Aberration compensation between anterior and posterior corneal surfaces after Small incision lenticule extraction and Femtosecond laser-assisted laser in-situ keratomileusis.

corneal aberration,lasik,laser insitu keratomileusis,posterior corneal surface,small incision lenticule extraction

Ophthalmic Physiol Opt. 2015 Sep;35(5):540-51. doi: 10.1111/opo.12226. Epub 2015 Jun 18.
Aberration compensation between anterior and posterior corneal surfaces after Small incision lenticule extraction and Femtosecond laser-assisted laser in-situ keratomileusis.
Li X1, Wang Y1, Dou R1.
Author information
Abstract
PURPOSE:
To investigate the aberration compensation between anterior and posterior corneal surfaces after SMILE and FS-LASIK.
METHODS:
Fifty-five subjects (55 eyes) undergoing SMILE and 51 subjects (51 eyes) undergoing FS-LASIK were enrolled in this study. Wavefront aberrations of anterior and posterior corneal surfaces and the whole cornea at 6 mm in diameter were measured using a Scheimpflug Camera preoperatively and one, three and 6 months postoperatively. The compensation factor (CF), where CF = 1 – (aberration of the whole cornea/aberration of anterior corneal surface), was calculated.
RESULTS:
Spherical aberration of the posterior surface and the whole cornea remained stable after SMILE. However, spherical aberration of posterior surface increased significantly at 6 months in the FS-LASIK group. The total higher-order aberration (tHOA) of the anterior surface and the whole cornea was lower at 6 months than at one and 3 months (p = 0.001 and 0.001, respectively) in the FS-LASIK group. Meanwhile, in the SMILE group, no significant difference in tHOA was found between various postoperative time points. There were significant decreases in the CF of tHOA compared with preoperative values in both groups. The CF of spherical aberration reduced significantly in both groups at 3 and 6 mm in diameter one, three and 6 months postoperatively. Significant decreases in the CF of vertical coma were found at three and 6 months postoperatively in the FS-LASIK group compared with preoperative values at 6 mm in diameter (p = 0.021 and 0.008, respectively). The change in CF (ΔCF) of spherical aberration was smaller in the SMILE group than in the FS-LASIK group at one and 3 months postoperatively (p = 0.003 and p < 0.0001, respectively). The ΔCF of spherical aberration was significantly lower in moderately myopic subjects than in subjects with high myopia at 1 month in the SMILE group (p = 0.041) and at one, three and 6 months in the FS-LASIK group (p = 0.014, 0.020, and 0.004, respectively).
CONCLUSIONS:
The posterior corneal surface plays an important role in compensating for spherical aberration of the anterior corneal surface. The compensation mechanisms of spherical aberration and higher-order aberration between anterior and posterior corneal surfaces were disrupted by the SMILE and the FS-LASIK procedures. The change in the CF of spherical aberration was smaller in the SMILE group compared with the FS-LASIK group, especially in subjects with high myopia.

Changes in Keratocyte Density and Visual Function Five Years After Laser In Situ Keratomileusis: Femtosecond Laser Versus Mechanical Microkeratome.

keratocyte, visual function, lasik, keratomileusis, femtosecond laser, microkeratome

Am J Ophthalmol. 2015 Jul;160(1):163-70. doi: 10.1016/j.ajo.2015.04.006. Epub 2015 Apr 11.
Changes in Keratocyte Density and Visual Function Five Years After Laser In Situ Keratomileusis: Femtosecond Laser Versus Mechanical Microkeratome.
McLaren JW1, Bourne WM1, Maguire LJ1, Patel SV2.
Author information
Abstract
PURPOSE:
To determine the effects of keratocyte loss on optical properties and vision after laser in situ keratomileusis (LASIK) with the flap created with a femtosecond laser or a mechanical microkeratome.
DESIGN:
Randomized clinical paired-eye study.
METHODS:
Both eyes of 21 patients received LASIK for myopia or myopic astigmatism. One eye of each patient was randomized by ocular dominance to flap creation with a femtosecond laser and the other eye to flap creation with a mechanical microkeratome. Before LASIK and at 1, 3, and 6 months and 1, 3, and 5 years after LASIK, keratocyte density was measured using confocal microscopy, and high-contrast visual acuity and anterior corneal wavefront aberrations were measured by standard methods. At each visit, all variables were compared between methods of creating the flap and to the same variable before treatment using paired tests with Bonferroni correction for multiple comparisons.
RESULTS:
Keratocyte density in the flap decreased by 20% during the first year after LASIK and remained low through 5 years (P < .001). High-order wavefront aberrations increased and uncorrected visual acuity improved immediately after surgery, but these variables did not change further to 5 years. There were no differences in any variables between treatments.
CONCLUSIONS:
A sustained reduction in keratocyte density does not affect vision or optical properties of the cornea through 5 years after LASIK. The method of creating a LASIK flap does not influence the changes in keratocyte density in the flap.

We compared early corneal nerve changes after small incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK).

corneal nerve, small incision lenticule extraction, SMILE, LASIK, keratomileusis

Invest Ophthalmol Vis Sci. 2014 Mar 25;55(3):1823-34. doi: 10.1167/iovs.13-13324.
Early corneal nerve damage and recovery following small incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK).
Mohamed-Noriega K1, Riau AK, Lwin NC, Chaurasia SS, Tan DT, Mehta JS.
Author information
Abstract
PURPOSE:
We compared early corneal nerve changes after small incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK).
METHODS:
A total of 12 rabbits underwent LASIK in one eye and SMILE in the fellow eye. Baseline and follow-up evaluations at 1, 2, and 4 weeks postoperatively were performed with in vivo confocal microscopy to evaluate 5 different areas within the treated zone: center, superior, inferior, nasal, and temporal. Cryosections of the corneas and whole mount of the extracted SMILE lenticules were analyzed with immunostaining of βIII-tubulin.
RESULTS:
One week after SMILE and LASIK, a decrease in nerve length and density was observed in all evaluated areas. A trend toward greater subbasal nerve length and density (SLD), more eyes with subbasal nerves (ESN), more eyes with subbasal nerves longer than 200 μm (SNL), and higher mean number of subbasal nerves by frame (NSN) in SMILE than in LASIK groups was observed at subsequent follow-up time points. Only the SMILE group showed a recovery of SLD, ESN, and NSN by week 4 (P > 0.05). A trend toward more eyes with sprouting subbasal nerves and greater mean number of sprouting nerves was observed in LASIK than in SMILE, indicating that more subbasal nerves were disrupted and undergoing regeneration after LASIK. Immunostaining at postoperative week 4 revealed a faster stromal nerve recovery in post-SMILE eyes compared to post-LASIK eyes. Immunostaining at postoperative week 4 revealed a faster stromal nerve recovery in post-SMILE eyes compared to post-LASIK eyes.
CONCLUSIONS:
Our findings suggest that SMILE results in less nerve damage and faster nerve recovery than LASIK.
CONCLUSIONS:
Our findings suggest that SMILE results in less nerve damage and faster nerve recovery than LASIK.

Keratomycosis due to Fusarium oxysporum treated with the combination povidone iodine eye drops and oral fluconazole.

keratomycosis, fusarium ,iodine, fluconazole

Keratomycosis due to Fusarium oxysporum treated with the combination povidone iodine eye drops and oral fluconazole.

[Article in French]

Abstract

In developing countries where systemic antifungal are often unavailable, treatment of filamentous fungi infection as Fusarium is sometimes very difficult to treat. We report the case of a keratomycosis due to Fusarium oxysporum treated by povidone iodine eye drops and oral fluconazole. The diagnosis of abscess in the cornea was retained after ophthalmological examination for a 28-year-old man with no previous ophthalmological disease, addressed to the Ophthalmological clinic at the University Hospital Le Dantec in Dakar for a left painful red eye with decreased visual acuity lasting for 15days. The patient did not receive any foreign body into the eye. Samples by corneal scraping were made for microbiological analysis and the patient was hospitalized and treated with a reinforced eye drops based treatment (ceftriaxone+gentamicin). The mycological diagnosis revealed the presence of a mold: F. oxysporum, which motivated the replacement of the initial treatment by eye drops containing iodized povidone solution at 1 % because of the amphotericin B unavailability. Due to the threat of visual loss, oral fluconazole was added to the local treatment with eye drops povidone iodine. The outcome was favorable with a healing abscess and visual acuity amounted to 1/200th. Furthermore, we noted sequels such as pannus and pillowcase. The vulgarization of efficient topical antifungal in developing countries would be necessary to optimize fungal infection treatment.

The mycological diagnosis revealed the presence of a mold: F. oxysporum, which motivated the replacement of the initial treatment by eye drops containing iodized povidone solution at 1 % because of the amphotericin B unavailability. Due to the threat of visual loss, oral fluconazole was added to the local treatment with eye drops povidone iodine. The outcome was favorable with a healing abscess and visual acuity amounted to 1/200th. Furthermore, we noted sequels such as pannus and pillowcase. The vulgarization of efficient topical antifungal in developing countries would be necessary to optimize fungal infection treatment.

Complications of Descemet’s membrane endothelial keratoplasty

Antigen–antibody reactions, Descemet’s membrane endothelial keratoplasty, Glaucoma, Tissue donors, Transplant

Complications of Descemet’s membrane endothelial keratoplasty.

[Article in German]

Abstract

Descemet’s membrane endothelial keratoplasty (DMEK) is a relatively new, but now established surgical procedure to cure corneal endothelial disorders. However, there are donor- and recipient-associated sources of potential complications, some of which can be identified and addressed prior to the procedure and others that may lead to intra- or postoperative problems. Preoperatively, risk factors for a limited visual outcome (ocular comorbidities, previous ocular surgery, subepithelial/stromal scars) and the specific indication for DMEK should be discussed with the patient. Intraoperatively, young donor age can be associated with a particularly elastic graft, which may be difficult to unfold. Such transplants are not appropriate for particularly difficult recipient situations (very opaque cornea, history of vitreoretinal surgery). Postoperatively, transplant dehiscence is the most common complication, which in many cases can be managed by reinjection of air (or a 20 % SF6 gas/air mix) into the anterior chamber. An elevation of the intraocular pressure after DMEK is often caused by a reaction to topical steroid therapy. Although immune rejections after DMEK are less likely than after Descemet’s stripping automated endothelial keratoplasty (DSAEK) and perforating keratoplasty, adequate treatment with topical steroidal drugs is recommended. These common and several rare complications are discussed in this review.

KEYWORDS:

Antigen–antibody reactions; Descemet’s membrane endothelial keratoplasty; Glaucoma; Tissue donors; Transplant recipients

bstract

Descemet’s membrane endothelial keratoplasty (DMEK) is a relatively new, but now established surgical procedure to cure corneal endothelial disorders. However, there are donor- and recipient-associated sources of potential complications, some of which can be identified and addressed prior to the procedure and others that may lead to intra- or postoperative problems. Preoperatively, risk factors for a limited visual outcome (ocular comorbidities, previous ocular surgery, subepithelial/stromal scars) and the specific indication for DMEK should be discussed with the patient. Intraoperatively, young donor age can be associated with a particularly elastic graft, which may be difficult to unfold. Such transplants are not appropriate for particularly difficult recipient situations (very opaque cornea, history of vitreoretinal surgery). Postoperatively, transplant dehiscence is the most common complication, which in many cases can be managed by reinjection of air (or a 20 % SF6 gas/air mix) into the anterior chamber. An elevation of the intraocular pressure after DMEK is often caused by a reaction to topical steroid therapy. Although immune rejections after DMEK are less likely than after Descemet’s stripping automated endothelial keratoplasty (DSAEK) and perforating keratoplasty, adequate treatment with topical steroidal drugs is recommended. These common and several rare complications are discussed in this review.

KEYWORDS:

Antigen–antibody reactions; Descemet’s membrane endothelial keratoplasty; Glaucoma; Tissue donors; Transplant recipients

Antigen–antibody reactions, Descemet’s membrane endothelial keratoplasty, Glaucoma, Tissue donors, Transplant

DSAEK and PK. Different paper

Objective Evaluation of Planned Versus Achieved Stromal Thickness Reduction in Myopic Femtosecond Laser-assisted LASIK.

J Refract Surg. 2015 Sep;31(9):628-32. doi: 10.3928/1081597X-20150820-09.

Objective Evaluation of Planned Versus Achieved Stromal Thickness Reduction in Myopic Femtosecond Laser-assisted LASIK.

Abstract

PURPOSE:

To evaluate corneal stromal thickness reduction and compare to attempted and achieved ablation depth in a consecutive case series study of myopic LASIK.

METHODS:

Stromal thickness reduction was retrospectively evaluated in 205 consecutive eyes of 205 patients undergoing myopic and myopic astigmatic LASIK. Anterior segment optical coherence tomography was performed preoperatively and 3 months postoperatively. Epithelial thickness remodeling was also accounted for to achieve objective stromal thickness reduction. The derived maximum stromal thickness reduction was then compared to the programmed (planned) maximum ablation depth. Deviation of planned versus achieved maximum stromal thickness changes was correlated with residual refractive error.

RESULTS:

The 3-month stromal reduction was 86.01 ± 28.28 µm, compared to the average programmed maximum ablation depth of 88.48 ± 26.05 µm. The attempted versus achieved thickness outliers correlated with deviations in achieved refractive correction.

CONCLUSIONS:

Actual objective stromal thickness reduction following myopic LASIK correlates well with the attempted versus achieved refractive change.

Objective Evaluation of Planned Versus Achieved Stromal Thickness Reduction in Myopic Femtosecond Laser-assisted LASIK.

Abstract

PURPOSE:

To evaluate corneal stromal thickness reduction and compare to attempted and achieved ablation depth in a consecutive case series study of myopic LASIK.

METHODS:

Stromal thickness reduction was retrospectively evaluated in 205 consecutive eyes of 205 patients undergoing myopic and myopic astigmatic LASIK. Anterior segment optical coherence tomography was performed preoperatively and 3 months postoperatively. Epithelial thickness remodeling was also accounted for to achieve objective stromal thickness reduction. The derived maximum stromal thickness reduction was then compared to the programmed (planned) maximum ablation depth. Deviation of planned versus achieved maximum stromal thickness changes was correlated with residual refractive error.

RESULTS:

The 3-month stromal reduction was 86.01 ± 28.28 µm, compared to the average programmed maximum ablation depth of 88.48 ± 26.05 µm. The attempted versus achieved thickness outliers correlated with deviations in achieved refractive correction.

CONCLUSIONS:

Actual objective stromal thickness reduction following myopic LASIK correlates well with the attempted versus achieved refractive change.

Intrastromal corneal ring segment implantation for ectasia after refractive surgery.

Arq Bras Oftalmol. 2015 Jul-Aug;78(4):212-5. doi: 10.5935/0004-2749.20150055.

Intrastromal corneal ring segment implantation for ectasia after refractive surgery.

Abstract

PURPOSE:

To evaluate the clinical outcomes of intrastromal corneal ring segment (ICRS) implantation to correct ectasia in eyes with prior refractive surgery.

METHODS:

Forty-one eyes of 25 patients (13 men, 12 women; mean age, 28.66 years) with ectasia after refractive surgery [photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK)] were included in a nonrandomized, retrospective, observational case series. Corneal tunnels were created by mechanical dissection in all eyes. Main outcome measures included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), refraction, keratometry, and computerized analysis of corneal topography. Patients were divided into two groups by the type of refractive surgery (Group A: PRK, Group B: LASIK).

RESULTS:

The mean preoperative manifest astigmatism decreased from -1.88 to -0.84 D in Group A (p=0.096) and -3.18 to -1.77 D in Group B (p=0.000). The mean keratometric astigmatism decreased from -2.58 to -1.66 D in Group A (p=0.010) and -4.80 to -2.78 D in Group B (p=0.000). The mean spherical equivalent decreased from -2.97 to -2.05 D in Group A (p=0.065) and -3.31 to -2.42 D in Group B (p=0.014). No significant between-group differences were noted on the comparison of preoperative and postoperative results. No intraoperative or postoperative complications were observed.

CONCLUSION:

ICRS implantation is a useful treatment option for ectasia following refractive surgery, and it has significantly reduced the refractive cylinder and increased best spectacle-corrected visual acuity.

RESULTS:

The mean preoperative manifest astigmatism decreased from -1.88 to -0.84 D in Group A (p=0.096) and -3.18 to -1.77 D in Group B (p=0.000). The mean keratometric astigmatism decreased from -2.58 to -1.66 D in Group A (p=0.010) and -4.80 to -2.78 D in Group B (p=0.000). The mean spherical equivalent decreased from -2.97 to -2.05 D in Group A (p=0.065) and -3.31 to -2.42 D in Group B (p=0.014). No significant between-group differences were noted on the comparison of preoperative and postoperative results. No intraoperative or postoperative complications were observed.

CONCLUSION:

ICRS implantation is a useful treatment option for ectasia following refractive surgery, and it has significantly reduced the refractive cylinder and increased best spectacle-corrected visual acuity.

Vector analysis of astigmatism before and after LASIK: a comparison of two different platforms for treatment of high astigmatism.

Astigmatism, Excimer laser, LASIK, Vector analysis

Graefes Arch Clin Exp Ophthalmol. 2015 Dec;253(12):2325-33. doi: 10.1007/s00417-015-3177-x. Epub 2015 Sep 24.

Vector analysis of astigmatism before and after LASIK: a comparison of two different platforms for treatment of high astigmatism.

Abstract

PURPOSE:

To compare the outcomes of astigmatic laser in-situ keratomileusis (LASIK) procedures between two different platforms using J0 and J45 vector analysis.

METHODS:

Patients were divided into four groups, depending on the type of astigmatism and laser platform on which they were treated. Astigmatism was between 2 and 7 diopters (D). One hundred and thirty-five patients with myopic astigmatism (246 eyes) and 102 patients with mixed astigmatism (172 eyes) underwent unremarkable LASIK correction on Wavelight Allegretto Eye-Q 400Hz and Schwind Amaris 750S laserplatform. The preoperative and postoperative sphere, negative cylinder [C] and axis (ø) of manifest refractions were subjected to vector analysis by calculations of the standard J0 (cos [4π(ø-90)/360]xC/2) and J45 (sin[4π(ø-90)/360]xC/2).

RESULTS:

Reporting the key results, we found J0 significantly reduced after LASIK in both groups (p < 0.001) but not J45. There was no significant association between individual pairs of pre and postoperative J0 & J45 values. There was no significant difference between the outcomes of the two platforms.

CONCLUSIONS:

Wavelight Allegretto 400Hz and Schwind Amaris 750S showed excellent results for treating patients with astigmatism, regardless whether it is mixed or myopic astigmatism. The J45 did not reduce significantly possibly because of the low number of eyes with oblique astigmatism. There was no genuine difference post-operatively between groups treated on two different laser platforms according to the vector analyses.

KEYWORDS:

Astigmatism; Excimer laser; LASIK; Vector analysis

CONCLUSIONS:

Wavelight Allegretto 400Hz and Schwind Amaris 750S showed excellent results for treating patients with astigmatism, regardless whether it is mixed or myopic astigmatism. The J45 did not reduce significantly possibly because of the low number of eyes with oblique astigmatism. There was no genuine difference post-operatively between groups treated on two different laser platforms according to the vector analyses.

KEYWORDS:

Astigmatism; Excimer laser; LASIK; Vector analysis

Femtosecond Laser Flap Creation for Laser In Situ Keratomileusis in the Setting of Previous Radial Keratotomy.

Asia Pac J Ophthalmol (Phila). 2015 Sep-Oct;4(5):283-5. doi: 10.1097/APO.0000000000000131.

Femtosecond Laser Flap Creation for Laser In Situ Keratomileusis in the Setting of Previous Radial Keratotomy.

Abstract

PURPOSE:

The aim of the study was to report the outcomes of laser in situ keratomileusis (LASIK) in subjects with previous radial keratotomy (RK) using a novel femtosecond laser setting on a proprietary femtosecond laser platform.

DESIGN:

This was a retrospective, consecutive chart review of patients at a single private practice institution.

METHODS:

The medical records of 16 eyes of 8 subjects who underwent femtosecond-assisted LASIK for consecutive hyperopia after RK were retrospectively reviewed. The preoperative characteristics, intraoperative details, and postoperative outcomes were analyzed.

RESULTS:

All 16 eyes had successful femtosecond laser flap creation without significant intraoperative or postoperative complications. Uncorrected visual acuity significantly improved postoperatively (P = 0.0142) and remained stable through the final follow-up interval at 9 to 12 months postoperatively. None of the subjects lost any lines of best spectacle-corrected visual acuity in the postoperative period.

CONCLUSIONS:

The novel femtosecond laser technique described in this study can provide a safe and effective method for patients undergoingLASIK after previous RK. Future investigations are required to further validate the findings reported in this study.

DESIGN:

This was a retrospective, consecutive chart review of patients at a single private practice institution.

METHODS:

The medical records of 16 eyes of 8 subjects who underwent femtosecond-assisted LASIK for consecutive hyperopia after RK were retrospectively reviewed. The preoperative characteristics, intraoperative details, and postoperative outcomes were analyzed.

RESULTS:

All 16 eyes had successful femtosecond laser flap creation without significant intraoperative or postoperative complications. Uncorrected visual acuity significantly improved postoperatively (P = 0.0142) and remained stable through the final follow-up interval at 9 to 12 months postoperatively. None of the subjects lost any lines of best spectacle-corrected visual acuity in the postoperative period.

CONCLUSIONS:

The novel femtosecond laser technique described in this study can provide a safe and effective method for patients undergoingLASIK after previous RK. Future investigations are required to further validate the findings reported in this study.

Soft Contact Lens Optimizes Visual Goals for a Patient with Keratoectasia.

Optom Vis Sci. 2015 Nov;92(11):e409-13. doi: 10.1097/OPX.0000000000000703.

Soft Contact Lens Optimizes Visual Goals for a Patient with Keratoectasia.

Abstract

PURPOSE:

To determine the usefulness of the KeraSoft IC lens with a patient with high visual and comfort demands with keratoectasia.

CASE REPORT:

A 30-year-old white woman was diagnosed as having bilateral corneal ectasia after laser-assisted in situ keratomileusis. She underwent a penetrating keratoplasty for her left eye with subsequent photorefractive keratectomy to improve visual acuity. She was referred by her corneal specialist for a specialty contact lens evaluation to improve contact lens visual acuity and comfort during demanding physical activities.

CONCLUSIONS:

This case highlights the success of the KeraSoft IC soft contact lens for irregular corneas to address specific visual and comfort demands during physical fitness activities.

Optom Vis Sci. 2015 Nov;92(11):e409-13. doi: 10.1097/OPX.0000000000000703.

Soft Contact Lens Optimizes Visual Goals for a Patient with Keratoectasia.

Abstract

PURPOSE:

To determine the usefulness of the KeraSoft IC lens with a patient with high visual and comfort demands with keratoectasia.

CASE REPORT:

A 30-year-old white woman was diagnosed as having bilateral corneal ectasia after laser-assisted in situ keratomileusis. She underwent a penetrating keratoplasty for her left eye with subsequent photorefractive keratectomy to improve visual acuity. She was referred by her corneal specialist for a specialty contact lens evaluation to improve contact lens visual acuity and comfort during demanding physical activities.

CONCLUSIONS:

This case highlights the success of the KeraSoft IC soft contact lens for irregular corneas to address specific visual and comfort demands during physical fitness activities.

Optom Vis Sci. 2015 Nov;92(11):e409-13. doi: 10.1097/OPX.0000000000000703.

Soft Contact Lens Optimizes Visual Goals for a Patient with Keratoectasia.

Abstract

PURPOSE:

To determine the usefulness of the KeraSoft IC lens with a patient with high visual and comfort demands with keratoectasia.

CASE REPORT:

A 30-year-old white woman was diagnosed as having bilateral corneal ectasia after laser-assisted in situ keratomileusis. She underwent a penetrating keratoplasty for her left eye with subsequent photorefractive keratectomy to improve visual acuity. She was referred by her corneal specialist for a specialty contact lens evaluation to improve contact lens visual acuity and comfort during demanding physical activities.

CONCLUSIONS:

This case highlights the success of the KeraSoft IC soft contact lens for irregular corneas to address specific visual and comfort demands during physical fitness activities.