Int Ophthalmol (2019) 39:1225–1230 https://doi.org/10.1007/s10792-018-0923-1 ORIGINAL PAPER Nd:YAG laser for epithelial ingrowth after laser in situ keratomileusis Osama Ali Mohammed . Amr Mounir . Amin Aboali Hassan . Alahmady Hamad Alsmman . Engy Mohamed Mostafa Received: 28 November 2017 / Accepted: 13 April 2018 / Published online: 4 May 2018 Ó Springer Science+Business Media B.V., part of Springer Nature 2018 Abstract Results Epithelial ingrowth was treated successfully Purpose To evaluate the efficacy of neodymium:yt- in all 41 eyes. The uncorrected visual acuities were trium–aluminum–garnet (Nd:YAG) laser for treat- 20/20, and there was no evidence of recurrent ment of epithelial ingrowth after laser in situ epithelial ingrowth after 6 months with no complica- keratomileusis (LASIK). tions reported. Patients and methods Fifty-eight patients with Conclusion YAG laser is a simple, effective outpa- epithelial ingrowth presented to Sohag refractive tient procedure for the management of epithelial center, Sohag, Egypt, between January 2015 and ingrowth after LASIK. March 2017. Only 41 patients (18 females and 23 males, mean age: 33.4 years) involving 41 eyes were Keywords Nd:YAG Á Epithelial ingrowth Á Laser indicated for treatment by Nd:YAG laser as the rest of in situ keratomileusis the eyes were only under observation. Patients with epithelial ingrowth were recognized at a mean of 6 months after primary LASIK procedure (range: 2–16 months). Four eyes had undergone previous Introduction LASIK enhancements. Four eyes had the epithelial ingrowth removed by flap lift and scrapping. The mean Flap-related complications after laser in situ ker- intensity of the spots used was 0.8 mJ with variable atomileusis (LASIK) are not uncommon [1]. Epithe- number of shots depending on the size and density of lial ingrowth after microkeratome flap creation has the epithelial ingrowth area. Twenty-eight eyes been reported to occur in 0–20% of cases [2, 3] with showed complete regression after one session, while decreasing incidence after the advent of femtosecond the rest necessitated 2–3 sessions for complete reso- laser for the creation of the corneal flap possibly due to lution. Mean follow-up period was 8 months (range its vertical cut [4, 5]. The mechanism of formation of 5–12 months). epithelial ingrowth is either corneal epithelium inva- sion of the interface at the flap edge, mostly due to bad coadaptation of the edge or planting of epithelial cells spread during surgery [2]. O. A. Mohammed Á A. Mounir Á A. A. Hassan Á Epithelial ingrowth can disappear, remain station- & A. H. Alsmman Á E. M. Mostafa ( ) ary or worsen by time due to keratolysis of the Ophthalmology Department, Faculty of Medicine, Sohag University, Nasr City, Sohag 82524, Egypt overlying stroma [6]. Thus, surgical removal is e-mail: [email protected] required essentially in clinically significant epithelial 123 1226 Int Ophthalmol (2019) 39:1225–1230 ingrowth [3] where it extends into the visual axis, introducing YAG laser in our protocol of affecting the quality of vision by nighttime glare, management. irregular astigmatism or causing foreign body sensa- Inclusion criteria were as follows: on slit-lamp tion or leading to the more devastating corneal melt examination, epithelial ingrowth appeared as epithe- [7]. lial pearls in the interface or confluent whitish opacity Risk factors for developing epithelial ingrowth either centrally or peripherally. These lesions would included: recurrent corneal erosions, corneal basement be either encroaching on the pupil or causing irritative membrane epithelial dystrophy intraoperative epithe- symptoms such as glare, halos or dryness or increasing lial defect, corneal flap integrity problems, hyperopic in size on follow-up visits. corrections and diabetes mellitus [8]. Several maneu- Half of the cases were isolated nests of ingrowth, vers have been suggested for removal such as: flap and the other half were continuous sheets growing lifting and manual debridement of the epithelial sheets from the flap edge. Patients’ symptoms ranged from with adjunctive sutures with or without the application affection of BCVA in 28 eyes (68.3%), while 13 eyes of ethanol or anti-metabolites, phototherapeutic ker- (31.7%) had irritative symptoms as glare and dryness. atectomy, the use of tissue adhesives and amniotic None of our patients were diabetic. The 41 patients membrane [9–13]. In 2008, Ayala et al. [14] reported enrolled in this study were with a majority of myopic the use of Nd:YAG laser to eliminate epithelial refraction (37 patients). None had flap complications, ingrowth. while only three eyes showed epithelial loss The aim of our study was to evaluate Nd:YAG for intraoperative. the management of epithelial ingrowth after LASIK as Neodymium:yttrium–aluminum–garnet laser tech- a noninvasive, simple and outpatient procedure. nique: Topical anesthetic drop of benoxinate hydrochloride 0.4% was applied to the eye at concern. Abraham capsulotomy lens (Ocular Instruments, Patients and methods Washington, USA) was used to stabilize the eye. The Nd:YAG laser (VisulasÒ YAG III, Carl Zeiss This is a retrospective chart review of fifty-eight Ophthalmic System Inc.) was used which employs patients with epithelial ingrowth presented to Sohag infrared light at a wavelength of 1064 nm. Spot size refractive center, Sohag, Egypt, between January 2015 used was 8 lm which gives rise to small vacuoles and March 2017. Only 41 eyes involving 41 patients (Fig. 1b) that may join together to produce large (18 females and 23 males, mean age: 28.6 years) were vacuoles leading to the disruption of nearby tissue. indicated for treatment by Nd:YAG laser. Seventeen The power used was 0.8 mJ aiming in the beginning at eyes with epithelial ingrowth were excluded from the the track of the implantation if there was a visible one. beginning of the study as the lesions were too Then, shots were applied centrally and moving small \ 1 mm or did not show visual manifestations centrifugally to make the air bubbles coalesce. Each or did not progress on follow-up visits. shot was at the edge of the adjacent vacuole formed by All eyes had LASIK procedures by the authors of the previous one until the whole area of the ingrowth this paper using the same technique. The corneal flap was treated. The number of spots and sessions varied was cut by the Moria M2 microkeratome (Moria, according to the size and density of the epithelial Antony, France). VISX S4 IR excimer laser system ingrowth. The power was limited to 0.8 mJ, and was used in all cases. There were no reported number of shots limited to 20 for fear of corneal melt. complications in the primary procedure. Patients with The sessions’ interval was 1 week apart. Postoperative epithelial ingrowth were recognized at a mean of treatment included fluorometholone eyedrops three 6 months after LASIK (range: 2–16 months). Four times daily for a week. eyes had undergone previous LASIK enhancements Informed consent was obtained from all patients within 3 months of the primary procedure. Four eyes after explaining the treatment plan. The study adhered had the epithelial ingrowth removed by flap lift and to the tenants of Helsinki Declaration and was scrapping with the application of mitomycin C 0.02%. approved by the Ethical Committee of the Faculty of These four eyes were managed as stated before Medicine, Sohag University. 123 Int Ophthalmol (2019) 39:1225–1230 1227 Fig. 1 a Pre-treatment; b air vacuole immediately after YAG session; c post-treatment by YAG laser for epithelial ingrowth Results of mere follow-up with no intervention due to the surgical risks of an increased incidence of epithelial- Forty-one patients (18 females and 23 males, mean ization, irregular astigmatism and tearing of the age: 28.6 years( involving 41 eyes (21 right, 20 left) corneal flap [1, 15, 16]. The surgical interventions were enrolled in this study. These patients were seen at for removing epithelial ingrowth ranged from manual a mean of 6 months after LASIK (range: scrapping alone [17] or the addition of laser (pho- 2–16 months). Four eyes (9.6%) had undergone one totherapeutic keratotomy [PTK]) [12] or a chemical enhancement. The epithelial ingrowth was primarily material such as alcohol [10] or mitomycin C or peripheral in 35 eyes (85.4%) and primarily central in adding a mechanical barrier as amniotic membrane 6 eyes (14.6%). Four eyes (9.6%) had undergone one [13] or fibrin glue [11] or suturing of the flap [18]. previous removal of epithelial ingrowth. Some advanced cases would require penetrating Mean uncorrected visual acuity (UCVA) improved keratoplasty [8]. All these maneuvers are invasive from 20/80 (range: 20/30 to 20/100) preoperatively to and do not ensure prevention of recurrence [14]. 20/30 (range: 20/20 to 20/40) at the last follow-up. Epithelial ingrowth has been classified into three Mean best-corrected visual acuity (BCVA) improved grades which was proposed by Probst and Machat from 20/60 (range: 20/25 to 20/80) preoperatively to [19]: Grade 1, ingrowth limited to within 2.0 mm of 20/250 (range: 20/20 to 20/30) at the last follow-up. In the flap edge with no associated visual changes; Grade the 28 eyes whose vision was affected, 15 eyes gained 2, ingrowth thickness at least 2.0 mm from the flap one line, 8 eyes gained 2 lines, and 5 gained 3 lines. No edge but with a normal edge anatomy; and Grade 3, eye lost any lines of BCVA. pronounced ingrowth of [ 2.0 mm from the flap edge, Twenty-eight eyes (68.3%) showed complete often with anatomic abnormalities in the edge itself. regression after one session, while the rest necessitated While observation is warranted in Grade 1, inter- 2–3 sessions for complete resolution (9 eyes needed 2 vention is needed once visual acuity or flap abnor- sessions and 4 eyes needed 3 sessions) (Figs.