1. Evaluating a binocular IPad game on fastening amblyopia treatment.
Done by: Ala’a AlSulaimi.
Supervised by: Lec. Noha M AlSaleem, MSc.
Introduction
Amblyopia (“lazy eye”) is a developmental disorder with early abnormal visual experience that disrupts neuronal circuitry in the visual cortex; it is the most common cause of visual loss in children(1,2). Amblyopia occurs in 2-4% of general population. Unilateral amblyopia is a difference in visual acuity of two lines or more with best correction(2).
Amblyopia should be detected and treated during the critical period which is believed to begin several months after birth until the age of 6-8 years(3).
The most known management of amblyopia is occlusion therapy which aims to improve the visual acuity and generally the binocular function while occluding the better eye and forcing the use of the amblyopic eye to avoid further suppression of the poorer eye(4).
Limitations with occlusion therapy are children with hyperactivity, stubbornness, poor compliance or mental problems(5). New studies have shown that using games on the IPad binocularly while patching the good eye can actually improve the vision quicker(4). This research studied the impact and the effect of IPad games on amblyopic eyes with patching.
Evaluation was conducted by testing their visual acuity and stereoacuity at baseline and a 4-weeks follow-up. Visual acuity was measured using LEA symbols test (Fig. 3) while sterioacuity was measured using the Randot stereo-test (Fig. 4).
Fig 4. Randot stereo-test
Fig 3. LEA symbols test
Fig 6. Comparison of the baseline- and 4-weeks primary outcome of Stereoacuity in both groups.
Statistical Analysis
Statistical analysis was performed by using a commercially available statistical software package (SPSS for Mac, version 23.0). The comparison between groups was conducted by paired two-sided t-test. P-values of 0.05 or less were considered statistically significant.
Discussion
Prior studies used reduced fellow eye contrast to allow amblyopic adults to experience binocular vision in supervised laboratory training sessions have reported similar visual acuity improvements like observed in the present study (0.17–0.26 logMAR over 1–9 weeks).(3,6)
However, stereoacuity in the present study did not significantly improve in amblyopic children compared with the prior studies which have reported 50-60% improvements in stereoacuity. Differences between the present study and these prior reports may have resulted from the use of random dot stereoacuity tests in the present study and contour or hybrid stereoacuity tests in the adult studies. The relationship between stereoacuity and visual acuity is complex, and stereoacuity alone does not fully characterize binocular vision. Therefore, lack of change in random dot stereoacuity during the present study should not be construed as inconsistent with the rationale for binocular treatment.
The present study was limited by the fact that it was not a randomized clinical trial; rather, it was an exploratory cohort study that was designed to determine whether an improvement in visual acuity could be observed in amblyopic preschool children following a brief, 4-week experience playing binocular iPad games. In addition, the sample size was relatively small which was due to the shortage of time. Moreover, a 4-weeks primary outcome was not efficient to make a final decision about the effectiveness of the binocular IPad game. Two more follow-ups and a 3 month follow-up after the cessation of the treatment will be done to ensure the stability of the visual acuity improvement.
Results
Thirty six amblyopic children aged 3.6–9.6 years were assigned to either the binocular treatment group or patching group; two dropped from the study before the 4-week primary outcome visit because of the child’s lack of interest in playing the iPad games. Baseline characteristics are summarized in (Table 1).
In the binocular iPad group, mean visual acuity (± Standard Error) improved from 0.55±0.05 logMAR (20/70 Snellen equivalent) at baseline to 0.38±0.05 (20/50 Snellen equivalent) at 4 weeks (mean improvement=0.17±0.04 logMAR; paired t-test=3.85; P<0.05). (Table 2).
On the other hand, mean visual acuity (± Standard Error) in the patching group improved from 0.45±0.06 logMAR (20/55 Snellen equivalent) at baseline to 0.35±0.05 (20/45 Snellen equivalent) at 4 weeks (mean improvement=0.10±0.02 logMAR; paired t-test=4.06; P<0.05). (Table 2).
Regarding the streoacuity in both groups, there was no significant improvement in the iPad group (mean improvement= 582 sec of arc; paired t-test= 2.02; P= 0.06) and in the patching group (mean improvement= 163 sec of arc; paired t-test= 0.66; P=0.51). (Table 2).
Nevertheless, BCVA and stereoacuity were not significantly associated with age, gender or prior treatment to amblyopia in both groups.
Table 1. Data demography.
Aims
- Evaluate the impact of IPad games on fastening amblyopia treatment with occlusion therapy.
- Compare the improvement of children vision that played the game with those who didn’t.
- Compare the IPad game with patching against patching alone to see which is superior.
Hypothesis
We assumed that using IPad games while doing patching therapy for amblyopic children, during the critical period, will fasten their treatment compared with other visual activities. This was evaluated by comparing the change on visual acuity and stereoacuity as an indication of amblyopia treatment improvement.
Table 2. Comparison of the baseline- and 4-weeks primary outcome of BCVA and Stereoacuity in both groups
Materials and Methods
Study design: Observational Longitudinal design.
Subjects: 36 amblyopic children from King Khalid Eye Specialist Hospital, age ranged from 3 to 9 years were enrolled in this study.
Method: Subjects were assigned (1:1) to either:
Binocular treatment group: binocular IPad game play 1 hour per day; 7 days a week, with a minimum of 4 days for children who could not play 7 days a week, with 2 hours a day patching at a different time than iPad game play (n=17).
Patching group: patching 2 hours a day; 7 days a week without playing the game. (n=19).
Materials: Treatment was full cycloplegic optical correction and a popular puzzle video game named Tetris. Tetris involves connecting blocks of different shapes and displacing them together as an integrated whole before falling to the bottom; Tetris trains the two eyes to work together and was used with anaglyph red/green glasses. (Fig. 1+2).
There was a personalized design schedule to record both the hours spent on playing the game and the patching time.
Conclusion
We evaluated the effectiveness of using binocular IPad game as a home treatment for amblyopia in children 3 to 9 years of age. Children who played the binocular IPad games for 1 hour a day over 4 weeks with 2 hours of patching had visual acuity improvement more than that achieved by only patching for 2 hours daily for 4 weeks .
The results of this study suggest that a binocular approach to amblyopia treatment may be an effective treatment for amblyopia in preschool children.
* P-value statistically significant
References
Knox P., Simmers A., Gray L. & Cleary M. (2012). An Exploratory Study: Prolonged Periods of Binocular Stimulation Can Provide an Effective Treatment for Childhood Amblyopia. Investigative Ophthalmology & Visual Science, 53(2):
Repka X., Kraker T. & Holmes M. (2014). Atropine vs. Patching for Treatment of Moderate Amblyopia: Follow-up at 15 Years of Age of a Randomized Clinical Trial. The Journal of the American Medical Association, 132(7):
Hess R., Mansouri B. & Thompson B. (2010). A new binocular approach to the treatment of amblyopia in adults well beyond the critical period of visual development. Restorative Neurology and Neuroscience Journal, 28(6):
Birch E., To L., Jost R., Jost S., Stager D., Dao L. & Li S. (2013). Binocular IPad Treatment for Amblyopia. Investigative Ophthalmology & Visual Science, 54(15):4981.
Hess R., Thompson B. & Black J. (2012). An iPod treatment of amblyopia: an updated binocular approach. Optometry, 83(2):87-94.
Fig 1. The anaglyphic Tetris game .
Fig 2. The anaglyph glasses .
Fig 5. Comparison of the baseline- and 4-weeks primary outcome of BCVA in both groups.