INTRAOPERATIVE FLAP INTRAOPERATIVE FLAP COMPLICATIONS IN LASIK COMPLICATIONS IN LASIK SURGERY PERFORMED BY SURGERY PERFORMED BY

OPHTHALMOLOGY RESIDENTS IN OPHTHALMOLOGY RESIDENTS IN TRAININGTRAINING

Arturo Gómez-Bastar MDArturo Gómez-Bastar MDArturo Ramirez-MirandaArturo Ramirez-Miranda MDMDLorena Romero Diaz de LeonLorena Romero Diaz de Leon MD MDJuan Carlos Serna-Ojeda Juan Carlos Serna-Ojeda MDMDAlejandro Navas Alejandro Navas MD MScMD MScEnrique O. Graue-HernandezEnrique O. Graue-Hernandez MD MScMD MSc

Department of Cornea and Refractive Surgery Department of Cornea and Refractive Surgery Instituto de OftalmologiaInstituto de Oftalmologia

““Fundacion Conde de ValencianaFundacion Conde de Valenciana””Mexico City, MexicoMexico City, Mexico

Dr. Ramirez-Miranda and Dr. Navas are consultants for Carl Zeiss Meditec. Dr. Ramirez-Miranda is a speaker of Thea Laboratoires.The remaining authors have no financial or proprietary interest in the materials presented herein.

IntroductionIntroduction

Laser in situ keratomileusis (LASIK) is a Laser in situ keratomileusis (LASIK) is a

common method for the surgical correction common method for the surgical correction

of myopia, hyperopia, and astigmatism. of myopia, hyperopia, and astigmatism.

The creation of the corneal flap is the first The creation of the corneal flap is the first

and most critical step during LASIK and most critical step during LASIK

surgery.surgery.

PurposePurpose

To report the flap-related complication To report the flap-related complication

rate in LASIK surgery performed by in-rate in LASIK surgery performed by in-

training ophthalmology residents and to training ophthalmology residents and to

analyze the risk factors involved in those analyze the risk factors involved in those

complications.complications.

MethodsMethods

Data CollectionData Collection

We analyzed flap sections performed during We analyzed flap sections performed during

subsequent primary LASIK surgeries from March subsequent primary LASIK surgeries from March

2013 to February 2014 in a prospective 2013 to February 2014 in a prospective

observational manner. observational manner.

MethodsMethods

PatientsPatients•All patients had stable refraction for 6 months All patients had stable refraction for 6 months before surgery, had a corrected distance visual before surgery, had a corrected distance visual acuity (CDVA) of 20/25 or better, and patient age acuity (CDVA) of 20/25 or better, and patient age more than 21 years. more than 21 years.

•Preoperative evaluation included a Preoperative evaluation included a comprehensive ophthalmic examination: comprehensive ophthalmic examination: uncorrected distance visual acuity (UDVA), uncorrected distance visual acuity (UDVA), manifest and cycloplegic refractions, CDVA, manifest and cycloplegic refractions, CDVA, contact tonometry, and computerized corneal contact tonometry, and computerized corneal topography (OCULUS Pentacam® and/or Orbscan topography (OCULUS Pentacam® and/or Orbscan II). II).

MethodsMethods

Keratectomy and surgical techniqueKeratectomy and surgical technique

•Corneal flaps were obtained using the Corneal flaps were obtained using the Moria M2 microkeratome with 90-μm or Moria M2 microkeratome with 90-μm or 130-μm plates and a superior hinge. One 130-μm plates and a superior hinge. One single use head was used in both eyes of single use head was used in both eyes of each patient each patient

•If a complication presented, it was If a complication presented, it was reported in the computerized patient reported in the computerized patient record system. record system.

ResultsResults

• We included all cases performed by 32 We included all cases performed by 32

ophthalmology residents (29 second and third ophthalmology residents (29 second and third

year residents and 3 cornea fellows). We year residents and 3 cornea fellows). We

analyzed 273 flap sections from 145 patients.analyzed 273 flap sections from 145 patients.

• These comprised 196 (70.25%) female eyes These comprised 196 (70.25%) female eyes

and 83 (28.75%) male eyes. There were 19 and 83 (28.75%) male eyes. There were 19

flap-related complications out of the 273 flap flap-related complications out of the 273 flap

sections involved (6.95%). sections involved (6.95%).

ResultsResults

• Mean patient age was 28.39 years (range: 18 to Mean patient age was 28.39 years (range: 18 to 52 years). The most common preoperative 52 years). The most common preoperative refraction was compound myopic astigmatism in refraction was compound myopic astigmatism in 199 eyes (71.32%). 199 eyes (71.32%).

ResultsResults

• Relative risks for flap-related complications were 2.03 Relative risks for flap-related complications were 2.03 for first LASIK surgery (CI 95% 0.64 to 6.48, p=0.22); for first LASIK surgery (CI 95% 0.64 to 6.48, p=0.22); and 1.26 (CI 95% 0.43 to 3.69, p=0.66) for the and 1.26 (CI 95% 0.43 to 3.69, p=0.66) for the surgeon’s first twenty flap sections.surgeon’s first twenty flap sections.

• Patient female gender presented a 2.2 (CI 95% 0.69 to Patient female gender presented a 2.2 (CI 95% 0.69 to 7.32, p=0.17) relative risk for complications7.32, p=0.17) relative risk for complications

DiscussionDiscussion

Following the introduction of LASIK, an Following the introduction of LASIK, an increased prevalence of flap-related increased prevalence of flap-related complications was documented among complications was documented among both novice and experienced ophthalmic both novice and experienced ophthalmic surgeons.surgeons.

During the initial LASIK surgical During the initial LASIK surgical experience, with flap complications experience, with flap complications ranging from 4.8% to 6.0% during the ranging from 4.8% to 6.0% during the early learning curve and declining to 1% or early learning curve and declining to 1% or less after the completion of more than 500 less after the completion of more than 500 procedures. procedures.

DiscussionDiscussion

In our study, an incidence of 6.95% In our study, an incidence of 6.95% compares favorably with those found by compares favorably with those found by other authors, which vary from 0.3-10%. other authors, which vary from 0.3-10%. However, in most studies executed with However, in most studies executed with trained LASIK surgeons the rates are about trained LASIK surgeons the rates are about 0.5-2%0.5-2%

DiscussionDiscussion

•The first flap section involves a 2.03 The first flap section involves a 2.03 relative risk of complication and that the relative risk of complication and that the first 20 flap sections, which is the mean first 20 flap sections, which is the mean number of sections for an resident at our number of sections for an resident at our institution, represent a 1.23 relative risk of institution, represent a 1.23 relative risk of complicationscomplications..

•We also found that there was no We also found that there was no significant relationship between free caps significant relationship between free caps and flattest keratometries, and and flattest keratometries, and buttonholes with steepest keratometriesbuttonholes with steepest keratometries. .

ConclusionConclusion

• Flap-related complications Flap-related complications are a common are a common

intraoperative complication during LASIK intraoperative complication during LASIK

surgery performed by in-training surgery performed by in-training

ophthalmologists. ophthalmologists.

• Surgeon’s Surgeon’s first surgery and first surgery and female gender female gender

represent a higher risk represent a higher risk for flap related for flap related

complications complications than biometric parameters than biometric parameters

of patient’s eye. of patient’s eye.

• Flap complications Flap complications do not seem to affect do not seem to affect

final visual outcome final visual outcome when the laser when the laser

treatment is rescheduled.treatment is rescheduled.