Intraexaminer repeatability and agreement in stereoacuity measurements made in young adults

AIM: To determine the repeatability and agreement of stereoacuity measurements made using some of the most widely used clinical tests: Frisby, TNO, Randot and Titmus.METHODS: Stereoacuity was measured in two different sessions separated by a time interval of at least 24 h but no longer than 1wk in 74 subjects of mean age 20.6y using the four methods. The study participants were divided into two groups: subjects with normal binocular vision and subjects with abnormal binocular vision.RESULTS: Best repeatability was shown by the Frisby and Titmus [coefficient of repeatability(COR): ±13 and±12s arc respectively] in the subjects with normal binocular vision though a clear ceiling effect was noted.In the subjects with abnormal binocular vision, best repeatability was shown by the Frisby(COR: ±69s arc)and Randot(COR: ±72s arc). In both groups, the TNO test showed poorest agreement with the other tests.CONCLUSION:Therepeatabilityofstereoacuitymeasures was low in subjects with poor binocular vision yet fairly good in subjects with normal binocular vision with the exception of the TNO test. The reduced agreement detected between the tests indicates they cannot be used interchangeably.

Factors influencing stereoacuity levels after surgery to correct unilateral developmental cataracts in children

·AIM: To evaluate factors influencing stereoacuity after surgery to correct unilateral developmental pediatric cataracts. ·METHODS: We retrospectively surveyed 110 patients who had undergone removal of unilateral acquired developmental cataracts and primary posterior chamber intraocular lens implantation between February 1992 and December 2009. In all patients, stereoacuity was assessed using the Titmus test at the last follow -up period of minimum 2 years after surgery. Patients were divided into two groups according to the extent of stereoacuity : group 1 ( = 42 ) had stereoacuity values ≤ 100sec/arc and group 2 ( =68) values 】100sec/arc. The values of ten parameters associated with stereoacuity were measured in each group: Cataract types, preoperative best corrected visual acuity (BCVA) of the affected eyes, preoperative inter -ocular difference of BCVA, age at cataract surgery, operative method, secondary cataract, postoperative strabismus, postoperative BCVA of the affected eyes, postoperative inter-ocular difference of BCVA, and anisometropia. ·RESULTS: The extent of stereoacuity was significantly associated with both operative method and secondary cataract ( =0.000 and =0.016, respectively). All patients in whom the posterior capsule was preserved, had poor stereoacuity 】100sec/arc. Significant correlations with the extent of stereoacuity were found with postoperative strabismus ( =0.048),postoperative BCVA of the affected eyes ( =0.002), anisometropia ( =0.034). ·CONCLUSION: Postoperative stereoacuity was better in patients who underwent either optic capture or anterior vitrectomy after posterior continuous curvilinear capsulorhexis, and who didn’t develop secondary cataracts or strabismus postoperatively. Furthermore, postoperative BCVA of the affected eyes, and anisometropia influenced the stereoacuity of the patients surgically treated for unilateral developmental pediatric cataracts. ·

A randomized study of network-based perception learning in the treatment of amblyopia children

AIM:To compare the effectiveness of network-based perception learning(NBPL) and traditional training in the treatment of amblyopia children.METHODS:This randomized controlled clinical trial recruited 56 participants aged 4-12 y with anisometropic and/or strabismic amblyopia. Participants were randomly divided into two groups:the NBPL group(n=28) who received patching and NBPL for 3 mo, and the control group(n=28) who got 3 mo of patching and traditional training. Best-corrected visual acuity(BCVA) in the amblyopic eye and stereoacuity were measured and compared at baseline, 1, 2, and 3 mo post-randomization.RESULTS:There were no significant differences in age, gender ratio, and BCVA between the two groups at baseline. At 3 mo, most patients gained lines(2 log MAR lines on average) of BCVA in both groups except one 11-year-old girl in the control group(P<0.05). But no significant difference in BCVA improvement of the amblyopic eye between the two groups was found(P=0.725), and amblyopia resolved(BCVA of 0.1 log MAR or better or within 1 log MAR line of the fellow eye) for 13(46.4%) participants in both groups. The number of patients with improvement of stereoacuity was 25 and 13 in the NBPL group and control group(P=0.041), respectively, and a significant difference exists in the distribution of stereopsis at 3 mo between the two groups(P=0.015). Besides, in patients with measurable stereopsis improvement degree and space for improvement in the two groups, the NBPL group also achieved better stereoscopic improvement than the control group(10/11 vs 4/11, P<0.05).CONCLUSION:The NBPL system has a significant effect on the improvement of BCVA and stereoacuity of amblyopia children and is better than traditional training in terms of stereoacuity improvement. Perceptual learning visual training may play a more important role in the treatment of amblyopia in the future.

Association between Anisometropia as Well as Visual Acuity, Aniseikonia, and Stereopsis in the Absence of Strabismus

Objective: The current study aimed to assess the association between the type of anisometropia and its effects on monocular and binocular best-corrected vision acuity (BCVA), aniseikonia, and stereopsis in the absence of strabismus. Methods: In total, 162 individuals with anisometropia and healthy eyes and without a previous history of amblyopia therapy and eye surgery were included in the analysis. According to spherical and cylindrical components and spherical equivalent, they were divided into the spherical hyperopic anisometropia (SHA, n = 31), spherical myopic anisometropia (SMA, n = 45), astigmatic or cylindrical hyperopic anisometropia (CHA, n = 22), and astigmatic or cylindrical myopic anisometropia (CMA, n = 64) groups. Patients without anisometropia (NA, n = 188) were classified under the control group. The effects of anisometropia on monocular and binocular BCVA, aniseikonia, and stereoacuity were examined. Results: The NA group had a significantly lower LogMAR of BCVA of the right eye (RE), left eye (LE), worse eye than the SHA, SMA, CMA, and CHA groups. Moreover, the SMA group had significantly lower LogMAR of BCVA than the CHA group (p Conclusion: Worse visual levels of the RE, LE, worse eye, BCVA difference, and lower stereopsis were evidenced in each type of anisometropia defined in this study. Cylindrical hyperopic anisometropia (CHA) resulted in a statically significant worsening VA level and stereopsis than cylindrical myopic (CMA) or spherical myopic anisometropia.