PRESBYOND Laser Blended Vision is a treatment option for presbyopic patients that combines micro‐anisometropia with increased depth of field through non‐linear aspheric ablation profiles. This ...technique substantially improves visual outcomes in comparison with the conventional monovision approach. Trials show that PRESBYOND is effective in presbyopic patients with refractive errors between +5.75 and −9.00 D, including emmetropic presbyopes. With the safety advantages of modern femtosecond LASIK, retention of functional stereo acuity, contrast sensitivity and quality of vision, the rapid bilateral surgical procedure and a recovery time of a few hours, patient satisfaction is extremely high. In patients with no visually significant cataract, performing a corneal treatment avoids the increased risks associated with intraocular surgery, particularly risks that are relatively higher in younger presbyopic patients such as retinal detachment.
Small-incision lenticule extraction Moshirfar, Majid, MD; McCaughey, Michael V., BS; Reinstein, Dan Z., MD, MA(Cantab), FRCOphth ...
Journal of cataract and refractive surgery,
03/2015, Letnik:
41, Številka:
3
Journal Article
Recenzirano
This review looks at the benefits, limitations, complications, and future applications of the small-incision lenticule extraction procedure. Using the search terms small incision lenticule extraction ...and femtosecond lenticule extraction , we obtained data from 56 articles (omitting German and Chinese articles) from the PubMed database. Small-incision lenticule extraction has shown efficacy, predictability, and safety that are proportionate to those of laser in situ keratomileusis (LASIK), with the additional benefit that it eliminates flap creation and the attendant risks. The potential advantages of the procedure related to improved biomechanical stability, postoperative inflammation, and dry-eye symptoms have not been fully established. Small-incision lenticule extraction–treated eyes have shown a reduced degree of postoperative corneal denervation and higher-order aberrations and an accelerated rate of corneal nerve convalescence relative to LASIK. Future possibilities related to long-term cryogenic storage of extracted lenticules with eventual reimplantation or donation have been investigated with encouraging preliminary results. Financial Disclosure Drs. Reinstein and Shah are consultants to Carl Zeiss Meditec AG. No author has a financial or proprietary interest in any material or method mentioned.
To develop a mathematical model to estimate the relative differences in postoperative stromal tensile strength following photorefractive keratectomy (PRK), LASIK, and small incision lenticule ...extraction (SMILE).
Using previously published data where in vitro corneal stromal tensile strength was determined as a function of depth, a mathematical model was built to calculate the relative remaining tensile strength by fitting the data with a fourth order polynomial function yielding a high correlation coefficient (R(2) = 0.930). Calculating the area under this function provided a measure of total stromal tensile strength (TTS), based only on the residual stromal layer for PRK or LASIK and the residual stromal layers above and below the lenticule interface for SMILE.
Postoperative TTS was greatest after SMILE, followed by PRK, then LASIK; for example, in a 550-μm cornea after 100-μm tissue removal, postoperative TTS was 75% for SMILE (130-μm cap), 68% for PRK, and 54% for LASIK (110-μm flap). The postoperative TTS decreased for thinner corneal pachymetry for all treatment types. In LASIK, the postoperative TTS decreased with increasing flap thickness by 0.22%/μm, but increased by 0.08%/μm for greater cap thickness in SMILE. The model predicted that SMILE lenticule thickness could be approximately 100 μm greater than the LASIK ablation depth and still have equivalent corneal strength (equivalent to approximately 7.75 diopters).
This mathematical model predicts that the postoperative TTS is considerably higher after SMILE than both PRK and LASIK, as expected given that the strongest anterior lamellae remain intact. Consequently, SMILE should be able to correct higher levels of myopia.
September consultation #7 Stuart, Alastair; Reinstein, Dan Z.
Journal of cataract and refractive surgery,
09/2021, Letnik:
47, Številka:
9
Journal Article
To illustrate the hypothesis that epithelial thickness profile maps could be used as an adjunctive tool to improve the sensitivity and specificity of keratoconus screening by presenting a case series ...of examples.
The Artemis very high-frequency digital ultrasound arc-scanner was used to obtain epithelial thickness profiles in addition to a comprehensive ophthalmic examination to screen for keratoconus. Five case examples are presented; a normal eye, an eye with advanced keratoconus, and three cases where a diagnosis of keratoconus was uncertain based only on the ophthalmic examination.
The epithelial thickness profile in the normal eye was slightly thinner superiorly, consistent with that previously described for a normal population. The keratoconic eye demonstrated an epithelial doughnut pattern of epithelial thinning over the cone surrounded by an annulus of epithelial thickening. In case 1, an epithelial doughnut pattern confirmed the presence of keratoconus in an eye with an abnormal front surface topography. In case 2, the absence of an epithelial doughnut pattern excluded a diagnosis of keratoconus in a patient with an abnormal front surface topography. In case 3, the presence of an epithelial doughnut pattern coincident with an eccentric posterior elevation best-fit sphere indicated a diagnosis of keratoconus. The epithelium appeared to have compensated for the stromal surface cone, resulting in an apparently normal front surface topography.
An epithelial doughnut pattern appears to indicate the presence of an underlying stromal cone; the lack of an epithelial doughnut pattern would indicate that an abnormal topography was not due to keratoconus. In very early keratoconus, epithelial compensation can mask the presence of an underlying cone on front surface topography, ie, a diagnosis of keratoconus might be missed.
To report the visual and refractive outcomes of small incision lenticule extraction for low myopia using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany).
A retrospective analysis of ...120 consecutive small incision lenticule extraction procedures was performed for low myopia. Inclusion criteria were preoperative spherical equivalent refraction up to -3.50 diopters (D), cylinder up to 1.50 D, and corrected distance visual acuity of 20/20 or better. Outcomes analysis was performed for all eyes with 1-year follow-up according to the Standard Graphs for Reporting Refractive Surgery, and also including mesopic contrast sensitivity.
One-year data were available for 110 eyes (92%). Preoperatively, mean spherical equivalent refraction was -2.61 ± 0.54 D (range: -1.03 to -3.50 D) and mean cylinder was 0.55 ± 0.38 D (range: 0.00 to 1.50 D). Postoperatively, mean spherical equivalent refraction was -0.05 ± 0.36 D (range: -0.94 to +1.25 D) and mean cylinder was ± 0.50 D in 84% and ± 1.00 D in 99% of eyes. Uncorrected distance visual acuity was 20/20 or better in 96% of eyes and 20/25 or better in 100% of eyes. One line of corrected distance visual acuity was lost in 9%, but no eyes lost two or more lines. There was an initial overcorrection in mean spherical equivalent refraction on day 1 (+0.37 D) as expected, which regressed to +0.10 D at 1 month and -0.05 D at 3 months, after which stability was reached (mean spherical equivalent refraction was -0.05 D at 1 year). Contrast sensitivity at 1 year was slightly increased at 3, 6, 12, and 18 cycles per degree (P < .05).
Small incision lenticule extraction for low myopia was found to be safe and effective with outcomes similar to those previously reported for LASIK.
To report the outcomes of small incision lenticule extraction (SMILE) for high myopia between -9.00 and -14.00 diopters (D).
This was a prospective study of SMILE for high myopia using the VisuMax ...femtosecond laser (Carl Zeiss Meditec). Inclusion criteria were attempted spherical equivalent refraction (SEQ) between -9.00 and -14.00 D, cylinder up to 7.00 D, corrected distance visual acuity (CDVA) of 20/40 or better, age 21 years or older, and suitable for SMILE. The sub-lenticule thickness was 220 µm or greater, and the total uncut stromal thickness was 300 µm or greater. Patients were to be followed up for 1 year. Standard outcomes analysis was performed using 12-month data where available or 3-month data otherwise.
Of 187 eyes treated, data were available at 12 months for 181 eyes (96.8%) and 3 months for 4 eyes (2.1%), and 2 eyes (1.1%) were lost to follow-up. Mean attempted SEQ was -10.55 ± 1.00 D (range: -9.00 to -12.99 D). Mean cylinder was -1.19 ± 0.83 D (range: 0.00 to -4.00 D). Preoperative CDVA was 20/20 or better in 73% of eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 57% and 20/25 or better in 82% of eyes. Mean SEQ relative to target was -0.22 ± 0.48 D (range: -1.63 to +1.38 D), 66% ± 0.50 D and 93% ±1.00 D. Mean SEQ 12-month change was -0.08 ± 0.34 D (range: -1.75 to +0.88 D). There was loss of one line of CDVA in 4% of eyes, and no eyes lost two or more lines. Contrast sensitivity was unchanged. Patient satisfaction was 8 or more out of 10 in 94% and 6 or more in 99% of patients.
Outcomes of SMILE for myopia greater than -9.00 D at 3 to 12 months showed excellent efficacy, safety, stability, and predictability, with high patient satisfaction.
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