JKOS Journal of the Korean Ophthalmological Society J Korean Ophthalmol Soc 0378-6471 2092-9374 Korean Ophthalmological Society 10.3341/jkos.2016.57.6.951 jkos-57-951 Original Article The Surgical Outcome and Stereopsis between Pseudodivergence Excess Type and Convergence Insufficiency Type KangSung Il MD 1 LeeYoung Chun MD, PhD 2 LeeSe Youp MD, PhD 1 Department of Ophthalmology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea Department of Ophthalmology and Visual Science, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu, Korea Address reprint requests to Se Youp Lee, MD, PhD Department of Ophthalmology, Keimyung University Dongsan Medical Center, #56 Dalseong-ro, Jung-gu, Daegu 41931, Korea Tel: 82-53-250-7720, Fax: 82-53-250-7705 E-mail: lsy3379@dsmc.or.kr 09 2016 25 09 2016 576 951 956 27082015 12102015 16012016 Copyright © 2016 Korean Ophthalmological Society 2016 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Purpose

To compare the surgical outcomes and stereopsis between pseudodivergence excess type and convergence insufficiency type in intermittent exotropia.

 Methods

In a retrospective comparative analysis of 42 eyes, 18 eyes that were of the convergence insufficiency type (group 1) and 24 eyes that were or the pseudodivergence excess type (group 2) were analyzed. Recession-resection was performed in the same eye. Success was defined to be within ±8 PD after 12 months postoperatively; more than ±8 PD was defined as recurrence. Stereopsis was measured by the Titmus test.

 Results

After the patch test, the mean preoperative near angle in group 1 was 35.56 ± 6.62 PD and the far angle was 23.06 ±6.22 PD. In group 2, the mean preoperative near angle was 26.92 ± 6.30 PD and the far angle was 28.29 ± 7.41 PD. The group 1 postoperative (12 months) mean near angle was 6.89 ± 8.46 PD and the far angle was 6.11 ± 7.90 PD. In group 2, the mean postoperative near angle was 1.75 ± 2.85 PD and the far angle was 3.42 ± 3.98 PD. The success rate of group 1 was 50% and the success rate of group 2 was 83.3%. The success rate of both group were statistically significant differences (p = 0.021). The postoperative (12 months) mean of near stereopsis for group 1 was 588 ± 1,124 seconds, and group 2 was 101.25 ± 102 seconds. There were no statistically differences in postoperative (12 months) stereopsis.

 Conclusions

The success rate of the pseudodivergence excess type was significantly higher than in the convergence insufficiency type.

 Convergence insufficiency type Intermittent exotropia Pseudodivergence excess type Stereopsis References Burian HM Exodeviations: their classification, diagnosis and treatment Am J Ophthalmol 1966 6211616 Jampolsky A Characteristics of suppression in strabismus AMA Arch Ophthalmol 1955 5468396 Kran BS Duckman R Divergence excess exotropia J Am Optom Assoc 1987 5892130 Lee SY Sim JH Lee YC Comparison of surgical results according to surgical methods in simulated divergence excess exotropia J Korean Ophthalmol Soc 2004 456149 Hermann JS Surgical therapy of convergence insufficiency J Pediatr Ophthalmol Strabismus 1981 182831 Haldi BA Surgical management of convergence insufficiency Am Orthopt J 1978 281069 Wright KW Spiegel PH Pediatric Ophthalmology and Strabismus 2nd ed. New York New York 2003 2248 Lee SY Lee YC Comparison of surgical results by initial abdominal alignment following bilateral lateral rectus recession and unilateral lateral rectus recession-medial rectus resection in abdominal dxotropes J Korean Ophthalmol Soc 1999 40260410 Fletcher MC Natural history of strabismus. A résumé Ann Ophthalmol 1971 35035 Choi DG Kim PS The surgical outcome of intermittent exotropia and the prognostic factors J Korean Ophthalmol Soc 1998 39125563 Park IK Chang BL The effect of monocular recession and abdominal in exodeviations: comparison between primary, right, left, up, down and near gaze J Korean Ophthalmol Soc 1998 39186872 Ko BW Shin SY The clinical features of patients with early abdominal and with orthophoria after intermittent exotropia surgery J Korean Ophthalmol Soc 2008 49110813 Koo NK Lee YC Lee SY Clinical study for the undercorrection factor in intermittent exotropia Korean J Ophthalmol 2006 201827 Lim SH Hong JS Kim MM Prognostic factors for recurrence with unilateral recess-resect procedure in patients with intermittent exotropia Eye (Lond) 2011 2544954 Jeoung JW Lee MJ Hwang JM Bilateral lateral rectus recession versus unilateral recess-resect procedure for exotropia with a abdominal eye Am J Ophthalmol 2006 1416838 Chia A Seenyen L Long QB Surgical experiences with two-abdominal surgery for the treatment of intermittent exotropia J AAPOS 2006 1020611 Baek JS Cho MJ Kim US abdominal results of intermittent exotropia surgery: comparison between motor and functional success J Korean Ophthalmol Soc 2014 55106470 von Noorden GK Resection of both medial rectus muscles in abdominal convergence insufficiency Am J Ophthalmol 1976 812236 Choi MY Hyung SM Hwang JM Unilateral recession-resection in children with exotropia of the convergence insufficiency type Eye 2007 213447 Yang HK Hwang JM Surgical outcomes in convergence abdominal-type exotropia Ophthalmology 2011 11815127 Chung YR Yang H Lew HM The assessment of stereoacuity in patients with strabismus J Korean Ophthalmol Soc 2008 49130916 Jin HC Lee YC Lee SY Relationship between control grade and stereoacuity in basic intermittent exotropia J Korean Ophthalmol Soc 2012 531337 Roh JH Paik HJ Clinical study on factors associated with abdominal and reoperation in intermittent exotropia J Korean Ophthalmol Soc 2008 4911149 Tables

Preoperative status

  Group 1 (n = 18) Group 2 (n = 24) p-value
Age (years) 8.28 ± 1.74 7.29 ± 2.10 0.055*
Sex (male/female) 9/9 12/12 1.000†
Preoperative BCVA OD (log MAR) 0.08 ± 0.11 0.06 ± 0.08 0.549*
Preoperative BCVA OS (log MAR) 0.08 ± 0.11 0.06 ± 0.10 0.645*
Symptom duration (months) 36.67 ± 34.31 30.50 ± 30.64 0.374*
Follow-up (months) 13.65 ± 4.30 15.45 ± 4.44 0.325*

Values are presented as mean ± SD unless otherwise indicated. Group 1: Convergence insufficiency type; Group 2: Pseudodivergence excess type.

BCVA = best corrected visual acuity; OD = oculus dexter; OS = oculus sinister.

Statistical significance were tested by Mann-Whitney U-test

Statistical significance were tested by Chi-squared test.

Angle of exotropia

  Group 1 (n = 18) Group 2 (n = 24) p-value*
Preop.      
 Near before patch test (PD) 35.56 ± 6.62 11.50 ± 4.23 0.000
 Near after patch test (PD) 35.56 ± 6.62 26.92 ± 6.30 0.000
 Far (PD) 23.06 ± 6.22 28.29 ± 7.41 0.004
Postop. 1 day      
 Near (PD) −5.33 ± 7.45 −8.96 ± 7.94 0.254
 Far (PD) −9.61 ± 7.04 −8.42 ± 5.93 0.531
Postop. 12 months      
 Near (PD) 6.89 ± 8.46 1.75 ± 2.85 0.019
 Far (PD) 6.11 ± 7.90 3.42 ± 3.98 0.250

Values are presented as mean ± SD unless otherwise indicated. Group 1: Convergence insufficiency type; Group 2: Pseudodivergence excess type.

Preop. = preoperation; Postop. = postoperation; PD = prism diopter.

Statistical significance were tested by Mann-Whitney U-test.

Surgical success rate and stereopsis

  Group 1 (n = 18) Group 2 (n = 24) p-value
Success rate (%) 50.0 83.3 0.021†
Preop. stereopsis (sec of arc) 576.67 ± 1,118.06 334.17 ± 835.13 0.074*
Postop. 12 months stereopsis (sec of arc) 588.33 ± 1,123.53 101.25 ± 102.97 0.694*
Preop. Stereopsis– Postop. Stereopsis (sec of arc) −11.67 ± 98.77 232.92 ± 740.21 0.329*

Values are presented as mean ± SD unless otherwise indicated. Group 1: Convergence insufficiency type; Group 2: Pseudodivergence excess type.

Preop. = preoperation; Postop. = postoperation.

Statistical significance were tested by Mann-Whitney U-test

Statistical significance were tested by Chi-squared test.

Comparisons of surgical success rate and stereopsis

  Success Fail p-value*
Group 1      
 Preop. stereopsis (sec of arc) 432.22 ± 969.40 721.11 ± 1,292.16 0.863
 Postop. 12 months stereopsis (sec of arc) 468.89 ± 980.40 707.78 ± 1,299.67 0.666
 Preop. Stereopsis– Postop. Stereopsis (sec of arc) −36.67 ± 137.39 13.33 ± 21.21 0.297
Group 2      
 Preop. stereopsis (sec of arc) 354.00 ± 905.19 235.00 ± 376.79 0.852
 Postop. 12 months stereopsis (sec of arc) 105.00 ± 108.51 82.50 ± 78.48 0.682
 Preop. Stereopsis– Postop. Stereopsis (sec of arc) 249.00 ± 804.70 152.50 ± 298.60 0.431
Group 1 + Group 2      
 Preop. stereopsis (sec of arc) 378.28 ± 908.76 571.54 ± 1,096.88 0.468
 Postop. 12 months stereopsis (sec of arc) 217.93 ± 558.54 515.38 ± 1,103.57 0.572
 Preop. Stereopsis– Postop. Stereopsis (sec of arc) 160.34 ± 680.36 56.15 ± 164.496 0.103

Values are presented as mean ± SD unless otherwise indicated. Group 1: Convergence insufficiency type; Group 2: Pseudodivergence excess type.

Preop. = preoperation; Postop. = postoperation.

Statistical significance were tested by Mann-Whitney U-test.