Clinical trial NCT01432834: Efficacy of the Wavefront Optimized (WFO) Profile in Non-anterior Astigmatisms
Official title: Evaluation of the Efficacy of the Allegretto Wave and the Wavefront Optimized Ablation Profile in Non-anterior Astigmatisms
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Astigmatism
Keywords: non-anterior astigmatism correction
Allegretto Wave excimer laser
wavefront optimized ablation profile (WFO)
LASIK
PRK
Lead sponsor: Democritus University of Thrace
Sponsor class: OTHER
First posted: 2011-09-13
Enrollment: 74
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The purpose of the study was to assess the efficacy of the Allegretto Wave excimer laser and the wavefront optimized ablation profile in correcting primarily non-anterior astigmatism faults, following laser in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).

Detailed description: Different optical components of the eye contribute to the total astigmatism error.In specific, the anterior corneal surface is responsible for the anterior component of astigmatism fault (anterior astigmatism), while the posterior corneal surface and the lens are responsible for the posterior one (posterior astigmatism).

Regarding our study, 74 refractive surgery candidates were recruited. Only one eye from each candidate was randomly enrolled in the study. Of them, 40 eyes underwent LASIK treatment (LG group), while 34 eyes underwent PRK treatment (PG group). The Allegretto Wave excimer laser (software version: 2.020 / WaveLight AG, Erlangen, Germany) was used for the ablation in all groups. Preoperatively, the ocular residual astigmatism (ORA) was calculated for each eye, according to which each astigmatism fault was characterized as primarily anterior or non-anterior.ORA is the vectorial value of astigmatism arising from non-anterior sources. Its amount on total astigmatism (R) is determined by the magnitude ratio ORA/R. Ratios below 1 indicate primarily anterior astigmatism, while ratios above 1 indicate primarily non-anterior astigmatism. 20 LG eyes and 16 PG eyes presented primarily anterior astigmatism (LG-A and PG-A subgroups, respectively), while 20 LG eyes and 18 PG eyes demonstrated primarily non-anterior astigmatism (LG-NA and PG-NA subgroups, respectively). Postoperatively, vector analysis of astigmatism correction was conducted; The following indexes were calculated: a) Correction index (CI), b) Difference vector (DV) and c) Index of Success (IOS).

Eligibility criteria: Inclusion Criteria:

* astigmatism fault

Exclusion Criteria:

* previous incisional eye surgery
* evidence of any type of corneal pathology
* evidence of any type of optic neuropathy
* history of optic neuropathy
* diabetes mellitus

Primary outcomes:
measure: vector analysis of astigmatism correction, following laser in-situ keratomileusis (LASIK) & photorefractive keratectomy (PRK) treatments.
timeFrame: 6 months postoperatively
Secondary outcomes:
Other outcomes:
Locations:
city: Alexandroupolis
country: Greece
facility: Eye Institute of Thrace (EIT)
Study officials:
References:
citation: Labiris G, Gatzioufas Z, Giarmoukakis A, Sideroudi H, Kozobolis V. Evaluation of the efficacy of the Allegretto Wave and the Wavefront-optimized ablation profile in non-anterior astigmatisms. Acta Ophthalmol. 2012 Sep;90(6):e442-6. doi: 10.1111/j.1755-3768.2012.02463.x. Epub 2012 Jun 13.