Characterizing Patients with Age-Related Divergence
Insufficiency Esotropia
M. X. Repka, E. Downing
Johns Hopkins University, Baltimore, Maryland, USA
ABSTRACT:
Introduction/Purpose: To describe the clinical characteristics of a group of patients older than 40
years of age with divergence insufficiency esotropia and the results of surgery performed on a
subgroup.
Methods: A retrospective review of 86 adult patients diagnosed with divergence insufficiency.
Clinical features evaluated include age at diagnosis, visual acuity, primary position deviations at
distance and near, treatment offered, post- surgical intervention deviations, and presence of neurological disease.
Results: We analysed 86 patients, 33 men and 49 women. The average age of diagnosis was
73.2 years, the average visual acuity was 20/22 in the better eye and 20/24 in the worst eye. The
average initial deviation at near was 12 prism diopters at distance and 5.2 prism diopters at near.
Following surgery the average deviations were less than 1 prism diopter at near and about 2
prism diopters at near. The percentage of patients with neurological disease was 8%.
Conclusions: In this study bilateral medial rectus recession surgery was effective at reducing
esotropia at distance with a slight tendency of overcorrection at near. Few (8.5%) patients had
accompanying neurological disease.
1 INTRODUCTION
Divergence insufficiency has been described in the literature for many decades. In some
studies there was concern about the use of this term and differentiating the condition from bilateral mild abducens nerve pareses.1 In recent years, Mittelman has called attention to an increasingly common form of esotropia in adults he has termed, “Adult Onset Age-Related Distance
Esotropia”.2 The strabismus was an acquired esotropia in adults with no prior history of strabismus or history of neurological problems. More recently he found that medial rectus recession
surgery was an effective treatment. He reported surgical success in in a group of 10 patients using bilateral medial rectus recession.3 In 2009 Rutar and Demer described the neuroimaging
findings of an adult with acquire esotropia without high myopia which they called “Divergence
Paralysis Esotropia”.4 They noted connective tissue degeneration with downward displacement
of the lateral rectus muscle along with thinning of the LR-SR band. Recently, Chaudhuri and
Demer reported in a group of 13 patients that bilateral medial rectus recessions are an effective
treatment of this condition.5 However, a substantial increase in surgical dose was required to
achieve success. Stager et al have also reviewed their experience with surgical treatment, preferring a unilateral lateral rectus resection, finding excellent success.6
In our clinic there is no standardized management protocol; bilateral medial rectus recessions
were most often performed, but unilateral recess-resect surgery was performed on a limited basis. Our purpose in this report is to describe a larger cohort of patients and evaluate surgical outcomes in the subgroup that underwent strabismus surgery.
2 METHODS
A retrospective chart review of adults older than 40 years of age at onset of an esotropia classified as divergence insufficiency in the Wilmer electronic database of patients seen between
1977 and 2011. Chart review was conducted confirming no prior history of strabismus, comitancy of the esotropia in lateral gazes and a distance esotropia 5 or more prism diopters greater
than the near angel. Demographic data, age at onset, treatment with prisms, treatment with surgery, ocular deviations at distance and near at diagnosis and following surgery if applicable.
Neurological assessment was by history and follow-up monitoring. Imaging was not standard
care for evaluation of these patients and performed on occasion.
3 RESULTS
There were 86 patients identified; 67% were female. The mean age was 74.0 years (range 43-95 years). A neurological diagnosis was reported in 7. Four of these were previously diagnosed with chronic CN VI, but no pathology was identified on imaging. No patient was subsequently diagnosed with neurological impairment. Mean refractive error was -1.49 D (+3.83 to 11.69 D).
Mean angles of esotropia were 12 at distance (range = ET 30 to orthotropia) and 5.2 at
near (range = ET 20 to XT6). Therapeutic prism was used by 60 of 86 (69%) with varying success.
The frequency of the diagnosis age-related divergence insufficiency esotropia has risen dramatically in our clinic with only 15 cases recorded between 1980 and 2005, but 40 cases between 2005 and 2011.
Surgery was performed with no specific protocol on 45 patients. All surgeries were performed with adjustable sutures. Thirty-eight cases (84%) were bilateral MR recessions with a
mean = 4.4 mm of recession per eye. There were 7 cases (16%) of unilateral recess-resect procedures. The outcomes for the two surgical techniques are in the Tables. Each surgical approach
collapsed the difference. However, there was a tendency for overcorrection at near with medial
rectus surgery and overcorrection at distance with recess-resect surgery
Table 1 – Outcome from Bilateral Medial Rectus Recessions
N=38
Preoperative ()
Postoperative ()
Mean Distance Angle
Mean Near Angle
13.6
0.7
5.4
-3.2
Distance-Near
Difference
8.2
3.9
Table 2 – Outcome for Unilateral Recess Medial Rectus – Resect Lateral Rectus
Distance-Near
N=7
Mean Distance Angle
Mean Near Angle
Difference
19.1
9.4
9.7
Preoperative ()
-1.7
0.3
-2.0
Postoperative ()
For both surgical approaches we found the surgical effect to be substantially diminished
compared with conventional surgical tables. There was a small 0.6 prism diopter change per mm
of medial rectus recession surgery shown in the Figure below.
4 DISCUSSION
Adult onset age-related distance esotropia is an increasingly common condition found in a
adult strabismus practice. In our practice the diagnosis was uncommon prior to 2005, but has increased dramatically in the last few years. While many ophthalmologists have worried in the
past about the possibility that this condition represents occult abducens nerve palsy or other neurological disease, which has not been our experience.
While our study is non-randomized, we found, as did Chaudhuri and Demer,5 strabismus
surgery could correct the esotropia in most cases, but the amount of medial rectus recession surgery required was substantially more than used for other forms of comitant strabismus. For this
reason we would recommend using adjustable sutures.
We believe that use of the term divergence insufficiency esotropia as a specific diagnostic
category for these adult patients should be abandoned. We agree with the more specific term
suggested by Mittelman, adult onset age-related distance esotropia, is preferable. This terminology could reasonably be shortened without losing specificity to “age-related distance esotropia”
to be more manageable in clinical use.
Limitations of this study include the retrospective chart review design. Additionally, neurological diagnoses were made by history and follow up monitoring with no development of neurological disease. Neuro-imaging was not required per any existing clinical protocol, but was
performed in many cases at clinician discretion. In no case was there a positive finding. Comparison of surgical techniques in this report or the earlier reports from Mittelman2 and
Chaudhuri and Demer5 is not possible because of the lack of randomization and the small number of unilateral recess-resect operations that were performed.
REFERENCES
1. Mittelman D. Divergence insufficiency esotropia is a misnomer. JAMA Ophthalmol
2013;131:547.
2. Mittelman D. Age-related distance esotropia. J AAPOS 2006;10:212-3.
3. Mittelman D. Surgical management of adult onset age-related distance esotropia. J Pediatr
Ophthalmol Strabismus 2011;48:214-6
4. Rutar T, Demer J. “Heavy Eye” syndrome in the absence of high myopia: A connective tissue
degeneration in elderly strabismic patients. J AAPOS 2009;13:36-44.
5. Chaudhuri Z, Demer JL. Medial rectus recession is as effective as lateral rectus resection in
divergence paralysis esotropia. Am J Ophthalmol 2012;130:1280-4.
6. Stager Sr DR, Black T, Felius J. Unilateral lateral rectus resection for horizontal diplopia in
adults with divergence insufficiency. Graefes Arch Clin Exp Ophthalmol 2013;251:1641-4.