The Visual Function Classification System: Translation, Validity, and Reliability of the Persian Version for...

Area of Science:

• Ophthalmology
• Pediatrics
• Rehabilitation Medicine

Background:

• Cerebral Palsy (CP) significantly impacts visual function in affected individuals.
• A validated classification system for visual function in individuals with CP was lacking in Iran.
• The Visual Function Classification System (VFCS) provides a framework for assessing visual capabilities.

Purpose of the Study:

• To translate and culturally adapt the Visual Function Classification System (VFCS) into Persian (P-VFCS).
• To evaluate the validity and reliability of the P-VFCS for use in Iranian clinical settings.
• To establish a standardized method for classifying visual function in children with CP in Iran.

Main Methods:

• The VFCS underwent translation into Persian, with back-translation and developer approval.
• Face validity was assessed by a panel of occupational therapists and parents.
• The P-VFCS was administered to 156 participants with CP (aged 1-19 years).
• Inter-rater reliability was assessed between 156 parents and 4 occupational therapists.
• Test-retest reliability was evaluated with 77 parents and 2 occupational therapists over 2-4 weeks.

Main Results:

• The P-VFCS demonstrated strong inter-rater reliability (weighted kappa = 0.88) between occupational therapists and parents.
• Test-retest reliability was high for both occupational therapists (weighted kappa = 0.91) and parents (weighted kappa = 0.90).
• Face validity was confirmed, with 100% of occupational therapists and 80% of parents deeming the P-VFCS suitable.

Conclusions:

• The Persian Visual Function Classification System (P-VFCS) is a reliable and valid tool.
• The P-VFCS is suitable for classifying visual functions in individuals with CP in clinical settings.
• This system addresses a critical need for visual function assessment in the Iranian CP population.