Orthoptic Changes Following Photorefractive Keratectomy

January 19, 2011 updated by: Shahid Beheshti University of Medical Sciences
Purpose: To detect orthoptic changes in patients undergoing photorefractive keratectomy (PRK). Method: This interventional case series was performed on 297 eyes of 150 patients who were candidates for PRK. Complete ophthalmic evaluations focusing on orthoptic examinations were performed before and 3 months after PRK. Results: Before PRK, two (1.3%) patients had esotropia that remained unchanged postoperatively. However, 3 (2%) patients had distance exotropia preoperatively which improved after PRK. Of 12 cases (8%) with preoperative exotropia at near, 3 (2%) cases became orthophoric. Six patients (4%) developed postoperative near exotropia. A significant reduction in means of convergence and divergence amplitudes (P<0.001) and a meaningful increase in mean of near point of convergence (NPC) (P<0.006) were noticed after PRK. A reduction of ≥10 PD in convergence amplitude and ≥5 PD in divergence amplitude were detected in 10 and 5 patients, respectively. Four patients had an preoperative NPC>10 cm which was not changed by the surgery. Out of 9 (6%) patients with baseline stereopsis >60 seconds of arc, 2 (1.33%) cases showed an improvement in stereopsis following PRK. None of the patients complained of postoperative diplopia. Conclusion: Eye deviation in patients undergoing PRK may improve or remain unchanged after operation and postoperative deviations can develop following this surgery. Diminishing of fusional amplitude and increasing of NPC as well as improving of stereopsis may also happen after PRK. Therefore, a preoperative orthoptic examination in patients with any concerning histories and/or motility issues on routine exam is recommended before performing PRK.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 59 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

>18 yrs / refractive errors / with consent

Exclusion Criteria:

< 18 / corneal opacity - keratoconus

Dry eye / diabetes / collages vacuolar disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Kerato refractive Surgery
Procedure: Kerato refractive Surgery
This interventional case series was performed on 297 eyes of 150 patients who were candidates for PRK. Complete ophthalmic evaluations focusing on orthoptic examinations were performed before and 3 months after PRK.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
orthoptic changes
Time Frame: before and after KRS
Prism / (deviation)
before and after KRS

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
VA , Streopsis , deviation , fusion , NPC
Time Frame: before and after KRS
Snellen , Titmus, prism, ruler
before and after KRS

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Shahid Beheshti University of Medical Sciences

Investigators

  • Principal Investigator: zhaleh rajavi, Assistant Professor, Imam Hossein medical center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 2008

Primary Completion (Actual)

January 1, 2009

Study Completion (Actual)

April 1, 2009

Study Registration Dates

First Submitted

January 19, 2011

First Submitted That Met QC Criteria

January 19, 2011

First Posted (Estimate)

January 20, 2011

Study Record Updates

Last Update Posted (Estimate)

January 20, 2011

Last Update Submitted That Met QC Criteria

January 19, 2011

Last Verified

April 1, 2008

More Information

Terms related to this study

Other Study ID Numbers

  • 8659 (Other Identifier: Fred Hutch/University of Washington Cancer Consortium)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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