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Pterygium-induced corneal astigmatism.
1Department of Ophthalmology, Rabin Medical Center, Petah Tiqva, Israel. ravisar@netvision.net.il
The Israel Medical Association Journal : IMAJ
|July 13, 2000
Summary
Pterygium growth over 1.0 mm from the limbus significantly induces astigmatism, potentially decreasing vision. Early surgical intervention for pterygium is recommended when the lesion exceeds this size to prevent vision impairment.
Area of Science:
- Ophthalmology
- Corneal Surgery
- Vision Science
Background:
- Previous studies suggest a link between pterygium size and induced corneal astigmatism.
- Pterygium, a wing-shaped fibrovascular growth, can affect ocular surface health and visual function.
Purpose of the Study:
- To quantitatively assess the relationship between pterygium size and induced corneal astigmatism.
- To determine if corneal astigmatism serves as an early indicator for surgical intervention in pterygium cases.
Main Methods:
- Evaluated 94 eyes with unilateral primary pterygium using computerized corneal analysis (TMS II) and slit-lamp measurements.
- Measured pterygium size from the limbus in millimeters to correlate with induced corneal astigmatism.
- Assessed best-corrected visual acuity.
Main Results:
- Primary pterygium induced with-the-rule astigmatism.
- Pterygia extending beyond 1.1 mm from the limbus or >16% of the corneal radius induced >1.0 diopter of astigmatism.
- Significant astigmatism was observed in 16.16% of eyes with pterygia 0.2-1.0 mm, 45.45% with pterygia 1.1-3.0 mm, and 100% with pterygia 5.1-6.7 mm.
- Decreased visual acuity correlated with increased topographic astigmatism.
Conclusions:
- Pterygia exceeding 1.0 mm from the limbus induce significant with-the-rule astigmatism (>1.0 diopter).
- The degree of induced astigmatism increases with pterygium size.
- Surgical removal of pterygium can improve topographic astigmatism.
- Early surgical intervention for pterygium is suggested when the lesion measures over 1.0 mm from the limbus.