Difference in myopia progression between dominant and non-dominant eye in patients with intermittent exotropia

Myopia management -A survey of optometrists and ophthalmologists in Israel

PURPOSE

Myopia management is practiced by ophthalmologists and optometrists. This study evaluated the approach and standard of myopia management among eye-care practitioners (ECPs) in Israel. The findings may ultimately affect the quality of care.

METHODS

A questionnaire was sent to 954 optometrists and 365 ophthalmologists, including demographic questions; whether they owned any devices to monitor myopia progression; the lowest progression they considered significant; various questions pertaining to myopia management and treatment methods.

RESULTS

Responses from 135 optometrists and 126 ophthalmologists were collected, the majority practicing more than five years; 94% of optometrists, and 64% of ophthalmologists. Around 53% of optometrists and 27% of the ophthalmologists proclaimed to practice myopia management. ECPs primary parameters influencing risk assessment for progression were age, genetic background and history of progression. Time outdoors, during daylight hours, is advised by ophthalmologists (97%) and optometrists (78%). Limiting screentime is encouraged by 87% of ophthalmologists and 69% of optometrists. Myopia progression of 0.50D-0.75D after six months is regarded to require intervention by 93% of ophthalmologists and 83% of optometrists. Optometrists selected multiple myopia management treatments, primarily optical (ophthalmic myopia management lenses 40%, multifocal ophthalmic lenses 24%, peripheral blur contact lenses 38%, orthokeratology 11%), while 95% of ophthalmologists chose atropine and only 3-11% selected any additional treatments to consider.

CONCLUSION

This study highlighted ECPs' agreement on the principles, importance of, and timeline of intervention with myopia management. The disconnect between the two professions lies in management methods. Genuine dialogue and co-management should be encouraged for maximum implementation, benefit and effectiveness of available patient treatments.

Refractive Profile of Surgical Patients with Intermittent Exotropia: A Large-Sample Cross-Sectional Study in Southern China

PURPOSE

To describe the refractive profile of surgical patients with intermittent exotropia (IXT) residing in southern China.

METHODS

Medical records of patients who received strabismus surgery between June 2014 and August 2020 were retrospectively reviewed. Clinical data, including age, sex, refractive errors, preoperative angle of deviation, types of exotropia, accommodative convergence to accommodation ratio (AC/A ratio) and stereopsis, were investigated.

RESULTS

A total of 2250 patients were included, and 93.6% of patients were younger than 30 years of age. The mean angle of exodeviation was 37.0 ± 14.7 prism degree (PD) and 37.5 ± 15.8 PD at distance and near, respectively. Mean spherical equivalent refraction (SER) values were -0.7 ± 2.4 D and -0.8 ± 2.5 D in the dominant eye and nondominant eye, respectively. Significant differences in SER were observed between the dominant eye and nondominant eye among children at 6 years old or younger. The percentage of myopia increased from 11.0% in children (≤6 years old) to 77.9% in teenagers (13-18 years of age). Significant positive associations between the magnitude of exodeviation and the magnitude of myopia were observed (p < 0.0001). Patients with convergence insufficiency type IXT (p < 0.0001) or AC/A < 2 (p < 0.05) showed a greater magnitude of myopia. The mild hyperopia group included a larger proportion of subjects showing a certain degree of stereopsis (p < 0.05).

CONCLUSIONS

Myopia was present in more than half of our patients (51.2%), which is much higher than the percentage in the general population of southern China. Patients with convergence insufficiency, an AC/A ratio < 2, or a larger angle of deviation tended to have a greater magnitude of myopia.

Myopic progression in school-aged children with moderate intermittent exotropia

Objective

It is still controversial whether intermittent exotropia (IXT) affects myopic progression during the critical period of visual development. This study retrospectively analyzed the long-term myopic changes and the impact of IXT surgery on myopic progression in school-aged children with moderate IXT.

Methods

The medical records of 65 children from 5 to 13 years old with or without IXT between 2015 and 2021 were retrospectively reviewed. Patients whose spherical equivalent refraction (SER) were less than -3.00 diopter (D) were included and divided into three groups: IXT surgery group (Group A), which comprised 22 IXT patients who received IXT surgery, IXT observation group (Group B), which comprises 19 IXT patients who only received long-term observational follow-up; and normal control group (Group C), which comprised 24 normal controls without IXT. The main outcome measurement was the rate of myopic progression, which was defined as the mean myopic shift in SER per year.

Results

The 3- and 5-years long-term follow-up rates of myopic progression were -0.47 ± 0.28 D per year and -0.48 ± 0.23 D per year respectively in Group B, and those were significantly slower than that in Group C (-0.73 ± 0.32 D per year and -0.76 ± 0.19 D per year respectively). However, there was no significant difference in the rate of myopic progression between Group A and B or between Group A and C.

Conclusion

Moderate IXT may have lower rate of myopic progression in school-aged children. Whether IXT surgery influence the rate of myopic progression still needs further study.

Comparing myopic error in patients with basic and convergence insufficiency intermittent exotropia in China

PURPOSE

To compare the degree of myopia between the dominant and non-dominant eyes in teenagers with intermittent exotropia (IXT) in China.

METHODS

A total of 199 IXT patients with myopia were included in this retrospective study and were divided into two groups according to the difference between near and distance exodeviation: basic IXT and convergence insufficiency (CI) IXT. Refractive errors were analyzed by spherical equivalent (SE) values. Patients were further stratified into anisometropia group and non-anisometropia group based on binocular SE values difference greater than 1.0D or not.

RESULTS

There were 127 patients in the CI IXT group, with a near deviation of 46.94 ± 20.53 prism diopters (PD) and a distance deviation of 28.36 ± 14.34 PD, and there were 72 (36.2%) patients in the basic IXT group, with a near deviation of 37.68 ± 22.21 PD and a distance deviation angle of 33.21 ± 23.96 PD. The near exodeviation was significantly larger in the CI group than in the basic IXT group(P < 0.001). In the CI IXT group, the mean SE was - 2.09 ± 1.45 diopters (D) in the dominant eye and - 2.53 ± 1.44D in the non-dominant eye, while in the basic IXT group, the mean SE was - 2.46 ± 1.56D in the dominant eye and - 2.89 ± 1.37D in the non-dominant eye. The anisometropia group included 43 patients, while non-anisometropia group included 156 patients. The near and distance exodeviation in the anisometropia group were 45.26 ± 24.41 PD and 33.53 ± 23.31 PD, respectively, and those in the non-anisometropia group were 43.42 ± 20.69 PD and 29.07 ± 16.84 PD, respectively. There were no significant differences in near and distance deviation (P = 0.78 and P = 0.73 respectively) between the two groups. The SE of the dominant eye was less myopic than of the non-dominant eyes in both the CI and anisometropia groups (P = 0.002 and P < 0.001, respectively).

CONCLUSIONS

Our study revealed that convergence insufficiency IXT is more common than the basic type in pediatric myopic population and is characterized by higher inter-eye differences of myopia. The dominant eye was found to be less myopic in IXT patients, particularly in those with convergence insufficiency and anisometropia.

Correlation between bilateral lateral rectus muscle recession and myopic progression in children with intermittent exotropia

Although several studies have reported about the relationship between the surgical correction of intermittent exotropia and myopic progression, it remains unclear, unlike the relationship between esotropia and hyperopia. Thus, this retrospective case control study evaluated the impact of bilateral lateral rectus recession in intermittent exotropia on myopic progression. This study included 388 patients with intermittent exotropia. The refractive errors and degree of exodeviation at each follow up period were analyzed. The rate of myopic progression was -0.46 ± 0.62 diopter (D)/year in patients who underwent surgery and -0.58 ± 0.78 D/year in patients who did not, with no significant difference between them (p = 0.254). Patients who had recurrences of more than 10 prism diopters were compared with patients who did not have. The rate of myopic progression was -0.57 ± 0.72 D/year in the recurrent group and -0.44 ± 0.61 D/year in the non-recurrent group, with no significant difference between them (p = 0.237). Patients with fast myopic progression had more recurrence than patients with slow progression (p = 0.042). Moreover, recurrence had a positive correlation with fast myopic progression (OR = 2.537, p = 0.021). Conclusively, the surgical correction of intermittent exotropia did not influence myopic progression.

Refractive changes after strabismus surgery in patients with intermittent exotropia

OBJECTIVES

To evaluate the long-term refractive changes after horizontal muscle surgery in patients with intermittent exotropia and investigate the correlation between changes in the postoperative refractive error and clinical factors.

METHODS

We retrospectively reviewed the clinical data of patients aged < 15 years who underwent unilateral strabismus surgery (lateral rectus recession and medial rectus resection [RR, n = 47], lateral rectus recession and medial rectus plication [RP, n = 81], or lateral rectus recession [LRc, n = 68]). Preoperative and postoperative refractive errors up to four years after surgery were recorded. A mixed model was applied to compare the refractive error between the operated and fellow eyes and identify the factors associated with postoperative refractive changes.

RESULTS

The mean age at surgery was 7.5±2.4years, and girls accounted for 56.1% of the study population. There was no significant difference in the change in the spherical equivalent of refractive error between both eyes throughout the postoperative period. In contrast, the operated eyes consistently and significantly showed higher cylindrical power in with-the-rule astigmatism by 0.25D than in fellow eyes. Age, sex, and preoperative refractive error were not correlated with changes in postoperative astigmatism. Meanwhile, the type of surgery showed a significant interaction with the astigmatism changes. RP had less effect on the changes in astigmatism than RR and LRc (p = 0.001 and p = 0.022, respectively).

CONCLUSIONS

Horizontal muscle surgery has no long-term effect on the change in the spherical equivalent. However, mild with-the-rule astigmatism is induced and sustained after surgery, and the type of surgery affects the postoperative change of astigmatism.

Accommodative responses under various viewing conditions in surgical patients with intermittent exotropia: an institutional, retrospective study

Purpose

To investigate the difference of spherical equivalent (SE) and pupil diameter in adult patients with intermittent exotropia (IXT) under various viewing conditions before and after surgery.

Methods

We retrospectively analyzed the medical records of 23 adult patients who underwent a surgery for IXT. The angle of deviation was measured by the prism and alternative cover test. Refractive error and pupil diameter were measured using the Grand Seiko WAM-5500 open-field autorefractor under binocular and monocular viewing conditions when patients stared at distance (6 m) and near (33 cm). Regression analyses were performed between accommodative load and the angle of deviation.

Results

Twenty-three patients (10 males, 13 females) with a mean age of 31.17±8.95 years, of whom 13 (56.5%) had the right eye as the dominant eye. The mean angle of deviation at near and at distance was 69.57±26.37 and 65.43±28.92 prism diopters respectively. There were no significant differences in accommodative response and pupil diameter between the dominant and non-dominant eyes. SE decreased when patients changed from monocular to binocular viewing, and from distant to near viewing (all P< 0.05), so as the pupil diameter (all P< 0.001). During binocular, not monocular viewing, SE was significantly greater after operation than it was before operation (P< 0.001). Accommodative load and pupillary constriction narrowed (p< 0.001) after the operation. Linear regression analysis showed a correlation between the angle of deviation at distance and accommodative load at distance (r²=0.278, p=0.010) and at near (r²=0.332, p=0.005).

Conclusion

In order to maintain ocular alignment, patients with IXT suffer a large accommodative load, which is related to the angle of deviation. Surgery helps eliminating extra accommodation.