Astigmatism in Duane Retraction Syndrome.

Purpose: To compare the prevalence, magnitude, and type of astigmatism among patients with different Duane Retraction Syndrome (DRS) types.

Method: This retrospective cross-sectional study reviewed the records of 312 DRS patients. Patients were categorized into DRS Types 1, 2, 3, and bilateral cases. Refractive errors and visual acuity were analyzed, emphasizing the prevalence of astigmatism types, specifically with-the-rule (WTR), against-the-rule (ATR), and oblique, as well as the power vectors for each DRS subtype.

Results: Our study included 312 patients with DRS, comprising 44.6% males and a median age of 18.5 years (interquartile range [IQR]: 7-27). Of these, 280 had unilateral DRS and 32 had bilateral DRS. The median age for unilateral DRS patients was 19 years (IQR: 7-27; 43.2% males), whereas for bilateral DRS patients, it was 16 years (IQR: 6-29.2; 56.3% males). In all DRS patients, 180 (57.7%) were diagnosed with Type 1 DRS, 87 (27.9%) with Type 2 DRS, and 45 (14.4%) with Type 3 DRS. In unilateral cases, WTR astigmatism was the most prevalent (56.8%), followed by oblique (23.6%) and ATR astigmatism (19.6%). Bilateral DRS patients exhibited a similar distribution in both eyes, with WTR astigmatism also being predominant. The comparative analysis of power vectors indicated that Type 1 DRS exhibited a greater prevalence of WTR and oblique astigmatism, whereas ATR astigmatism was the predominant pattern in Types 2 and 3. A comparison of cylindrical powers and power vectors among fellow eyes of different DRS subtypes revealed that Type 2 DRS had significantly higher cylindrical power (p = 0.017) and a greater tendency toward ATR astigmatism (p = 0.038) than fellow eyes in other subtypes, suggesting that astigmatic changes may also occur in fellow eyes.

Conclusion: Our study demonstrates a high prevalence of astigmatism, particularly WTR astigmatism, in DRS patients. Furthermore, we found significant associations between specific astigmatism patterns and DRS subtypes, suggesting a potential link between extraocular muscle innervation, co-contraction, and corneal shape. These findings highlight the importance of comprehensive astigmatism assessment in DRS patients for optimal refractive management.