Corneal Epithelial Autograft for Pterygium

A Randomized Controlled Clinical Trial of Corneal Epithelial Autograft for Pterygium

The purpose of the study is to explore whether femtosecond laser-assisted cornea epithelial autograft is more effective than limbal conjunctival autograft for ocular surface reconstruction after excision of pterygium.

Study Overview

• Status: Unknown
• Conditions: Pterygium
• Intervention / Treatment: Device: Femtosecond laser; Device: Diamond knife; Procedure: Corneal epithelial autograft; Procedure: Limbal conjunctival autograft; Procedure: Simple removal

• Study Type: Interventional
• Enrollment (Anticipated): 45
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510000
      • Recruiting
      • Zhongshan Ophthalmic Center, Sun Yat-sen Univerisity

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Age between 18 to 80 years old;
2. Primary pterygium, scheduled for elective surgical excision;
3. Pterygium encroaching from the nasal side onto the cornea, with less than 180° limbal involvement and without approaching the central visual axis (pupil area);
4. Morphologically intact palisades of Vogt in a given limbal region;
5. Absence of any one of the following structures in the limbal region underneath the pterygium: (1) epithelial basal cells with dark cytoplasm and reflective cell borders; (2) at least two prominent palisade ridge structures; (3) at least one circular and/or oval-shaped focal stromal projection;
6. Informed consent signed by patient or legal guardian; Having the ability to comply with study assessments for the full duration of the study.

Exclusion Criteria:

1. Limbal stem cell deficiency by ocular surface disorders other than pterygium;
2. Inability to determine whether the palisades of Vogt underneath the pterygium is absent or not using in vivo confocal microscopy;
3. High myopia with a spherical equivalent of -15.0 D or less;
4. Corneal or ocular surface infection within 30 days prior to study entry;
5. Ocular surface malignancy;
6. Uncontrolled diabetes with most recent Hemoglobin A1c greater than 8.5%;
7. Renal failure with creatinine clearance< 25ml/min;
8. Alanine aminotransferase > 40IU/L, or aspartate aminotransferase > 40IU/L;
9. Platelet levels < 150,000 or > 450,000 per microliter;
10. Hemoglobin < 12.0 g/dL (male) or < 11.0 g/dL (female);
11. Prothrombin time > 16s and activated partial thrombin time > 35s in patients not accepting anticoagulant therapy; An international normalized ratio greater than 3 in patients accepting anticoagulant therapy;
12. Pregnancy (positive test) or lactation;
13. Participation in another simultaneous medical investigation or clinical trial;
14. Severe cicatricial eye disease;
15. Ocular comorbidities that affect the prognosis of transplantation, such as advanced glaucoma or retinal diseases;
16. Severe dry eye disease as determined by Schirmer's test < 2mm at least in one eye;
17. Any medical or social condition that in the judgement of the investigator would interfere with or serve as a contraindication to adherence to the study protocol or ability to give informed consent;
18. Signs of current infection, including fever and treatment with antibiotics;
19. Active immunological diseases;
20. History of allo-limbal transplantation, penetrating keratoplasty or anti-glaucoma filtering surgeries.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Corneal epithelial autograft; pterygium resection combined with femtosecond laser assisted corneal epithelial autograft	Device: Femtosecond laser; A commercial femtosecond laser to create a particular shaped graft for transplantation; Procedure: Corneal epithelial autograft; After removal of the recipient's pterygium tissue, a donor epithelial tissue equal in length to the bared limbus, will be obtained from the peripheral epithelial of the same eye (corneal epithelial autograft) using femtosecond laser technology. The epithelial graft will be sutured to the recipient limbal bed, with the goal of reconstruction of palisades of Vogt. The graft will act as a barrier to regrowth of pterygium. The area of the graft will be left with the Tenon capsule exposed.
Active Comparator: Limbal conjunctival autograft; pterygium resection combined with diamond knife assisted limbal conjunctival autograft	Device: Diamond knife; A diamond knife to create a particular shaped limbal graft for transplantation; Procedure: Limbal conjunctival autograft; After removal of the recipient's pterygium tissue, an adjustable diamond knife will be used to create a superficial circumferential incision at the corneal end of the limbal vascular arcade, equal in length to the bared limbus. This will be followed by harvesting the limbal-conjunctival flap. The limbal-conjunctival autograft will be sutured to the recipient bed, with the Tenon capsule exposed. The graft will serve as a barrier to regrowth of pterygium.
Active Comparator: Simple removal; Simple removal of pterygium	Procedure: Simple removal; Simple removal of the recipient's pterygium tissue, with the Tenon capsule exposed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Restoration of corneal surface	Restoration of a completely epithelized, stable, and avascular corneal surface	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recurrence of pterygium	To observe recurrence of pterygium using slit-lamp microscopy	1 year
Reconstruction of palisades of Vogt	To observe the reconstruction of palisades of Vogt using in vivo confocal microscopy.	1 year
Best corrected visual acuity	To assess changes of best corrected visual acuity using ETDRS chart	1 year
Corneal power and astigmatism	To assess changes of corneal power and astigmatism using autorefractor keratometer	1 year
Corneal haze measurement	To observe the scatter of corneal haze using in vivo confocal microscopy	1 year

Collaborators and Investigators

• Sponsor: Chunxiao Wang

Study record dates

Study Major Dates

• Study Start (Actual): July 20, 2017
• Primary Completion (Anticipated): December 30, 2018
• Study Completion (Anticipated): December 30, 2019

Study Registration Dates

• First Submitted: July 12, 2017
• First Submitted That Met QC Criteria: July 12, 2017
• First Posted (Actual): July 14, 2017

Study Record Updates

• Last Update Posted (Actual): February 22, 2018
• Last Update Submitted That Met QC Criteria: February 21, 2018
• Last Verified: February 1, 2018

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Conjunctival Diseases; Pterygium
• Other Study ID Numbers: 2017KYPJ050

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No