SMILE Rescue: Delayed Lenticule Removal in a Patient With High Myopia

Analysis of factors associated with unintended initial dissection of the posterior plane during small incision lenticule extraction

Background

To investigate potential risk factors for unintended initial dissection of the posterior plane in the initial learning curve of small incision lenticule extraction (SMILE).

Methods

Data were derived from consecutive 263 eyes of 136 patients who underwent SMILE at the beginning of the surgeon's learning curve. Probabilities of unintended initial dissection of the posterior plane in left and right eyes were analyzed. Preoperative sphere, cylinder, spherical equivalent (SE), J0, J45, lenticular diameter, lenticular thickness, corneal thickness, and axial length were assessed between eyes in which posterior plane dissection was unintended and those in which it was not.

Results

Unintended initial dissection of the posterior plane occurred in 29 eyes, corresponding to an incidence rate of 11.03%. The probability of difficulty in plane dissection in the left eye was significantly higher than that in the right eye (P=0.003). Significant differences were found in sphere (T =2.8, P=0.006), SE (T =2.37, P=0.019), J0 (T =2.05, P=0.043) and axial length (T =-2.79, P=0.006) between eyes with and without unintended initial dissection of the posterior plane.

Conclusions

In the present study, difficulty in plane dissection during SMILE was encountered significantly more often in left eyes for a right-hand doctor, and in eyes with low SE or high J0 values. Special attention should be paid to prevent unintended initial dissection of the posterior plane in such situations.

Decade - long journey with small incision lenticule extraction: The learnings

Over the past decade, small incision lenticule extraction (SMILE) has revolutionized the field of keratorefractive surgery. With the promise of superior corneal biomechanics and reduced postoperative dry eye, SMILE afforded a distinct advantage over flap-based procedures. Our evolving understanding of the surgical technique and management of its unique complications has further enhanced the outcomes. This review will highlight specific pearls on various preoperative and intraoperative principles allowing optimization of outcomes with SMILE.

Customized Wavefront-Optimized Transepithelial Photorefractive Keratectomy for a Retained Lenticule Fragment After Primary SMILE

PURPOSE

To describe the surgical outcomes after transepithelial photorefractive keratectomy (PRK) for a case of retained intrastromal lenticule fragment after small incision lenticule extraction (SMILE).

METHODS

Transepithelial PRK was performed to minimize corneal irregularity and to correct residual refractive errors in a patient who had undergone failed lenticule extraction, which resulted in a refractive lenticule fragment being retained for 14 months after primary SMILE.

RESULTS

At the postoperative 6-month visit, uncorrected distance visual acuity and corrected distance visual acuity improved to 20/20 and 20/20, respectively, and corneal tomography depicted normalization of the corneal surface. Corneal higher order aberrations, including coma, trefoil, and spherical aberration, were markedly reduced.

CONCLUSIONS

Transepithelial PRK is a potential option for the management of a retained lenticule fragment after primary SMILE. [J Refract Surg. 2020;36(6):395-399.].

Triamcinolone acetonide for remnant lenticule identification in small incision lenticule extraction

Lenticule fragments retained postoperatively are a unique complication of small incision lenticule extraction. Large or central remnants with pursuant complications, including irregular astigmatism, induced corneal aberrations, and reduction in visual acuity, warrant surgical removal. Currently described modalities to delineate lenticule remnants include the use of anterior segment optical coherence tomography or CIRCLE software. However, the incurred cost and restricted availability of the described techniques limit their widespread use. The intraoperative administration of diluted triamcinolone acetonide into the intrastromal pocket to delineate lenticule edges, aiding subsequent removal is shown here.

Identification of separated lenticular planes using optical coherence tomography

PURPOSE

To discuss how optical coherence tomography can be used to identify separated lenticular planes during small incision lenticule extraction (SMILE).

METHODS

SMILE procedures were performed on 26 eyes of 13 patients. An anterior segment optical coherence tomography examination was performed after laser scan. Anterior segment optical coherence tomography examinations were conducted again both after separation of the anterior lenticular plane in the right eye and after separation of the posterior lenticular plane in the left eye. Lenticule extraction was then completed, followed by another anterior segment optical coherence tomography examination. Anterior segment optical coherence tomography was also conducted on both eyes on the first day after surgery. Each measurement consisted of four line scans along the 45°, 90°, 135°, and 180° meridians. The brightness scores were compared between the two planes after the separation of one plane.

RESULTS

Anterior segment optical coherence tomography showed two bright lines after laser scan. Along with all meridians, the brightness of the anterior plane was less in the right eye, for which only the anterior plane was separated, and the brightness of the posterior plane was less in the left eye, for which only the posterior plane was separated (all P < 0.001). After lenticule extraction in both eyes, anterior segment optical coherence tomography revealed that a smooth hyperreflective line existed between the cap and the residual stromal bed, and this line remained throughout the first day after surgery.

CONCLUSION

The bubbles produced by the creation of the lenticule in SMILE mostly disappear by manual separation, and anterior segment optical coherence tomography can help the surgeon identify the separated lenticular planes.

Aborted small-incision lenticule extraction resulting from false plane creation and strategy for subsequent removal based on corneal layered pachymetry imaging

We describe a complication of false plane creation during small-incision lenticule extraction (SMILE) and the surgical plan for subsequent lenticule removal. During a primary SMILE procedure to treat high myopia, the separator instrument entered a false lamellar plane as a result of an area of resistance caused by an area of opaque bubble layer (OBL). The procedure was aborted to avoid removing an irregular lenticule. Based on measurements of the anatomic landscape, a new inferonasal small incision was created. The lenticule was separated and removed without further incidence. The patient recovered as normal and at 6 months, the uncorrected distance visual acuity was 20/16^-1. This case highlights the importance of monitoring the bubble layer creation and interface separation to avoid creating or removing an irregular lenticule. It also shows the importance of layered corneal imaging to analyze and diagnose complications as well as of aborting a procedure and planning lenticule removal at a later time if deemed appropriate.

Management and Outcomes of Retained Lenticules and Lenticule Fragments Removal After Failed Primary SMILE: A Case Series

PURPOSE

To describe the management of and report the outcomes following the removal of retained lenticules or lenticule fragments after a complicated small incision lenticule extraction (SMILE).

METHODS

Three patients were referred for consultation due to intraoperative complications during SMILE. In case 1, the lenticule was torn during extraction and a central fragment was retained in the pocket. In case 2, the inferior part of the lenticule remained attached at the anterior plane and its detached, superior part was dislocated and folded at the inferior part of the pocket. In case 3, the lenticule was completely attached at the anterior plane. All cases underwent secondary surgery. The lenticule fragment was detached using the dissector's body and tip and was extracted using the advanced lenticule forceps. The retained lenticules were extracted after dissection of tissue bridges at the anterior plane and periphery.

RESULTS

Postoperatively, all eyes showed improvement of visual acuity and topographic regularization of the anterior corneal curvature. Complete removal of lenticule remnants was accomplished in cases 1 and 2. In case 3, the photodisruption during primary SMILE was incomplete at a peripheral area next to the incision. A small peripheral fragment, corresponding to the described peripheral area, remained attached after the lenticule removal and was left in situ but did not have any impact on visual acuity and quality.

CONCLUSIONS

Retained lenticules or lenticule fragments may induce irregular astigmatism and loss of visual acuity. Prompt removal restores visual acuity and induces the desired effect of the primary SMILE procedure. [J Refract Surg. 2017;33(12):848-853.].