Effect of Pterygium Excision on Intraocular Lens Power Calculation for Subsequent Cataract Operation

Sponsor

Hospital Authority, Hong Kong (Other)

Overall Status

Unknown status

CT.gov ID

NCT00563667

Collaborator

(none)

Enrollment

Locations

Duration (Months)

13.3

Patients Per Site

1.1

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Pterygium is known to induce with-the-rule astigmatism. Excision of pterygium will steepen the cornea and reduce corneal astigmatism. We postulate that the alteration of keratometry reading will indirectly affect the IOL power calculation in cases with concurrent pterygium and cataract. Concurrent pterygium and cataract is common in Hong Kong and other tropical regions. The effect of pterygium excision on intraocular lens power calculation is investigated.

Condition or Disease	Intervention/Treatment	Phase
Pterygium Cataract Astigmatism	Procedure: pterygium excision	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

40 participants

Allocation:

Non-Randomized

Intervention Model:

Single Group Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Effect of Pterygium Excision on IOL Power Calculation: Concurrent Cataract and Pterygium

Study Start Date :

Dec 1, 2003

Anticipated Study Completion Date :

Dec 1, 2004

Outcome Measures

Primary Outcome Measures

IOL power [1 and 3 months post pterygium excision]
Astigmatism [1 and 3 months post pterygium excision]

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Inclusion Criteria:

All cases with concomitant cataract and primary pterygium, which are indicated for surgery.

Exclusion Criteria:

Pterygium smaller than 1mm, which is not visually significant.
Double headed pterygium
Pterygium obscuring visual axis that preclude keratometry or autorefraction measurements.
Previous corneal refractive surgery that alter the keratometric power of the cornea.
Patients with medical problems that preclude staged ocular surgery, e.g. dementia, heart disease, on warfarin.