scholarly journals Intrastromal Corneal Ring Segments in Children with Keratoconus

2017 ◽  
Vol 6 (2) ◽  
pp. 45-48
Author(s):  
Paulo Ferrara ◽  
Leonardo Torquetti ◽  
Guilherme Ferrara
Keyword(s):  
Visual Acuity ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Intrastromal Corneal Ring ◽  
Corrected Distance Visual Acuity ◽  
Long Term Follow Up ◽  
Corneal Asphericity ◽  
The Mean ◽  
Belo Horizonte ◽  
Corneal Flattening

ABSTRACT Purpose To evaluate the long-term follow-up of Ferrara intrastromal corneal ring segments (ICRSs) (Ferrara Ophthalmics, Belo Horizonte, Brazil) implantation for the management of keratoconus in children. Study design Paulo Ferrara Eye Clinic, Belo Horizonte, Minas Gerais, Brazil. Materials and methods A total of 58 eyes of 37 children with keratoconus were included. One or two ring segments were inserted into the cornea, embracing the keratoconus area. Statistical analysis included preoperative and postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), asphericity, pachymetry, and keratometry. Results Ferrara ICRS implantation significantly improved the mean UDVA and CDVA. Corneal tomography (Pentacam®) showed corneal flattening in all eyes implanted with the Ferrara ring. The mean K decreased, and the corneal asphericity and pachymetry increased in all cases. Conclusion The Ferrara ICRS improved all parameters after 2 years of implantation in children with keratoconus. There was significant corneal flattening after ring implantation with improvement of the UDVA and the CDVA. All studied parameters remained stable over time. How to cite this article Ferrara G, Ferrara P, Torquetti L. Intrastromal Corneal Ring Segments in Children with Keratoconus. Int J Kerat Ect Cor Dis 2017;6(2):45-48.

scholarly journals Intrastromal Corneal Ring Segments Implantation in Patients with Mild Keratoconus

2014 ◽  
Vol 3 (3) ◽  
pp. 122-126
Author(s):  
Pablo F Rodrigues ◽  
Wagner G Dias
Keyword(s):  
Visual Acuity ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Intrastromal Corneal Ring ◽  
Corrected Distance Visual Acuity ◽  
Corneal Volume ◽  
Corneal Asphericity ◽  
The Mean ◽  
Early Indication ◽  
Better Than

ABSTRACT Purpose The purpose of this study is to evaluate the topographic, topometric and visual changes after implantation of Ferrara intrastromal corneal ring segments (ICRS) in grades I and II keratoconus patients. Materials and methods The chart records of 50 consecutively operated keratoconus patients were reviewed. The patients were operated on by the same surgeon, with the manual technique. All patients were preoperatively and postoperatively evaluated with the Pentacam (OCULUS Optikgeräte, Wetzlar, Germany). The studied parameters were: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry, corneal asphericity and corneal volume. Results Fifty eyes of 42 patients (26 males and 16 females) were analyzed. The mean preoperative UDVA was 0.91 ranging from LogMAR 0.10 to 1.30. The mean postoperative CDVA was 0.19 ranging from 0.00 to 0.54 LogMAR. The postoperative CDVA was equal or better than 0.18 in 37 cases (74%). The mean K1 decreased from 45.80D (±2.52) preoperatively to 44.27D (± 2.10) postoperatively and the mean K2 value, from 49.06D (± 2.09) to 46.22D (±1.89). The mean asphericity increased from −0.71 preoperatively to −0.29 postoperatively. The average preoperative corneal volume was 56.89 ± 3.11 mm3 while the average postoperative corneal volume was 57.64 ± 3.05 mm3. Conclusion The study supports the early indication of implantation of Ferrara ICRS in mild to moderate keratoconus cases in order to achieve good visual, keratometric and ashpericity outcomes. How to cite this article Rodrigues PF, Ferrara G, Ferrara P, Dias WG, Torquetti L. Intrastromal Corneal Ring Segments Implantation in Patients with Mild Keratoconus. Int J Kerat Ect Cor Dis 2014;3(3):122-126.

Outcomes of a 320-degree intrastromal corneal ring segment implantation for keratoconus: Results of a 6-month follow-up

2018 ◽  
Vol 30 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Guilherme Andrade do Nascimento Rocha ◽  
Paulo Ferrara de Almeida Cunha ◽  
Leonardo Torquetti Costa ◽  
Luciene Barbosa de Sousa
Keyword(s):  
Visual Acuity ◽  
Spherical Equivalent ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Intrastromal Corneal Ring ◽  
Corrected Distance Visual Acuity ◽  
Ring Segment ◽  
The Mean ◽  
Corneal Tomography

Importance: This study shows that a newer long-arc length intrastromal corneal ring segment is efficient and safe for keratoconus treatment. Background: To evaluate visual, tomographic results and complications of a 320-degree intrastromal corneal ring segment implantation with the femtosecond laser for keratoconus treatment. Design: A prospective, nonrandomized, and interventional study. Participants: A total of 34 eyes of 31 patients diagnosed with keratoconus were enrolled. Methods: Patients were divided into two groups based on the strategy used for 320-degree intrastromal corneal ring segment thickness selection. In one group, this selection was based on spherical equivalent (SE group) and in the other on the mean asphericity (Q group). The uncorrected and corrected distance visual acuities, spherical equivalent, K1, K2, Km, Kmax, and mean asphericity ( Q) on corneal tomography were evaluated preoperatively and at 3 and 6 months postoperatively. For astigmatism improvement, we analyzed the corneal tomographic vectorial astigmatism change preoperatively and at 6 months postoperatively. The mean follow-up period was 6.63 ± 0.96 months. Results: The mean uncorrected distance visual acuity and corrected distance visual acuity improved with a significant spherical equivalent improvement ( p < 0.05), with no differences between the 320-degree intrastromal corneal ring segment groups. All corneal tomographic parameters improved significantly ( p < 0.05) between the preoperative and postoperative intervals, with a significant better performance when we used spherical equivalent for the 320-degree intrastromal corneal ring segment thickness selection. Finally, the mean vectorial corneal tomographic astigmatism significantly improved after 6 months, again with no differences between groups. Conclusion: This study suggests that implanting a 320-degree intrastromal corneal ring segment is a safe and effective procedure for treating patients with keratoconus. It also suggests that for thickness selection spherical equivalent is the better strategy.

Efficacy of progressive thickness intrastromal corneal ring segments in the treatment of duck phenotype keratoconus

2021 ◽  
pp. 112067212110017
Author(s):  
Juan G Arbelaez ◽  
Maria C Arbelaez
Keyword(s):  
Visual Acuity ◽  
Clinical Outcomes ◽  
Effective Means ◽  
Study Cohort ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Intrastromal Corneal Ring ◽  
Manifest Refraction ◽  
Corrected Distance Visual Acuity ◽  
Belo Horizonte

Purpose:To evaluate clinical outcomes in patients with asymmetric duck phenotype keratoconus implanted with asymmetric progressive thickness intrastromal corneal ring segments (PT-ICRS, Keraring AS, Mediphacos, Belo Horizonte, Brazil), and to demonstrate improved visual acuity and symmetry in corneal flattening.Methods:This single-center, retrospective, observational study evaluated the clinical outcomes at 1, 3, and 6 months after implantation of PT-ICRS in patients with duck phenotype keratoconus. After creating the intrastromal tunnel with a femtosecond laser, one 160-degree arc length PT-ICRS, either 150/250 µm or 200/300 µm, was implanted. Changes in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction (MR), manifest refraction spherical equivalent (MRSE), mean keratometry (Kmean), maximum keratometry (Kmax), Coma@5mm, and manifest and topographical astigmatism were documented.Results:The study cohort included 23 eyes of 17 patients with a mean age of 24.6 years. From baseline to 6 months following implantation, mean UDVA improved from 0.70 logarithm of the minimum angle of resolution (logMAR) (20/100 Snellen) to 0.22 logMAR (20/33 Snellen), CDVA improved from 0.33 logMAR (20/42 Snellen) to 0.14 logMAR (20/27 Snellen), the mean sphere and MRSE decreased from −1.05 diopters (D) and −2.70 D to −0.25 D and −0.80 D, respectively, and the Kmean and Kmax improved from 46.5 D and 53.7 D to 44.6 D and 48.7 D, respectively.Conclusions:The Keraring AS ICRS offers a safe, effective means of improving visual acuity while reducing refractive error, mean and max keratometry, and aberrations in patients with duck phenotype keratoconus.

scholarly journals Clinical Outcomes of Sequential Intrastromal Corneal Ring Segments and an Extended Range of Vision Intraocular Lens Implantation in Patients with Keratoconus and Cataract

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
C. Lisa ◽  
R. Zaldivar ◽  
A. Fernández-Vega Cueto ◽  
R. M. Sanchez-Avila ◽  
D. Madrid-Costa ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Intraocular Lens ◽  
Iol Implantation ◽  
Distance Visual Acuity ◽  
Refractive Outcomes ◽  
Uncorrected Distance Visual Acuity ◽  
Intrastromal Corneal Ring ◽  
Corrected Distance Visual Acuity ◽  
Extended Range ◽  
The Mean

Purpose. To evaluate efficacy, safety, and predictability of sequential Ferrara-type intrastromal corneal ring segments (ICRS) and an extended range of vision intraocular lens (IOL) implantation in patients with keratoconus and cataract. Methods. This study comprised patients with keratoconus and cataract that had ICRS implantation followed 6 months later by extended range of vision IOL implantation. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and residual refractive errors, analysed using vector analysis, were recorded preoperatively, 6 months after ICRS implantation, and 6 months after IOL implantation, respectively. Results. The study enrolled 17 eyes (11 patients). The mean UDVA (logMAR scale) was 1.15 ± 0.67 preoperatively, 0.88 ± 0.69 six months after ICRS implantation (P=0.005), and 0.27 ± 0.18 six months after IOL implantation (P<0.0001). The CDVA changed from 0.26 ± 0.15 (logMAR) before surgery to 0.17 ± 0.08 six months after Ferrara-type ICRS implantation (P=0.002) and to 0.07 ± 0.06 six months after IOL implantation (P<0.0001). The spherical equivalent and the refractive cylinder declined steeply after IOL implantation (P<0.001). The magnitude of depth of focus was 2.60 ± 1.02 D. There were no statistically significant differences in visual acuity for a defocus range from +0.50 D to −0.50 D (P>0.1). Conclusion. Sequential Ferrara-type ICRS and an extended range of vision IOL implantation provided good visual and refractive outcomes, being an effective, safe, and predictable procedure for the treatment of selected cases of patients with keratoconus and cataract. In addition, this approach provides an increase of tolerance to defocus.

scholarly journals Prospective Randomized Multicenter Comparison of the Clinical Outcomes of V4c and V5 Implantable Collamer Lenses: A Contralateral Eye Study

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Takashi Kojima ◽  
Yoshihiro Kitazawa ◽  
Tomoaki Nakamura ◽  
Masahide Takahashi ◽  
Kazutaka Kamiya ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Refractive Surgery ◽  
Night Vision ◽  
Visual Performance ◽  
Distance Visual Acuity ◽  
Refractive Outcomes ◽  
Uncorrected Distance Visual Acuity ◽  
Corrected Distance Visual Acuity ◽  
The Mean ◽  
Contralateral Eye

Purpose. To compare the visual and refractive outcomes and night vision performance questionnaire results between V4c and V5 implantable Collamer lenses in a prospective, randomized, multicenter study.Settings. Four refractive surgery centers.Design. Prospective randomized multicenter single-masked comparative study.Methods. Twenty-three patients were enrolled in this study. A conventional V4c model (EVO Visian ICL) was implanted in one eye, and a V5 model (EVO+ Visian ICL), which has a larger optic diameter than the V4c model, was implanted in the contralateral eye. The uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were evaluated before and 6 months after surgery. At 6 months after surgery, a questionnaire on night vision disturbances was administered. The efficacy, safety, and predictability of the two implanted ICL models were compared.Results. There were no significant differences in the postoperative UDVA and CDVA between the two ICL models. The mean efficacy indexes for the V4c and V5 lenses were 1.16 ± 0.22 and 1.03 ± 0.23, respectively. The mean safety indexes of the V4c and V5 lenses were 1.21 ± 0.20 and 1.19 ± 0.20, respectively. The night vision performance questionnaire revealed that 7 patients (37%) noticed a difference in visual performance between the eyes, and all of them reported that they could see better at night with the V5-implanted eye compared with the V4c-implanted eye.Conclusion. The V4c and V5 ICL models achieved similar visual and refractive outcomes, whereas the V5 model showed a possible advantage in reducing night vision disturbances.

scholarly journals Toric phakic IOLs in keratoconus—evaluation of preoperative parameters on the outcome of phakic anterior chamber lens implantation in patients with keratoconus

2021 ◽  
Author(s):  
Isaak R. Fischinger ◽  
Jascha Wendelstein ◽  
Kristin Tetz ◽  
Matthias Bolz ◽  
Manfred R. Tetz
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Intraocular Lenses ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Significant Difference ◽  
Corrected Distance Visual Acuity ◽  
Lens Implantation ◽  
Efficacy Index ◽  
The Mean

Abstract Purpose To evaluate the influence of the type of the keratectasia and preoperative keratometry readings on the efficacy of implantation of iris-fixated phakic anterior chamber intraocular lenses (pIOL) in patients with keratoconus. Methods In this retrospective study, iris-fixated pIOLs (Artisan/Artiflex (Ophtec®), Verisyse/Veriflex (AMO®)) were implanted in 38 eyes of 22 patients with stable keratoconus. Thirty-six eyes underwent corneal crosslinking (CXL) prior to the lens implantation. The refractive outcome was evaluated 6 weeks postoperatively and the influence of preoperative refraction and topo- and tomographical factors were analyzed. Results The mean postoperative uncorrected distance visual acuity (UDVApost) was 0.25 ± 0.15 logMAR and was not statistically different from the mean preoperative corrected distance visual acuity (CDVApre), which was 0.24 ± 0.13 logMAR. Twenty-seven eyes (71%) reached UDVApost/CDVApre ≥ 1 (efficacy index), whereas patients with PMD-like ectasia (n = 14) showed significantly (p = 0.003) higher efficacy index (100%) than patients diagnosed with keratoconus (n = 24) (54%). Higher eccentricity of the maximum posterior elevation showed a significant beneficial influence on the efficacy index (p = 0.021). Furthermore, a higher Amsler-Krumeich stage and preoperative MAE were correlated with a worse UDVApost. The mean absolute spherical equivalent was significantly decreased from 5.71 ± 4.96 D to 1.25 ± 1.20 D (p < 0.001). No significant difference was found in endothelial cell count. Conclusion The results indicate that the implantation of phakic iris-fixated anterior chamber IOLs is a reasonable refractive option for patients with keratoconus. Keratoconus patients with a pellucidal marginal degeneration (PMD)-like appearance ectasia seem to benefit most from such procedures.

scholarly journals Femtosecond laser-assisted cataract surgery compared with phacoemulsification: the FACT non-inferiority RCT

2021 ◽  
Vol 25 (6) ◽  
pp. 1-68
Author(s):  
Alexander C Day ◽  
Jennifer M Burr ◽  
Kate Bennett ◽  
Rachael Hunter ◽  
Catey Bunce ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Standard Deviation ◽  
Confidence Interval ◽  
Femtosecond Laser ◽  
Cataract Surgery ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Corrected Distance Visual Acuity ◽  
The Mean

Background Cataract surgery is one of the most common operations. Femtosecond laser-assisted cataract surgery (FLACS) is a technique that automates a number of operative steps. Objectives To compare FLACS with phacoemulsification cataract surgery (PCS). Design Multicentre, outcome-masked, randomised controlled non-inferiority trial. Setting Three collaborating NHS hospitals. Participants A total of 785 patients with age-related cataract in one or both eyes were randomised between May 2015 and September 2017. Intervention FLACS (n = 392 participants) or PCS (n = 393 participants). Main outcome measures The primary outcome was uncorrected distance visual acuity in the study eye after 3 months, expressed as the logarithm of the minimum angle of resolution (logMAR): 0.00 logMAR (or 6/6 if expressed in Snellen) is normal (good visual acuity). Secondary outcomes included corrected distance visual acuity, refractive outcomes (within 0.5 dioptre and 1.0 dioptre of target), safety and patient-reported outcome measures at 3 and 12 months, and resource use. All trial follow-ups were performed by optometrists who were masked to the trial intervention. Results A total of 353 (90%) participants allocated to the FLACS arm and 317 (81%) participants allocated to the PCS arm attended follow-up at 3 months. The mean uncorrected distance visual acuity was similar in both treatment arms [0.13 logMAR, standard deviation 0.23 logMAR, for FLACS, vs. 0.14 logMAR, standard deviation 0.27 logMAR, for PCS, with a difference of –0.01 logMAR (95% confidence interval –0.05 to 0.03 logMAR; p = 0.63)]. The mean corrected distance visual acuity values were again similar in both treatment arms (–0.01 logMAR, standard deviation 0.19 logMAR FLACS vs. 0.01 logMAR, standard deviation 0.21 logMAR PCS; p = 0.34). There were two posterior capsule tears in the PCS arm. There were no significant differences between the treatment arms for any secondary outcome at 3 months. At 12 months, the mean uncorrected distance visual acuity was 0.14 logMAR (standard deviation 0.22 logMAR) for FLACS and 0.17 logMAR (standard deviation 0.25 logMAR) for PCS, with a difference between the treatment arms of –0.03 logMAR (95% confidence interval –0.06 to 0.01 logMAR; p = 0.17). The mean corrected distance visual acuity was 0.003 logMAR (standard deviation 0.18 logMAR) for FLACS and 0.03 logMAR (standard deviation 0.23 logMAR) for PCS, with a difference of –0.03 logMAR (95% confidence interval –0.06 to 0.01 logMAR; p = 0.11). There were no significant differences between the arms for any other outcomes, with the exception of the mean binocular corrected distance visual acuity with a difference of –0.02 logMAR (95% confidence interval –0.05 to 0.00 logMAR) (p = 0.036), which favoured FLACS. There were no significant differences between the arms for any health, social care or societal costs. For the economic evaluation, the mean cost difference was £167.62 per patient higher for FLACS (95% of iterations between –£14.12 and £341.67) than for PCS. The mean QALY difference (FLACS minus PCS) was 0.001 (95% of iterations between –0.011 and 0.015), which equates to an incremental cost-effectiveness ratio (cost difference divided by QALY difference) of £167,620. Limitations Although the measurement of outcomes was carried out by optometrists who were masked to the treatment arm, the participants were not masked. Conclusions The evidence suggests that FLACS is not inferior to PCS in terms of vision after 3 months’ follow-up, and there were no significant differences in patient-reported health and safety outcomes after 12 months’ follow-up. In addition, the statistically significant difference in binocular corrected distance visual acuity was not clinically significant. FLACS is not cost-effective. Future work To explore the possible differences in vision in patients without ocular co-pathology. Trial registration Current Controlled Trials ISRCTN77602616. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 6. See the NIHR Journals Library website for further project information. Moorfields Eye Charity (grant references GR000233 and GR000449 for the endothelial cell counter and femtosecond laser used).

Three-year follow-up of intrastromal corneal ring segment implantation in central keratoconus with regular astigmatism: ‘Bow-tie’ shape

2019 ◽  
Vol 30 (4) ◽  
pp. 643-649 ◽  
Author(s):  
Luis Fernández-Vega-Cueto ◽  
Carlos Lisa ◽  
Aranzazu Poo-López ◽  
José F Alfonso ◽  
David Madrid-Costa
Keyword(s):  
Visual Acuity ◽  
Postoperative Period ◽  
Spherical Equivalent ◽  
Distance Visual Acuity ◽  
Post Surgery ◽  
Uncorrected Distance Visual Acuity ◽  
Intrastromal Corneal Ring ◽  
Corrected Distance Visual Acuity ◽  
Bow Tie

Purpose: To assess the outcomes of implanting Ferrara-type intrastromal corneal ring segments in central ‘bow-tie’-shaped keratoconus over 3 years of follow-up. Methods: A total of 20 eyes with central ‘bow-tie’-shaped keratoconus were evaluated before and after implanting Ferrara-type intrastromal corneal ring segments (AJL Ophthalmic, Spain). LogMAR uncorrected distance visual acuity and best corrected distance visual acuity and residual refractive errors analysed using vector analysis were recorded preoperatively, at 6 months, 1 year, and 3 years postoperatively. Results: The mean uncorrected distance visual acuity (LogMAR scale) rose from a preoperative 0.75 ± 0.28 to a 6-month postoperative 0.38 ± 0.28 (p < 0.0001). The corrected distance visual acuity, in turn, improved from 0.07 ± 0.06 to 0.05 ± 0.06 (p = 0.0008). Both the uncorrected distance visual acuity and corrected distance visual acuity were stable over the postoperative period in both groups (p > 0.05). None of the eyes lost uncorrected distance visual acuity and corrected distance visual acuity lines over the postoperative follow-up period. The spherical equivalent and the refractive cylinder declined steeply after intrastromal corneal ring segments implantation (p < 0.0001). Both the spherical equivalent and refractive cylinder were stable over the postoperative period. None of the eyes had an increase in maximum or minimum keratometry greater than 0.75D over the postoperative period. Conclusion: The planning for intrastromal corneal ring segments insertion proposed in this study reduces the spherical equivalent and refractive cylinder in this type of keratoconus, while improving post-surgery uncorrected distance visual acuity and corrected distance visual acuity. These results remain stable over 3 years of follow-up. Therefore, this procedure could be considered as an effective therapeutic alternative in patients affected by this type of keratoconus.

scholarly journals Comparison of Visual Outcomes for Myopia after Refractive Surgery using Femtosecond Laser-Assisted and Flap-off Epi-LASIK

2020 ◽  
Author(s):  
JUNJIE PIAO ◽  
Woong-Joo Whang ◽  
Choun-Ki Joo
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Refractive Surgery ◽  
Distance Visual Acuity ◽  
Visual Outcomes ◽  
Uncorrected Distance Visual Acuity ◽  
Significant Difference ◽  
Manifest Refraction ◽  
Corrected Distance Visual Acuity ◽  
Corneal Asphericity

Abstract Background This study clinically evaluated the visual outcomes after refractive surgery for myopia using femtosecond laser-assisted in situ keratomileusis (femto-LASIK) and epi-LASIK (flap-off). Methods In this prospective cohort study, 40 eyes of 27 patients were divided into two groups depending on the technique used for refractive surgery. Femto-LASIK flaps and epi-LASIK flaps (flap-off) were created using femtosecond laser and Epi-K TM epikeratome, respectively. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction (MR), corneal asphericity (Q-value), and corneal higher-order aberrations (HOAs) were assessed pre- and postoperatively. Results The improvement in LogMAR UDVA after refractive surgery was statistically significant for both groups ( P < 0.001 for all groups); it was significantly improved in the femto-LASIK group, 1 day and 1 week postoperatively ( P < 0.001, P = 0.019, respectively). With regard to the front and total corneal HOAs, there were significant differences in spherical aberrations (Z 4,0 ) between the femto-LASIK and flap-off epi-LASIK groups ( P = 0.016 and P = 0.017, respectively). With regard to the back corneal HOAs, there were significant differences in vertical coma (Z 3,-1 ) aberration, 0.027 ± 0.027 μm (femto-LASIK) and 0.001 ± 0.034 μm (flap-off epipolis LASIK); horizontal secondary astigmatism (Z 4,2 ) aberration, -0.008 ± 0.012 μm (femto-LASIK) and 0.007 ± 0.018 μm (flap-off epipolis LASIK); oblique tetrafoil (Z 4,-4 ) aberration, -0.008 ± 0.029 μm (femto-LASIK) and 0.015 ± 0.026 μm (flap-off epi-LASIK), respectively ( P = 0.018, P = 0.007, and P = 0.022, respectively). However, the back corneal HOA changes did not have a significant effect on the total corneal HOA changes. Conclusion Femto-LASIK yielded better early visual outcomes than did flap-off epi-LASIK, but there was no significant difference between the outcomes of the two procedures, 1 week postoperatively.

Comparison of clinical outcomes between manual and femtosecond laser techniques for intrastromal corneal ring segment implantation

2019 ◽  
Vol 30 (6) ◽  
pp. 1246-1255 ◽  
Author(s):  
Tiago Monteiro ◽  
José F Alfonso ◽  
Nuno Franqueira ◽  
Fernando Faria-Correira ◽  
Renato Ambrósio ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Mean Square ◽  
Spherical Equivalent ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Intrastromal Corneal Ring ◽  
Corrected Distance Visual Acuity ◽  
Manual Group ◽  
Ring Segment

Purpose: The purpose was to compare the visual, refractive and aberrometric results of intrastromal corneal ring segments implantation with manual dissection and femtosecond laser–assisted surgery. Methods: This is a multicentre study, which included consecutive patients with paracentral keratoconus, in which the difference between the axes of the topographic flattest and the coma aberration was <60°, who had Ferrara-type intrastromal corneal ring segment implantation using manual dissection or femtosecond laser technique. LogMAR uncorrected (uncorrected distance visual acuity) and corrected (corrected distance visual acuity) distance visual acuity, refractive errors and the root mean square for corneal coma-like aberration were recorded before and at 6 months after surgery. Results: The study included 84 and 110 eyes in the manual group and in the femtosecond group, respectively. After surgery, there was a statistically significant improvement in uncorrected distance visual acuity and corrected distance visual acuity for both groups ( p < 0.0001), and there were no statistically significant differences between groups ( p > 0.3). For both groups, there was a reduction in spherical equivalent after intrastromal corneal ring segment implantation ( p < 0.0001). There were no statistically significant differences between groups in the magnitude of spherical equivalent reduction ( p = 0.34) The magnitude of the root mean square coma-like reduction was 0.93 ± 0.76 and 0.83 ± 0.80 μm in the manual and femtosecond group, respectively ( p = 0.2). While in the femtosecond laser group no complications were reported, in the manual group, the intraoperative or postoperative complications rate was 13.09%. Conclusion: Although both surgical techniques provide comparable visual, refractive and aberrometric outcomes, it should be noted that the femtosecond laser is a safer surgical procedure, with no complications reported.

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