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 Table of Contents  
Year : 2021  |  Volume : 1  |  Issue : 4  |  Page : 630-631

A case of epithelial ingrowth after small incision lenticule extraction

Department of Ophthalmology, Foshan Eye Institute, The Second People's Hospital of Foshan, Foshan, China

Date of Submission16-Feb-2021
Date of Acceptance18-Mar-2021
Date of Web Publication09-Oct-2021

Correspondence Address:
Dr. Xue Li
Department of Ophthalmology, Foshan Eye Institute, The Second People's Hospital of Foshan, No. 78 Weiguo Road, Foshan - 528000
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijo.IJO_379_21

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A 31-year-old woman who had undergone bilateral small incision lenticule extraction (SMILE) surgery developed visually significant epithelial ingrowth in her left eye. She then underwent epithelial removal without lifting the cap. No corneal haze or irregular astigmatism was observed through follow-up. The patient had a medical history significant for hyperthyroidism, suggesting that epithelial basement membrane degeneration in patient with hyperthyroidism may be a risk factor for epithelial ingrowth after SMILE.

Keywords: Epithelial abrasion, epithelial ingrowth, small incision lenticule extraction

How to cite this article:
Li X, Luo F, Lu Q. A case of epithelial ingrowth after small incision lenticule extraction. Indian J Ophthalmol Case Rep 2021;1:630-1

How to cite this URL:
Li X, Luo F, Lu Q. A case of epithelial ingrowth after small incision lenticule extraction. Indian J Ophthalmol Case Rep [serial online] 2021 [cited 2021 Oct 19];1:630-1. Available from: https://www.ijoreports.in/text.asp?2021/1/4/630/327740

Small incision lenticule extraction (SMILE) is a flap-free intrastromal technique for the correction of myopia and myopia astigmatism. SMILE forms a small peripheral corneal incision through which the lenticule gets extracted. It damages less the corneal biomechanical stability, reduces injury to the subbasal nerve plexus, and avoids flap-related complications.[1] Epithelial ingrowth after SMILE is an infrequent complication. In view of its rarity, surgeons are not aware of its risk factors. We report a case in which epithelial ingrowth located visual axis occurred after SMILE with incision's epithelial abrasion. The patient had hyperthyroidism.

  Case Report Top

A 31-year-old woman who had undergone bilateral SMILE a week ago in our hospital came with painless reducing vision in the left eye which had a preoperative sphere of −3.50 D, cylinder of −1.50 D. The patient had a medical history significant for stable hyperthyroidism. She complained of decreased visual acuity in her left eye. The manifest refraction was −1.75 DS/−0.25 DC × 45, with an uncorrected distance visual acuity (UDVA) of 0.4 LogMAR and a corrected distance visual acuity (CDVA) of 0.3 LogMAR 1 week after surgery. The slit-lamp examination showed a significant epithelial ingrowth into the interface pocket affecting visual axis [Figure 1]. Epithelial near the incision was abrasive and loose. This case conformed to the tenets of the declaration of Helsinki and was approved by the institutional ethics committee. After discussing with the patient and informed consent was obtained, we performed epithelial removal. The flap spatula double ended(Suzhou Mingren Medical Equipment Co.,Ltd) was used to open the cap side-cut incision and separated the interface, scraped the epithelial ingrowth manually. Then the epithelial ingrowth was extracted with microforceps. After that, we used a balanced salt solution to irrigate the interface pocket meticulously without lifting the cap. Postoperatively, a soft bandage contact lens was worn for one night and levofloxacin (Santen Pharmaceutical Co., Ltd. Japan) and loteprednol etabonate 0.5% (Bausch & Lomb Co., Ltd. United States) acetate eye drops were used for 2 weeks in an attempt to reduce postoperative inflammation and corneal scarring. One week after epithelial removal [Figure 2], the patient's UDVA was −0.1 LogMAR, manifest refraction was +0.25 DS. The patient was treated and no corneal haze or irregular astigmatism through follow-up three months.
Figure 1: Slit-lamp images of the left eye demonstrated a 1 mm * 1.5 mm epithelial ingrowth with formed pseudopodia in the interface pocket after SMILE 1 week

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Figure 2: Slit-lamp images of the left eye demonstrated epithelial removal after 1 week

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  Discussion Top

Epithelial ingrowth rates of 0.02–0.5% with SMILE are far lower compared to a complication rate of 0.17–13.55% with laser-assisted in-situ keratomileusis (LASIK).[1],[2],[3],[4] Anders Ivarsen et al.[5] demonstrated that epithelial ingrowth near the incision was found in 10/1500 (0.67%) eyes undergoing SMILE, which were not progressive after 3 months follow-up and disappeared spontaneously over time. Thulasi et al.[6] reported the first progressive, visually significant epithelial ingrowth, and suggested that as in LASIK, diabetes may be a risk factor for this complication. Risk factors include epithelial basement membrane degeneration, intraoperative epithelial defects, decentered flaps, trauma, diabetes, older age, previous corneal surgery, and surgeon's learning curve in both LASIK and flap lift enhancement techniques.[7],[8]

In our case, epithelial ingrowth was found after underwent SMILE 1 week, earlier than previous reports. The reason for this patient's rapid course could be multifactorial. The initial lenticule removal was likely traumatic to the epithelium at the site of the incision. Pieces of epithelial were taken into the interface pocket and irrigated deficiently, leading to facilitate epithelial ingrowth. The cytotoxic effect of topical anesthetic on epithelial cells and epithelial basement membrane degeneration on patient with hyperthyroidism are risk factors as well.[9] Prevention of epithelial ingrowth needs to protect the integrity of epithelial, avoid excessive manual operation and examine the interface cautiously at the end of surgery. These measures, while believed to facilitate SMILE, and to reduce epithelial.

  Conclusion Top

Measures to prevent epithelial ingrowth include maintanance of the integrity of epithelium, avoiding excessive manipulation, and examination of the interface cautiously at the end of surgery. These measures to reduce epithelial ingrowth have not been studied in patients with hyperthyroidism to the best of our knowledge.


This study was funded by the Foshan Municipal Health Bureau Scientific Research (No. 20210334).

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

This study was funded by the Foshan Municipal Health Bureau Scientific Research (No. 20210334).

Conflicts of interest

There are no conflicts of interest.

  References Top

Moshirfar M, McCaughey MV, Reinstein DZ, Shah R, Santiago-Caban L, Fenzl CR. Small-incision lenticule extraction. J Cataract Refract Surg 2015;41:652-65.  Back to cited text no. 1
Wang Y, Ma J, Zhang L, Zou H, Li J, Zhang Y, et al. Postoperative corneal complications in small incision lenticule extraction: Long-term study. J Refract Surg 2019;35:146-52.  Back to cited text no. 2
Güell JL, Verdaguer P, Mateu-Figueras G, Elies D, Gris O, Manero F, et al. Epithelial ingrowth after LASIK: Visual and refractive results after cleaning the interface and suturing the lenticule. Cornea 2014;33:1046-50.  Back to cited text no. 3
Ortega-Usobiaga J, Llovet-Osuna F, Katz T, Djodeyre MR, Druchkiv V, Bilbao-Calabuig R, 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;93:60-8.  Back to cited text no. 4
Ivarsen A, Asp S, Hjortdal J. Safety and complications of more than 1500 small-incision lenticule extraction procedures. Ophthalmology 2014;121:822-8.  Back to cited text no. 5
Thulasi P, Kim SW, Shetty R, Randleman JB. Recalcitrant epithelial ingrowth after SMILE treated with a hydrogel ocular sealant. J Refract Surg 2015;31:847-50.  Back to cited text no. 6
Randleman JB, Shah RD. LASIK interface complications: Etiology, management, and outcomes. J Refract Surg 2012;28:575-86.  Back to cited text no. 7
Henry CR, Canto AP, Galor A, Vaddavalli PK, Culbertson WW, Yoo SH. Epithelial ingrowth after LASIK: Clinical characteristics, risk factors, and visual outcomes in patients requiring flap lift. J Refract Surg 2012;28:488-92.  Back to cited text no. 8
Kocabeyoglu S, Mocan MC, Cevik Y, Irkec M. Ocular surface alterations and in vivo confocal microscopic features of corneas in patients with newly diagnosed graves' disease. Cornea 2015;34:745-9.  Back to cited text no. 9


  [Figure 1], [Figure 2]


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