Laser in situ keratomileusis (LASIK) flap creation may need to be aborted for a variety of reasons. These include suction loss, buttonhole formation, vertical bubble break, decentered ablation, or inability to lift the flap.1–4 These events make it risky or impossible to continue with the surgery. Surface ablation (laser epithelial keratomileusis [LASEK] or photorefractive keratectomy [PRK]) can be performed at a later date to achieve the intended refractive target.
The safety of a secondary surface ablation on a LASIK flap has been well established.5–19 However, the best timing of laser treatment on an aborted LASIK flap is not clear. Many surgeons recommend waiting 3 months or longer to achieve refractive stability before proceeding with surface ablation. In a case series of 31 eyes by 8 surgeons,6 the average time between the first and second procedure was 3.9 months (range: 1 to 25 months). In another case series,8 the mean time to second surgery was 135 days (4.5 months). Neira-Zalentein et al.9 suggested 2 years as a safe time for secondary surface ablation, whereas Liu and Manche10 postulated that a 3- to 6-month interval may reduce the incidence of corneal haze compared to a longer interval.
In this retrospective case series, we report the results of patients who had secondary surface ablation within 4 weeks of a primary aborted LASIK procedure.
Patients and Methods
The electronic medical records of patients undergoing LASIK at the Boston Eye Group were retrospectively reviewed. Patients were included if they experienced a flap complication that resulted in the procedure being aborted with or without an attempt to lift the flap. Patients were excluded if they did not have at least three postoperative visits following surface ablation or if surface ablation was performed more than 4 weeks after the aborted LASIK procedure.
All cases were performed by a single surgeon (SM) in Brookline, Massachusetts, between 2009 and 2015. All patients received a full ophthalmic evaluation and corneal topography prior to LASIK. Lasers used to create the femtosecond flap included the FS200 (Alcon Laboratories, Inc., Fort Worth, TX) and IntraLase FS60 (Johnson & Johnson Vision, Jacksonville, FL). All patients received excimer treatment with the Wavelight EX500 (Alcon Laboratories, Inc.) or STAR VISX S4 (Johnson & Johnson Vision).
Patients were examined at the slit lamp 30 minutes after the aborted LASIK procedure and were required to return for 1-day and 1-week follow-up examinations to measure visual acuity, refraction, and further slit-lamp examination of the LASIK flap. Patients completed the normal postoperative drop regimen consisting of prednisolone acetate and moxifloxacin for 5 days.
Patients underwent repeat refraction followed by surface ablation when deemed stable. Surface ablation (LASEK or PRK) was performed in a standard fashion using 20% ethyl alcohol to mobilize the epithelium. All patients received mitomycin C for 40 seconds after ablation prior to applying a bandage contact lens. Patients were treated with topical antibiotics for 1 week and prednisolone acetate 1% in a tapering fashion over 4 weeks. All patients were instructed to take oral vitamin C 1,000 mg/day for 3 months.
The retrospective chart review of LASIK surgeries performed between January 2009 and December 2015 (7,142 eyes) identified 20 eyes in which the procedure was aborted (0.003%). Only 16 eyes of 16 patients met the inclusion and exclusion criteria; 2 eyes were excluded for not having three follow-up appointments after secondary advanced surface ablation and 2 eyes were excluded for having waited longer than 4 weeks before secondary surgery. The data evaluated included age, sex, operative eye, type of complication that occurred, manifest refraction before both procedures, keratometry, pachymetry, ablation depth, and uncorrected (UDVA) and corrected (CDVA) visual acuity both preoperatively and postoperatively.
Table 1 lists the complications that resulted in the procedure being aborted in favor of future surface ablation. The majority (63%) of flap complications occurred as a result of an incomplete flap, whereas 19% of complications occurred due to a decentered flap. The remaining complications occurred due to a loss of suction in the visual axis, the creation of a thick flap, and central vertical bubble breakthrough.
Type of Complication and Corresponding No. of Eyes Experiencing Complications
Table 2 displays the characteristics of the 16 patients before the first LASIK procedure and just prior to the second surface ablation procedure. Nine men and 7 women had flap complications, of which 10 were right eyes and 6 were left eyes. The average preoperative age of patients was 36 years (range: 24 to 60 years). All patients had a CDVA of 20/20 prior to surgery. Fifteen patients were myopic and 1 was hyperopic, and 11 of 16 had some degree of astigmatism. One eye was targeted for monovision. The average corneal thickness was 559.9 µm (range: 502 to 623 µm).
Preoperative Measurements and Surgical Details for First and Second Procedures
All patients received a repeat manifest refraction just prior to the secondary surface ablation (reported in Table 3). Eight of the 16 eyes did not experience any changes in sphere, cylinder, or axis between refractions and 7 of the 16 eyes experienced a minor change in the refraction (< 0.50 diopters [D] change in either direction in sphere or cylinder). Axis changes were not considered significant because no patient with more than 0.50 D of cylinder had more than a 10° change in corrective axis. Only 1 patient had a 0.75 D decrease in the cylinder value between refractions. Overall, eyes showed refractive stability between the initial aborted LASIK procedure and second surgery.
Time Between Aborted LASIK and Surface Ablation and Final Visual Outcome
The average duration between both procedures was 11.3 days (range: 4 to 28 days). Nine of the 16 patients underwent the second surgery within 1 week, 4 patients underwent the procedure within 2 weeks, and the remaining 3 patients waited 3 (1) and 4 (2) weeks.
In total, 5 of the patients did not have a UDVA of 20/20 at their last follow-up examination. Two eyes were 20/25 with a small refractive error; 1 of these was targeted for monovision, so this UDVA was appropriate. Another 2 eyes were worse than 20/40 with a more significant refractive error but corrected to 20/20. One patient developed corneal haze with a UDVA of 20/40 and a CDVA of 20/25.
Laser ablation on an aborted LASIK flap has been a recognized treatment modality to achieve spectacle independence. Investigators have differed in their recommendation as to the optimal timing of that intervention.5–19 This case series demonstrates that surface ablation can be safely performed as soon as 1 week after an aborted FS-LASIK procedure.
The femtosecond laser is a reliable method to create LASIK flaps, but complications such as incomplete flaps, decentration, vertical bubble breaks, and suction loss can still occur.1,2 The best time to perform surface ablation after an aborted LASIK procedure is not clear. A common time frame suggested by surgeons is 3 to 4 months.6,8 Most patients in this case series had surgery within 1 to 2 weeks with good outcomes. Although 3 of the 13 patients who had surface ablation within 2 weeks lost one line of UDVA, 2 of the 3 were 20/25 uncorrected and all corrected to 20/20.
One concern about performing surface ablation after only 1 week is whether the patient has achieved refractive stability by that time. Our results mirror prior findings by Al-Mezaine et al.,6 who found minimal change in refractive error between refraction before and after the aborted LASIK procedure. In their case series of 31 eyes by 8 surgeons, the average time between the first and second procedure was 3.9 months (range: 1 to 25 months). In the same series, the refractive change between the two procedures was minimal with a myopic change of −0.35 ± 0.24 D in 14 eyes and a hyperopic change of +0.58 ± 0.41 D in 13 eyes. In another case series by Jabbur et al.,8 at an average of 4.5 months, 14 of 16 eyes had minimal or no change in refraction by our criteria. One eye had a 1.00 D increase in cylinder and one eye had a 1.50 D hyperopic shift. The mean change in manifest refraction spherical equivalent was 0.25 D. There are limitations in comparing our series to these prior published studies. In these studies, a keratome was used to create the LASIK flap versus the femtosecond laser in ours. A femtosecond laser flap is not a true free flap unless dissected and lifted because of microadhesions in the interface. This may theoretically lead to less refractive change than a true keratome flap. These two studies also did not report refractive data at specified intervals between 1 and 3 months after aborted LASIK, so it is impossible to know when refractive stability was achieved. Finally, in Al-Mezaine et al.'s series,6 LASIK was repeated as a secondary procedure in many cases (as opposed to surface ablation).
Despite these differences, our experience was similar in that only 1 of the 16 patients had a significant change in refraction by losing 0.75 D of cylinder. Furthermore, 11 of 16 eyes in our series achieved UDVA of 20/20, 13 of 16 achieved a UDVA of 20/25 or better, and 15 of 16 had a CDVA of 20/20. Only one patient had a bothersome residual refractive error after the secondary procedure that required enhancement (this patient improved to a UDVA of 20/20 with PRK enhancement). This supports the notion that refractive stability after an aborted FS-LASIK procedure occurs earlier than 3 to 4 months as suggested in prior studies and maybe as soon as 1 week.
However, it should be noted that in our one patient with a significant refractive change, secondary surgery was still performed at 7 days and she did not end up with UDVA of 20/20. Thus, it may be prudent to delay surface ablation when the refraction changes by more than 0.50 D in any direction. Interestingly, this patient had against-the-rule astigmatism that decreased by 0.75 D after aborted LASIK. The patient's ultimate refractive error after surface ablation was plano −0.75 × 170, resulting in a “flipped” axis of astigmatism to with the rule.
Another concern of surface ablation after LASIK is that a higher treatment may ablate entirely through the flap, leaving a donut of stromal tissue that could be friable and easily disturbed early on. In this series, we do not know the true LASIK flap thickness because not all flaps were lifted and measured, but the intended depth was 100 µm. Eight of 16 eyes in this series had ablations of greater than 50 µm, which had the potential to penetrate through the 100-µm LASIK flap (50 µm being epithelium). All 8 of these patients had good outcomes with no complications other than refractive error.
It is challenging to compare our data to prior retrospective analyses and U.S. Food and Drug Administration (FDA) data due to different reporting methods and follow-up times. However, some conclusions can be drawn. Table A (available in the online version of this article) displays distance visual acuity and refractive outcomes in the Alcon EX500 FDA PRK trial from 2016,20 the current series, and the two prior published series. In all three series of PRK following aborted LASIK, visual outcomes were not as good as virgin corneas undergoing PRK from the FDA trial.21,22 However, the two prior series by Jabbur et al.8 and Al-Mezaine et al.6 showed no significant visual acuity outcome advantage when waiting 3 months or longer to perform secondary surface ablation versus 1 month in our series. In fact, the Al-Mezaine et al. series only reported CDVA outcomes that were worse than our UDVA outcomes.
Comparing Final Outcomes in Current Study to Prior Published Data
Specific complications can occur when applying an excimer laser ablation on a LASIK flap. Diffuse lamellar keratitis could happen because of the large epithelial defect induced during surface ablation.22 None of the patients developed an inflammatory reaction in our series. All patients were treated with mitomycin C because of the concern for postoperative haze with surface ablation over a LASIK flap. A longer duration of application than typical was used (40 seconds) because these patients may be at higher risk than patients undergoing primary surface ablation.11 One patient developed postoperative haze despite a small ablation (22 µm) and mitomycin C application. This patient's haze was relatively mild with a CDVA of 20/25. Unfortunately the patient was lost to follow-up.
Creating a second, deeper LASIK flap (“Re-LASIK”) is also a reported option for managing these cases. The authors favor secondary surface ablation for several reasons. In the rare event of creation of two transecting LASIK flaps, there can be significant visual consequences.23 Furthermore, in the case of FS-LASIK, there may be some inherent anatomical quality (corneal scar), patient anatomy (deep orbit), or lack of patient cooperation that contributed to the incomplete or decentered LASIK flap, which resulted in the aborted procedure. We prefer to remove these variables from the equation for a secondary procedure and perform surface ablation.
This study suffers from a few limitations. The number of patients who met the inclusion criteria was relatively low. These events are rare (0.003% in this review) and thus performing statistical analysis is challenging. A second limitation is the duration of follow-up. We do not have data to report on long-term refractive stability or late corneal haze for every patient. Six patients had less than 3 months of follow-up after the secondary surface ablation procedure. However, all 6 of those patients had a UDVA of 20/20. Finally, this retrospective analysis did not compare different types and severity of flap complications. For example, some patients suffered one-third or two-thirds flap defects in different spatial regions, with some over the pupillary area and some in non-pupillary areas. This has the potential to affect the refractive stability and outcomes but could not be evaluated in this study.
This is the first case series to report outcomes of early (less than 1 month) surface ablation on aborted FS-LASIK flaps. The data show that 73% of patients attained UDVA of 20/20 and 81% attained 20/25 within 2 to 4 months after the aborted LASIK procedure; 94% of patients had a CDVA of 20/20 at the last visit. This case series indicates that early surface ablation after an aborted FS-LASIK procedure may be performed safely with good visual outcomes.
- Shah DN, Melki S. Complications of femtosecond-assisted laser in-situ keratomileusis flaps. Semin Ophthalmol. 2014;29:363–375. doi:10.3109/08820538.2014.959194 [CrossRef]
- Melki SA, Azar DT. LASIK complications: etiology, management, and prevention. Surv Ophthalmol. 2001;46:95–116. doi:10.1016/S0039-6257(01)00254-5 [CrossRef]
- Espandar L, Meyer J. Intraoperative and postoperative complications of laser in situ keratomileusis flap creation using IntraLase femtosecond laser and mechanical microkeratomes. Middle East Afr J Ophthalmol. 2010;17:56–59.
- Haft P, Yoo SH, Kymionis GD, Ide T, O'Brien TP, Culbertson WW. Complications of LASIK flaps made by the IntraLase 15-and 30-kHz femtosecond lasers. J Refract Surg. 2009;25:979–984. doi:10.3928/1081597X-20091016-02 [CrossRef]
- Jadav DS, Desai N, Taylor KR, Caldwell MC, Panday VA, Reilly CD. Visual outcomes after femtosecond laser in situ keratomileusis flap complications. J Cataract Refract Surg. 2015;41:2487–2492. doi:10.1016/j.jcrs.2015.05.024 [CrossRef]
- Al-Mezaine HS, Al-Amro SA, Al-Fadda A, Al-Obeidan S. Outcomes of retreatment after aborted laser in situ keratomileusis due to flap complications. Middle East Afr J Ophthalmol. 2011;18:232–237. doi:10.4103/0974-9233.84054 [CrossRef]
- Fahed DC, Fahed CD. Visual outcome and aberration measurement in patients with aborted LASIK flaps. J Refract Surg. 2007;23:14–15. doi:10.3928/1081-597X-20070101-04 [CrossRef]
- Jabbur NS, Myrowitz E, Wexler JL, O'Brien TP. Outcome of second surgery in LASIK cases aborted due to flap complications. J Cataract Refract Surg. 2004;30:993–999. doi:10.1016/j.jcrs.2003.09.067 [CrossRef]
- Neira-Zalentein W, Moilanen JA, Tuisku IS, Holopainen JM, Tervo TM. Photorefractive keratectomy retreatment after LASIK. J Refract Surg. 2008;24:710–712.
- Liu A, Manche EE. Visually significant haze after retreatment with photorefractive keratectomy with mitomycin-C following laser in situ keratomileusis. J Cataract Refract Surg. 2010;36:1599–1601. doi:10.1016/j.jcrs.2010.06.004 [CrossRef]
- Srinivasan S, Drake A, Herzig S. Photorefractive keratectomy with 0.02% mitomycin c for treatment of residual refractive errors after LASIK. J Refract Surg. 2008;24:S64–S67. doi:10.3928/1081597X-20080101-12 [CrossRef]
- Lee BS, Gupta PK, Davis EA, Hardten DR. Outcomes of photorefractive keratectomy enhancement after LASIK. J Refract Surg. 2014;30:549–556. doi:10.3928/1081597X-20140711-08 [CrossRef]
- Ortega-Usobiaga J, Llovet-Osuna F, Katz T, et al. Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap. Arch Soc Esp Oftalmol. 2018;93:60–68. doi:10.1016/j.oftal.2017.05.007 [CrossRef]
- Schallhorn SC, Venter JA, Hannan SJ, Hettinger KA, Teenan D. Flap lift and photorefractive keratectomy enhancements after primary laser in situ keratomileusis using a wavefront-guided ablation profile: refractive and visual outcomes. J Cataract Refract Surg. 2015;41:2501–2512. doi:10.1016/j.jcrs.2015.05.031 [CrossRef]
- Beerthuizen JJ, Siebelt E. Surface ablation after laser in situ keratomileusis: retreatment on the flap. J Cataract Refract Surg. 2007;33:1376–1380. doi:10.1016/j.jcrs.2007.04.024 [CrossRef]
- Taneri S, Koch JM, Melki SA, Azar DT. Mitomycin-C assisted photorefractive keratectomy in the treatment of buttonholed laser in situ keratomileusis flaps associated with epithelial in-growth. J Cataract Refract Surg. 2005;31:2026–2030. doi:10.1016/j.jcrs.2005.06.035 [CrossRef]
- Muller LT, Candal EM, Epstein RJ, Dennis RF, Majmudar PA. Transepithelial phototherapeutic keratectomy/photorefractive keratectomy with adjunctive mitomycin-C for complicated LASIK flaps. J Cataract Refract Surg. 2005;31:291–296. doi:10.1016/j.jcrs.2004.04.044 [CrossRef]
- Weisenthal RW, Salz J, Sugar A, Mandelberg A, Furlong M, Bagan S, Kandleman S. Photorefractive keratectomy for treatment of flap complications in laser in situ keratomileusis. Cornea. 2003;22:399–404. doi:10.1097/00003226-200307000-00002 [CrossRef]
- Shaikh NM, Wee CE, Kaufman SC. The safety and efficacy of photorefractive keratectomy after laser in situ keratomileusis. J Refract Surg. 2005;21:353–358.
- Alcon EX500 2016 FDA Trial Data for PRK. PMA P020050/S023. Accessed September 5, 2018. https://www.accessdata.fda.gov/cdrh_docs/pdf2/P020050S023B.pdf.
- Randleman JB, Shah RD. LASIK interface complications: etiology, management, and outcomes. J Refract Surg. 2012;28:575–586. doi:10.3928/1081597X-20120722-01 [CrossRef]
- Gil-Cazorla R, Teus MA, de Benito-Llopis L, Fuentes I. Incidence of diffuse lamellar keratitis after laser in situ keratomileusis associated with the IntraLase 15 kHz femtosecond laser and Moria M2 microkeratome. J Cataract Refract Surg. 2008;34:28–31. doi:10.1016/j.jcrs.2007.08.025 [CrossRef]
- Rubinfeld RS, Hardten DR, Donnenfeld ED, et al. To lift or recut: changing trends in LASIK enhancement. J Cataract Refract Surg. 2003;29:2306–2317. doi:10.1016/j.jcrs.2003.08.013 [CrossRef]
Type of Complication and Corresponding No. of Eyes Experiencing Complicationsa
|Complication||No. of Eyes|
|Vertical bubble breakthrough central||1|
|Loss of suction in axis||1|
Preoperative Measurements and Surgical Details for First and Second Procedures
|Sex/Birth Year||Age (y)||Eye||First Procedure (Aborted LASIK)||Secondary Surface Ablation|
|MRx Before LASIK (D)||Keratometry (D)||Pachymetry (µm)||CDVA||Flap Complication||Time (Days)||MRx Before PRK||Last Postop UDVA||Final FU||Last Available MRx (D) (Time)||Ablation Depth (µm)|
|M/1975||36||OD||−1.75, −2.00 × 001||42.00/44.00||572||20/20||Loss of suction in axis||11||No change||20/20||4 mo||N/A||37|
|F/1973||41||OD||−2.50, −0.25 × 166||43.75/44.75||546||20/20||Incomplete||7||−2.75, −0.25 × 125||20/25a||3.5 mo||−0.25 −0.75 × 177, 20/20 (3.5 mo)||52|
|M/1979||35||OD||−1.25, sphere||42.50/42.75||518||20/20||Incomplete||4||No change||20/20||2 mo||N/A||20|
|F/1984||30||OD||−1.00, sphere||42.50/43.50||583||20/20||Incomplete||7||No change||20/15||3 y||+0.50 −0.25 × 135, 20/15 (3 y)||16|
|M/1984||30||OS||−3.75, −0.75 × 005||44.50/45.50||502||20/20||Incomplete||7||−4.00, −0.50 × 005||20/15||2.5 mo||N/A||80|
|F/1969||46||OD||−6.25, −1.25 × 090||45.25/45.75||548||20/20−||Too thick||7||−6.25, −0.50 × 095||20/25a||4.5 mo||pl −0.75 × 170,20/20 (4.5 mo)||116|
|M/1958||56||OD||−4.00, −0.75 × 10||45.50/46.50||608||20/20−||Decentered||21||−3.75, −1.00 × 20||20/50a||1 y||+1.50 −0.50 × 135, 20/20 (1 y)||71|
|M/1951||60||OD||0.25, −2.00 × 085||44.00/44.75||574||20/20||VBB central||28||pl, −1.75 × 090||20/20−||5 wks||N/A||45|
|F/1988||26||OS||−6.50, −0.25 × 059||44.25/45.00||516||20/20||Incomplete||4||No change||20/20||1 y||N/A||84|
|M/1977||38||OD||−1.25, −1.00 × 120||43.75/44.25||573||20/20||Decentered||7||−1.00, −1.00 × 122||20/20−||2 mo||N/A||27|
|F/1984||29||OD||−7.25, −0.50 × 035||43.25/44.00||567||20/20||Incomplete||7||−7.25, −0.25 × 010||20/20+||2 mo||N/A||111|
|M/1989||24||OS||−4.00, −1.25 × 167||43.75/45.50||548||20/20||Incomplete||12||No change||20/70a||3 y||−1.00 −0.50 × 60, 20/20 (3 y)||71|
|F/1964||45||OS||−3.75, −1.25 × 170||42.70/44.70||557||20/20||Incomplete||7||No change||20/15||8.5 mo||pl, 20/15, (8.5 mo)||46|
|M/1983||26||OS||−5.50, sphere||43.00/43.20||573||20/20||Incomplete||12||No change||20/20||6 mo||N/A||84|
|F/1983||26||OD||−2.50, sphere||43.37/44.00||551||20/20||Incomplete||12||No change||20/20||6 wks||N/A||47|
|M/1980||29||OS||−0.75, sphere||42.70/43.40||623||20/20||Decentered||28||No change||20/40b||6 mo||−0.25 −0.75 × 5, 20/25 (6 mo)||22|
Time Between Aborted LASIK and Surface Ablation and Final Visual Outcome
|Time Between Procedures||No. of Eyes||Preoperative LASIK CDVA||Last Postoperative UDVA||Last Postoperative CDVA|
|1 week||9||20/20 (9)||20/20 (7); 20/25 (2)||20/20 (9)|
|2 weeks||4||20/20 (3)||20/20 (3); 20/70 (1)||20/20 (4)|
|1 month||2||20/20 (2)||20/20 (1); 20/40 (1)||20/20 (1); 20/25 (1)a|
Comparing Final Outcomes in Current Study to Prior Published Data
|Final Outcome||Alcon EX500 PRK FDA Trial at 3 Months20||Current Series||Jabbur et al.8||Al-Mezaine et al.6|
|UDVA 20/20 or better||288/317 (90.9%)||11/15 (73%)a||7/16 (43.8%)||5/11 (45.4%)b|
|UDVA 0/40 or better||297/297 (100%)||13/15 (87%)a||16/16 (100%)||11/11 (100%)b|
|MRSE ±0.50 D||293/317 (92.4%)||13/16 (81%)||N/A||N/A|
|MRSE ±1.00 D||315/317 (99.4%)||14/16 (88%)||N/A||N/A|