 2%/s, the patients were instructed to press a button on the controller to indicate blurring, flickering, and diplopia. The value at which the patient responded was considered the aniseikonia tolerance value and assessed thrice per eye, five times if the values were highly variable, and then averaged. The mean aniseikonia tolerance was approximately 3%; the median value was approximately 2% (range, 1.0 to 11.5%; dominant eye, 3.3 ± 2.6%; nondominant eye, 2.9 ± 1.8%). No significant difference in aniseikonia tolerance between the dominant and nondominant eyes was observed for the enlarged optotypes. No case showed changes in the ocular alignment before discomfort occurred. No significant correlation was observed between aniseikonia tolerance and anisometropia, axial length difference, corneal power difference, and ocular deviation. Aniseikonia should be maintained at <2% for a comfortable visual environment. Aniseikonia tolerance may be an important indicator for cataract surgery, refractive surgery, and spectacle correction.

Vision-Related Parameters Affecting Stereopsis after Retinal Detachment Surgery

Even after successful surgery, the stereopsis of retinal detachment (RD) patients is inferior to that of normal subjects. However, it is unclear which visual dysfunction in the affected eye is responsible for the postoperative stereopsis impairment. This study included 127 patients after successful surgery for unilateral RD. Stereopsis, best-corrected visual acuity (BCVA), severity of metamorphopsia, letter contrast sensitivity and amount of aniseikonia were examined at 6-month postoperatively. Stereopsis was assessed using the Titmus Stereo Test (TST) and TNO stereotest (TNO). Postoperative stereopsis (log) in patients with RD were 2.09 ± 0.46 in the TST and 2.56 ± 0.62 in the TNO. Multivariate analysis with stepwise regression revealed postoperative TST was associated with BCVA, and TNO was associated with BCVA, letter contrast sensitivity, metamorphopsia and absolute values of aniseikonia. In a subgroup analysis that selected those with more impaired stereopsis, postoperative TST was associated with BCVA (p < 0.001), and TNO was associated with letter contrast sensitivity (p < 0.005) and absolute values of aniseikonia (p < 0.05) by multivariate analysis. Deterioration of stereopsis after RD surgery was affected by a variety of visual dysfunctions. The TST was affected by visual acuity, while the TNO was affected by contrast sensitivity and aniseikonia.

A cross-sectional study of ophthalmologic examination findings in 5385 Koreans presenting with intermittent exotropia

The Korean Intermittent Exotropia Multicenter Study (KIEMS) was a retrospective, cross-sectional and multicenter study for the investigation of intermittent exotropia involved 65 strabismus specialists from 53 institutions in Korea. Purpose of this study was to present ophthalmologic findings of intermittent exotropia from the KIEMS. Consecutive patients with intermittent exotropia of ≥ 8 prism diopters (PD) at distance or near fixation were included. Best-corrected visual acuity, cycloplegic refraction data, angles of deviation at several cardinal positions, ocular dominance, fusion control, oblique muscle function, and binocular sensory outcomes were collected. A total of 5385 participants (2793 females; age 8.2 years) were included. Non-dominant eye was more myopic than the dominant eye (− 0.60 vs. − 0.47 diopters, P < 0.001). Mean exodeviation angles were 23.5 PD at distance and 25.0 PD at near fixation. Basic type (86.2%) was the most, followed by convergence insufficiency (9.4%) and divergence excess (4.4%) types. Alternating ocular dominance and good fusion control were more common at near than at distance fixation. Good stereopsis at 40 cm was observed in 49.3% in Titmus stereo test (≤ 60 arcsec) and in 71.0% in Randot stereo test (≤ 63 arcsec). Intermittent exotropia was mostly diagnosed in childhood and patients with the condition showed relatively good binocular functions. This study may provide objective findings of intermittent exotropia in a most reliable way, given that the study included a large study population and investigated comprehensive ophthalmology examinations.

Comparison of stereoacuity in patients of anisometropia, isometropia and emmetropia.

To compare the stereoacuity in patients with anisometropia, isometropia, and emmetropia. A cross-sectional study was conducted on 1403 subjects (range: 5-45 years) divided into anisometropes (n = 403), isometropes (n = 500), and emmetropes (n = 500). There were 258 amblyopic eyes among anisometropes and 156 amblyopic eyes among isometropes. Stereoacuity was measured using the Titmus stereo test consisting of a combination of contour targets. There were 675 males and 728 females. A significant (P < 0.001) reduction in stereoacuity was found in anisometropes as compared to isometropes and emmetropes. The stereoacuity was even worse in amblyopes as compared to non-amblyopes. Most patients with anisometropia of <3.0 D had fair stereoacuity. However, as the degree of anisometropia increased to >3.0 D, stereoacuity deteriorated gradually. Marked reduction of stereoacuity was observed in severe degree of anisometropia (>6.0 D). Overall, an anisometropia of ≥2.12 D was associated with reduced stereoacuity. Among the anisometropes, it was found to be the poorest in myopia, followed by myopia with astigmatism, hypermetropia with astigmatism, and hypermetropia. The level of stereoacuity was worse in anisometropes as compared to isometropes and emmetropes. Amblyopes had a greater reduction in stereoacuity than non-amblyopes. Stereoacuity decreased as the degree of anisometropia increased. Among the anisometropes, myopes had worst stereoacuity than hypermetropes.

Comparison of sensory outcomes in patients with successful motor outcome versus recurrent exotropia after surgery for intermittent exotropia

Here, we compared sensory outcomes between patients with successful motor outcomes and recurrent exotropia after intermittent exotropia surgery. We retrospectively analyzed 303 patients who underwent surgery for intermittent exotropia, divided into two groups: successful motor outcome defined as an alignment between 10 prism diopters (PD) exodeviation and 5PD esodeviation at the final follow-up (Group A, n = 177) and residual or recurrent exotropia defined as exodeviation > 10 PD (Group B, n = 126). Preoperative and postoperative (at final visit) sensory outcomes were compared using the Titmus stereotest and distance Worth 4-dot test. Stereoacuity significantly improved postoperatively in both successful motor outcome group (Group A) and residual or recurrent exotropia group (Group B). However, stereoacuity did not differ between groups preoperatively and postoperatively. On the other hand, fusion rates for the Worth 4-dot test were significantly higher in group A than in group B, preoperatively and postoperatively, and significantly increased postoperatively only in group A. Therefore, the distance Worth 4-dot test may be useful for evaluating postoperative prognosis and preoperative sensory status.

Visual Functions Affecting Vision-Related Quality of Life Following Intravitreal Ranibizumab Therapy for Central Retinal Vein Occlusion.

Visual functions that affect vision-related quality of life (VR-QoL) before and after intravitreal injection of ranibizumab in patients with cystoid macular edema secondary to central retinal vein occlusion (CRVO-CME) are poorly understood. This multicenter, open-label, single-arm prospective study included 23 treatment-naïve patients with CRVO-CME. The best-corrected visual acuity (BCVA), letter contrast sensitivity (LCS), severity of metamorphopsia (M-CHARTS), amount of aniseikonia (New Aniseikonia Test), and stereopsis (Titmus Stereo Test and TNO stereotest) were examined every month from before treatment to 12 months after treatment. For VR-QoL assessment, the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) was provided to the patients before treatment and at 3, 6, and 12 months after treatment. Stepwise multiple regression analysis revealed that the BCVA of the fellow eye was related to the VFQ-25 composite score before treatment, and that the BCVA of the fellow eye and TNO values were related to the VFQ-25 composite score 12 months after treatment. Changes in LCS were significantly correlated with changes in the VFQ-25 composite score. In patients with CRVO-CME, visual acuity of the fellow eye had the strongest impact on VR-QoL. The contrast sensitivity of the affected eye and stereopsis were also associated with VR-QoL.

Correlation between Frisby-Davis Distance Stereoacuity Scores and Long-term Surgical Outcomes in Intermittent Exotropia

Purpose: We analyzed postoperative Frisby-Davis distance (FD2) stereotest scores and changes in the angle of deviation, and the correlation between postoperative FD2 stereotest scores and long-term surgical outcomes, in patients with intermittent exotropia.Methods: This retrospective study included patients aged less than 12 years with intermittent exotropia who underwent at least 28 months of postoperative follow-up. We analyzed the changes in the postoperative angle of deviation and preoperative and postoperative Titmus and FD2 stereotest scores. Surgical success rates at 28 months postoperatively were compared between the good (FD2 at 10 months postoperatively ≤ 10 arcsec) and bad (FD2 at 10 months postoperatively ≥ 15 arcsec) stereotest groups. Surgical success was defined as a horizontal deviation on distance measurement of 5 prism diopter (PD) esodeviation to 10 PD exodeviation at 1 year postoperatively.Results: This study included 101 patients. No significant difference was identified between preoperative and postoperative Titmus test scores. However, the FD2 stereotest scores were significantly improved at 10 months postoperatively (p = 0.001). A significant, positive correlation was observed between FD2 stereotest scores at 10 months postoperatively and the angles of deviation at distance at 10, 16, 22, and 28 months postoperatively (p ≤ 0.001 for all). The surgical success rates at 28 months postoperatively were 73.1% and 43.5% in the good and bad stereotest groups, respectively (p = 0.008).Conclusions: Distance stereoacuity within 1 year postoperatively correlated with the postoperative angle of deviation at distance. Good distance stereoacuity (i.e., &lt; 10 arcsec) within 1 year postoperatively correlated with a higher surgical success rate compared to bad distance stereoacuity.

Relationship between stereopsis and vision-related quality of life in patients with branch retinal vein occlusion.

BackgroundTo investigate the relationship between stereopsis and vision-related quality of life (VR-QOL) in patients with branch retinal vein occlusion (BRVO) before and after treatment with intravitreal ranibizumab (IVR).MethodsThis prospective multicentred observational study included 37 patients undergoing IVR treatment for unilateral BRVO and 24 age-matched healthy controls.Stereopsis was evaluated using the TNO stereo test (TNO) and Titmus stereo test (TST) every month, and the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) was administered at baseline, then at 3, 6 and 12 months after treatment.ResultsTime course of the changes in stereopsis and VR-QOL. IVR treatment significantly reduced central fovea thickness and improved both the TNO and the TST from 2 to 12 months (both p<0.05). Stereopsis before and after IVR injection in the eyes with BRVO were significantly worse than those in control subjects (TNO, p<0.001; TST, p<0.001). The VFQ-25 composite score significantly improved from 3 to 12 months after IVR treatment (p<0.05). Univariate analysis showed that the TNO score at baseline was significantly correlated with the VFQ-25 composite score at baseline and after treatment (p<0.05, p<0.05, respectively). TST score was not associated with the VFQ-25 composite score at baseline or after treatment.ConclusionsTreatment with IVR for BRVO improved cystoid macular oedema, which was correlated to improved stereopsis, although not to the control level. The TNO score at baseline was associated with VR-QOL in patients with BRVO.

Stereopsis and Eye Movement Abnormalities in Parkinson's Disease and Their Clinical Implications.

BackgroundParkinson’s disease (PD) is not exclusively a motor disorder. Among non-motor features, patients with PD possess sensory visual dysfunctions. Depth perception and oculomotor deficits can significantly impact patients’ motor performance. Stereopsis and eye behavioral study using 3D stimuli may help determine their implications in disease status.ObjectiveThe objective of this study is to investigate stereopsis and eye movement abnormalities in PD with reliable tools and their correlation with indicators of PD severity. We hypothesize that patients with PD exhibit different eye behaviors and that these differences may correlate to the severity of motor symptoms and cognitive status.MethodsControl and PD participants were first evaluated for visual acuity, visual field, contrast acuity, and stereo perception with 2D and Titmus stereotests, followed by the assessment with a 3D active shutter system. Eye movement behaviors were assessed by a Tobii X2-60 eye tracker.ResultsScreening visual tests did not reveal any differences between the PD and control groups. With the 3D active shutter system, the PD group demonstrated significantly worse stereopsis. The preserved cognitive function was correlated to a more intact stereo function. Patients with PD had longer visual response times, with a higher number of fixations and bigger saccade amplitude, suggesting fixation stabilization difficulties. Such changes showed a positive correlation with the severity of motor symptoms and a negative correlation with normal cognitive status.ConclusionWe assessed stereopsis with a 3D active shutter system and oculomotor behaviors with the Tobii eye tracker. Patients with PD exhibit poorer stereopsis and impaired oculomotor behaviors during response time. These deficits were correlated with PD motor and cognitive status. The visual parameters may potentially serve as the clinical biomarkers for PD.

Screening for Stereopsis Using an Eye-Tracking Glasses-Free Display in Adults: A Pilot Study.

Purpose:To explore the feasibility and repeatability of a novel glasses-free display combined with random-dot stimulus and eye-tracking technology for screening stereopsis in adults.Methods:A total of 74 patients aged 18–44 years were recruited in this study (male: female, 32:42), including 33 patients with high myopia [≤ -6.0 diopters (D)] and 41 patients with moderate-to-low myopia (>-6.0 D). Stereopsis was measured using glasses-free, polarized, and Titmus stereotests. All patients completed a visual fatigue questionnaire after the polarized stereotest and glasses-free test. Kendall's W and Cohen's Kappa tests were used to evaluate repeatability and consistency of the glasses-free stereotest.Results:The stereotest results using the glasses-free monitor showed strong repeatability in the three consecutive tests (W = 0.968, P < 0.01) and good consistency with the polarized stereotest and Titmus test results (vs. polarization: Kappa = 0.910, P < 0.001; vs. Titmus: Kappa = 0.493, P < 0.001). Stereopsis levels of the high myopia group were significantly poorer than those of the moderate-to-low myopia group in three stereotest monitors (all P < 0.05). There was no significant difference in visual fatigue level between the polarized and the glasses-free display test (P = 0.72). Compared with the polarized test, 56.76% of patients preferred the glasses-free display and found it more comfortable, 20.27% reported both tests to be acceptable.Conclusions:In our adult patients, the new eye-tracking glasses-free display system feasibly screened stereopsis with good repeatability, consistency, and patient acceptance.

Relationship between stereopsis and vision-related quality of life following intravitreal ranibizumab injections for central retinal vein occlusion

The study aimed to evaluate changes in stereopsis and vision-related quality of life (VR-QOL) in patients with central retinal vein occlusion (CRVO) following intravitreal ranibizumab injection (IVR) and investigate the relationship between stereopsis and VR-QOL. This study included 23 treatment-naïve patients with non-ischemic CRVO and 13 age-matched normal controls. Stereopsis, best-corrected visual acuity (BCVA), VR-QOL, and retinal microstructures were examined pre-treatment and 12 months post-treatment. The Titmus Stereo Test (TST) and TNO stereotest (TNO) were used to evaluate stereopsis. VR-QOL was evaluated using the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25). IVR immediately and significantly improved the TST values, TNO values, composite VFQ-25 score, BCVA, and central foveal thickness in patients with CRVO. The 12-month post-treatment TST and TNO values were significantly worse in the CRVO group compared to those in the normal group. At the baseline, the composite VFQ-25 score significantly correlated only with the TST value. Multivariate analysis revealed significant associations between the 12-month post-treatment composite VFQ-25 score and the baseline and 12-month post-treatment TNO values. In conclusion, IVR immediately improved stereopsis in CRVO, albeit below normal levels. Stereopsis (not visual acuity) was associated with pre- and post-treatment VR-QOL in patients with CRVO.

Stereoacuity and its determinants in 7-year-old children: the Lhasa Childhood Eye Study.

To explore the distribution of stereoacuity and to examine its determinants in school-age children in Tibetan plateau, Southwest China. This is the cross-sectional part of a school-based cohort study of 7-year-old children in Lhasa, Tibet Autonomous Region, Southwest China. Children in first year of primary school were invited to undergo a comprehensive examination, including height, weight, visual acuity, cycloplegic autorefraction (1% cyclopentolate), anterior segment, cover and uncover test, and stereoacuity (Titmus Stereo Test). A total of 1833 eligible subjects were included, with a mean age of 6.82 ± 0.46years. Mean stereoacuity was 1.78 ± 0.21 in log units (median: 60 arcsec). Children with stereoacuity equal to 40 arcsec and stereoacuity worse than 100 arcsec accounted for 29.24% and 8.18% of the cohort, respectively. Tibetan ethnicity (OR = 1.98; 95%CI, 1.30-3.03), astigmatism (OR = 1.65; 95%CI, 1.26-2.17), strabismus (OR = 2.92; 95%CI, 1.38-6.18), and amblyopia (OR = 3.77; 95%CI, 1.14-12.49) were risk factors for normal stereoacuity (= 40 arcsec). Shorter height, younger age, strabismus, and worse BCVA (P < 0.05 for all) were both related to lower stereoacuity in Spearman correlation analysis and associated with lower stereoacuity in multivariate regression analysis. Stereoacuity maturation does not appear fully completed in 7-year-old children, while few children present stereoacuity worse than 100 arcsec (8.18%). Lower stereoacuity was associated with younger age, shorter height, strabismus, and lower best-corrected visual acuity.

Detection of Static and Dynamic Stereopsis after Femtosecond Laser Small Incision Lenticule Extraction for High Myopia.

Purpose The purpose of this study is to test binocular visual function after femtosecond laser small incision lenticule extraction (SMILE) for high myopia. The traditional Titmus stereotest and dynamic stereotest based on the visual perception biological model were used for comparative analysis. Methods A total of 43 patients were enrolled in this prospective study. At Week 1, Month 1, and Month 3 after surgery, the Titmus stereotest and dynamic stereotest generated by MATLAB were conducted. Dynamic stereopsis consists of randomly flickering Gabor spots and is divided into two models of high energy and low energy according to flicker frequency. Results The preoperative manifest refraction spherical equivalent was −7.21 ± 0.70 D. The preoperative anisometropia was 0.52 ± 0.54D. The quartiles of static stereoacuity in preoperation and 3 follow-ups were as follows: 50.00 (25.00, 100.00) in preoperation, 63.00 (40.00, 63.00) at Week 1, 40.00 (32.00, 63.00) at Month 1, and 40.00 (25.00, 50.00) at Month 3. Static stereopsis improved at Month 1 and Month 3 compared with preoperation and Week 1 (P < 0.05). There were statistically significant differences in high energy dynamic stereopsis at Week 1 and Month 1 compared to preoperation (P < 0.05). In addition, significant differences in low energy dynamic stereopsis were detected between Month 1 and preoperation and also at Month 3 compared to Month 1 (P < 0.05). Conclusion Most high myopia patients have a dynamic stereopsis deficiency before refractive correction. SMILE surgery can improve both static and dynamic stereopsis early in the postoperation period. However, in the long term, there is no significant difference or even a decrease in dynamic stereopsis.

Evaluation of stereoacuity with a digital mobile application

PurposeStereopsis is a fundamental skill in human vision and visual actions. There are many ways to test and quantify stereoacuity: traditional paper and new digital applications are both valid ways to test the stereoacuity. The aim of this study is to compare the results obtained using standard tests and the new Stereoacuity Test App developed by the University of Bergamo.MethodsA group of 497 children (272 males), aged between 6 and 11 years old, were tested using different tests for the quantification of stereopsis at near. These tests were TNO, Weiss EKW, and the new developed Stereoacuity Test App.ResultsA one-way repeated measure ANOVA showed that the three tests give different thresholds of stereoacuity (p < 0.0001). Post hoc analyses with Bonferroni correction showed that all tests showed different thresholds (p < 0.0001). The lower threshold was obtained by Titmus Stereo Test followed by Stereoacuity App, Weiss MKW, and TNO.ConclusionThe stereoacuity based on global stereopsis showed that the better values were obtained in order by Stereoacuity Test App, TNO, and Weiss EKW. However, the clinical significance of their values is similar. The new digital test showed a greater compliance by the child, showing itself in tune with the digital characteristics of today’s children.

Evaluation of cerebral visual functions in low myopic adolescents

AIM: To explore whether low myopia would affect cerebral visual functions by comparing perceptual eye position (PEP), fixation stability and stereoacuity tests between low myopic and normal adolescents. METHODS: Totally 120 adolescents matched in age and gender participated in our study. Subjects were divided into three groups according to their refractive states. The cerebral visual functions tested in our study included perceptual eye position (PEP), fixation stability and stereoacuity. Stereoacuity tests involved in our study could be categorized into two parts. The first part was classical stereo tests including Titmus and synoptophore stereo test. The second part was 3D random-dot test for zero-order stereoacuity (hereinafter as zero-order test) at different viewing distances (0.8 m and 1.5 m). RESULTS: The deviation of horizontal PEP was significantly larger in non-anisometropia when compared to control group. Both horizontal and vertical PEP bias pixels were significantly larger in anisometropia group. Both non-anisometropia group and anisometropia group had more trouble in holding their fixation stable. Moreover, anisometropia group had more abnormal results than other two groups. And in zero-order test at 1.5 m, both non-anisometropia and anisometropia had more abnormal results in stereoacuity than control group. The correlation between fixation stability and near stereoacuity (Titmus and zero-order stereoacuity at 0.8 m) was weak and positive. CONCLUSION: Low myopic adolescents still have certain defects in cerebral visual functions. Examinations used in our study are useful in assessing cerebral visual functions. They could provide better follow-up evaluation and solid ground for further specific treatments in treating defects of cerebral visual functions. So far, local retinal environment has been the focus of the development in myopia. Our results suggested that researchers might pay more attention on visual cortex in studying the mechanisms of myopia in the near future.

Visual functions affecting stereopsis in patients with branch retinal vein occlusion.

To quantify stereopsis and other visual functions in patients with unilateral branch retinal vein occlusion (BRVO) and to investigate vision-related parameters that affect stereopsis. Prospective observational study. Forty-five patients undergoing intravitreal ranibizumab (IVR) treatment for unilateral BRVO. We examined stereopsis using the Titmus stereo test (TST) and TNO stereotest (TNO), best corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia and degree of aniseikonia before and 6 months after IVR. Visual functions that affect stereopsis. Baseline stereopsis in patients with BRVO was 2.7 ± 0.6 (range, 1.6-3.5) in the TST and 2.8 ± 0.5 (range, 1.8-3.3) in TNO. TST and TNO scores were significantly correlated with BCVA and letter contrast sensitivity at baseline (P < 0.001) but not with other visual functions. IVR treatment significantly improved stereopsis, BCVA, and letter contrast sensitivity. After treatment, TST scores were significantly correlated with BCVA (P < 0.001), letter contrast sensitivity (P < 0.001), and aniseikonia (P < 0.01). TNO scores were significantly correlated with BCVA (P < 0.01) and letter contrast sensitivity (P < 0.01). TST and TNO scores after treatment were significantly correlated with BCVA at baseline (P < 0.01 for both). Deterioration of stereopsis in patients with BRVO was associated with changes in visual acuity and contrast sensitivity after treatment. Initial visual acuity is a prognostic factor for posttreatment stereopsis.