Comparison of Anterior Corneal Optical Aberration Induced by CK and Hyperopic LASIK

Comparison of Anterior Corneal Optical Aberration Induced by Conductive Keratoplasty and Hyperopic Laser in Situ Keratomileusis

Conductive keratoplasty (CK) had shown to be a safe and effective procedure for the treatment of low to moderate hypeopia. It had been approved by the U.S. Food and Drug Administration (FDA) to treat presbyope in early 2004. CK appeals to both surgeons and patients as it avoids the need for flap creation, the use of high intraocular pressure (IOP), or tissue ablation. It utilizes "blended vision" rather than the true monovision used with laser in situ keratomileusis (LASIK), which patients tolerate more readily. There is very little reported research about the induction of wavefront aberration by CK. The symptomatology of high order aberrations (HOA) and the way individual Zernike functions were correlated with visual acuity, contrast sensitivity, visual symptoms. This study measured the HOA created by surgically induced myopic shift via CK and LASIK in an effort to better understand the phenomena of regression, multifocality, pseudo-accommodation and monovision.

Study Overview

• Status: Unknown
• Conditions: Refractive Error
• Intervention / Treatment: Procedure: CK surgery

Detailed Description

To investigate anterior corneal optical higher order aberration (HOA) induced by conductive keratoplasty (CK) and laser in situ keratomileusis (LASIK). 69 eyes with hyperopia or presbyopia were enrolled. 47 eyes of 47 patients underwent CK procedure, 22 eyes underwent LASIK. Data were acquired preoperatively, and at 3 and 6 months postoperatively. The total Root Mean Square (RMS) of the HOA as well as the individual Zernike polynomials of coma, trefoil, and spherical aberration were analyzed. In CK group, the high order RMS showed significant elevation at 3 months, but it returned to near preoperative levels at 6 months postoperatively. Trefoil (Z33) is the exclusive Zenike pattern to increase significantly following CK, peaking at 3 months and then decreasing back to near preoperative level at 6 months after CK. In the hyperopic LASIK group, coma increased to a peak at 3 month postoperatively, and persisted at sixth month after LASIK. Spherical aberration decreased significantly at 3 months and persisted till the sixth postoperative month. There was significant correlation between ΔSE and Δspherical aberration showed in both groups. The HOA and main Zernike polynomials pattern and their natural changes induced by CK is significantly different from that induced by LASIK in the hyperopic corrected treatment. The amount of achieved hyperopic corrections induced by CK or LASIK is not correlated to the change of HOA patterns such as coma and trefoil, but it is correlated to the change of spherical aberration.

• Study Type: Observational
• Enrollment (Anticipated): 69

Contacts and Locations

Study Locations

• China
  • Shanghai
    • Shanghai, Shanghai, China, 200052
      • Recruiting
      • Shanghai Guanghua Integrated Traditional Chinese and Western Medicine Hospital
      • Contact: Hongxia Wang, director; Phone Number: 18302183233 18302183233; Email: whxeye@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

In this consecutive case series, 69 eyes of 57 patients (30 female and 27 male) with hyperopia or presbyopia were enrolled. Inclusion criteria included age of over 40 years old (yrs), stable refraction, and patients who were planned to induce a myopic shift ranging of -1.00 diopters (D) to -2.50D. Mean patient age was 52.9±5.7 yrs (range from 42 to 68 yrs). The ophthalmic examination for each patient included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA) (Snellen chart), near vision (Jaeger chart), manifest and cycloplegic refraction, videokeratography, central and peripheral corneal ultrasound pachymetry (thickness), slit-lamp microscopy, dilated fundus examinations, IOP.

Description

Inclusion Criteria:

• age of over 40 years old (yrs)
• stable refraction
• planned to induce a myopic shift

Exclusion Criteria:

• age of less than 40 years old (yrs)
• significant systemic illnesses
• congenital myopia,
• media opacity uveitis
• glaucoma
• intraocular surgery refractive surgery
• neurologic diseases
• retinal disease

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
CK surgery; Conductive keratoplasty (CK) had shown to be a safe and effective procedure for the treatment of low to moderate hypeopia. It had been approved by the U.S. Food and Drug Administration (FDA) to treat presbyope in early 2004. CK appeals to both surgeons and patients as it avoids the need for flap creation, the use of high intraocular pressure (IOP), or tissue ablation.	Procedure: CK surgery; CK and LASIK are both effective methods for the correction of hypeopia. They have been proved to offer many advantages in terms of visual acuity, corneal sensitivity, and corneal biomechanics compared with traditional refractive surgeries.
LASIK surgery; LASIK surgery is femtosecond laser assisted conventional refractive surgery and has also been proved to offer many advantages in terms of visual acuity, corneal sensitivity, and corneal biomechanics compared with traditional refractive surgeries.	Procedure: CK surgery; CK and LASIK are both effective methods for the correction of hypeopia. They have been proved to offer many advantages in terms of visual acuity, corneal sensitivity, and corneal biomechanics compared with traditional refractive surgeries.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
uncorrected visual acuity	uncorrected visual acuity change from baseline at 6 months	change from baseline with EDTRS chart at 6 months
best spectacle-corrected visual acuity	best spectacle-corrected visual acuity change from baseline with EDTRS chart at 6 months	change from baseline with EDTRS chart at 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
near vision	near vision change from baseline with EDTRS chart at 6 months	change from baseline with EDTRS chart at 6 months
central and peripheral corneal ultrasound pachymetry	central and peripheral corneal ultrasound pachymetry change from baseline with EDTRS chart at 6 months	change from baseline with EDTRS chart at 6 months

Collaborators and Investigators

• Sponsor: Wang Hongxia
• Collaborators: Tianjin Eye Hospital
• Investigators: Study Director: Hongxia Wang, director, Shanghai Guanghua Integrated Traditional Chinese and Western Medicine Hospital

Publications and helpful links

General Publications

• Du TT, Fan VC, Asbell PA. Conductive keratoplasty. Curr Opin Ophthalmol. 2007 Jul;18(4):334-7. Review.
• Lin DY, Manche EE. Two-year results of conductive keratoplasty for the correction of low to moderate hyperopia. J Cataract Refract Surg. 2003 Dec;29(12):2339-50.
• Pallikaris lG, Naoumidi TL, Panagopoulou SI, Alegakis AK, Astyrakakis NI. Conductive keratoplasty for low to moderate hyperopia: 1-year results. J Refract Surg. 2003 Sep-Oct;19(5):496-506.

Study record dates

Study Major Dates

• Study Start (Anticipated): December 1, 2020
• Primary Completion (Anticipated): December 1, 2021
• Study Completion (Anticipated): December 1, 2021

Study Registration Dates

• First Submitted: December 15, 2020
• First Submitted That Met QC Criteria: December 15, 2020
• First Posted (Actual): December 21, 2020

Study Record Updates

• Last Update Posted (Actual): December 21, 2020
• Last Update Submitted That Met QC Criteria: December 15, 2020
• Last Verified: December 1, 2020

More Information

Terms related to this study

• Keywords: LASIK; conductive keratoplasty; corneal optical aberrations; hyperopic corrections
• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors
• Other Study ID Numbers: 2020-K-107

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

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