Share this article on:

Vision Therapy for Post-Concussion Vision Disorders

Gallaway, Michael; Scheiman, Mitchell; Mitchell, G. Lynn

doi: 10.1097/OPX.0000000000000935
Original Articles

Purpose To determine the frequency and types of vision disorders associated with concussion, and to determine the success rate of vision therapy for these conditions in two private practice settings.

Methods All records over an 18-month period of patients referred for post-concussion vision problems were reviewed from two private practices. Diagnoses of vergence, accommodative, or eye movement disorders were based on pre-established, clinical criteria. Vision therapy was recommended based on clinical findings and symptoms.

Results Two hundred eighteen patient records were found with a diagnosis of concussion. Fifty-six percent of the concussions were related to sports, 20% to automobile accidents, and 24% to school, work, or home-related incidents. The mean age was 20.5 years and 58% were female. Eighty-two percent of the patients had a diagnosis of an oculomotor problem [binocular problems (62%), accommodative problems (54%), eye movement problems (21%)]. The most prevalent diagnoses were convergence insufficiency (CI, 47%) and accommodative insufficiency (AI, 42%). Vision therapy was recommended for 80% of the patients. Forty-six per cent (80/175) either did not pursue treatment or did not complete treatment. Of the 54% (95/175) who completed therapy, 85% of patients with CI were successful and 15% were improved, and with AI, 33% were successful and 67% improved. Clinically and statistically significant changes were measured in symptoms, near point of convergence, positive fusional vergence, and accommodative amplitude.

Conclusions In this case series, post-concussion vision problems were prevalent and CI and AI were the most common diagnoses. Vision therapy had a successful or improved outcome in the vast majority of cases that completed treatment. Evaluation of patients with a history of concussion should include testing of vergence, accommodative, and eye movement function. Prospective clinical trials are necessary to assess the natural history of concussion-related vision disorders and treatment effectiveness.

*OD, PhD

OD, PhD, FAAO

MAS

Pennsylvania College of Optometry at Salus University, Philadelphia, Pennsylvania (MG, MS); and The Ohio State University College of Optometry, Columbus, Ohio (GLM).

Michael Gallaway Pennsylvania College of Optometry at Salus University 1200 W. Godfrey Ave Philadelphia, PA 19141, e-mail: mgallaway@salus.edu

Up to 3.6 million concussions are reported annually from causes such as motor vehicle accidents, sports, and household injuries.1,2 Traumatic brain injury (TBI) from blast injuries was the signature injury of the Iraq and Afghanistan wars. Studies with both military3–8 and civilian9–11 populations have found that oculomotor deficits such as convergence insufficiency (CI), accommodative insufficiency (AI), and saccadic dysfunction (SD) occur 30 to 42% of the time after concussion, which is much higher than the 5 to 15% estimated in the general population.12,13 A recent hospital-based study by Master et al. found very similar prevalence rates in adolescents after concussion, with CI and AI reported in approximately 50% of the sample.14

Treatment of concussion-related vision disorders often involves the use of vision therapy/rehabilitation to remediate vergence, accommodation, and versional eye movements. In a retrospective study in a university optometric clinic, Ciuffreda et al. reported that 90% of patients (n = 33) with TBI-related oculomotor abnormalities experienced improvement in signs and symptoms after vision therapy.15 In a recent placebo-controlled randomized clinical trial, the authors found clinically and statistically significant improvements in vergence, accommodative, and versional findings and visual attention.16–18

As awareness of concussion-related vision disorders has grown over the past 5 to 10 years, more optometrists are diagnosing and treating these disorders. Although there is strong evidence for the effectiveness of vision therapy for CI and accommodative dysfunction in non-concussed patients,19–22 there are limited published data on the treatment of concussion-related vision disorders. The purpose of the current study was to assess the frequency and types of concussion-related vision disorders and the effectiveness of treatment for these conditions in a private practice setting.

Back to Top | Article Outline

METHODS

Institutional Review Board approval was obtained to perform this retrospective chart review. A record search (18-month period from January 2012 to July 2013) was completed in two private practice settings that specialize in vision therapy/neuro-optometric rehabilitation. Eligibility criteria included all patients who were referred for visual evaluation after a medical diagnosis of concussion. Referral sources included sports medicine physicians, physiatrists, neurologists, pediatricians, athletic trainers, and physical therapists.

The diagnosis of concussion included a history of a direct or indirect force transmitted to the head causing signs or symptoms of headache, dizziness, nausea, balance problems, fatigue, light and noise sensitivity, sleep problems, cognitive deficits (memory, attention, executive functioning, reaction time), and emotional issues (irritability, sadness, nervousness, anxiety and depression).23,24 Patients were generally referred to the authors’ offices due to visual symptoms such as blur, diplopia, eye fatigue, headaches, and loss of place with reading and close work.

Vision testing included well-established clinical measures of accommodation, vergence, and ocular motility.25 Ocular alignment/phoria was measured with the cover test at distance and near with prism bar neutralization. Near point of convergence (NPC) break and recovery were measured with a 20/30 accommodative target and an accommodative convergence rule from the patient’s mid-brow. Step vergences to assess positive and negative fusional vergence blur, break, and recovery at 40 cm were performed with a prism bar. Vergence facility was assessed at 40 cm with a 12BO/3BI prism. Accommodative amplitude was measured with a push-up technique and 20/30 target to first sustained blur. Accommodative facility was assessed monocularly and binocularly with +2.00/−2.00 lens flippers. Saccadic speed and accuracy was measured with the Developmental Eye Movement Test (DEM), a timed visual-verbal test. In addition, the Convergence Insufficiency Symptoms Survey (CISS)26,27 was administered to monitor changes in symptoms with patients who were subsequently treated with vision therapy.

Diagnosis of vision disorders was based on the criteria listed in Table 1. Some patients had more than one diagnosis. Patients with convergence excess or accommodative insufficiency without CI were offered a reading prescription in addition to vision therapy.

TABLE 1

TABLE 1

Vision therapy consisted of once or twice weekly, 45-minute in-office sessions with approximately 15 min/day and 3 to 5 days per week of home activities. Therapy procedures were similar to those used in the Convergence Insufficiency Treatment Trials (CITT)19,21,22,28 with the addition of saccadic and pursuit activities such as Hart Chart, thumb rotations, rotating pegboard, and the Sanet Vision Integrator (SVI).25 Balance and head movements were added as needed for vestibular and vestibulo-ocular reflex stimulation. Criteria for success or improvement in signs and symptoms are listed in Table 2.

TABLE 2

TABLE 2

Statistical analyses were completed using SAS version 9.3 and SPSS version 21. One-sample t-tests were used to compare treatment improvements to zero. The area under the receiver-operator characteristic (ROC) curve is used as an indicator of the accuracy of the given patient characteristic to identify a patient with any vision disorder. It is constructed by plotting the value of sensitivity versus specificity for all possible cut-points for a given characteristic. An area of 1.0 represents a perfect test whereas an area of 0.50 represents a test no better than flipping a fair coin. Commonly used classification schemes characterize values over 0.90 as excellent, 0.80 to 0.90 as good, 0.70 to 0.80 as fair, 0.60 to 0.70 as poor, and values less than 0.60 as failure to discriminate.29 The ability of combinations of patient characteristics to discriminate was completed by first using a logistic regression to calculate the probability of vision disorder. These probabilities were then used to construct the ROC curve.

Back to Top | Article Outline

RESULTS

Two hundred eighteen records were found for patients who were referred after a concussion during the 18-month period. The mean age was 20.5 years and 58% were female. Sixty-seven percent of the patients were between the ages of 12 and 19. The causes of concussion were 56% sports-related accidents, 20% motor vehicle accident, 17% home accident, and 7% school or workplace accident. This was the first documented concussion in 70% of the patients. A summary of descriptive statistics for the sample is listed in Table 3.

TABLE 3

TABLE 3

Eighty-two percent of patients had at least one diagnosis. Sixty-two percent (135/218) of the sample had a binocular vision disorder, 54% (118/218) had an accommodative disorder, and 21.6% (47/218) had saccadic dysfunction. Table 4 lists the specific diagnoses.

TABLE 4

TABLE 4

Vision therapy was recommended for 175 of the 218 patients (80%). Of these, 80 (45.7%) either chose not to begin therapy (52) or did not complete therapy (28) (discussed below). Of the 95 patients who completed treatment, the most common diagnoses were CI, AI, and SD. For patients treated for CI, 85% (35/41) had a successful outcome and 15% (6/41) were improved. Among the patients with AI, 33% (13/39) were successful and 67% (26/39) were improved, and for patients treated for SD, 83% (15/18) were successful and 5% (1/16) were improved. The mean number (±SD) of VT sessions for patients who completed treatment was 14.6 (±5). The variability in the number of sessions reflects the variable time course of post-concussion treatment, which is less predictable than with non-concussion accommodative and vergence disorders.

Clinically and statistically significant changes were seen in NPC, positive fusional vergence (base out break and recovery) and CISS for patients with CI, and in accommodative amplitude and CISS in patients with AI (Table 5). Improved speed was seen on the DEM in patients with SD. Data on accommodative facility and vergence facility are not reported because these test results were often recorded as pass/fail and not quantified.

TABLE 5

TABLE 5

The ability of any one patient characteristic to discriminate those with and without a concussion-related vision disorder varied (Table 6). NPC break and recovery along with accommodative amplitude and DEM ratio percentile have fair accuracy (ROC area between 0.70 and 0.80). For example, the probability of a more receded NPC break observed in a patient with any vision disorder (relative to a patient with normal vision) is 0.79. The accuracy of DEM vertical time percentile and DEM errors is poor (values between 0.60 and 0.70). A combination of NPC break, accommodative amplitude, and DEM ratio percentile offers the greatest ability to discriminate between those with and without a vision disorder with an area under the ROC curve of 0.89 (95% CI 0.84–0.95).

TABLE 6

TABLE 6

Back to Top | Article Outline

DISCUSSION

The results of this retrospective study provide additional evidence about the prevalence of concussion-related vision disorders in patients referred to optometrists after concussion. The data also indicate an excellent success rate for patients electing to be treated with vision therapy. A recent review article30 confirmed that oculomotor abnormalities are much more common after concussion than the prevalence rates in the general population. This may be due to the widespread neural architecture of the visual system, which includes frontal and posterior cortical regions, cerebellum, cranial nerves, and interconnections between these areas. The neurometabolic and structural impacts of concussion in the form of diffuse axonal injury render the visual brain especially vulnerable.31 As a result, vision therapy is emerging as a treatment modality in concussion treatment, although more data are needed to assess effectiveness.32

The most common types of concussion-related vision disorders in this sample were CI, AI, and SD. This finding is consistent with previous literature in military subjects,3–8 the adult civilian population,9,33 and children.14 Other conditions such as convergence excess, comitant vertical deviations, and accommodative infacility were diagnosed less frequently. It is possible that some of these problems were premorbid, and that concussion may have exacerbated symptoms or increased the level of oculomotor dysfunction. It is interesting that there were no cranial nerve palsies in this sample, underscoring the notion that cranial nerve palsies are much more likely to occur from more focal damage seen in moderate or severe TBI.34

Seventy-eight percent of the patients reported having previous or concurrent vestibular therapy, reflecting the high prevalence of vestibular disorders after concussion.23,24 It may also reflect practice patterns in the authors’ practice area, where vestibular therapy administered by physical therapists sometimes includes convergence and ocular motor activities. Pre-existing vestibular dysfunction may also have contributed to this high prevalence.

Nearly 46% of patients for whom vision therapy was recommended either did not finish treatment or did not elect treatment in the authors’ practices. Some patients may have sought treatment elsewhere (including with physical therapists) or waited to see if resolution or improvement of their problems occurred through natural healing. Some were also prescribed reading glasses that may have lessened symptoms and reduced the motivation for therapy, whereas others may not have been able to afford the cost of vision therapy.

The ROC curve analysis suggests that a combination of NPC break, accommodative amplitude, and DEM ratio score has very good ability to predict the presence of a vision disorder. This information may be helpful for screening purposes for physicians and primary care optometrists.

In our sample, the success rates for vision therapy suggest that cortical neuroplasticity is still present and that treatment can be effective in this population. Strengths of this study were that all patients with concussion-related vision disorders over an 18-month period were included. In addition, the two investigators used similar assessment and treatment methods. Limitations of this study were its retrospective design, the use of unmasked examiners, the high percentage of patients who did not start or complete vision therapy, and a lack of a control group. It is possible that factors such as a placebo effect, regression to the mean, and continued natural healing accounted for some of the treatment effect. Despite these limitations, these data provide insight into the prevalence of vision problems of patients referred to optometrists post-concussion and about the effectiveness of vision therapy for concussion-related vision disorders. Currently, there is only one randomized clinical trial comparing treatments for concussion-related oculomotor problems. In this study by Ciuffreda and colleagues,16–18 all of the subjects (n = 12) were at least 1 year removed from their brain injury, and they still demonstrated significant ocular motor plasticity as the result of vision therapy. The evidence from the Ciuffreda study, plus the data from this large retrospective study, suggests that vision therapy is a valuable treatment for concussion-related vision disorders and argue for a large, multicenter randomized clinical trial that would be able to minimize factors that introduce bias in study results.

In summary, the high prevalence of concussion-related vision disorders supports the need for appropriate clinical testing of vergence, accommodation, and eye movements. Our data suggest vision therapy can be an effective intervention, but a large-scale randomized clinical trial is warranted to rigorously determine the effectiveness of vision therapy for concussion-related vision disorders and to better understand the time course of natural healing.

Back to Top | Article Outline

ACKNOWLEDGMENTS

Initially presented as a poster at the American Academy of Optometry annual meeting, New Orleans, Louisiana, in October 2015.

The authors have no financial conflicts to disclose.

Received January 13, 2016; accepted May 24, 2016.

Back to Top | Article Outline

REFERENCES

1. Langlois JA, Rutland-Brown W, Wald MM. The epidemiology and impact of traumatic brain injury: a brief overview. J Head Trauma Rehabil 2006;21:375–8.
2. Faul M, Xu L, Wald MM, et al. Traumatic Brain Injury in the United States: Emergency Department Visits, Hospitalizations and Deaths 2002–2006 Atlanta: Centers for Disease Control and Prevention, National Center for Injury Prevention and Control; 2010. Available at: http://www.cdc.gov/traumaticbraininjury/pdf/blue_book.pdf. Accessed May 24, 2016.
3. Goodrich GL, Flyg HM, Kirby JE, et al. Mechanisms of TBI and visual consequences in military and veteran populations. Optom Vis Sci 2013;90:105–12.
4. Brahm KD, Wilgenburg HM, Kirby J, et al. Visual impairment and dysfunction in combat-injured service members with traumatic brain injury. Optom Vis Sci 2009;86:817–25.
5. Cockerham GC, Goodrich GL, Weichel ED, et al. Eye and visual function in traumatic brain injury. J Rehabil Res Dev 2009;46:811–8.
6. Goodrich GL, Kirby J, Cockerham G, et al. Visual function in patients of a polytrauma rehabilitation center: a descriptive study. J Rehabil Res Dev 2007;44:929–36.
7. Stelmack JA, Frith T, Van Koevering D, et al. Visual function in patients followed at a Veterans Affairs polytrauma network site: an electronic medical record review. Optometry 2009;80:419–24.
8. Capó-Aponte JE, Urosevich TG, Temme LA, et al. Visual dysfunctions and symptoms during the subacute stage of blast-induced mild traumatic brain injury. Mil Med 2012;177:804–13.
9. Suchoff IB, Kapoor N, Waxman R, et al. The occurrence of ocular and visual dysfunctions in an acquired brain-injured patient sample. J Am Optom Assoc 1999;70:301–8.
10. Tannen B, Darner R, Ciuffreda KJ, et al. Vision and reading deficits in post-concussion patients: a retrospective analysis. Vis Dev Rehab 2015;1:206–13.
11. Alvarez TL, Kim EH, Vicci VR, et al. Concurrent vision dysfunctions in convergence insufficiency with traumatic brain injury. Optom Vis Sci 2012;89:1740–51.
12. Scheiman M, Gallaway M, Coulter R, et al. Prevalence of vision and ocular disease conditions in a clinical pediatric population. J Am Optom Assoc 1996;67:193–202.
13. Porcar E, Martinez-Palomera A. Prevalence of general binocular dysfunctions in a population of university students. Optom Vis Sci 1997;74:111–3.
14. Master C, Scheiman M, Gallaway M, et al. Vision diagnoses are common after concussion in adolescents. Clin Pediatr 2016;55:260–7.
15. Kapoor N, Ciuffreda KJ, Han Y. Oculomotor rehabilitation in acquired brain injury: a case series. Arch Phys Med Rehabil 2004;85:1667–78.
16. Thiagarajan P, Ciuffreda KJ. Effect of oculomotor rehabilitation on accommodative responsivity in mild traumatic brain injury. J Rehabil Res Dev 2014;51:175–91.
17. Thiagarajan P, Ciuffreda KJ. Accommodative and vergence dysfunctions in mTBI: treatment effects and systems correlations. Optom Vis Perf 2014;2:539–54.
18. Thiagarajan P, Ciuffreda K. Effect of oculomotor rehabilitation on vergence responsivity in mild traumatic brain injury. J Rehabil Res Dev 2013;50:1223–40.
19. Convergence Insufficiency Treatment Trial (CITT) Study Group. Randomized clinical trial of treatments for symptomatic convergence insufficiency in children. Arch Ophthalmol 2008;126:1336–49.
20. Scheiman M, Cotter S, Kulp MT, et al. Convergence Insufficiency Treatment Trial Study Group. Treatment of accommodative dysfunction in children: results from a randomized clinical trial. Optom Vis Sci 2011;88:1343–52.
21. Scheiman M, Gwiazda J, Li T. Non-surgical interventions for convergence insufficiency. Cochrane Database Syst Rev 2011;16:CD006768.
22. Scheiman M, Mitchell GL, Cotter S, et al. A randomized clinical trial of treatments for convergence insufficiency in children. Convergence Insufficiency Treatment Trial (CITT) Study Group. Arch Ophthalmol 2005;123:14–24.
23. Harmon KG, Drezner J, Gammons M, et al. American Medical Society for Sports Medicine position statement: concussion in sport. Clin J Sport Med 2013;23:1–18.
24. McCrory P, Meeuwisse WH, Aubry M, et al. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012. Br J Sports Med 2013;47:250–8.
25. Scheiman M, Wick B. Clinical Management of Binocular Vision: Heterophoric, Accommodative and Eye Movement Disorders. 4th ed. Philadelphia: Lippincott, Williams and Wilkins; 2014.
26. Rouse M, Borsting E, Mitchell GL, et al. Validity of the convergence insufficiency symptom survey: a confirmatory study. Convergence Insufficiency Treatment Trial (CITT) Investigator Group. Optom Vis Sci 2009;86:357–63.
27. Borsting EJ, Rouse MW, Mitchell GL, et al. Convergence Insufficiency Treatment Trial Group. Validity and reliability of the revised convergence insufficiency symptom survey in children aged 9 to 18 years. Optom Vis Sci 2003;80:832–8.
28. Scheiman M, Mitchell GL, Cotter S, et al. A randomized clinical trial of vision therapy/orthoptics versus pencil pushups for the treatment of convergence insufficiency in young adults. Convergence Insufficiency Treatment Trial (CITT) Study Group. Optom Vis Sci 2005;82:583–95.
29. Youngstrom EA. A primer on receiver operating characteristic analysis and diagnostic efficiency statistics for pediatric psychology: we are ready to ROC. J Pediatr Psychol 2014;39:204–21.
30. Hunt AW, Mah K, Reed N, et al. Oculomotor-based vision assessment in mild traumatic brain injury: a systematic review. J Head Trauma Rehabil 2015;19: epub ahead of print: doi 10.1097/HTR.0000000000000174.
31. Grady MF, Master CL, Gioia GA. Concussion pathophysiology: rationale for physical and cognitive rest. Pediatr Ann 2012;41:377–82.
32. Broglio SP, Collins MW, Williams RM, et al. Current and emerging rehabilitation for concussion: a review of the evidence. Clin Sports Med 2015;34:213–31.
33. Ciuffreda KJ, Kapoor N, Rutner D, et al. Occurrence of oculomotor dysfunctions in acquired brain injury: a retrospective analysis. Optometry 2007;78:155–61.
34. Ventura RE, Balcer LJ, Galetta SL. The neuro-ophthalmology of head trauma. Lancet Neurol 2014;13:1006–16.
Keywords:

vision therapy; vision rehabilitation; concussion; convergence insufficiency; accommodative insufficiency; near point of convergence

© 2017 American Academy of Optometry