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ORIGINAL ARTICLE
Year : 2007  |  Volume : 14  |  Issue : 2  |  Page : 58-62 Table of Contents     

Outcome of laser in situ keratomileusis (LASIK) of initial cases performed by supervised anterior segment fellows


Anterior Segment Division, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia

Date of Web Publication11-Nov-2009

Correspondence Address:
Faisal M Al-Tobaigy
KKESH Excimer Laser Study Group, King Khaled Eye Specialist Hospital, PO Box 7191, Riyadh 11462
Saudi Arabia
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Source of Support: None, Conflict of Interest: None


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   Abstract 

Purpose. To determine the outcome of initial laser in situ keratomileusis (LASIK) procedures performed by anterior segment fellows in a supervised training program.
Patients and Methods. A retrospective chart review of the first 20 LASIK procedures performed by supervised anterior segment fellows at King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, between March 1 and December 31, 2003, was conducted.
Results. During the study period, 10 anterior segment fellows each performed LASIK on 20 eyes of 10 patients. The mean spherical refractive error was -4.82 diopters (D) (range,-1.5 to -11.00 D). The mean patient age was 28.0 years (range, 18-50 years), and the follow-up period was 123.8 days (range, 14-389 days). After primary LASIK and 8 enhancement procedures (4.0%), 163 eyes (81.5%) had postoperative uncorrected visual acuity (UCVA) that was within 1 line of preoperative best spectacle corrected visual acuity (BSCVA); 194 eyes (97.0%) had postoperative UCVA that was within 2 lines of preoperative BSCVA. The difference between the mean preoperative BSCVA (20/22.25) and the postoperative UCVA (20/26.06) was -0.381 lines of Snellen acuity. Of 200 eyes, 6 eyes (3.0%) lost 2 or more lines of BSCVA. Prior to enhancement, 180 eyes (90.0%) were within 1 D of intended correction, including 14 eyes (7.0%) with undercorrection and 6 eyes (3.0%) with overcorrection. After 8 enhancements (all for undercorrection), 188 eyes (94.0%) were within 1 D of emmetropia. The incidence of intraoperative complications was 2.5%, all of which were incomplete flaps. There were no complete or buttonhole flaps. Postoperative complications occurred in 2.5% of eyes, the most serious being bilateral ectasia, which occurred in 1 patient with no preoperative evidence of keratoconus.
Conclusion. LASIK should be taught in a well-structured, supervised setting to minimize the adverse impact of complications that may occur during the early learning curve of this procedure.

Keywords: laser in situ keratomileusis (LASIK), flap complications


How to cite this article:
Al-Tobaigy FM, KKESH Excimer Laser Study Group. Outcome of laser in situ keratomileusis (LASIK) of initial cases performed by supervised anterior segment fellows. Middle East Afr J Ophthalmol 2007;14:58-62

How to cite this URL:
Al-Tobaigy FM, KKESH Excimer Laser Study Group. Outcome of laser in situ keratomileusis (LASIK) of initial cases performed by supervised anterior segment fellows. Middle East Afr J Ophthalmol [serial online] 2007 [cited 2019 Dec 5];14:58-62. Available from: http://www.meajo.org/text.asp?2007/14/2/58/57696

Refractive surgical procedures are being performed in greater numbers and by an increasing number of ophthalmologists. [1] The number of refractive procedures performed increased from approximately 76 000 eyes in 1996 to an estimated 861 000 eyes in 2000 in the United States. [1] Refractive surgical procedures will have more than doubled to 1 962 000 annually by 2005, as indicated by recent reports. [1]

The optimal setting for teaching LASIK is controversial. Alternative positions include incorporating appropriate training in residency programs or in subspecialty refractive training programs; another option is to defer training until after formal education is complete, and rely on industry and university-supported certification courses to provide training for otherwise experienced surgeons. [2]

Residency and fellowship programs have been reluctant to provide "hands-on" experience performing LASIK because of the number of complications that occur during the learning curve. This issue is particularly important because LASIK is an elective procedure that is often performed on relatively young patients with excellent preoperative vision, and some patients who undergo LASIK may experience complications that result in permanent loss of best corrected visual acuity (BCVA). The learning curve of initial LASIK procedures, even by experienced surgeons, is well documented. [3],[4],[5],[6] In a series of 1019 consecutive initial LASIK cases performed by an otherwise experienced refractive surgeon, intraoperative microkeratome-related complications occurred in 6% of the first 100 eyes, 2.3% of the next 600 eyes, and 0.3% of the following 319 eyes. [3] In a series of 1000 consecutive initial LASIK cases by another experienced refractive surgeon, there was an intraoperative microkeratome-related complication rate of 4.5% for the first 200 eyes, 3.0% for the second 200 eyes, 1.5% for the third 200 eyes, and 0.25% for the last 400 eyes. [4] Physician experience with the microkeratome and with the handling of the corneal flap clearly decreases the incidence of flap complications, but complication rates of less than 1.0% are seldom achieved prior to performing LASIK on at least 500 eyes. [3],[4],[5],[6]

There is a general perception that inexperienced resident surgeons learning a new technique, such as LASIK, have a higher complication rate than that of experienced surgeons learning the same technique. It might be argued, however, that this "learning curve gap" may be narrowed if a new procedure, such as LASIK, is introduced after trainees have acquired a reasonable amount of anterior segment surgical experience. If this argument holds true, it would be reasonable to consider incorporating LASIK training into the final months of residency education programs or into subspecialty anterior segment fellowships, thus providing trainees with the benefit of acquiring these skills while being supervised by experienced LASIK surgeons in all phases of the LASIK experience (ie, preoperative evaluation, surgical technique, postoperative care, and management of complications).

Unfortunately, there is limited data available regarding visual outcomes and complication rates of LASIK performed by relatively inexperienced surgeons, such as residents and fellows. This study provides an opportunity to evaluate the visual outcomes and complication rates of initial LASIK procedures performed by anterior segment fellows who recently graduated from a residency program with a strong surgical training curriculum.


   Patients and Methods Top


After obtaining approval of the Institutional Review Board, we retrospectively reviewed the charts of the first 10 consecutive patients (20 eyes) who had LASIK performed by a supervised anterior segment fellow at King Khaled Eye Specialist Hospital in Riyadh, Saudi Arabia, between March 1 and August 31, 2003. All 10 of the fellows had successfully completed residency training in October 2002 and were certified by the Saudi Board of Ophthalmology in December 2002. Each fellow had completed at least 100 anterior segment procedures during residency training as well as during the first 2 months of fellowship training, but had not performed any LASIK procedures prior to the initiation of the training program.

Patient Examination and Selection

All patients underwent a complete ophthalmologic evaluation, including manifest and cycloplegic refraction, corneal topography, ultrasonic pachymetry, intraocular pressure, slit lamp examination of the anterior segment, and dilated fundus examination. Preoperative examinations were conducted by the operating fellow and reviewed by the supervising faculty member, who approved scheduling the case. The patients were aware that the fellow would be the operating surgeon at the time informed consent was obtained.

Patients included in this study had the following outcomes: BCVU of 20/50 or better in both eyes, myopia between -1.5 and -12.0 diopters (D), astigmatism of ≤ 2.0 D, spherical equivalent ≤ -12.0 D, flattest corneal curvature of at least 40.0 D, steepest corneal curvature of < 47.0 D, no topographic evidence of keratoconus, calculated residual stromal thickness of ≥ 250 μm, and normal ophthalmic examination with the exception of refractive error.

Surgical Technique

All cases were performed with the Moria LSK2 CB manual microkeratome to create a 9.0-mm superior hinged flap. A -1 ring was used for mean keratometry of < 41 D, a 0 ring was used for mean keratometry of 41 to 43 D, a +1 ring was used for mean keratometry of 43 to 46 D, and a +1 or +2 ring was used if the mean keratometry was > 46 D. Using the nomogram of the supervising faculty member, laser ablation was performed with either the Star S3 (VISX, Santa Clara, CA, USA) excimer laser (169 eyes) or the EC-5000 (NIDEK CO, LTD, Gamagori, Japan) excimer laser (31 eyes). The optical zone size ranged from 6.0 to 6.5 mm, and the transition zone size ranged from 7.0 to 8.5 mm.

Postoperative Care and Enhancement

Patients were seen postoperatively at 1 day, 1 week, 1 month, and 3 months. Topical prednisolone acetate 1.0% was administered 4 times daily for 1 week and then quickly tapered and discontinued. Ofloxacin 0.3% was administered 4 times daily for 1 week and then discontinued. Unpreserved tear lubricants were used at least 4 times daily for 3 months. At the 3-month follow-up visit, refraction and topography were performed. Patients who were dissatisfied with the visual outcome and had residual refractive errors underwent enhancement if no contraindications were present. All enhancements were performed between 3 and 12 months after the initial procedure. The follow-up schedule, postoperative medications, and follow-up after enhancement were the same as for primary LASIK.

Data Analysis

Preoperative data (uncorrected visual acuity [UCVA], BCVA, manifest and cycloplegic refraction, minimum and maximum corneal keratometry, pachymetry), microkeratome-related intraoperative flap complications (incomplete flap, complete flap, buttonhole flap), postoperative flap complications (striae, diffuse lamellar keratitis, ectasia, epithelial ingrowth, flap dislocation, microbial keratitis), refractive outcome (UCVA, BCVA, manifest refraction, cycloplegic refraction), and results of enhancement (if performed) were extracted from each chart and analyzed using an Excel spreadsheet.


   Results Top


During the study period, 10 anterior segment fellows each performed LASIK on 20 eyes of 10 patients. The mean spherical refractive error was -4.82 D (range, -1.5 to -11.00 D) [Table 1], which included 130 eyes (65.0%) with low myopia, 68 eyes (34.0%) with moderate myopia, and 2 eyes (1.0%) with high myopia. The mean patient age was 28.0 years (range, 18-50 years), and the follow-up period was 123.8 days (range, 14-389 days). Enhancements were performed in 8 eyes (4.0%), at a rate of 7.4% in eyes with moderate myopia in comparison to 2.3% in eyes with low myopia.

A comparison of preoperative best spectacle corrected visual acuity (BSCVA) and postoperative UCVA is provided in [Table 2] and [Figure 1]. After primary LASIK and 8 enhancement procedures, 163 eyes (81.5%) had postoperative UCVA that was within 1 line of preoperative BSCVA, whereas 194 eyes (97.0%) had UCVA that was within 2 lines of preoperative BSCVA. Of 200 eyes, 6 eyes (3.0%) lost 2 or more lines of BSCVA. The difference between the mean preoperative BSCVA (20/22.25) and the postoperative UCVA (20/26.06) was -0.381 lines of Snellen acuity. There were no statistically significant differences in visual outcome between eyes treated with the VISX Star S3 and the NIDEK EC-5000 excimer lasers.

The refractive accuracy of the LASIK procedures is summarized in [Table 3] and [Figure 2]. Prior to enhancement, 180 eyes (90.0%) were within 1 D of intended correction, including 14 eyes (7.0%) with undercorrection and 6 eyes (3.0%) with overcorrection. After 8 enhancements (all for undercorrection), 188 eyes (94.0%) were within 1 D of emmetropia. There were no statistically significant differences in refractive outcome between eyes treated with the VISX Star S3 and the NIDEK EC-5000 excimer lasers.

Intraoperative and postoperative complications are summarized in [Table 4]. The incidence of intraoperative complications was 2.5%, all of which were incomplete flaps. In all 5 cases, the procedure was completed 3 months later. In 2 eyes, the final BSCVA was reduced from 20/20 to 20/30. There were no complete or buttonhole flaps. Postoperative complications occurred in 2.5% of eyes, the most serious being bilateral ectasia, which occurred in 1 patient with no preoperative evidence of keratoconus. In this case, the BSCVA was reduced bilaterally from 20/20 to 20/40.


   Discussion Top


This study confirms that ophthalmology fellows who begin LASIK training after successfully completing a surgically intensive residency program can perform LASIK under the supervision of experienced faculty surgeons and have complication rates similar to those reported by more experienced surgeons initially learning the procedure. [3],[4] The 2.5% incidence of microkeratome-related flap complications found in this study was lower than the rate of 6.0% in the first 100 cases of one series [3] and of 4.5% in the first 200 cases of another series [4] of otherwise well-experienced ophthalmic surgeons, presumably because of improvements in microkeratome design that have occurred since these earlier reports.

Of greater importance than the actual incidence of microkeratome-related flap complications is the likelihood that such untoward events contribute to permanent visual loss. None of the 21 eyes in the series by Lin and Maloney [3] or the 19 eyes in the series by Gimbel et al [4] with microkeratome-related complications resulted in a loss of 2 or more lines of BCVA. In the present series, 2 eyes with a microkeratome-related complication experienced a loss of 2 lines of BCVA, whereby the BCVA was reduced from 20/20 to 20/30.

Serious postoperative complications are much more likely to result in permanent impairment of visual acuity than intraoperative complications. In the present series, there were no sight-threatening complications, such as persistent epithelial defects, sterile flap ulceration, or microbial keratitis; however, there was 1 case of bilateral ectasia in a patient without obvious predisposing risk factors, whereby the BSCVA was reduced from 20/20 to 20/40.

For the purposes of this study, we used functional visual outcome as the gold standard of success in achieving the goal of the procedure, which was defined as the difference between preoperative BSCVA and postoperative UCVA. This difference, referred to as the "net loss," represented the amount of functional acuity that the patient "sacrificed" in return for elimination of reliance on optical aids. In this study, the mean difference between the preoperative BSCVA and the postoperative UCVA was slightly less than one-half line (-0.381) of Snellen acuity. In addition, 81.5% of eyes had a difference of 1 line or less between the preoperative BSCVA and the postoperative UCVA, and 97.0% were within 2 lines after primary LASIK and 8 enhancements. However, 3.0% of eyes lost more than 2 lines of BSCVA.

This study supports previous observations that flap complications are a reality of the learning curve of LASIK. It also lends credibility to arguments that optimal training of ophthalmologists in LASIK occurs in settings where experienced LASIK surgeons participate in the supervision of all phases of the LASIK procedure. The supervision of the management of microkeratome-related complications and postoperative complications during initial LASIK training is valuable not only in minimizing the adverse impact of such events on final visual outcome but also in facilitating the ability of the trainee to manage LASIK complications adequately after graduation.

We recommend conducting a follow-up study to assess the complication rates and visual outcomes of LASIK procedures by supervised trainees after the initial 20 procedures. In addition, the inherent limitations of comparisons with historical controls logically suggests that a comparison of the results of trainee cases with those of their faculty supervisors would provide a more realistic assessment of the differences in outcomes between novice and experienced LASIK surgeons.

The KKESH Excimer Laser Study Group: The authors would like to thank the KKESH Excimer Laser Study Group for its participation in this study. Faculty: Abdullah Al-Assiri, MD; Hamad Al-Fraikh, MD; Sabah Jastaneiah, MD; Fayez Al-Khamees, MD; Soliman Al-Kharashi, MD; Saeed Al-Motowa, MD; Abdulaziz Al-Rajhi, MD; Ali Al-Rajhi, MD; Abdullah Al-Torbak, MD; Abdul-Elah Al-Towerki, MD; Klaus D. Teichmann, MD; Michael D. Wagoner, MD (Principal Investigator). Anterior Segment Fellows 2003: Khaled Abdulwahab, MD; Abdulrazak Al-Emadi; Huda Al-Ghadeer, MD; Mohammad Al-Hummadi, MD; Abdulmalik Al-Qahtani, MD; Samar Al-Swailem, MD; Faisal Al-Tobaigy, MD; Ashraf Baksh, MD; Abdulaziz Dabaan, MD; Mohammad Malik, MD; Zaki Al-Shammari, MD. Data Coordination Unit: El-Sayed Gonnah, CEBT; Jamila Al-Shahrani, BSC; Abid Al-Tahli, CEBT.

 
   References Top

1.Lindstrom RL, Maller BS. Market trends in refractive surgery. J Cataract Refract Surg 1999;25:1408-1411.  Back to cited text no. 1  [PUBMED]  [FULLTEXT]  
2.Aaron MM, Aaberg TM. Ophthalmology resident training in refractive surgery. Am J Ophthalmol 2001;131:241-243.  Back to cited text no. 2  [PUBMED]  [FULLTEXT]  
3.Lin RT, Maloney RK. Flap complications associated with lamellar refractive surgery. Am J Ophthalmol 1999;127:129-136.  Back to cited text no. 3  [PUBMED]  [FULLTEXT]  
4.Gimbel HV, Penno EE, van Westenbrugge JA, et al. Incidence and management of intraoperative and early postoperative complications in 1000 consecutive laser in situ keratomileusis cases. Ophthalmology 1998;105:1839-1847; discussion 1847-1848.  Back to cited text no. 4  [PUBMED]  [FULLTEXT]  
5.Yo C, Vroman C, Ma S, et al. Surgical outcomes of photorefractive keratectomy and laser in situ keratomileusis by inexperienced surgeons. J Cataract Refract Surg 2000;26:510-515.  Back to cited text no. 5  [PUBMED]  [FULLTEXT]  
6.Davidorf JM, Zaldivar R, Oscherow S. Results and complications of laser in situ keratomileusis by experienced surgeons. J Refract Surg 1998;14:114-122.  Back to cited text no. 6  [PUBMED]    


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]



 

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