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| CASE REPORT |
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| Year : 2020 | Volume
: 32
| Issue : 2 | Page : 177-178 |
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Commentary: Guidelines for the management of Post LASIK Epithelial Ingrowth or PLEI
Aneeta Jabbar
I Vision Eye Care Centre, Chalakudy, Kerala, India
| Date of Submission | 21-Apr-2020 |
| Date of Acceptance | 22-Apr-2020 |
| Date of Web Publication | 25-Aug-2020 |
Correspondence Address:
Dr. Aneeta Jabbar
I Vision Eye Care Centre, Chalakudy, Kerala
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/kjo.kjo_46_20
How to cite this article:
Jabbar A. Commentary: Guidelines for the management of Post LASIK Epithelial Ingrowth or PLEI. Kerala J Ophthalmol 2020;32:177-8 |
The creation of a potential space or the interphase between the LASIK flap and the corneal stroma underlying leads to flap-related complications, such as post-LASIK epithelial ingrowth (EI).
With femtosecond-created flaps, the incidence of EI is much lower (around 0.2%) than mechanical flaps (0.3 to 9%). This can be attributed to the fact that a more perpendicular side cut is created using a femtosecond (75°–110°) whereas a blade cuts at an angle of 27° in a mechanical flap.[1] This difference in architecture in a femtosecond-created flap makes it difficult for the epithelial cells to enter the interphase. Furthermore, femto-created flaps adhere more firmly over time and Letko et al.[2] observed that the risk of EI following flap lift was significantly lower in initially femto-created flap as compared with microkeratome-created flap.
| When Does Epithelial Ingrowth Happen? | |  |
In simple words, EI can happen after retreatment or after some traumatic event to the flap.
EI may prove benign or become a real threat to vision, and surgeons have to decide when to wait and watch as well as when to intervene.
| When to Treat? | | |
You need not go after it just because it is there. If it is Machat Stage 1,[3] cells can be seen within 1–2 mm of the flap edge. If you can see a demarcation line, an area of scarring at the anterior edge of the epithelium, then it will not progress and you need to watch it every 3 months. Dead epithelial cells contain collagenase which can melt the flap. Clear signs that demand immediate treatment are progressive ingrowth with no demarcation line, elevation of the flap edge, induced cylinder, changes on topography, dry spots, symptomatic glare, or necrotic cells.[4]
| Treatment | | |
Once you have decided to treat, the essential tip is getting rid of all the cells, approximating and securely re-sealing the flap to prevent recurrence. The source of the epithelial cells is to be found out. Treatment involves lifting the flap and scraping both the bed and the under surface of the flap. Some surgeons use blade, others use shallow PTK (5 μ of PTK depth), and the important point is to ensure the tight realignment of the flap edges. If there is a rolled edge from the flap melt, a recurrence of EI is far more likely, and it will be better if you suture the flap edges or use fibrin glue.
The discovery of the source of these “unwanted “epithelial cells by a very careful slit lamp examination gives good results. Because once inside the Operating Room the flap can be sutured down ie ; put a suture where the epithelium was coming in thus closing the path and if you do it right the cells won't come back.
Fibrin glue also produce good results in preventing recurrence,[5] but it is easy for it to dislodge, and if it does not hold for long enough, you can still get ingrowth underneath.
Some surgeons use Nd:Yag[6] (0.6–0.8 mJ) photodisruption for Grade 2 and 3 ingrowth affecting visual acuity.
| Repeat as Required | | |
Once the path has been created, the cells will grow back all over again like unwanted guests. Hence, regular follow-up is essential, and if it recurs and continues to progress, then repeat the processes such as lifting the flap, debridement, and use of adjutants such as suturing/glue. The role of mitomycin-C is unclear in preventing recurrence.
Once EI occurs, we are only 80% effective in eliminating it. If ingrowth is very minimal, the first treatment can be 98% effective. However, if you do not treat a rapidly advancing EI with no demarcation line or necrotic epithelial cells, the cell walls that move in will drag the flap edge and it will get rolled. Treatment of progressive EI, i.e., Grade 3, will be only 80% effective.
| References | | |
| 1. | Xia LK, Yu J, Rui-Chai G, Wang D, Li Y. Comparison of femtosecond laser and mechanical microkeratome for flap cutting in LASIK. Int J Ophthalmol 2015;8:784-90.  |
| 2. | Letko E, Price MO, Price FW Jr. Influence of original flap creation method on incidence of epithelial ingrowth after LASIK retreatment. J Refract Surg 2009;25:1039-41. |
| 3. | Machat JJ, Slade SG, Probst LE. The Art of LASIK Edition. Thorofare, NJ: Slack; 1999. |
| 4. | Brennan K. Shutting the door on epithelial ingrowth. Rev Ophthalmol 2018;18:24. |
| 5. | Yeung AM, Faraj LA, McIntosh OD, Dhillon VK, Dua HS. Fibrin glue inhibits migration of ocular surface epithelial cells. Eye (Lond) 2016;30:1389-94. |
| 6. | Lapid-Gortzak R, Hughes JM, Nieuwendaal CP, Mourits MP, van der Meulen IJ. LASIK flap breakthrough in Nd: YAG laser treatment of epithelial ingrowth. J Refract Surg 2015;31:342-5. |
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