PURPOSE: To identify parameters influencing the postoperative vault of the Implantable Collamer Lens (ICL) (STAAR Surgical) using the Artemis Insight 100 very high-frequency (VHF) digital ultrasound robotic scanner (ArcScan, Inc) and develop a model to improve lens vault prediction. METHODS: This was a retrospective analysis of 147 consecutive V4c EVO and EVO+ ICL implantation procedures performed over three phases in myopic eyes. In the initial phase, lens size was defined by published sulcus-to-sulcus and crystalline lens rise measurements (Kojima formula) from VHF digital ultrasound biometry. From these data, a stepwise multivariate regression analysis was performed to develop a model for predicting central vault including the following variables: ICL size, ICL power, sulcus-to-sulcus (STS), ciliary body inner diameter (CBID), zonule-to-zonule, STS lens rise (STSL), ACD, anterior chamber angle, scotopic pupil diameter (SPD), angle-to-angle, and white-to-white diameter. The resulting regression model was used in coordination with the Kojima formula to select the lens size for the next series of eyes. The regression analysis was then repeated and a further series were treated. The postoperative achieved vault at 1 month was compared to the target vault predicted by the formula. A comparison analysis of the new model was made to previously published lens sizing formulas. RESULTS: Statistically significant variables were ICL size, ICL power, CBID, STSL, and SPD. The primary 42 eyes (Kojima formula) achieved a mean vault of 506 ± 233 µm, a range of 810 µm (114 to 924 µm), and an interquartile range (IQR) of 391 µm. Using the Reinstein formula v1.0 for the next 36 eyes, the mean vault relative to target was +7 ± 123 µm, range of 569 µm (−278 to +291 µm), and IQR of 169 µm. Using the Reinstein formula v2.0 for the next 69 eyes, the mean vault relative to target was +67 ± 121 µm, range of 573 µm (−219 to +354 µm), and IQR of 131 µm. The achieved vault was within ±100, ±200, and ±300 µm of target in 33%, 50%, and 74% of eyes, respectively, for the training group, 58%, 89%, and 100% for the Reinstein formula v1.0 group, and 62%, 84%, and 94% for the Reinstein formula v2.0 group. CONCLUSIONS: This is the first report describing the ciliary body inner diameter, which proved to be more highly correlated with vault than STS, and thus CIBD supersedes STS from the previous widely accepted improvement over WTW sizing. The new model also found scotopic pupil size to be a significant predictor, which has not been a part of any previously published model. The significant improvement in vault predictability afforded by these parameters and the new model enables charting attempted versus achieved vault outcomes for the first time. [ J Refract Surg . 2022;38(5):272–279.]
PURPOSE: To develop a comprehensive protocol for suction stability management during small incision lenticule extraction (SMILE). METHODS: This was a retrospective video review of all SMILE cases where suction loss occurred or eye movement was noted in the medical record. The different types of eye movement were collated. A suction stability grading scale was derived to represent the magnitude of eye movements. A decision tree protocol was developed to define the management in each scenario depending on the suction stability grading and the femtosecond laser cutting progress. RESULTS: Eight types of eye movement were identified: fixation light tracking, Bell's reflex, saccades, oscillations, anxiety/uncooperative patient, nociceptive reflex movement, false suction, and nystagmus. Type I eye movements were defined as small movements that shift the corneal position by a clinically negligible amount. The surgeon may want to pause the femtosecond laser cutting, regain control of the patient, then continue. Type II eye movements were defined as large movements that shift the corneal position by a clinically relevant amount, in which case the surgeon may choose to release suction (ie, a surgeon-initiated suction loss). Type III eye movements were defined as those with sufficient force to break suction (ie, a patient-generated suction loss). A comprehensive decision tree was developed to cover all possible eye movement and suction loss scenarios. Example scenarios outside the preprogrammed machine restart treatment module include converting to laser in situ keratomileusis (LASIK) if there was tracking of the interface and restarting SMILE with a thinner cap if the original cap thickness was 135 μ m or greater. CONCLUSIONS: With appropriate management, it is possible for the SMILE procedure to be completed on the same day by either continuing with SMILE or converting to LASIK depending on the progress of the femtosecond laser cutting. [ J Refract Surg . 2018;34(12):809–816.]
Purpose: To report the incidence and outcomes of suction loss during small incision lenticule extraction (SMILE). Methods: The incidence of suction loss was measured over 4000 consecutive SMILE procedures and categorized by cause, the interface in which suction was lost and management (restart/continue SMILE, re-SMILE thinner cap, convert to laser in-situ keratomileusis [LASIK]). One-year outcomes were compared to the fellow eye where no suction loss occurred. Results: There were 20 cases of suction loss (0.50%): during the lenticule interface in seven eyes, lenticule side cut in one eye, cap interface in nine eyes and small incision for three eyes. Small incision lenticule extraction (SMILE) was continued in seven eyes, thinner cap SMILE in four eyes, LASIK in eight eyes, and the small incision was manually completed in one eye. Suction loss was caused by a Bell's reflex in 10 eyes, fixation light tracking in six eyes, patient anxiety in two eyes, a nociceptive reflex in one eye and false suction in one eye. There was no difference in results for suction loss and fellow eyes, respectively: uncorrected distance visual acuity was 20/20 or better in 100% in both groups, spherical equivalent was within AE0.50 D in 85% and 79%, one line loss of corrected distance visual acuity in 5% and 0%, and no eyes lost two lines. Conclusion: Suction loss can be managed depending on the interface during which suction is lost. Treatment was completed on the same day in all instances. Visual and refractive outcomes were unaffected compared to the fellow eye in this series. PatientsThis was a retrospective non-comparative case series of all myopic SMILE e72 Acta Ophthalmologica 2020
Re-treatment after SMILE by LASIK achieved excellent visual and refractive outcomes, although these results indicate that myopic LASIK retreatment after primary myopic SMILE requires a different nomogram than for myopic LASIK re-treatment after primary myopic LASIK. [J Refract Surg. 2018;34(9):578-588.].
PURPOSE: To describe a femtosecond laser–assisted small incision sutureless intrastromal lamellar keratoplasty in an eye with severe keratoconus and report on the outcome with a 1-year follow-up. METHODS: A 20-year-old man with a history of keratoconus presented for evaluation at the Tilganga Institute of Ophthalmology, Kathmandu, Nepal. The patient had previously undergone a deep anterior lamellar keratoplasty in the left eye. Examination of the right eye revealed an uncorrected distance visual acuity (UDVA) of counting fingers with a manifest refraction of −5.00 −3.50 × 170, giving a corrected distance visual acuity (CDVA) of 20/80. Thinnest pachymetry was 425 µm and progression of both anterior and posterior corneal elevation tomography and maximum keratometry was noted compared to examination 2 years prior. The VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) was used to prepare the donor and recipient cornea. The donor graft was inserted into the recipient through the 3-mm small incision. No sutures were applied. RESULTS: At 2 weeks postoperatively, UDVA was 20/50 with a manifest refraction of −1.00 −5.00 × 145 (20/32). One year postoperatively, UDVA was 20/80 with a manifest refraction of −2.50 −3.50 × 125 (20/40 −2 ), with the maximum keratometry decreasing from 64.08 to 56.74 diopters. CONCLUSIONS: This femtosecond laser–assisted sutureless intrastromal corneal transplantation technique may provide an option to improve the quality of vision for some patients with keratoconus, affording a simpler postoperative follow-up course compared to traditional anterior lamellar or full-thickness corneal transplantation. [ J Refract Surg. 2019;35(10):663–671.]
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