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Purpose: To investigate the postoperative straylight changes during the visual recovery phase after small incision lenticule extraction (SMILE) and their association. Methods: Seventy consecutive eyes from 37 patients with a mean age of 30.92 ± 7.26 years and a mean preoperative spherical equivalent of −5.24 ± 1.90 dioptres undergoing myopic or myopic astigmatism SMILE correction were included in this prospective study. Patients were followed up at days 1, 3, 7, 14, 21 and 28 after standard SMILE. Straylight was measured using the C-Quant straylight meter (Oculus GmbH, Germany) preoperatively and at each postoperative visit. Results: Preoperatively, the mean straylight measurement was 1.16 ± 0.16. After SMILE, the mean straylight values were 1.12 ± 0.14 and 1.13 ± 0.13 at days 7 and 14, which were significantly reduced compared to preoperative values (p≤ 0.028). Straylight returned to baseline by week 3 (p= 0.160) and remained stable onwards (p= 0.651). A lower ablation ratio was associated with less straylight level at days 1, 3, 14 and 21 (p≤ 0.0497) in the multivariable regression model. Likewise, better visual acuity was associated with lower straylight at days 7, 14 and 28 postoperatively (p≤ 0.038). A small proportion of eyes (range: 0–12.86%) had ≥0.30 log(s) increase in postoperative straylight within the first month after SMILE. Conclusions: SMILE induced a temporary decrease in straylight. It gradually returned to the preoperative level, which could be related to a number of dynamic processes during corneal healing. In the small proportion of patients with an increase in straylight postoperatively, this can affect their visual recovery during the early postoperative period.

BackgroundWe described a modified ‘hydroexpression’ technique for the lenticule removal during small-incision lenticule extraction (SMILE) surgery and compared the results with conventional forceps method.MethodsThis was a retrospective, comparative study of 50 patients who underwent SMILE surgery by the same surgeon. We compared the 1-week and 3-months postoperative results after SMILE using the hydroexpression technique with the conventional forceps technique. Main outcome measures included uncorrected distance visual acuity, corrected distance visual acuity, refractive accuracy, safety index and efficacy index.ResultsThe baseline characteristics were comparable between both groups. At postoperative 1 week, the safety index in forceps and hydroexpression group was 0.93±0.11 and 0.97±0.10, respectively (P=0.246). At 3 months, they were 1.00±0.06 and 0.99±0.09 (P=0.850). For efficacy indices, at 1 week they were 0.84±0.17 and 0.91±0.17 (P=0.158). At 3 months, they were 0.92±0.13 and 0.94±0.19 (P=0.624). All eyes aimed for a plano target. 96% in forceps group and 90% in hydroexpression group were within ±0.50 dioptre (D) in spherical equivalent refraction (SEQ) correction at postoperative 3 months (P=0.567). The mean errors of SEQ correction were −0.10±0.21 D in forceps group and −0.08±0.30 D in hydroexpression group (P=0.705).ConclusionHydroexpression was simple and safe and had early results comparable to the conventional forceps technique. This technique was particularly useful for cases with more adhesions between lenticule and anterior cap, thin lenticule cases and for the inexperienced SMILE surgeons.

New advances in imaging allow objective measurements for dry eye as well as define new parameters that cannot be measured by clinical assessment alone. A combination of these modalities provides unprecedented information on the static and dynamic properties of the structural and functional parameters in this multifactorial disease. A literature search was conducted to include studies investigating the use of imaging techniques in dry eye disease. This review describes the application of non-invasive tear breakup time, optical coherence tomography, meibomian gland imaging, interferometry, in vivo confocal microscopy, thermography and optical quality assessment for this condition.

ObjectivesTo evaluate and compare the change in corneal biomechanical properties after microincision lenticule extraction (MILE) and small incision lenticule extraction (SMILE).MethodsIn this prospective study, 60 eyes received MILE surgery with 2 mm opening incision, while 64 eyes received SMILE procedure with 5 mm opening incision. Corneal hysteresis (CH), corneal resistance factor (CRF) and 37 other biomechanical waveform parameters were quantitatively assessed using ocular response analyser (ORA) preoperatively and up to 6 months postoperatively. All changes were calculated as the difference between preoperative and postoperative values (Δ).ResultsBoth CH and CRF values decreased significantly after MILE and SMILE (p<0.001). ΔCRF (o=0.028) and ΔCRF index (ΔCRF/preoperative CRF) (p=0.043) were statistically lower for all eyes at 1-week follow-up. ΔCH index (ΔCH/preoperative CH) was statistically lower at 1-week (p=0.043) and 1-month (p=0.015) follow-ups in MILE group when compared with SMILE group. In both MILE and SMILE group, ΔCH index and ΔCRF index were positively correlated with preoperative manifest refraction spherical equivalent, residual stromal thickness (RST) index (RST/preoperative central corneal thickness) and negatively correlated with lenticule thickness (p<0.05).ConclusionsBoth MILE and SMILE procedures significantly altered the biomechanical characteristics of cornea. Smaller opening incision was associated with less reduction in ORA parameters during early postoperative period.

PURPOSE:To analyze the visual and refractive outcomes of LASIK with and without simultaneous cross-linking for correction of myopia.METHODS:Patients who received femtosecond laser-assisted LASIK with and without adjunctive cross-linking according to patient's preference were examined longitudinally for 6 months. Patients with myopic manifest refraction spherical equivalent of 5.00 diopters (D) or greater and estimated residual stromal thickness of greater than 250 Patients who received femtosecond laser-assisted LASIK with and without adjunctive cross-linking according to patient's preference were examined longitudinally for 6 months. Patients with myopic manifest refraction spherical equivalent of 5.00 diopters (D) or greater and estimated residual stromal thickness of greater than 250 µm were included.RESULTS:Overall, 120 eyes of 60 patients were included (60 eyes of 30 patients for LASIK with cross-linking; 60 eyes of 30 patients with LASIK only). No significant difference was observed in age, preoperative corrected distance visual acuity, manifest refraction spherical equivalent, manifest sphere and cylinder, minimal corneal thickness, and residual stromal bed thickness between both groups (Overall, 120 eyes of 60 patients were included (60 eyes of 30 patients for LASIK with cross-linking; 60 eyes of 30 patients with LASIK only). No significant difference was observed in age, preoperative corrected distance visual acuity, manifest refraction spherical equivalent, manifest sphere and cylinder, minimal corneal thickness, and residual stromal bed thickness between both groups (P≥ .245). The uncorrected distance visual acuity and efficacy index were significantly worse on day 1 in eyes receiving adjunctive cross-linking (P= .0001). At 6 months, 86.7% and 95% of the eyes achieved uncorrected distance visual acuity of 20/25 or better in LASIK with cross-linking and LASIK only, respectively. The variance of postoperative spherical equivalent and sphere was significantly higher in eyes undergoing LASIK with cross-linking from 1 week up to 6 months compared to LASIK only (P≤ .002). None of the patients required re-treatment up to 6 months postoperatively.CONCLUSIONS:Adjunctive cross-linking during LASIK was associated with worse visual outcomes during the first postoperative week. The variance of spherical equivalent was also high in these patients over a 6-month follow-up.[[J Refract Surg.2016;32(10):664–670.]

To evaluate the performance of a point-of-care test for detection of matrix metalloproteinase 9 (MMP-9) levels in post-laser-assisted in situ keratomileusis (LASIK) dry eyes.