Small incision lenticule extraction (SMILE) uses a femtosecond laser for the creation of 4 sequential photo-disruptive cuts to fashion an intrastromal lenticule. The lenticule is subsequently separated from the surrounding stroma and removed to offer a refractive correction. Incomplete photo disruption or surgical failure may result in retained lenticular fragments with pursuant consequences, including irregular astigmatism, induced corneal aberrations, and reduction in visual acuity.
The use of anterior segment optical coherence tomography (AS-OCT) as a preoperative and intraoperative tool to aid extraction of retained tissue fragments is well established.1,2 However, the limited availability and incurred cost of the diagnostic tool are potential limitations. We describe a technique for intraoperative delineation of the lenticule remnant with the application of diluted triamcinolone acetonide injected into the intrastromal pocket.
The study adhered to the tenets of declaration of Helsinki. Ethics committee approval was obtained and an informed consent was given. A 24-year-old woman underwent SMILE for refractive correction of −1.50 diopter (D) sphere in both eyes elsewhere. The surgical course in the right eye was eventful resulting in suboptimal visual outcomes postoperatively. She presented to us on postoperative day 2 with complaints of persistent defective vision in the right eye, and a corrected distance visual acuity of 20/30 (−2.00 −3.50 × 5). The left eye showed an uncorrected distance visual acuity of 20/16. Review of the surgical video demonstrated an adequate femtosecond laser pass with an ideal opaque bubble layer formation and no dark spots (Video 1; watch the video at http://links.lww.com/JRS/A45).
The extraction of the lenticule, however, was suboptimal with piecemeal removal, secondary to tearing of the thin 35 μm lenticule. Corneal tomography (Pentacam HR, Oculus Optikgeräte GmbH) revealed irregular astigmatism with central steepening (Figure 1, A). An edge of the remnant lenticule was faintly visible on dilated retro illumination technique using slitlamp biomicroscopic evaluation. AS-OCT (Avanti-Optovue) was performed but it failed to demonstrate or delineate the lenticule remnant clearly (Figure 1, B). The patient was advised to have surgical exploration for lenticule removal.
The procedure was performed under topical anesthesia with proparacaine 0.5% eyedrops. The interface was irrigated with diluted preservative-free triamcinolone acetonide (Figure 2, A) and 0.1 mL of 40 mg/mL solution (Aurocort, Aurolab) was reconstituted and diluted to 0.4 mL using a balanced salt solution, with a final concentration of 1 mg/0.1 mL. The deposit of triamcinolone crystals at the lenticule edge allowed clear intraoperative delineation (Figure 2, B). The remnant was separated from the surrounding stroma and subsequently extracted using micro forceps (Figure 2, C). Spreading the lenticule on the corneal surface to ensure complete removal is recommended (Figure 2, D). A thorough interface wash was carried out to remove the excessive triamcinolone particles (Video 1; watch the video at http://links.lww.com/JRS/A45).
Postoperative regimen included loteprednol etabonate ophthalmic suspension 0.5% w/v (L-Pred) 4 times a day for 1 week, moxifloxacin hydrochloride 0.5% (Vigamox) 4 times a day for 1 week and polyethylene glycol 400 and propylene glycol ophthalmic solution (Systane Ultra) for 2 months. Corneal tomography demonstrated corneal regularization, and the patient achieved an uncorrected distance visual acuity of 20/20 (Figure 1, C).
Retained lenticule fragment is a unique complication of SMILE and is commonly associated with thinner lenticules (thickness lower than 50 μm), suboptimal laser disruption secondary to inadequate opaque bubble layer or interface debris, and inadequate surgical experience.3 Larger or central fragments with resultant corneal surface irregularities mandate a surgical exploration for their removal.4
The use of AS-OCT both preoperatively and intraoperative has been described for the diagnosis of remnant lenticule size and location, aiding subsequent removal. However, with thin lenticules the resolution of the AS-OCT may not be sufficient to clearly delineate the fragment. The limited availability and incurred cost of the intraoperative OCT is also a potential shortcoming. In addition, the intraoperative OCT may be of limited value in exceedingly thin lenticules or in eyes with stromal fibrosis, limiting clear lenticule delineation.
The use of the CIRCLE software (Carl Zeiss Meditec AG) affords conversion of the SMILE cap into a flap, allowing open exploration and subsequent remnant removal.5 However, the construction of a flap nullifies the potential biomechanical advantage of the SMILE procedure. In addition, the use of the CIRCLE software may be limited in the immediate postoperative period secondary to corneal edema or haze.
Triamcinolone acetonide as an adjunct for the management of posterior segment disorders and vitreous visualization following posterior capsular dehiscence is well established. We describe the use of diluted triamcinolone acetonide in the interface pocket allowing delineation of lenticule edges. Potential advantages include easy availability, low cost, and application in eyes with thin lenticules or reduced visibility secondary to haze or edema.
No increase in intraocular pressure was noted with gradual dissolution of triamcinolone crystals from the interface at the day 3 postoperative visit. We recommend the use of preservative-free solution and a thorough interface wash with a balanced salt solution after lenticule extraction. In addition, the low concentration of triamcinolone (1 mg/0.1 mL) utilized is sufficient to delineate the lenticule while being devoid of any side effects.6
In conclusion, we described a simple yet effective technique for identifying any remnant lenticule with the use of triamcinolone acetonide, a readily available compound.
WHAT WAS KNOWN
- Lenticule remnant after small incision lenticule extraction is associated with corneal surface irregularities and mandates surgical removal.
- The use of anterior segment-optical coherence tomography and CIRCLE software has been demonstrated for removal of lenticule fragments. However, associated limitations include incurred cost and restricted availability.
WHAT THIS PAPER ADDS
- The use of diluted triamcinolone acetonide into the intrastromal pocket allows intraoperative lenticule delineation and subsequent extraction.
- This simple yet effective technique highlights the use of a readily available compound.
1. Titiyal JS, Rathi A, Kaur M, Falera R. AS-OCT as a rescue tool during difficult lenticule extraction in SMILE. J Refract Surg 2017;33:352–354
2. Urkude J, Titiyal JS, Sharma N. Intraoperative optical coherence tomography–guided management of cap–lenticule adhesion during SMILE. J Refract Surg 2017;33:783–786
3. Shah R. Complications after SMILE and its management including re-treatment techniques. In: Sekundo W, ed. Small Incision Lenticule Extraction (SMILE): Principles, Techniques, Complication Management, and Future Concepts. Cham, Switzerland: Springer; 2015:97–105
4. Tong JY, Cherepanoff S, Males JJ. SMILE rescue: delayed lenticule removal in a patient with high myopia. J Refract Surg 2017;33:199–202
5. Ganesh S, Brar S, Manasa KV. CIRCLE software for the management of retained lenticule tissue following complicated SMILE surgery. J Refract Surg 2019;35:60–65
6. Akova Budak B, Kivanc SA, Baykara M. Inadvertent intracorneal triamcinolone injection during cataract extraction. J Cataract Refract Surg 2014;40:1928–1929