Ignite Creation Date:
2024-05-05 @ 11:08 AM
Last Modification Date:
2024-10-26 @ 9:01 AM
Study NCT ID:
NCT00000121
Status:
COMPLETED
Last Update Posted:
2009-09-17
First Post:
1999-09-23
Brief Title:
The Prism Adaptation Study PAS
Sponsor:
National Eye Institute NEI
Organization:
National Eye Institute NEI
Study Overview
Official Title:
None
Status:
COMPLETED
Status Verified Date:
2009-09
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
To determine whether the preoperative use of prisms in eyeglasses can improve the outcome of surgery for acquired esotropia a type of strabismus
To determine whether patients who respond to prism adaptation by developing a new stable angle of -deviation have a better surgical result than do patients who do not respond to prism adaptation
To determine whether patients who respond to prism adaptation are more accurately corrected by operating for the prism-adapted angle or the original angle of deviation
To determine the usefulness of certain input variables eg age at the time of surgery size of the deviation visual acuity binocular function refractive error in predicting which patients are more likely to benefit from prism adaptation
To determine whether patients who respond to prism adaptation by developing a new stable angle of -deviation have a better surgical result than do patients who do not respond to prism adaptation
To determine whether patients who respond to prism adaptation are more accurately corrected by operating for the prism-adapted angle or the original angle of deviation
To determine the usefulness of certain input variables eg age at the time of surgery size of the deviation visual acuity binocular function refractive error in predicting which patients are more likely to benefit from prism adaptation
Detailed Description:
Acquired esotropia crossed eyes that develop after a child reaches the age of 6 months accounts for 25 percent of all patients with misaligned eyes Surgery to correct esotropia is done primarily to attain functional use of the two eyes together The cosmetic aspect of the surgery is secondary In 40 to 50 percent of cases more than one operation is needed to accomplish the primary goal and in some cases even three and four operations are needed
Preliminary studies from two eye care centers reported that the use of prisms on eyeglasses for about a month before surgery led to good results after a single operation in more than 90 percent of patients These uncontrolled preliminary studies pointed to the need for a multicenter randomized controlled clinical trial designed to prove or disprove scientifically the beneficial effect of prisms
The Prism Adaptation Study was a double randomization trial involving 286 patients Three-fifths of the patients were randomly selected for prism adaptation before surgery Of the patients who responded to the prisms one-half were randomly selected to have surgery based on the amount of prism required to stabilize the deviation and the other half had surgery based on the amount of esotropia originally measured Patients who did not respond to the prisms also had surgery based on the amount of esotropia measured as did the two-fifths of the patients who did not undergo prism adaptation
Patients were examined postoperatively at 1 week 1 month 3 months 6 months and 1 year An independent examiner masked to the treatment assignment evaluated the patient at the 6-month followup The results were analyzed to determine whether the outcome was better in patients who underwent prism adaptation or in those who underwent conventional treatment Because the examiner did not know what type of treatment a patient had received he or she would have no bias in evaluating the results
Preliminary studies from two eye care centers reported that the use of prisms on eyeglasses for about a month before surgery led to good results after a single operation in more than 90 percent of patients These uncontrolled preliminary studies pointed to the need for a multicenter randomized controlled clinical trial designed to prove or disprove scientifically the beneficial effect of prisms
The Prism Adaptation Study was a double randomization trial involving 286 patients Three-fifths of the patients were randomly selected for prism adaptation before surgery Of the patients who responded to the prisms one-half were randomly selected to have surgery based on the amount of prism required to stabilize the deviation and the other half had surgery based on the amount of esotropia originally measured Patients who did not respond to the prisms also had surgery based on the amount of esotropia measured as did the two-fifths of the patients who did not undergo prism adaptation
Patients were examined postoperatively at 1 week 1 month 3 months 6 months and 1 year An independent examiner masked to the treatment assignment evaluated the patient at the 6-month followup The results were analyzed to determine whether the outcome was better in patients who underwent prism adaptation or in those who underwent conventional treatment Because the examiner did not know what type of treatment a patient had received he or she would have no bias in evaluating the results
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None