Clinical trial NCT04676620: Comparison of Anterior Corneal Optical Aberration Induced by CK and Hyperopic LASIK
Official title: Comparison of Anterior Corneal Optical Aberration Induced by Conductive Keratoplasty and Hyperopic Laser in Situ Keratomileusis
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Refractive Error
Keywords: conductive keratoplasty
corneal optical aberrations
hyperopic corrections
LASIK
Lead sponsor: Shanghai Guanghua Hospital of Integrated Traditional Chinese and Western Medicine
Sponsor class: OTHER
Collaborators: name: Tianjin Eye Hospital
First posted: 2020-12-21
Enrollment: 69
Sex: ALL
Minimum age (years): 40
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
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.

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: uncorrected visual acuity
timeFrame: change from baseline with EDTRS chart at 6 months
measure: best spectacle-corrected visual acuity
timeFrame: change from baseline with EDTRS chart at 6 months
Secondary outcomes:
measure: near vision
timeFrame: change from baseline with EDTRS chart at 6 months
measure: central and peripheral corneal ultrasound pachymetry
timeFrame: change from baseline with EDTRS chart at 6 months
Other outcomes:
Locations:
city: Shanghai
country: China
facility: Shanghai Guanghua Integrated Traditional Chinese and Western Medicine Hospital
state: Shanghai
Study officials:
affiliation: Shanghai Guanghua integrated traditional Chinese and Western Medicine Hospital
name: Hongxia Wang, director
role: STUDY_DIRECTOR
References:
citation: Du TT, Fan VC, Asbell PA. Conductive keratoplasty. Curr Opin Ophthalmol. 2007 Jul;18(4):334-7. doi: 10.1097/ICU.0b013e3281df2cf0.
citation: 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. doi: 10.1016/j.jcrs.2003.09.022.
citation: 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. doi: 10.3928/1081-597X-20030901-04.