Namaeh, Mashael OD, PhD; Scheiman, Mitchell M. OD, PhD, FAAO; Yaramothu, Chang PhD; Alvarez, Tara L. PhD

A Normative Study of Objective Measures of Disparity Vergence and Saccades in Children 9 to 17 Years Old

publication date
February 5, 2020
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This study establishes normative data for objective outcome measures of vergence and saccade eye movements for the pediatric population. These data should facilitate future clinical trial design.


This study was designed to establish normative data for objective measures of disparity vergence and saccades in children between the ages 9 and 17 years using an objective binocular eye movement tracking system.


Participants (aged 9 to 17 years) had a vision examination including refraction, accommodative, and binocular vision testing. Eligibility criteria included 20/25 visual acuity with best correction, normal accommodation, and binocular vision. The ISCAN RK-826PCI binocular tracking system (ISCAN, Woburn, MA) was used to objectively record horizontal, symmetrical disparity vergence, and saccadic eye movements. Parameters assessed included peak velocity, time to peak velocity, latency, and response amplitude for both disparity vergence and saccades.



One hundred eighteen participants were recruited (54.94% female; mean age, 13.5 years), and 77.1% (91/118) of the participants completed the assessment with usable data. A sample of the normative data included peak velocity (°/s), which had a mean ± standard deviation of 25.4 ± 2.9, 22.0 ± 3.0, 225 ± 16.7, and 332.5 ± 20.5 for 4° convergence, 4° divergence, 5° saccades, and 10° saccades, respectively. The mean ± standard deviation for the latency (seconds) measures were 0.28 ± 0.1, 0.28 ± 0.16, 0.23 ± 0.05, and 0.23 ± 0.05 for 4° convergence, 4° divergence, 5° saccades, and 10° saccades, respectively.


Normative data enable researchers to have benchmark results for comparison with patient populations with binocular dysfunction. These objective disparity vergence measures can serve as outcome measures in future clinical trials to assess the effectiveness of therapeutic interventions by determining whether post-treatment results are similar to normal data.


I haven't actually used the optometrist side, so my review is limited to the vision therapy offered.  This office was recommended by my occupational therapist for the treatment of my double vision following a stroke.

Claire A.

Love this location. I had a brain injury accident from day one one. All the team make you feel you still important and hope in the horizon after when the medical system fell you miserably. Dr. Ikeda very professional and very understanding about your issue. Two tombs up.

Jim K.

My husband and I were immediately impressed with Dr Ikeda. I was hit by a car while cycling which caused broken bones and three brain injuries. The brain injuries caused double vision. Dr. Ikeda examined my eyes and got me started on vision therapy with his occupational therapist who specializes in vision therapy.  She (Chris) is absolutely great.  I am impressed with the array of tools used to help recover my binocular vision.  I am doing things I never thought were possible (balance boards etc).  Chris pushes me and keeps me motivated. I really enjoy my sessions with her.  The office staff is always friendly and they have a wonderful appointment reminder tool that makes it easy to keep my calendar up to date. I am happy the rehab center at Little Co. of Mary recommended them!!

Teresa S.

The Vision Therapy is handled in a separate office through a different door from the shared waiting room. Chris, the vision therapist, has a wide and varied assortment of tools, equipment and resources to best evaluate and treat most vision issues. After just a few visits, my double vision became easier to control, using exercises developed during the therapy process. It was time well-spent.

Joe M.

I have been coming here since I can remember. I love it here. The staff is so amazing and nice. They explain everything they gonna do and never make you feel rushed. Dr. Ikeda has always been my doctor and I would never want another one. He is the doctor for my whole family and is always asking how everyone is doing. I am also so crazy about picking out my frames and have to try so many and each person who helps me take the time and lets me try them all on. I would never want to go anywhere else! I definitely would recommend this office to anyone looking for a great eye doctor.

Kayla W.

This is not for the eye exam but for the frames selection portion. I brought my prescription from Kaiser here with my VSP insurance. The reception staff was very polite and professional.  Manny helped me to pick out frames and explain my coverage.  Very helpful and patient not like the individual at the other place I rated here on Yelp.  I was running late and he still helped me and was not bothered at all.  I am so glad I came here ..........very pleased.

Very professional staff and pleasant.

Daniel G.
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