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Original Contribution  |   November 2016
Effect of Osteopathic Cranial Manipulative Medicine on Visual Function
Author Notes
  • From Nova Southeastern University College of Osteopathic Medicine in Fort Lauderdale, Florida (Dr Sandhouse); Nova Southeastern University College of Optometry in Fort Lauderdale, Florida (Drs Shechtman and Fecho); and private practice in Ocoee, Florida (Dr Timoshkin). Dr Sandhouse holds a master’s degree in educational leadership. 
  • Support: This study was supported by the Osteopathic Heritage Foundation grant number 02-09-520. 
  •  *Address correspondence to Mark Sandhouse, DO, MS, Health Professions Division, Nova Southeastern University College of Osteopathic Medicine, 3200 S University Dr, Rm 1401, Fort Lauderdale, FL 33328-2018. E-mail: marksand@nova.edu
     
Article Information
Neuromusculoskeletal Disorders
Original Contribution   |   November 2016
Effect of Osteopathic Cranial Manipulative Medicine on Visual Function
The Journal of the American Osteopathic Association, November 2016, Vol. 116, 706-714. doi:10.7556/jaoa.2016.141
The Journal of the American Osteopathic Association, November 2016, Vol. 116, 706-714. doi:10.7556/jaoa.2016.141
Abstract

Context: The effects of osteopathic cranial manipulative medicine (OCMM) on visual function have been poorly characterized in the literature. Based on a pilot study conducted by their research group, the authors conducted a study that examined whether OCMM produced a measurable change in visual function in adults with cranial asymmetry.

Study Design: Randomized, controlled, double-blinded clinical trial. The intervention and control (sham therapy) were applied during 8 weekly visits, and participants in both groups received 8 weekly follow-up visits.

Participants: Adult volunteers aged between 18 and 35 years with unremarkable systemic or ocular history were recruited. Inclusion criteria were refractive error between 6 diopters of myopia and 5 diopters of hyperopia, regular astigmatism of any amount, and cranial somatic dysfunction.

Intervention: All participants were evaluated for cranial asymmetry and randomly assigned to the treatment or sham therapy group. The treatment group received OCMM to correct cranial dysfunctions, and the sham therapy group received light pressure applied to the cranium.

Outcome Measures: Preintervention and postintervention ophthalmic examinations consisted of distance visual acuity testing, accommodative system testing, local stereoacuity testing, pupillary size measurements, and vergence system testing. A χ2 analysis was performed to determine participant masking. Analysis of variance was performed for all ophthalmic measures.

Results: Eighty-nine participants completed the trial, with 47 in the treatment group and 42 in the sham therapy group. A hierarchical analysis of variance revealed statistically significant within-groups effects (P<.05) from before the intervention to visit 16 in distance visual acuity of both eyes, local stereoacuity, Donder pushup in both eyes, and near point of convergence break and recovery. For treatment group vs sham therapy group, a statistically significant effect (P<.05) was observed from before the intervention to visit 16 in pupillary size under bright light in the left eye and in near point of convergence break.

Conclusion: Osteopathic cranial manipulative medicine may affect visual function in adults with cranial asymmetry. Active motion testing of the cranium for somatic dysfunction may affect the cranial system to a measurable level and explain interrater reliability issues in cranial studies. (ClinicalTrials.gov number NCT02728713)

Keywords: ophthalmic, osteopathic cranial manipulative medicine, osteopathic manipulative treatment, vision

Anecdotal evidence indicates that patients who undergo osteopathic cranial manipulative medicine (OCMM) claim to have an improvement in visual function. Although existing studies have described the effect of OCMM on intraocular pressure, range of the visual field, and binocular alignment of the eyes, few studies1-8 have described changes in visual function resulting from OCMM, other than in cases associated with visual perception deficit or closed head trauma. 
A pilot study9 conducted by our research group demonstrated that a single OCMM session produced statistically significant differences (P<.05) within groups for multiple ophthalmic parameters. In the present study, we examined whether there was evidence of a measurable change in visual function after OCMM. Three important limitations of the pilot study were addressed in the design of the current study: sample size, number of treatment sessions, and follow-up to measure the temporal permanence of effects. 
Methods
Design
This study was designed as a randomized, double-blind, sham therapy–controlled, repeated-intervention clinical trial (ClinicalTrials.gov number NCT02728713) of OCMM in volunteer participants. The Nova Southeastern University (NSU) institutional review board approved the procedures and interventions used in this study. 
Study Population
Participants were recruited from the student and employee populations at the Health Professions Division of NSU in Fort Lauderdale, Florida. All prospective participants were required to complete a screening questionnaire and were provisionally admitted to the study if they met the following inclusion and exclusion criteria: (1) age between 18 and 35 years; (2) refractive error between 6 diopters (D) of myopia and 5 D of hyperopia with any amount of regular astigmatism; (3) best-corrected visual acuity to 20/40 OU or better; (4) no known active ophthalmic or systemic disease; (5) not known to be pregnant at the time of the study; (6) no history of previous closed head trauma or traumatic brain injury; (7) no history of receiving OCMM; and (8) not enrolled in the previous pilot study. Additionally, students from the College of Osteopathic Medicine and College of Optometry in the NSU Health Professions Division were excluded from this study to prevent bias based on knowledge of the osteopathic manipulative treatment and visual assessment procedures used in the study. 
A predoctoral osteopathic principles and practice fellow reviewed the screening questionnaires to assess the eligibility of prospective participants and also obtained written informed consent from participants entered into the study. Participants who completed the study received $250. 
Randomization, Assessment, and Interventions
All provisionally admitted participants were evaluated for cranial strain patterns of sphenobasilar synchondrosis (SBS). Any provisionally admitted participant who had no cranial strain patterns of the SBS was excluded from the study. Participants were then randomly assigned to either the treatment or sham therapy group by use of a randomization table generated by Excel 2003 software (Microsoft Corporation). Participants were not advised of their group assignments at any time during the study. 
Both groups underwent an initial ophthalmic examination consisting of best-corrected distance visual acuity testing, local and global stereopsis testing, Donder pushup (accommodative system) testing, near point of convergence (NPC) testing, and pupil testing in both bright and dim lighting. All testing procedures were noninvasive and required no eye drops. The specific tests used to measure the ophthalmic parameters were the same as those used in the pilot study. The descriptions are reproduced from the pilot study9 and are as follows: 
  • Best-corrected distance visual acuity testing—Determines the ability to distinguish fine detail at a distance. An Early Treatment of Diabetic Retinopathy Study distance contrast sensitivity chart was used. The participant was asked to read the letters from the chart with each eye individually. They read from the top of the chart down until he or she reached a line where a minimum of 3 letters could not be read. The participant was scored on the number of letters that he or she read correctly out of a total of 70. Participants who had corrective lenses prescribed wore their spectacles or contact lenses during the testing.
  • Donder pushup (accommodative system) testing—Determines the ability to focus on near objects. This examination consisted of accommodative amplitude testing using a Donder pushup card. Participants were required to read a small letter (or number) from a card with one eye while covering the other eye. The card was moved closer to the participants until the first sustained blur point was reached. The accommodative amplitude (in diopters) was recorded as the reciprocal of the distance (in meters) from the card to the participants at the first sustained blur.
  • Local stereoacuity testing—Determines the ability to appreciate depth. A Random Dot “E” test was used, with the test booklet placed at a distance of 40 cm. This test can identify the smallest target separation needed for the participant to perceive depth. The participant was required to wear polarized glasses and identify shapes in the booklet until he or she made 2 consecutive errors. The last correct response was recorded as the participant’s local stereopsis in seconds of arc. This test can measure stereoacuity up to 20 seconds of arc. (Global stereoacuity testing was performed only on the first visit to make sure that the participant met the inclusion criteria.)
  • Pupillary testing—Provides information on the neurologic system. Measurement of pupil size in bright light was performed with all room lights turned on and a stand lamp set behind the participant. He or she was asked to fixate at a distant target. The size of each pupil was measured by placing a pupillary (hemisphere) scale against the participant’s face and sliding the gauge until the semicircle under the eye was the same size as the pupil being measured. Measurement in dim light was done in the same manner, but the overhead lights were turned off and a stand lamp was used as a backlight.
  • Retinoscopy—Assesses spectacle prescription. The participant was asked to look straight ahead while viewing a distant target, and a streak of light was shined in his or her eye. Lenses were used to change the appearance of the reflex until the examiner saw a bright flash of light. After compensating for the examiner’s working distance, the participant’s prescription was obtained. This procedure was performed only at the first visit to assess eligibility for the study and to confirm that the current prescription was appropriate for testing.
  • Vergence system testing—Determines the ability to use both eyes (fusion). The following tests were used:
     
    • Cover test with prism neutralization—An objective measurement of alignment of the eyes. First, the unilateral cover test was performed by placing the cover paddle over the left eye while viewing the right eye for movement. This procedure was repeated for the other eye. Movement indicated a strabismus, in which case the participant was excluded from the study. Next, the alternating cover test was performed. The cover paddle was placed over the left eye, and some time was allowed to help break fusion. The cover paddle was then rapidly placed over the other eye without giving the participant time to regain fusion. If a movement was seen, the patient was said to have a phoria. The magnitude of this deviation was measured with a prism during the alternating cover test. Different prisms were placed in front of the participant’s eye until no movement was seen. Additional prisms were added until the movement reversed direction. If multiple prisms produced no movement until the movement reversed direction, the midpoint of those that caused no movement was recorded.
    • Near point of convergence—Subjective measurement of the maximum ability to cross the eyes (converge) on a near target. The participant was required to view a small letter as it was moved toward him or her. The target was slowly moved toward the participant until the he or she reported seeing double images, until one eye deviated, or until the target reached the participant’s nose. The distance (in centimeters) was recorded as the NPC break. The target was then moved away from the patient until it again appeared as a single image or until the participant’s eyes regained fixation on the target. The distance (in centimeters) was recorded as the NPC recovery.
Participants with strabismus or refractive error outside the inclusion criteria during initial ophthalmic testing were excluded from the study. 
Participants in the treatment group underwent balanced membranous tension, a cranial manipulation technique, to correct the SBS dysfunctions found on examination. The technique was applied by exaggeration of the somatic dysfunctions toward a point of balanced forces and held until a tissue release was noted. Participants in the sham therapy group had a light pressure applied to the cranium. The interventions for both groups were performed with the participant supine on the treatment table for approximately 5 minutes. No other interventions were performed during the visits. 
After completion of the assigned intervention, participants were reassessed for the presence of SBS strain patterns and subsequently underwent a repeated ophthalmic examination. The osteopathic physician (M.E.S.) performing the cranial assessment and both interventions was blinded to the ophthalmic findings, and the optometrists (D.S. and G.F.) were unaware of the results of the cranial assessments or the group assignments. 
Concerns regarding interexaminer reliability were addressed by having the same osteopathic physician (M.E.S.) examine and apply the intervention to all participants. This physician was trained by the Osteopathic Cranial Academy and had been in clinical practice for more than 16 years at the time of the study. Assessment of cranial strain patterns has been shown to have substantial intraobserver reliability when performed on healthy participants.10 Additionally, the preintervention and postintervention ophthalmic examinations at each visit were also performed by the same optometrist (D.S. or G.F.). A predoctoral fellow served as a record keeper to maintain all information and to perform the randomization procedures. 
This protocol was carried out for a total of 8 visits, no less than 1 week apart, during the intervention phase. All participants then returned for 8 follow-up visits no less than 1 week apart during which only the ophthalmic measurements were performed. A questionnaire was filled out by each participant after the intervention phase to assess their perception of group assignment. The participant flow is summarized in the Figure. 
Statistical Analysis
Descriptive statistics using SPSS statistical software version 15.0 for Windows (SPSS Inc) were calculated for all study variables. A 2-way (repeated-measures) analysis of variance was performed for data from each of the measured variables (α=.05) for net change in preintervention vs postintervention values. A t test for paired samples was performed to assess equality of means in terms of participant age for both treatment and sham therapy groups. A χ2 analysis was performed to compare participants’ perceived group vs their actual group assignment. 
Figure.
Flow chart of the study of the effects of osteopathic cranial manipulative medicine (OCMM) on visual function.
Figure.
Flow chart of the study of the effects of osteopathic cranial manipulative medicine (OCMM) on visual function.
Results
One hundred thirteen participants were screened and enrolled in the study. Eighty-nine participants completed the study: 47 in the treatment group and 42 in the sham therapy group. None of the participants who dropped out of the study did so because of adverse effects. The mean (SD) age of the participants was 25.24 (5.18) years. Eighty-four percent of the participants were women. These demographics were similar to those in the pilot study. No statistically significant difference in age or sex distribution was present between the treatment and sham therapy groups. A χ2 analysis of data from the questionnaires demonstrated that participants were well blinded to which group they were assigned (χ2=0.66; P=.42). 
The mean (SD) values for each of the measured variables are shown in Table 1. Statistically significant differences were observed in within-group preintervention vs postintervention main effects in both treatment and sham therapy groups (P<.05) in best-corrected distance visual acuity of the right eye and left eye, local stereoacuity, Donder pushup, and NPC break and recovery (Table 2). 
In addition, a statistically significant difference was observed in preintervention vs postintervention effects for the treatment group vs the sham therapy group (P<.05) in pupillary size measured under bright light OS (F2,160=3.14; P=.05; 1−β=.60) and NPC break (F2,134=3.47; P=.03; 1−β=.64). 
Discussion
The results of the present study suggest that the application of OCMM may affect visual function. Several main effects were observed in both treated and sham therapy participants after the intervention. Participants in both groups showed an improvement in distance visual acuity, with each eye able to read more letters on the Early Treatment of Diabetic Retinopathy Study visual acuity chart after the intervention than before the intervention. Participants in both groups also showed a postintervention decrease in accommodative amplitude in both eyes, indicated by a decrease in diopters as measured by Donder pushup testing. Furthermore, participants in both groups showed a postintervention decrease in local stereoacuity indicated by a decrease in seconds of arc; altered NPC break indicated by an increase in target distance for the first reported seeing double stimulus images; and altered NPC recovery indicated by an increase in target distance for the first reported view of the stimulus as a single object. In most cases, these changes were observed at the first postintervention visit (visit 9) and remained throughout the postintervention measurement period (visit 16). In addition, the 2 variables that demonstrated a statistically significant change between treatment and sham therapy groups in the present study were pupillary size measured under bright light for the left eye and NPC break. Both variables increased from preintervention to the end of the study. 
The results in this study are similar to those obtained in the pilot study. The pilot study demonstrated statistically significant within-group changes in the following parameters: distance visual acuity in both eyes, local stereoacuity, pupillary size in dim light for both eyes, and NPC break and recovery. The pilot study also demonstrated a statistically significant between-group change in pupillary size in bright light in the right eye, with an increase in the treatment group vs a decrease in the sham therapy group.9 Although some of the variables affected are different in the present study than the pilot study, distance visual acuity in both eyes, local stereoacuity, and NPC break and recovery demonstrated statistically significant within-group changes in both studies. 
Table 1.
Effect of Osteopathic Cranial Manipulative Medicine on Visual Acuity: Optometric Variables (N=89)a
Treatment Group (n=47) Control Group (n=42)
Postintervention Postintervention
Variable Before Intervention Visit 9 Visit 16 Before Intervention Visit 9 Visit 16
Distance VAb
OD 54.26 (7.18) 56.74 (6.78) 56.98 (6.78) 53.50 (9.88) 55.54 (10.57) 55.48 (10.49)
OS 55.09 (6.10) 56.46 (6.27) 56.94 (6.20) 53.95 (9.54) 56.90 (5.91) 57.57 (5.73)
Donder Pushup, D
OD 10.74 (2.35) 9.86 (2.28) 8.95 (1.76) 11.46 (2.93) 10.02 (3.26) 9.83 (2.88)
OS 10.66 (2.33) 9.79 (2.39) 9.10 (1.80) 11.87 (3.15) 9.91 (2.74) 9.95 (3.09)
Local Stereoacuity, s arc 35.26 (18.89) 28.70 (16.34) 28.40 (16.05) 38.78 (22.44) 31.75 (22.69) 30.12 (21.65)
Pupil Size, mm
Bright light OD 3.41 (0.93) 3.41 (0.86) 3.66 (0.99) 3.56 (1.12) 3.48 (1.08) 3.64 (1.21)
Bright light OS 3.41 (0.96) 3.43 (0.88) 3.69 (1.02) 3.58 (1.12) 3.54 (1.10) 3.64 (1.22)
Dim light OD 5.55 (1.20) 5.56 (1.07) 5.41 (1.38) 5.55 (1.26) 5.41 (1.04) 5.43 (1.22)
Dim light OS 5.55 (1.29) 5.54 (1.06) 5.45 (1.34) 5.57 (1.27) 5.46 (1.07) 5.45 (1.26)
Vergence
CT near, prism D −1.96 (3.96) −2.13 (5.19) −1.98 (5.12) −2.52 (3.34) −1.93 (3.80) −1.83 (4.01)
NPC break, cm 5.47 (2.67) 7.34 (3.50) 7.29 (3.05) 6.24 (2.27) 6.75 (3.17) 7.81 (3.40)
NPC recovery, cm 9.55 (3.03) 11.21 (2.90) 13.36 (17.26) 10.61 (2.95) 11.19 (3.20) 11.32 (3.01)

a Data are given as mean (SD).

b Each participant was scored on the number of letters that he or she read correctly, out of a total of 70.

Abbreviations: CT, cover test with prism neutralization; D, diopters; NPC, near point of convergence; OD, right eye; OS, left eye; VA, visual acuity.

Table 1.
Effect of Osteopathic Cranial Manipulative Medicine on Visual Acuity: Optometric Variables (N=89)a
Treatment Group (n=47) Control Group (n=42)
Postintervention Postintervention
Variable Before Intervention Visit 9 Visit 16 Before Intervention Visit 9 Visit 16
Distance VAb
OD 54.26 (7.18) 56.74 (6.78) 56.98 (6.78) 53.50 (9.88) 55.54 (10.57) 55.48 (10.49)
OS 55.09 (6.10) 56.46 (6.27) 56.94 (6.20) 53.95 (9.54) 56.90 (5.91) 57.57 (5.73)
Donder Pushup, D
OD 10.74 (2.35) 9.86 (2.28) 8.95 (1.76) 11.46 (2.93) 10.02 (3.26) 9.83 (2.88)
OS 10.66 (2.33) 9.79 (2.39) 9.10 (1.80) 11.87 (3.15) 9.91 (2.74) 9.95 (3.09)
Local Stereoacuity, s arc 35.26 (18.89) 28.70 (16.34) 28.40 (16.05) 38.78 (22.44) 31.75 (22.69) 30.12 (21.65)
Pupil Size, mm
Bright light OD 3.41 (0.93) 3.41 (0.86) 3.66 (0.99) 3.56 (1.12) 3.48 (1.08) 3.64 (1.21)
Bright light OS 3.41 (0.96) 3.43 (0.88) 3.69 (1.02) 3.58 (1.12) 3.54 (1.10) 3.64 (1.22)
Dim light OD 5.55 (1.20) 5.56 (1.07) 5.41 (1.38) 5.55 (1.26) 5.41 (1.04) 5.43 (1.22)
Dim light OS 5.55 (1.29) 5.54 (1.06) 5.45 (1.34) 5.57 (1.27) 5.46 (1.07) 5.45 (1.26)
Vergence
CT near, prism D −1.96 (3.96) −2.13 (5.19) −1.98 (5.12) −2.52 (3.34) −1.93 (3.80) −1.83 (4.01)
NPC break, cm 5.47 (2.67) 7.34 (3.50) 7.29 (3.05) 6.24 (2.27) 6.75 (3.17) 7.81 (3.40)
NPC recovery, cm 9.55 (3.03) 11.21 (2.90) 13.36 (17.26) 10.61 (2.95) 11.19 (3.20) 11.32 (3.01)

a Data are given as mean (SD).

b Each participant was scored on the number of letters that he or she read correctly, out of a total of 70.

Abbreviations: CT, cover test with prism neutralization; D, diopters; NPC, near point of convergence; OD, right eye; OS, left eye; VA, visual acuity.

×
Several of the limitations in the pilot study were addressed in the present study. The sample size in this study was of sufficient size (N=89) to provide greater power than that in the pilot study (N=29). In addition, the single-intervention protocol used in the pilot study could have limited potential changes due to the lack of repeated interventions. This issue was addressed in the present study by having each participant undergo multiple interventions. A third limitation of the pilot study was that it did not assess whether any changes noted would remain over time. The present study addressed this limitation by performing repeated visual function tests after cessation of the intervention. 
Potential mechanisms behind the changes observed in the present study are the same as those discussed in the pilot study: alterations in the shape of the eyes affecting axial length and extraocular mobility, and alterations to autonomic innervation of the eyes.9 Variables affected by changes in axial length and extraocular mobility that demonstrated statistically significant changes within both the treatment and sham therapy groups in the present study were distance visual acuity, local stereoacuity, Donder pushup results, and NPC break and recovery. Variables affected by changes in autonomic innervation that demonstrated statistically significant changes within groups in the present study were local stereoacuity, Donder pushup results, and NPC break and recovery. 
Table 2.
Effect of Osteopathic Cranial Manipulative Medicine on Visual Acuity: Within-Group Data for Optometric Variables (N=89)a
Variable df F Ratiob P Value 1–β
Distance VA
OD 2,138 15.48 <. 01c >.99
OS 2,146 11.04 <.01c .99
Donder Pushup
OD 2,154 22.97 <. 01c >.99
OS 2,162 23.3 <.01c >.99
Local Stereoacuity 2,132 27 <.01c >.99
Pupil Size
Bright light OD 2,160 0.84 .43 .19
Bright light OS 2,160 0.51 .60 .13
Dim light OD 2,156 0.13 .87 .07
Dim light OS 2,158 0.37 .69 .11
Vergence
CT near 2,138 0 >.99 .05
NPC break 2,134 8.42 <.01c .96
NPC recovery 2,140 4.58 .01c .77

a Study included 47 participants in the treatment (balanced membranous tension) group and 42 participants in the control (sham therapy) group.

b Based on preintervention measurement vs postintervention measurement.

c Difference between preintervention and postintervention main effects within treatment and control groups was statistically significant (P<.05).

Abbreviations: CT, cover test with prism neutralization; NPC, near point of convergence; OD, right eye; OS, left eye; VA, visual acuity.

Table 2.
Effect of Osteopathic Cranial Manipulative Medicine on Visual Acuity: Within-Group Data for Optometric Variables (N=89)a
Variable df F Ratiob P Value 1–β
Distance VA
OD 2,138 15.48 <. 01c >.99
OS 2,146 11.04 <.01c .99
Donder Pushup
OD 2,154 22.97 <. 01c >.99
OS 2,162 23.3 <.01c >.99
Local Stereoacuity 2,132 27 <.01c >.99
Pupil Size
Bright light OD 2,160 0.84 .43 .19
Bright light OS 2,160 0.51 .60 .13
Dim light OD 2,156 0.13 .87 .07
Dim light OS 2,158 0.37 .69 .11
Vergence
CT near 2,138 0 >.99 .05
NPC break 2,134 8.42 <.01c .96
NPC recovery 2,140 4.58 .01c .77

a Study included 47 participants in the treatment (balanced membranous tension) group and 42 participants in the control (sham therapy) group.

b Based on preintervention measurement vs postintervention measurement.

c Difference between preintervention and postintervention main effects within treatment and control groups was statistically significant (P<.05).

Abbreviations: CT, cover test with prism neutralization; NPC, near point of convergence; OD, right eye; OS, left eye; VA, visual acuity.

×
It is important to note that both the present study and the pilot study demonstrated statistically significant within-group changes over time in multiple visual function parameters. The only commonality between the treatment and sham therapy groups that could account for these changes is the active motion testing of the SBS performed twice on each participant at each visit during the intervention period. 
Future studies designed to assess the effects of OCMM on visual function should expand the design of the current study in several ways. First, the participants could undergo refraction to more accurately determine visual correction and astigmatism. Second, a slit lamp examination could be performed to verify ophthalmic health. Third, a pupilometer could be used to more accurately measure pupillary size. Fourth, the data could be separated into subgroups (eg, participants with myopia vs participants with hyperopia). This further breaking down would allow the data to be more rigorously evaluated to determine both statistical and clinical significance. Last, a true control group, in which the participants are not touched at all but undergo ophthalmic testing, could be added to further elucidate the cause of observed changes. 
Conclusion
The present study was performed to address whether OCMM affected visual function and to assess the temporal permanence of any changes found. Although this study did not consistently demonstrate a statistically significant change in the measured aspects of visual function after OCMM over time, statistically significant changes in multiple visual function parameters were observed in both the treatment and sham therapy groups. Active motion testing of the SBS was the only external force applied to participants in both treatment and sham therapy groups during each intervention visit. Critics of the teaching and use of OCMM have cited poor interrater reliability as justification to discount this treatment modality.11 The present study showed measurable changes in multiple objective parameters that may have resulted from active motion testing of the SBS, which could explain the lack of observed interrater reliability in other studies and could have an important impact on future research on OCMM. 
References
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Figure.
Flow chart of the study of the effects of osteopathic cranial manipulative medicine (OCMM) on visual function.
Figure.
Flow chart of the study of the effects of osteopathic cranial manipulative medicine (OCMM) on visual function.
Table 1.
Effect of Osteopathic Cranial Manipulative Medicine on Visual Acuity: Optometric Variables (N=89)a
Treatment Group (n=47) Control Group (n=42)
Postintervention Postintervention
Variable Before Intervention Visit 9 Visit 16 Before Intervention Visit 9 Visit 16
Distance VAb
OD 54.26 (7.18) 56.74 (6.78) 56.98 (6.78) 53.50 (9.88) 55.54 (10.57) 55.48 (10.49)
OS 55.09 (6.10) 56.46 (6.27) 56.94 (6.20) 53.95 (9.54) 56.90 (5.91) 57.57 (5.73)
Donder Pushup, D
OD 10.74 (2.35) 9.86 (2.28) 8.95 (1.76) 11.46 (2.93) 10.02 (3.26) 9.83 (2.88)
OS 10.66 (2.33) 9.79 (2.39) 9.10 (1.80) 11.87 (3.15) 9.91 (2.74) 9.95 (3.09)
Local Stereoacuity, s arc 35.26 (18.89) 28.70 (16.34) 28.40 (16.05) 38.78 (22.44) 31.75 (22.69) 30.12 (21.65)
Pupil Size, mm
Bright light OD 3.41 (0.93) 3.41 (0.86) 3.66 (0.99) 3.56 (1.12) 3.48 (1.08) 3.64 (1.21)
Bright light OS 3.41 (0.96) 3.43 (0.88) 3.69 (1.02) 3.58 (1.12) 3.54 (1.10) 3.64 (1.22)
Dim light OD 5.55 (1.20) 5.56 (1.07) 5.41 (1.38) 5.55 (1.26) 5.41 (1.04) 5.43 (1.22)
Dim light OS 5.55 (1.29) 5.54 (1.06) 5.45 (1.34) 5.57 (1.27) 5.46 (1.07) 5.45 (1.26)
Vergence
CT near, prism D −1.96 (3.96) −2.13 (5.19) −1.98 (5.12) −2.52 (3.34) −1.93 (3.80) −1.83 (4.01)
NPC break, cm 5.47 (2.67) 7.34 (3.50) 7.29 (3.05) 6.24 (2.27) 6.75 (3.17) 7.81 (3.40)
NPC recovery, cm 9.55 (3.03) 11.21 (2.90) 13.36 (17.26) 10.61 (2.95) 11.19 (3.20) 11.32 (3.01)

a Data are given as mean (SD).

b Each participant was scored on the number of letters that he or she read correctly, out of a total of 70.

Abbreviations: CT, cover test with prism neutralization; D, diopters; NPC, near point of convergence; OD, right eye; OS, left eye; VA, visual acuity.

Table 1.
Effect of Osteopathic Cranial Manipulative Medicine on Visual Acuity: Optometric Variables (N=89)a
Treatment Group (n=47) Control Group (n=42)
Postintervention Postintervention
Variable Before Intervention Visit 9 Visit 16 Before Intervention Visit 9 Visit 16
Distance VAb
OD 54.26 (7.18) 56.74 (6.78) 56.98 (6.78) 53.50 (9.88) 55.54 (10.57) 55.48 (10.49)
OS 55.09 (6.10) 56.46 (6.27) 56.94 (6.20) 53.95 (9.54) 56.90 (5.91) 57.57 (5.73)
Donder Pushup, D
OD 10.74 (2.35) 9.86 (2.28) 8.95 (1.76) 11.46 (2.93) 10.02 (3.26) 9.83 (2.88)
OS 10.66 (2.33) 9.79 (2.39) 9.10 (1.80) 11.87 (3.15) 9.91 (2.74) 9.95 (3.09)
Local Stereoacuity, s arc 35.26 (18.89) 28.70 (16.34) 28.40 (16.05) 38.78 (22.44) 31.75 (22.69) 30.12 (21.65)
Pupil Size, mm
Bright light OD 3.41 (0.93) 3.41 (0.86) 3.66 (0.99) 3.56 (1.12) 3.48 (1.08) 3.64 (1.21)
Bright light OS 3.41 (0.96) 3.43 (0.88) 3.69 (1.02) 3.58 (1.12) 3.54 (1.10) 3.64 (1.22)
Dim light OD 5.55 (1.20) 5.56 (1.07) 5.41 (1.38) 5.55 (1.26) 5.41 (1.04) 5.43 (1.22)
Dim light OS 5.55 (1.29) 5.54 (1.06) 5.45 (1.34) 5.57 (1.27) 5.46 (1.07) 5.45 (1.26)
Vergence
CT near, prism D −1.96 (3.96) −2.13 (5.19) −1.98 (5.12) −2.52 (3.34) −1.93 (3.80) −1.83 (4.01)
NPC break, cm 5.47 (2.67) 7.34 (3.50) 7.29 (3.05) 6.24 (2.27) 6.75 (3.17) 7.81 (3.40)
NPC recovery, cm 9.55 (3.03) 11.21 (2.90) 13.36 (17.26) 10.61 (2.95) 11.19 (3.20) 11.32 (3.01)

a Data are given as mean (SD).

b Each participant was scored on the number of letters that he or she read correctly, out of a total of 70.

Abbreviations: CT, cover test with prism neutralization; D, diopters; NPC, near point of convergence; OD, right eye; OS, left eye; VA, visual acuity.

×
Table 2.
Effect of Osteopathic Cranial Manipulative Medicine on Visual Acuity: Within-Group Data for Optometric Variables (N=89)a
Variable df F Ratiob P Value 1–β
Distance VA
OD 2,138 15.48 <. 01c >.99
OS 2,146 11.04 <.01c .99
Donder Pushup
OD 2,154 22.97 <. 01c >.99
OS 2,162 23.3 <.01c >.99
Local Stereoacuity 2,132 27 <.01c >.99
Pupil Size
Bright light OD 2,160 0.84 .43 .19
Bright light OS 2,160 0.51 .60 .13
Dim light OD 2,156 0.13 .87 .07
Dim light OS 2,158 0.37 .69 .11
Vergence
CT near 2,138 0 >.99 .05
NPC break 2,134 8.42 <.01c .96
NPC recovery 2,140 4.58 .01c .77

a Study included 47 participants in the treatment (balanced membranous tension) group and 42 participants in the control (sham therapy) group.

b Based on preintervention measurement vs postintervention measurement.

c Difference between preintervention and postintervention main effects within treatment and control groups was statistically significant (P<.05).

Abbreviations: CT, cover test with prism neutralization; NPC, near point of convergence; OD, right eye; OS, left eye; VA, visual acuity.

Table 2.
Effect of Osteopathic Cranial Manipulative Medicine on Visual Acuity: Within-Group Data for Optometric Variables (N=89)a
Variable df F Ratiob P Value 1–β
Distance VA
OD 2,138 15.48 <. 01c >.99
OS 2,146 11.04 <.01c .99
Donder Pushup
OD 2,154 22.97 <. 01c >.99
OS 2,162 23.3 <.01c >.99
Local Stereoacuity 2,132 27 <.01c >.99
Pupil Size
Bright light OD 2,160 0.84 .43 .19
Bright light OS 2,160 0.51 .60 .13
Dim light OD 2,156 0.13 .87 .07
Dim light OS 2,158 0.37 .69 .11
Vergence
CT near 2,138 0 >.99 .05
NPC break 2,134 8.42 <.01c .96
NPC recovery 2,140 4.58 .01c .77

a Study included 47 participants in the treatment (balanced membranous tension) group and 42 participants in the control (sham therapy) group.

b Based on preintervention measurement vs postintervention measurement.

c Difference between preintervention and postintervention main effects within treatment and control groups was statistically significant (P<.05).

Abbreviations: CT, cover test with prism neutralization; NPC, near point of convergence; OD, right eye; OS, left eye; VA, visual acuity.

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