Effect of suction on macular thickness and retinal nerve fiber layer thickness during LASIK used femtosecond laser and Moria M2 microkeratome

Retinal Nerve Fibre Layer Thickness Change Following Femtosecond Laser-Assisted in situ Keratomileusis

Purpose: To evaluate the effect of femtosecond laser-assisted in situ keratomileusis (FS-LASIK) on retinal fovea thickness, volume, and retinal nerve fibre layer (RNFL) thickness. Methods: Thirty-seven eyes (37 patients) undergoing FS-LASIK were included in this prospective study. Optical coherence tomography (OCT) was performed 1 day before, 1 h and 1 day after FS-LASIK surgery. Result: Eighteen male and nineteen females were enrolled. Mean patient age was 22.94 ± 4.22 years. One hour postoperatively, macula fovea thicknesses, macula fovea volume, macula parafovea thickness, macula parafovea volume, macula perifovea thickness, macula perifove volume, temporal RNFL thickness, and superior RNFL thickness measures showed significant decrease (t = 6.171, 6.032, and 9.837, 9.700, 2.532, 4.393, 4.926, 2.265; p = 0.000, 0.000, 0.000, 0.000, 0.016, 0.000, 0.000, and 0.011). Day 1 post-operation, macula fovea thicknesses, macula fovea volume, macula parafovea thickness, macula parafovea volume, and inferior RNFL thickness measures showed significant change compared to preoperative measures (t = 3.620, 3.220, 2.901, 2.910, 3.632; p = 0.001, 0.003, 0.006, 0.006, and 0.001). Conclusion: Our data suggest there are alterations in retinal foveal and RNFL measurements by OCT 1 h and 1 day after FS-LASIK surgery.

Effects of SMILE Surgery on Intraocular Pressure, Central Corneal Thickness, Axial Length, Peripapillary Retinal Nerve Fiber Layer, and Macular Ganglion Cell Complex Thickness

Purpose. To evaluate the change in intraocular pressure (IOP), central corneal thickness (CCT), axial length, peripapillary retinal nerve fiber layer (RNFL) thickness, and macular ganglion cell complex (GCC) thickness after small incision lenticule extraction (SMILE) surgery. Methods. This prospective observational study was conducted in Espace Nouvelle Vision, Ophthalmological Clinic, Paris, France. Fifty eyes of 25 patients were enrolled in this study and underwent SMILE surgeries. IOP, central corneal thickness (CCT), axial length (AL), peripapillary RNFL thickness, and macular GCC thickness were measured before and at 3 months after SMILE. Results. The mean preoperative spherical equivalent was −3.15 ± 1.50 diopters (D), and the mean postoperative value was 0.15 ± 0.28 D. After SMILE surgery, IOP decreased from 15.03 ± 2.79 mmHg to 11.02 ± 2.73 mmHg and 10.02 ± 2.21 mmHg at 1 and 3 months, respectively ( $P<0.01$ for both comparisons). The mean decrease in measured IOP as a function of ablation depth was 0.065 ± 0.031 mmHg/μm. CCT decreased from 545.98 ± 26.61 μm to 478.40 ± 30.26 μm after SMILE surgery ( $P<0.01$ ). AL decreased from 24.80 ± 0.84 mm to 24.70 ± 0.83 mm ( $P<0.01$ ). There was no statistically significant change in mean peripapillary RNFL or mean GCC thickness after SMILE surgery. Conclusions. SMILE surgery modified IOP measurement, CCT, and AL but did not change peripapillary RNFL and macular GCC thicknesses. The postoperative drop in measured IOP might be explained by the decreased CCT. An accurate re-evaluation of AL should be performed before cataract surgery among post-SMILE patients.

Short-term changes in the anterior segment and retina after small incision lenticule extraction

Background

To analyse short-term changes in the anterior segment and retina after small incision lenticule extraction (SMILE).

Methods

Patients with myopia scheduled for SMILE were recruited from Ruijin Hospital, Shanghai, China. Basic patient information such as age, sex, and refractive errors was recorded. Ocular measurements were taken before surgery, and 1 day and 1 week after surgery; they included axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), white to white (WTW), pupil diameter (PD), macular thickness (MT), ganglion cell layer thickness (GCL), retinal nerve fiber layer thickness (RNFL), choroidal thickness (CT), macular vessel density, and optic disc vessel density.

Results

Sixty-one eyes of 31 patients were selected for this study. AL, CCT, ACD, and postoperative PD were significantly reduced (p < 0.05), while LT was thickened after surgery (p < 0.05). MT at the fovea decreased 1 day and 1 week after surgery (p < 0.05). GCL showed no significant changes after surgery. RNFL was unchanged 1 day after surgery, but the inferior sector was thickened 1 week after surgery. CT was thicker at the fovea 1 day after surgery and 1.0 mm from the fovea in the nasal sector 1 week after surgery. Macular vessel density was significantly decreased 1 day after surgery and most recovered in 1 week. Optic disc vessel density decreased at the peripapillary part 1 day after surgery and recovered after 1 week. ΔACD and ΔLT showed no significant correlation 1 day after surgery. ΔACD was negatively correlated with ΔLT and sphere 1 week after surgery (r = − 0.847, p < 0.000; r = − 0.398, p = 0.002). ΔLT was positively correlated with the sphere 1 week after surgery (r = 0.256, p = 0.048).

Conclusion

The anterior segment was the most affected, while the retina also underwent changes with regard to MT, RNFL, CT, macular vessel density, and peripapillary vessel density.

Evaluation of Retinal Ganglion Cell Layer Thickness in the Early Period After Femtosecond LASIK Surgery

Objectives:

To evaluate the early effects of femtosecond laser-assisted in situ keratomileusis (LASIK) surgery on retinal ganglion cell thickness (GCT), peripapillary retinal nerve fiber thickness (NFT), and central macular thickness (CMT) obtained by spectral domain optical coherence tomography (SD-OCT) in a healthy population.

Materials and Methods:

This case-control study included data from the right eye of 40 subjects without any disease other than refractive error and who had undergone femtosecond LASIK surgery. The preoperative, postoperative 1-hour, and postoperative 3-week GCT, NFT, and CMT values obtained by SD-OCT were compared.

Results:

The mean age was 27.54±5.99 years (18-45 years). GCT, NFT, and CMT were 18.43±6.03 μm, 107.90±9.01, and 234.3±21.2 μm preoperatively; 18.05±5.93 μm, 108.08±8.92 μm, and 230.1±22.6 μm at postoperative 1 hour; and 17.86±5.27 μm, 107.98±10.13, and 236.3±25.1 μm at postoperative 3 weeks (p=0.159, 0.85, and 0.254, respectively).

Conclusion:

There were no changes in GCT, NFT, and CMT values evaluated with SD-OCT in the early period after femtosecond LASIK surgery.

Comparison of choroidal thickness in high myopic eyes after FS-LASIK versus implantable collamer lens implantation with swept-source optical coherence tomography

AIM

To investigate the changes in choroidal thickness (CT) in high myopic eyes after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery or central hole implantable collamer lens (ICL V4c) implantation using swept-source optical coherence tomography (SS-OCT).

METHODS

We examined the right eyes of 116 patients with high myopia who were candidates for FS-LASIK surgery and ICL implantation. Sixty eyes underwent ICL V4c implantation and 56 eyes were subjected to FS-LASIK surgery. The CT was measured with SS-OCT. All data were recorded preoperatively and 2h, 1wk, 1 and 3mo postoperatively. Other demographic information was collected, including age, sex, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), spherical equivalent (SE), intraocular pressure (IOP) and axial length (AL).

RESULTS

The UCVA improved in both groups and showed no significant differences between groups. There also were no significant differences between the two groups in postoperative BCVA and SE (P=0.581 and 0.203, respectively). The foveal CTs, inner nasal and outer nasal CTs were significantly thicker at 2h postoperatively in both groups (P<0.05) but returned to baseline levels in 1wk; after 1mo, no significant differences were found relative to the preoperative values. At 3mo in each group, nine regions showed variations in the CT as compared with preoperative thickening, but only the foveal and nasal area CTs preoperative differences were statistically significant (P<0.05). In addition, there was no significant difference in 9 regions of CT between the two groups at all follow-up times (P>0.05).

CONCLUSION

The CTs after ICL implantation and FS-LASIK surgery are significantly thicker than those before operation, especially in the foveal and nasal areas, but there is no significant difference between the two methods.

Retinal nerve fiber layer thickness after laser-assisted subepithelial keratomileusis and femtosecond LASIK: a prospective observational cohort study

Purpose

Based on the assumption that high levels of intraocular pressure (IOP) during femtosecond laser-assisted in situ keratomileusis (FS-LASIK) may compromise the retinal nerve fiber layer (RNFL), newer femtosecond platforms that operate without causing significant IOP elevation have been developed in recent years. However, this assumption has not been adequately tested. The aim of the current study was to evaluate possible changes in RFNL thickness in nonglaucomatous myopic patients undergoing FS-LASIK using the 60 KHz IntraLase^® device that significantly elevates the IOP for an appreciable period of time vs an advanced surface ablation technique (laser-assisted subepithelial keratomileusis, LASEK) that does not induce any IOP elevation.

Methods

This was a prospective, observational, controlled cohort study. One randomly selected eye of 114 consecutive eligible patients was analyzed. Inclusion criteria were myopia up to -6.00 diopters and astigmatism up to -2.00 diopters. As clinically indicated, 50 patients underwent LASEK and 64 underwent FS-LASIK. The RNFL thickness was determined with a spectral-domain optical coherence tomography device preoperatively and 3 months postoperatively by the same masked observer.

Results

There was no significant difference in preoperative refractive error, age, or sex between the groups. Preoperatively, central corneal thickness was significantly lower in the LASEK group (529.1±36.1 vs 562.4±31.6 µm, P=0.001). For the LASEK group, there was no significant difference between preoperative and postoperative RNFL thickness in the studied sectors (superior-temporal, temporal, inferior-temporal, average). For the FS-LASIK group, compared to preoperative RNFL measures, statistically significant thicker postoperative values were found for the average RNFL (mean difference: 0.67 µm, 0.7% increase, P=0.008) and the inferior-temporal sector (mean difference: 0.92 µm, 0.6% increase, P=0.02).

Conclusion

LASIK with a femtosecond platform that induces high intraoperative IOP did not cause RNFL thinning. The observed differences between preoperative and postoperative values are below the axial resolution limit of optical coherence tomography devices.

Analysis of Macular and Retinal Nerve Fiber Layer Thickness in Children with Refractory Amblyopia after Femtosecond Laser-assisted Laser In situ Keratomileusis: A Retrospective Study

Background:

Localized macular edema and retinal nerve fiber layer (RNFL) thinning have been reported shortly after laser in situ keratomileusis (LASIK) in adults. However, it is still unclear how LASIK affects the retina of children. This study aimed to investigate the macular retina and RNFL thickness in children with refractive amblyopia who underwent femtosecond laser-assisted LASIK (FS-LASIK).

Methods:

In this study, we included 56 eyes of 32 patients with refractive amblyopia who underwent FS-LASIK in our hospital from January 2012 to December 2016. Foveal (foveal center retinal, parafoveal retinal, and perifoveal), macular inner retinal (superior and inferior), and peripapillary RNFL thicknesses (superior, inferior, temporal, and nasal) were measured using Fourier-domain optical coherence tomography before surgery and 1 day, 3 days, and 1 week after surgery. We divided these patients into three groups based on their refractive error: High myopic group with 22 eyes (equivalent sphere, >6.00 D), mild myopic group with 19 eyes (equivalent sphere, 0–6.00 D), and hyperopic group with 15 eyes (equivalent sphere, >+0.50 D). We compared the macular retina and RNFL thickness before and after LASIK. A paired simple t-test was used for data analysis.

Results:

One week after surgery, the visual acuity for all 56 eyes of the 32 patients reached their preoperative best-corrected vision. Visual acuity improved two lines or better for 31% of the patients. The residual refractive errors in 89% of the patients were within ±0.5 D. In the high myopic group, the foveal center retinal and parafoveal retinal thicknesses were thicker 1 day and 3 days after surgery than before surgery (t = 2.689, P = 0.012; t = 2.383, P = 0.018, respectively); no significant difference was found 1 week after surgery (P > 0.05). The foveal center retinal and parafoveal retinal thicknesses were greater 1 day after surgery than they were before surgery (P = 0.000 and P = 0.005, respectively) in the mild myopic and hyperopic groups. No significant difference was found 3 days or 1 week after surgery (P > 0.05). In all three groups, no significant difference was found in the macular inner retinal or peripapillary RNFL thickness 1 day, 3 days, or 1 week after surgery (P > 0.05).

Conclusions:

The foveal center retinal edema after FS-LASIK is mild and reversible in children, that mostly occurred in the high myopic group with no effect on the visual acuity, and is always relieved within 1 week.