Binocular Single Vision Field
2009; Elsevier BV; Volume: 116; Issue: 2 Linguagem: Inglês
10.1016/j.ophtha.2008.08.046
ISSN1549-4713
AutoresHirohiko Kakizaki, Naomi Umezawa, Yasuhiro Takahashi, Dinesh Selva,
Tópico(s)Cerebral Venous Sinus Thrombosis
ResumoThe binocular single vision field (BSVF) assessment is an examination for detection of eye movement disorders1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar or for confirmation of diplopia area.2Van Eeckehoutte L. De Clippeleir L. Apers R. et al.A protocol for extraocular muscle surgery after orbital floor fracture ("blow-out").Binocular Vision and Ocular Motility. 1998; 13: 29-36PubMed Google Scholar Although the normal BSVF in Caucasians has been investigated,1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar it has been not examined in Asians including Japanese. The Caucasian BSVF shows a pear configuration (Fig 1 [available online at http://aaojournal.org]),1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar, 3Traquair H.M. Scott G.I. Traquair's Clinical Perimetry.in: 7th ed. Henry Kimpton, London1957: 7-8Google Scholar and is altered by facial structures. Japanese people have less defined facial features and the normal Caucasian BSVF may not be simply applied to Japanese.Although the ΙΙΙ4e target of the Goldmann perimeter has been used traditionally in the BSVF examination,1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar some studies have used alternate target sizes (I4e4Summers C.G. Lavoie J.D. Letson R.D. Use of a modified binocular visual field to assess cyclodiplopia.Ophthalmology. 1987; 94: 231-234Abstract Full Text PDF PubMed Scopus (9) Google Scholar or V4e5Sullivan T.J. Kraft S.P. Burack C. O'Reilly C. A functional scoring method for the field of binocular single vision.Ophthalmology. 1992; 99: 575-581Abstract Full Text PDF PubMed Scopus (33) Google Scholar). The most reliable target size in BSVF testing yet to be determined. Therefore, we examined the normal BSVF in Japanese and determined the most credible target size for BSVF testing.Forty Japanese volunteers participated in the study. The average age was 39.8 years (range, 20–59). Sixteen participants were male and 24 were female. Exclusion criteria were eye movement disorders, strabismus of ≥5°, <0.3 near vision, abnormal monocular visual field, and past history of cataract surgery. All participants were informed of the study, and proper consent and approval were obtained. Ethical approval was obtained from the local Institutional Review Board.We used the Goldmann perimeter (Haag Streit, Bern, Switzerland) to examine the BSVF. The chin and headrest were adjusted with the fixation target at eye level and centered between the eyes. The targets of I4e, III4e, and V4e were used with 31.5 apostilbs background luminance. The participants were directed to follow the target with both eyes open. The points where the participants first experienced diplopia were plotted. The targets were moved from within the BSVF and moved outward along the representative 8 meridians with counterclockwise 45° intervals from 0° (horizontal right position).The boundaries limited by the nose were also examined using the III4e target with the contralateral eye closed in the 2 inferior directions (225° in the right eye and 315° in the left eye). The boundaries obstructed by forehead, cheek, and eyelid were also examined. All tests were performed by one examiner (NU). The participants were asked after BSVF testing which target size was the most discernible.Statistical analysis was performed using a Tukey-Kramer post hoc test following a one-factor ANOVA test. Significance was defined as P<0.05. All statistical analysis was carried out using SPSS II for Windows (SPSS Japan Inc., Tokyo, Japan).Normal values (mean value ± standard deviation) for each target size of I4e, III4e, and III4e were lowest at 90° (I4e, 41.3±6.18°; III4e, 42.2±5.38°; III4e, 45.1±5.29°) and increased in the inferior direction. The values were highest at 270° (I4e, 60.3±6.89°; III4e, 60.5±6.89°; III4e, 64.3±6.46°; Table 1 [available online at http://aaojournal.org]). The shape of each BSVF was almost round, differing from that typically seen in Caucasians (Fig 2A–C [available online at http://aaojournal.org]).Table 1Mean Degree (± Standard Deviation) of Boundaries in 8 Directions in Each Target Size0°45°90°135°I4e49.5±7.12°45.1±6.87°41.3±6.18°45.1±7.53°III4e50.2±6.64°45.6±6.62°42.2±5.38°46.0±7.55°V4e52.3±6.17°48.6±6.91°45.1±5.29°48.0±5.81°180°225°270°315°I4e50.5±6.65°55.5±5.00°60.3±6.89°53.0±4.54°III4e51.2±7.17°54.5±4.01°60.5±6.89°54.5±4.55°V4e51.8±6.25°57.1±3.99°64.3±6.46°55.3±4.88°0° = horizontal right position, moving in a counterclockwise direction to 45°, 90°, 135°, 180°, 225°, 270°, and 315°.There were statistically significant differences between I4e and V4e at 90°, 270° and 315°, and between III4e and V4e at 225° and 270°. Open table in a new tab Figure 2Binocular single vision field in each target size with the Goldmann perimeter. The solid lines are the mean boundaries of the binocular single vision. The areas within the diagonal lines are the area determined by the mean degrees ± standard deviations. A, I4e target. B, III4e target. C, V4e target.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Most plots in each target size did not show a significant difference (Table 1 [available online at http://aaojournal.org]). However, the V4e values were statistically larger than those examined with I4e at 90°, 270°, and 315°, and those with III4e at 225° and 315°.Twenty-five volunteers (62.5%) found the III4e target to be the most discernable size. The I4e target was selected as the most favorable by 8 participants (20%), and 7 participants (17.5%) selected V4e target as the best.The degrees (mean value ± standard deviation) masked by the nose in 225° and 315° were 57.7±3.89° and 57.1±2.58°, respectively (Table 2 [available online at http://aaojournal.org]). These values were always located outside the normal range of the BSVF. No participants experienced targets hidden by the forehead, cheek, or eyelid.Table 2Comparison between the Degrees of Boundaries in the Binocular Single Vision Field and the Degrees Masked by the Nose at 225°and 315° with the III4e TargetNoseNormal225°57.7±3.89°54.5±4.01°315°57.1±2.58°54.5±4.55° Open table in a new tab This study is the first to assess the normal BSVF in Japanese patients, and demonstrates the area masked by nose was always outside the normal BSVF; other facial components also had no apparent effect on the BSVF. In addition, the III4e was identified as the most perceptible target size in BSVF testing. The primary difference of the normal BSVF between Japanese and Caucasians was in the effect of the facial eminences.1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar, 3Traquair H.M. Scott G.I. Traquair's Clinical Perimetry.in: 7th ed. Henry Kimpton, London1957: 7-8Google Scholar The binocular single vision field (BSVF) assessment is an examination for detection of eye movement disorders1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar or for confirmation of diplopia area.2Van Eeckehoutte L. De Clippeleir L. Apers R. et al.A protocol for extraocular muscle surgery after orbital floor fracture ("blow-out").Binocular Vision and Ocular Motility. 1998; 13: 29-36PubMed Google Scholar Although the normal BSVF in Caucasians has been investigated,1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar it has been not examined in Asians including Japanese. The Caucasian BSVF shows a pear configuration (Fig 1 [available online at http://aaojournal.org]),1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar, 3Traquair H.M. Scott G.I. Traquair's Clinical Perimetry.in: 7th ed. Henry Kimpton, London1957: 7-8Google Scholar and is altered by facial structures. Japanese people have less defined facial features and the normal Caucasian BSVF may not be simply applied to Japanese. Although the ΙΙΙ4e target of the Goldmann perimeter has been used traditionally in the BSVF examination,1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar some studies have used alternate target sizes (I4e4Summers C.G. Lavoie J.D. Letson R.D. Use of a modified binocular visual field to assess cyclodiplopia.Ophthalmology. 1987; 94: 231-234Abstract Full Text PDF PubMed Scopus (9) Google Scholar or V4e5Sullivan T.J. Kraft S.P. Burack C. O'Reilly C. A functional scoring method for the field of binocular single vision.Ophthalmology. 1992; 99: 575-581Abstract Full Text PDF PubMed Scopus (33) Google Scholar). The most reliable target size in BSVF testing yet to be determined. Therefore, we examined the normal BSVF in Japanese and determined the most credible target size for BSVF testing. Forty Japanese volunteers participated in the study. The average age was 39.8 years (range, 20–59). Sixteen participants were male and 24 were female. Exclusion criteria were eye movement disorders, strabismus of ≥5°, <0.3 near vision, abnormal monocular visual field, and past history of cataract surgery. All participants were informed of the study, and proper consent and approval were obtained. Ethical approval was obtained from the local Institutional Review Board. We used the Goldmann perimeter (Haag Streit, Bern, Switzerland) to examine the BSVF. The chin and headrest were adjusted with the fixation target at eye level and centered between the eyes. The targets of I4e, III4e, and V4e were used with 31.5 apostilbs background luminance. The participants were directed to follow the target with both eyes open. The points where the participants first experienced diplopia were plotted. The targets were moved from within the BSVF and moved outward along the representative 8 meridians with counterclockwise 45° intervals from 0° (horizontal right position). The boundaries limited by the nose were also examined using the III4e target with the contralateral eye closed in the 2 inferior directions (225° in the right eye and 315° in the left eye). The boundaries obstructed by forehead, cheek, and eyelid were also examined. All tests were performed by one examiner (NU). The participants were asked after BSVF testing which target size was the most discernible. Statistical analysis was performed using a Tukey-Kramer post hoc test following a one-factor ANOVA test. Significance was defined as P<0.05. All statistical analysis was carried out using SPSS II for Windows (SPSS Japan Inc., Tokyo, Japan). Normal values (mean value ± standard deviation) for each target size of I4e, III4e, and III4e were lowest at 90° (I4e, 41.3±6.18°; III4e, 42.2±5.38°; III4e, 45.1±5.29°) and increased in the inferior direction. The values were highest at 270° (I4e, 60.3±6.89°; III4e, 60.5±6.89°; III4e, 64.3±6.46°; Table 1 [available online at http://aaojournal.org]). The shape of each BSVF was almost round, differing from that typically seen in Caucasians (Fig 2A–C [available online at http://aaojournal.org]). 0° = horizontal right position, moving in a counterclockwise direction to 45°, 90°, 135°, 180°, 225°, 270°, and 315°. There were statistically significant differences between I4e and V4e at 90°, 270° and 315°, and between III4e and V4e at 225° and 270°. Most plots in each target size did not show a significant difference (Table 1 [available online at http://aaojournal.org]). However, the V4e values were statistically larger than those examined with I4e at 90°, 270°, and 315°, and those with III4e at 225° and 315°. Twenty-five volunteers (62.5%) found the III4e target to be the most discernable size. The I4e target was selected as the most favorable by 8 participants (20%), and 7 participants (17.5%) selected V4e target as the best. The degrees (mean value ± standard deviation) masked by the nose in 225° and 315° were 57.7±3.89° and 57.1±2.58°, respectively (Table 2 [available online at http://aaojournal.org]). These values were always located outside the normal range of the BSVF. No participants experienced targets hidden by the forehead, cheek, or eyelid. This study is the first to assess the normal BSVF in Japanese patients, and demonstrates the area masked by nose was always outside the normal BSVF; other facial components also had no apparent effect on the BSVF. In addition, the III4e was identified as the most perceptible target size in BSVF testing. The primary difference of the normal BSVF between Japanese and Caucasians was in the effect of the facial eminences.1Feibel R.M. Roper-Hall G. Evaluation of the field of binocular single vision in incomitant strabismus.Am J Ophthalmol. 1974; 78: 800-805PubMed Scopus (27) Google Scholar, 3Traquair H.M. Scott G.I. Traquair's Clinical Perimetry.in: 7th ed. Henry Kimpton, London1957: 7-8Google Scholar
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