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The Effect of Cyclopentolate on Ocular Biometric Components
Hassan Hashemi1, Amir Asharlous2, Mehdi Khabazkhoob3
1Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran.
Insights
Cyclopentolate 1% eye drops significantly alter ocular biometrics in children, reducing lens thickness and increasing anterior chamber depth. These cycloplegia-induced changes vary among refractive error groups, impacting axial length and pupil diameter.
Area of Science:
- Ophthalmology
- Pediatric Ophthalmology
- Ocular Biometry
Background:
- Cycloplegic eye drops induce biometric changes, but effects vary and are not well-documented across refractive error groups.
- Understanding these variations is crucial for accurate refractive assessment in children.
Purpose of the Study:
- To investigate the impact of cyclopentolate 1% on ocular biometric components in children with different refractive errors.
- To analyze how cycloplegia affects axial length, lens thickness, and anterior chamber depth based on refractive status.
Main Methods:
- A cross-sectional study involving 113 schoolchildren (226 eyes) in Iran.
- Objective refraction and ocular biometry (Allegro Biograph) were performed before and after cyclopentolate 1% instillation.
- Mixed-effect model regression analyzed biometric changes across refractive error groups.
Main Results:
- Cycloplegia significantly decreased vitreous chamber depth, lens thickness, axial length, and lens power.
- Anterior chamber depth, anterior segment length, lens central point, and pupil diameter significantly increased.
- Changes in anterior chamber depth and vitreous chamber depth differed significantly between hyperopes and emmetropes, with lens center shifting posteriorly in myopes.
Conclusions:
- Cycloplegia with cyclopentolate 1% reduces crystalline lens thickness, increasing anterior chamber depth.
- Ocular biometric responses to cycloplegia are dependent on the type of refractive error.
Significance:
It is apparent that a variety of biometric changes are caused by different types of cycloplegic eye drops. However, these effects are inconsistent and have not been reported in different refractive groups.
Purpose:
The purpose of this study was to determine the effect of cyclopentolate 1% on ocular biometric components in different types of refractive errors in children.
Methods:
This cross-sectional study was conducted on 226 eyes of 113 schoolchildren in Shahroud, northeast Iran, with a mean ± standard deviation age of 9.20 ± 1.65 years. All participants had noncycloplegic and cycloplegic objective refraction using an autorefractometer. Cycloplegia was induced using cyclopentolate 1% eye drops. Biometric measurements were made with Allegro Biograph (WaveLight AG, Erlangen, Germany) before and after administering cycloplegic drops. Mixed-effect model regression was used to analyze the data.
Results:
After cycloplegia, the vitreous chamber depth (VCD) (-0.043; 95% confidence interval [CI], -0.067 to -0.019 mm), lens thickness (-0.146; 95% CI, -0.175 to -0.117 mm), axial length (-0.009; 95% CI, -0.012 to -0.006 mm), and lens power (-0.335; 95% CI, -0.463 to -0.208 D) decreased significantly, whereas the anterior chamber depth (ACD) (0.183; 95% CI, 0.164 to 0.202 mm), anterior segment length (0.036; 95% CI, 0.014 to 0.058) mm), lens central point (0.109; 95% CI, 0.094 to 0.124 mm), and pupil diameter (1.599; 95% CI, 1.482 to 1.716 mm) increased (P value for all tests, <.001). For changes in VCD and ACD, a significant interaction was observed between different types of refractive errors and cycloplegia, such that the adjusted mean change for ACD was significantly lower and for VCD was significantly higher in hyperopes compared with emmetropes. Lens center moves backward in myopes (0.17 mm) and stays the same in hyperopes under cycloplegia.
Conclusions:
According to the findings of this study, cycloplegia reduces the thickness of the crystalline lens and subsequently causes an increase in the ACD. Cycloplegia-related ocular biometric changes were different by type of refractive error.
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