A 46-year-old man was transferred to the doctor (Prof. Xingtao Zhou) of our refractive surgery center after complicated refractive surgery. Only some preoperative information and operation parameters were available. Preoperative ophthalmic examinations were normal, with the exception of hyperopia with astigmatism and amblyopia. Uncorrected distance visual acuity (UDVA) was 20/125 for both eyes. Manifest refraction was OD: +7.25 diopters sphere (DS)/-1.25 diopters cylinder (DC)×10°with corrected distance visual acuity (CDVA) of 20/40, OS: +7.75DS/-1.25DC×5°with CDVA of 20/50. The right eye was the dominant eye and the addition power was +0.25D. Corneal tomography was evaluated by a Scheimpflug camera (Pentacam; Oculus, Wetzlar, Germany). The preoperative central corneal thickness (CCT) and mean keratometry readings were 523 μm and 41.3 D in the right eye; these values were 517 μm and 41.4 D in the left eye, respectively. Intraocular pressure (IOP) was normal in both eyes.
The patient complained about vision fatigue at both far and near distances, and he was scheduled for bilateral femtosecond laser-assisted in situ keratomileusis (FS-LASIK) to treat hyperopia and astigmatism. The patient’s right eye underwent an uneventful FS-LASIK procedure for hyperopia and astigmatism first. But his left eye mistakenly underwent a SMILE procedure using the VisuMax femtosecond laser (Carl Zeiss Meditec AG, Jena, Germany) for myopic astigmatism (refractive correction: -8.50DS/-1.50DC×175°) due to medical record error. The attempted lenticule thickness was 134 μm, with cap thickness of 110 μm and optical zone of 6.1 mm. A 90° single side cut with a length of 2 mm was created in the superior position. The mistake was quickly recognized and the extracted lenticule was maintained in balanced salt solution (BSS) temporarily, and the patient was immediately transferred to the Dr. Zhou.
The extracted lenticule of the left eye was re-implanted in situ within 2 hours. A lamellar dissector was inserted to gently release the pocket adhesions. The refractive lenticule was grasped with a forceps and partially folded, then inserted into the original site gradually through the small incision. Thereafter, the lamellar dissector was used to spread the lenticule; each edge of the lenticule was carefully flattened and smoothened with a spatula. To remove the striae, the cap was hydrostretched with sponge swabs soaked in BBS. Each step of the treatment was carefully evaluated and adjusted to enable proper positioning of the refractive lenticule.
The patient was followed up at 1day, 3 weeks, 3 months, and 8 months postoperatively. On the first day after surgery, both eyes displayed mild edema under slit-lamp observation. Anterior optical coherence tomography (OCT) (RTVue, Optovue, Fremont, CA, USA) examination demonstrated that the re-implanted lenticule in the left eye was well attached to the stromal bed with visible demarcation lines (Figure 1A). No displacement or striae were observed. Corneal topography assessments revealed CCT of 520 μm and mean keratometry (K) value of 45.1 D in the left eye (Figure 2B). At 8 months after lenticule in situ implantation, the refraction had remained stable since 3 months and indicated reduction of hyperopia compared with preoperative level (+5.00DS/-1.25DC×100°）with a stable CDVA of 20/50. The lenticule remained smoothly spread in the interface and identifiable with visible demarcation lines that showed partial hyper-reflection (Figure 1C). The CCT was 502 μm and mean keratometry value was 43.8 D (Figure 2E).
Due to contact lens and glasses intolerance, poor visual acuity, and severe anisometropia, the patient asked for a retreatment. After the risks, benefits, and alternatives were explained and informed consent was obtained, the patient underwent standard FS-LASIK on the left eye for correcting hyperopia and astigmatism 8 months after lenticule re-implantation. The flap had a diameter of 7.9 mm, a thickness of 90 μm, standard 90° hinges, and 90° side cut angles. Refractive correction was +5.0DS/-0.75DC×100°with attempted ablation thickness of 90 μm and optical zone of 6.5 mm. A MEL 80 excimer laser (Carl Zeiss Meditec) was used for stromal ablation with a pulse energy of 185 nJ, followed by flap reposition. A silicone hydrogel contact lens was applied as a bandage after surgery and removed the next day.
At postoperative day 1, the cornea exhibited moderate edema and the lenticule was spread smoothly on the stromal bed with decreased peripheral thickness (Figure 1D & 3C ). Corneal topography assessments revealed a CCT of 477 μm and mean keratometry value of 51.3 D (Figure 2F). The UDVA, manifest refraction, CDVA, mean keratometry, CCT, and corneal volume (as measured by Pentacam) before operation, after refractive lenticule re-implantation, and after LASIK are displayed in Table 1. Figures 1-3 show the patient’s assessments over the postoperative course. During 2 years of follow-up, the cornea was transparent with no flap striae, inflammation, epithelial ingrowth, or diffuse lamellar keratitis under slit-lamp examination. Corneal tomography showed no signs of ectasia (Figure 2). The UDVA, manifest refraction, and CDVA of the left eye were 20/63, -0.75DS/-0.25DC×165°, and 20/50 at the last visit; these values were 20/40, +0.5DS/-0.5DC×150°, and 20/32 for the right eye. The patient gained binocular uncorrected distance visual acuity of 20/40 and near visual acuity of 20/50, achieving improved satisfaction.