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Fresnel membrane prisms: clinical experience.
1Department of Ophthalmology, McGill University Health Centre, Montreal, Que.
Canadian Journal of Ophthalmology. Journal Canadien D'Ophtalmologie
|December 22, 1999
Summary
Fresnel prisms effectively treat adult diplopia from various causes, offering a successful and often permanent solution. This visual aid provides relief when permanent lens incorporation isn
Area of Science:
- Ophthalmology
- Optometry
- Neurology
Background:
- Limited published data exists on the clinical use of Fresnel membrane prisms for adult diplopia.
- This study investigates Fresnel prism application in patients with fourth and sixth cranial nerve palsies, thyroid-related restrictive motility, and convergence insufficiency.
Observation:
- 141 adult patients with diplopia were treated with Fresnel prisms.
- Prisms were applied horizontally, vertically, or obliquely, predominantly on the nondominant eye's spectacle lens.
- Follow-up averaged 15 months.
Findings:
- 80% of patients (113/141) achieved successful diplopia relief with Fresnel prisms.
- 19% transitioned to ground-in prism correction, while 50% opted for permanent Fresnel prism wear due to cost or impossibility of incorporation.
- 8% discontinued use due to side effects like blurred vision or aberrations.
Implications:
- Fresnel prisms are a valuable tool for managing adult diplopia, providing effective and often permanent visual correction.
- They serve as a practical alternative when fused prism incorporation into spectacle lenses is not feasible or cost-prohibitive.
- The study highlights the preference for a fused, albeit blurred, image over persistent double vision.