# Exploring the impact of age of onset on stereoacuity in patients with myasthenia gravis

## TL;DR

This study found that myasthenia gravis patients who developed the condition before age 7 are at higher risk of severe stereoacuity impairment.

## Contribution

The study is the first to show a strong association between early-onset myasthenia gravis and severe stereoacuity loss.

## Key findings

- Patients with MG onset before age 7 had 14.73 times higher risk of being unable to identify any stereo chart.
- Ptosis and diplopia were associated with weak stereoacuity, while EOM disorder was linked to severe stereoacuity impairment.
- Early-onset MG may lead to long-term binocular vision issues and impact quality of life.

## Abstract

Myasthenia gravis (MG) is an autoimmune disorder that can result in fluctuating muscle strength and various ocular manifestations. Common ocular signs and symptoms in MG patients include ptosis, limited eye movement, and diplopia.

This study aimed to investigate the association between the clinical characteristics of MG, specifically the age of onset, and stereoacuity in MG patients.

This was a cross-sectional study that enrolled 150 MG patients.

Stereoacuity was assessed using the Butterfly Stereo Acuity Test. Main analysis was conducted using multinomial logistic regression to explore the relative risk associated with different levels of stereoacuity.

This study included 150 MG patients: 58 (38.7%) with normal stereoacuity, 80 (53.3%) with weak stereoacuity, and 12 (8%) unable to identify any stereo chart. Patients with MG onset before age 7 (n = 15) had a significantly higher risk of being unable to identify any stereo chart [relative risk ratio (RRR) = 14.73; p = 0.03]. Among ocular manifestations, ptosis (RRR = 2.33; p < 0.05) and diplopia (RRR = 2.26; p < 0.05) were associated with weak stereoacuity, whereas extraocular movement (EOM) disorder was significantly associated with being unable to identify any stereo chart (RRR = 10.57; p < 0.01).

Findings suggest that an early onset of MG may contribute to impaired stereoacuity. For patients diagnosed with MG before the age of 7, it is advisable to ensure optimal management of MG itself. Future studies should explore the potential long-term implications of early-onset MG on binocular vision, ophthalmoplegia, and the impact of ocular signs and symptoms on patients’ quality of life.