scholarly journals Clinical Effect and Rotational Stability of TICL in the Treatment of Myopic Astigmatism

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Manhui Zhu ◽  
Linling Zhu ◽  
Qiujian Zhu ◽  
Cailian Xu ◽  
Peng Yu ◽  
...  
Keyword(s):  
Risk Factors ◽  
Visual Acuity ◽  
Rotational Stability ◽  
Spherical Equivalent ◽  
Implantable Collamer Lens ◽  
Manifest Refraction ◽  
Efficacy Index ◽  
The Mean ◽  
Myopic Astigmatism ◽  
High Myopic Astigmatism

Purpose. To investigate the clinical outcomes and possible risk factors associated with rotational stability after the implantation of a V4c toric implantable Collamer lens (TICL) for the correction of moderate to high myopic astigmatism. Methods. A total of 112 eyes of 66 patients with moderate to high myopic astigmatism underwent TICL implantation. All patients were followed up for more than 1 year. The uncorrected and best-corrected visual acuity (UCVA and BCVA), astigmatism and spherical equivalent, intraocular pressure, vault, endothelial cell morphometry, and rotation of the TICL axis were assessed at l day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively. Postoperative rotation was defined as the angle between the intended axis and the achieved axis. Regression analysis was used to investigate the possible risk factors for TICL rotation postoperatively. Results. The mean efficacy index and safety index 12 months postoperatively were 1.03 ± 0.09 and 1.05 ± 0.10, respectively. All patients had the same or better visual acuity than preoperatively. The mean astigmatism value decreased from −1.86 ± 0.79 D preoperatively to −0.37 ± 0.35 D. The mean absolute axis deviation of the TICL at the last follow-up was 2.75 ± 2.04° (range, 0°∼11°). The mean manifest refraction spherical equivalent (MRSE) changed from -9.04 ± 2.67 D preoperatively to −0.67 ± 0.51 D postoperatively. The logistic regression demonstrated that the absolute degree of TICL rotation had a significant association with the fixation angle of the TICL and the size of the lens ( P = 0.003 , P = 0.026 , resp.). Conclusion. The results of our study support that TICL implantation is safe, effective, and predictable in the treatment of moderate to high myopic astigmatism, with relatively good postoperative rotational stability.

scholarly journals Implantable Collamer Lens for Correction of Refractive Errors in Patients with Keratoconus following Collagen Cross-Linking: One Year Follow-up

2014 ◽  
Vol 3 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Hassenien Safa Shuber
Keyword(s):  
Visual Acuity ◽  
Cross Linking ◽  
Refractive Errors ◽  
Implantable Collamer Lens ◽  
Uncorrected Visual Acuity ◽  
Efficacy Index ◽  
The Mean ◽  
One Year ◽  
Collagen Cross Linking

ABSTRACT Objective The purpose of this study is to assess the predictability, safety, efficacy and stability of correction of refractive errors in patients with keratoconus using Visian implantable collamer lens (ICL) following collagen cross-linking. Materials and methods This prospective, non-comparative study evaluated 20 eyes of 14 patients with keratoconus subjected to implantation of intraocular collamer lens at least 1 year following collagen cross-linking and stable refraction. Mean preoperative myopia was −8.43 ± 5.13 Diopters (D) (–3.5 to −20.0D and mean cylinder was −2.19 ± 1.28D (0.0 to −4.5D). The preoperative spherical equivalent (SE) was −9.52 ± 5.33D (–3.75 to −21.25D). During the 12 months follow-up, uncorrected visual acuity, best corrected visual acuity, refraction, intraocular pressure and vaulting are measured. Results At 12 months postoperatively, 90% of eye had refractive cylinder of <1.0D with (p = 0.003) and 20 (100%) eyes was within ±0.75D of sphere at 1 year (r2 = 0.99) and (p = 0.0085). The mean postoperative BCVA in decimal was 0.498 ± 0.232, while the mean preoperative BCVA was 0.484 ± 0.285. The safety index at 12 months was 1.02. The mean postoperative UCVA in decimal was 0.498 ± 0.232 and the mean preoperative BCVA is 0.484 ± 0.29 and the efficacy index at 12 months was 1.01. Conclusion Implantation of Visian Intraocular collamer lens is predictable, safe and effective way to correct refractive error in patients with keratoconus following collagen cross-linking. How to cite this article Shuber HS. Implantable Collamer Lens for Correction of Refractive Errors in Patients with Keratoconus following Collagen Cross-Linking: One Year Follow-up. Int J Kerat Ect Cor Dis 2014;3(1):29-35.

scholarly journals Three-year Clinical Outcomes of Aspheric Micro-monovision LASIK for Correction of Presbyopia and Myopic Astigmatism

2020 ◽  
Author(s):  
Fang Liu ◽  
Ting Zhang ◽  
Quan Liu
Keyword(s):  
Visual Acuity ◽  
Spherical Equivalent ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
High Satisfaction ◽  
Manifest Refraction ◽  
Corrected Distance Visual Acuity ◽  
Uncorrected Visual Acuity ◽  
Registration Number ◽  
Myopic Astigmatism

Abstract Background: To investigate the long-term safety and efficacy of aspheric micro-monovision LASIK for the correction of presbyopia and myopic astigmatism. Methods: In total, 114 eyes of 57 patients with a mean age of 48 ± 4.05 years (range: 43 to 62 years) who were undergoing aspheric micro-monovision LASIK treatment were enrolled. Visual acuity, manifest refraction, amplitude of accommodation, contrast sensitivity, entire eye aberrations and patients’ subjective ratings were evaluated from 1 day to 3 years postoperatively. Results: None of the eyes showed a spherical equivalent change of over 0.75 D between 3 months and 3 years, while 95% of the eyes were within ±0.50 D of the target correction of the spherical equivalent. The percentage of patients showing monocular uncorrected distance visual acuity ≥20/20 was 95%, and all eyes achieved a visual acuity of 20/25 or better. The percentage of patients showing binocular uncorrected near visual acuity ≥J2 was 93%, and all patients achieved a visual acuity of J4 or better. Ninety-one percent of the patients had an uncorrected visual acuity of 20/20 in both eyes and J2 or better binocular visual acuity. Six of 108 eyes (6%) lost 1 line, and no eyes lost 2 lines of corrected distance visual acuity. The overall satisfaction score for surgery was 93 ± 6. Conclusions: Aspheric micro-monovision LASIK using the Carl Zeiss Meditec MEL 80 Platform was an efficacious option for older myopic patients with presbyopia. Three-year postoperative outcomes in the Chinese population indicated improvements in uncorrected binocular vision at far and near distances with high satisfaction. Trial registration: The registration number is ChiCTR-IPC-15005842, and the date of registration is January 16, 2015.

scholarly journals Visual Performance after a Unilateral or Bilateral Implantation of Enlarged Depth-of-Focus Intraocular Lens in Patients with Cataract: A Prospective Clinical Trial

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Se Hyun Choi ◽  
Hyo kyung Lee ◽  
Chang Ho Yoon ◽  
Mee Kum Kim
Keyword(s):  
Visual Acuity ◽  
Intraocular Lens ◽  
Mean Absolute Error ◽  
Absolute Error ◽  
Numerical Error ◽  
Spherical Equivalent ◽  
Depth Of Focus ◽  
Manifest Refraction ◽  
The Mean ◽  
Best Fit

Purpose. To investigate visual performances after a unilateral or bilateral implantation of enlarged depth-of-focus intraocular lens in patients with cataract. Methods. In this prospective study, uneventful phacoemulsification and TECNIS® Symfony intraocular lens implantation were performed in 20 eyes of 17 patients. At postoperative 1, 4, and 12 weeks, the logarithm of the minimal angle of resolution visual acuity at far, intermediate, and near distances and the spherical equivalent in manifest refraction and automated refraction were measured. A questionnaire was used to investigate glare, spectacle dependency, and satisfaction at 12 weeks. The mean numerical error and mean absolute error were compared between intraocular lens formulas to assess the best-fit formula. Results. The logarithm of the minimal angle of resolution visual acuity significantly improved to 0.02 at far, 0.02 at intermediate, and 0.27 at near distances at 12 weeks (p<0.05). Spherical equivalent was −0.79 D on automated refraction and was significantly lower than −0.26 D measured on manifest refraction. Patients’ satisfaction score was 9.06, 8.94, and 6.65 for far, intermediate, and near distances, respectively. Near glasses were required in 5 patients and 2 patients complained of photic phenomenon. Visual performances were not significantly different between bilateral and unilateral implanted patients. No patients reported bilateral imbalance due to unilateral surgery. The mean numerical error was closest to 0 D using the Barrett Universal II formula. The mean absolute error was not significantly different between these formulas. Conclusion. Unilateral or bilateral implantation of the enlarged depth-of-focus intraocular lens seems to be equally effective in improving visual performances in patients with cataract.

scholarly journals Clinical and Refractive Outcomes of Toric Phakic Implantable Collamer lens Implantat for correction of myopic astigmatism

2019 ◽  
Vol 13 (1) ◽  
pp. 70-75
Author(s):  
Suzan Amana
Keyword(s):  
Crystalline Lens ◽  
Posterior Chamber ◽  
Implantable Collamer Lens ◽  
Corneal Surgery ◽  
Refractive Outcomes ◽  
Lens Implantation ◽  
Positive Linear Correlation ◽  
The Mean ◽  
Myopic Astigmatism ◽  
High Myopic Astigmatism

Background: Currently there are four general approaches to correct refractive errors: refractive corneal surgery, crystalline lens surgery and implantation of an intraocular lens in anterior or posterior chamber. Objective: To evaluate the predictability, safety and stability of toric phakic implantable collamer lens implantation to correct moderate to high myopic astigmatism. in  Eye Specialty Private Hospital, Baghdad, Iraq. Type of the Study: a prospective non randomize intervention study. Methods: 60 eyes of 40 patients underwent implantation of a toric implantable collamer lens (V4c design).Mean spherical refraction was ₋11.32 diopter (D) ±3.17 (SD) with range from ₋6.00 to ₋18.00D and the mean cylinder was -2.61(D) ±1.16 with range from ₋1.00 to ₋5.50D .The outcome measures that evaluated during a 12 months follow-up period include UDVA, refractive outcomes, CDVA, vault and adverse events. Results: At 12 months postoperatively the mean Snellen decimal UDVA was 0.77±0.23 and mean CDVA was 0.80±0.21, with an efficacy index 1.16. Twenty nine  eyes (48.33%) showed gain in CDVA with safety index     1.21.The treatment was highly predictable for spherical equivalent and astigmatic component .The mean SE dropped from (₋12.63D ±3.11) to ( ₋0.11 D±0.20) with 58 eyes within ±0.50 D and 60 eyes with ± 1.00D of target correction . For achieved cylinder 60 eyes (100%) had ≤0.50D and 51 eyes (85%) had ≤0.25D with strong positive linear correlation between achieved and expected cylinder(r=0.94) Conclusions: The results of the present study support safety, efficacy, predictability of toric implantable collamer lens implantation to treat moderate to high myopic astigmatism.

scholarly journals 3-month surgical outcomes of Implantable Collamer Lens implantation for myopic regression after laser vision correction surgeries: a retrospective case series

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Byunghoon Chung ◽  
Joon Hyun Kim ◽  
David S. Y. Kang ◽  
Dong Jun Kang ◽  
Eung Kweon Kim ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Surgical Outcomes ◽  
Spherical Equivalent ◽  
Efficacy And Safety ◽  
Implantable Collamer Lens ◽  
Distance Visual Acuity ◽  
Vision Correction ◽  
Laser Vision ◽  
The Mean ◽  
Safety Indices

Abstract Background To investigate the surgical outcomes of implantable collamer lens (ICL) implantation in eyes with residual myopia after primary laser vision correction (LVC) surgeries. Methods This study included patients who underwent ICL implantation and had a history of LVC surgery, including photorefractive keratectomy (PRK) or laser-assisted in situ keratomileusis (LASIK). Visual acuity and refractive error were assessed pre and 3-months postoperatively and the efficacy and safety indices calculated accordingly. Results A total of 30 eyes of 17 patients were included in this study. At 3 months, the mean logMAR uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and spherical equivalent were − 0.03 ± 0.11 (include logMAR), − 0.04 ± 0.09 (include logMAR), and − 0.06 ± 0.33 diopters (D), respectively. The 3-month Snellen UDVA was better than 20/20 for 83% of eyes, and 97% of eyes showed an unchanged or improved CDVA after surgery. The mean efficacy and safety indices were 1.11 ± 0.22 and 1.13 ± 0.20, respectively. Further, 93 and 100% of eyes were within ±0.5 and ± 1.0 D of the attempted spherical equivalent refraction, respectively. Conclusions ICL implantation in eyes with myopic regression after previous LVC surgery showed safe, effective, and predictable outcomes. Trial registration retrospectively registered.

Comparison between Small Incision Lenticule Extraction and Wavefront-Guided Femtosecond Laser-Assisted In Situ Keratomileusis in Correction of Myopic Astigmatism

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Khaled M Al-Boraie ◽  
Tamer M. El Mekkawy ◽  
Mohammad G Metwally ◽  
Ashraf H Soliman
Keyword(s):  
Visual Acuity ◽  
Higher Order ◽  
Small Incision Lenticule Extraction ◽  
Higher Order Aberrations ◽  
Significant Difference ◽  
Manifest Refraction ◽  
Lenticule Extraction ◽  
The Mean ◽  
Myopic Astigmatism

Abstract Aim of the Work To compare visual acuity, refractive and topographic outcome between small incision lenticule extraction (SMILE) and wavefront-guided femtosecond laser-assisted in situ keratomileusis (WFG FS-LASIK) in patients with myopic astigmatism. Patients and methods This prospective, non-randomized, comparative clinical study included 60 eyes of 30 patients with simple or compound myopic astigmatism presenting for refractive error correction. Femtosecond assisted LASIK group included 30 eyes and SMILE group included 30 eyes. The following tests were done for all patients preoperatively and at 3 months postoperatively: full ophthalmological examination, manifest refraction, UDVA, CDVA, corneal topography using combined schimflug and placcido disc imaging namely Pentacam. (Oculus Inc.) and wavefront analysis using ATLAS 9000 (Carl Zeiss Meditec) Main Outcome Measures: Uncorrected distance visual acuity (UDVA), corrected disctance visual acuity (CDVA), manifest refraction, Efficacy, safety, predictability, corneal higher order aberrations. Results At 3 months, the mean manifest refractive spherical equivalent (MRSE) in SMILE group was -0.33 ± 0.34 D and the mean MRSE in FS- LASIK group was 0.23 ± 0.35 D and there was a statistically significant difference between both groups (P &lt; 0.05). mean postoperative cylinder was -0.56 ± 0.28 D in SMILE group and -0.53 ± 0.38D in FS-LASIK with statistically significant difference ( P = 0.254 ) 93% and 93% of eyes in the SMILE and FS-LASIK groups were within ± 0.5 D; 96.67% and 100% of eyes in the SMILE and FS-LASIK groups, respectively, were within ± 1 D. There were 86.66% of treated eyes in the SMILE group, and 93.33% treated eyes in the FS-LASIK group that had 20/25 or better UDVA. Regarding safety, the CDVA in the SMILE group, 20 eyes (66.67%) showed no change, 8 eyes (27%) gained 1 line, 2 eyes (7%) lost 1 line, and no eyes lost more than 1 line. whereas in the FS-LASIK group, 27 eyes (90%) exhibited no change, 2 eyes (6.66%) gained 1 line, 1 eye (3.33%) lost 1 line, and no eyes lost more than 1 line and There was no statistically significant difference between both groups (P = 0. 554 ). Regarding corneal asphericity, both procedures increased Q-value with no statistically significant difference between both groups (P = 0. 052). Regarding corneal higher order aberrations, both procedures significantly increased total corneal aberrations but there was no statistically significant difference in the change in RMS of total corneal higher order aberration (P = 0.434) .but SMILE increased RMS of coma aberration significantly more than FS-LASIK (P = 0. 029). Conclusion both SMILE and FS-LASIK procedures have shown excellent efficacy, safety, and predictability for the correction of myopia and myopic astigmatism. SMILE was closer to emmetropia regarding sphere and spherical equivalent, However, astigmatic undercorrection was noted after both surgeries with increased astigmatism. Both procedures increased the total corneal higher order aberrations with no statistically significant difference between both groups. A higher vertical coma was found in SMILE than WFG FS-LASIK.

Clinical Profile on Keratoconus Presenting at A Tertiary Eye Care Centre- Tilganga Institute of Ophthalmology

2019 ◽  
Vol 11 (2) ◽  
pp. 138-144
Author(s):  
Rachana Singh Rana ◽  
Leena Bajracharya ◽  
Reeta Gurung
Keyword(s):  
Visual Acuity ◽  
Clinical Profile ◽  
Spherical Equivalent ◽  
Care Centre ◽  
Younger Age ◽  
Manifest Refraction ◽  
Uncorrected Visual Acuity ◽  
The Mean ◽  
Spectacle Correction

Introduction: Keratoconus (KC), is a bilateral, noninflammatory degenerative disease of the cornea which is characterized by progressive corneal ectasia and loss of visual function. The onset of KC is commonly seen at puberty and affects approximately 1 in 2000 in the general population. Objective: The aim of this study was to assess the clinical profile of keratoconus in the tertiary eye centre in Nepal. Material and methods: It is a retrospective, hospital based, consecutive study from June 2017 to May 2018. A total of 66 patients (114 eyes) were diagnosed cases of Keratoconus presented in Cornea clinic of Tilganga institute of Ophthalmology. Parameters investigated included patients’ demography, keratometric readings, visualacuity and manifest refraction. Classification of keratoconus was based on Amslern-Krumeich grading system (modified). Results: The mean age of subjects was 18.73 (range: 10-65). Male/female distribution was 48 (72.7%) and 18 (27.3%) respectively. 48 (72.7%) had bilateral keratoconus and 18 (27.3%) were unilateral. Mean Uncorrected visual acuity (UCVA) was 0.80 (range: 0.01-1.00), mean visual acuity ( VA) with spectacle correction was 0.47 (range: 0.01-1.00). Mean spherical amount of refractive was –2.17 (range: −0.50 to −17.00D) and mean cylindrical amount of refraction was -2.85 (range: 0.00 to −6.00). Mean spherical equivalent (SE) of refraction was −4.26 (range: −0.50 to −22.50D). Mean flattest keratometric reading (K1) was 49.63 (range: 40.63-76.70D) and mean steepest keratometric reading (K2) was 53.14 (range: 41.63-73.21D). Mean average keratometric reading was 51.43 (range: 41.63-72.10D). Regarding disease severity, 35.68% of subjects were classified as mild keratoconus, 29.73% as moderate keratoconus, 9.73% as advance keratoconus, while 24.86% were found with the severestage of keratoconus. 78.9% of total eyes presented with minimum pachymetry of 401 to 500 mm. Conclusion: Clinical profile of Nepalese keratoconus patients looks similar to that reported earlier worldwide. The condition was found to manifest at a younger age and was more common in males.

scholarly journals One year outcomes after small incision lenticule extraction ReLEX in the correction of myopia and myopic astigmatism

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cristina Ariadna Nicula ◽  
Dorin Nicula ◽  
Sorana D. Bolboacă ◽  
Adriana Elena Bulboacă
Keyword(s):  
Visual Acuity ◽  
Spherical Equivalent ◽  
Small Incision Lenticule Extraction ◽  
Distance Visual Acuity ◽  
Small Incision ◽  
Lenticule Extraction ◽  
The Mean ◽  
One Year ◽  
Myopic Astigmatism

Abstract Purpose To report the visual and refractive outcomes of small incision lenticule extraction ReLEX (SMILE) technique using VisuMax femtosecond laser in myopia and myopic astigmatism patients. Material and methods A non-randomized clinical study has been conducted on patients with myopia and myopic astigmatism who underwent ReLEX SMILE technique, using the Zeiss VisuMax Laser system (Carl Zeiss Meditec AG, Jena, Germany) at Oculens Clinic, Cluj-Napoca, Romania. Patients older than 18 years, with ocular astigmatism up to -5 diopters (D), spherical equivalent up to -10.00 D, corrected distance visual acuity (CDVA) of 0.3 or better before the surgery, stable refraction for one year, and with a minimum calculated post operator residual stromal bed of 250μ were included in the study. Results The study involved a total of 25 myopic eyes (median of sphere diopters equal with -4D) and 67 myopic astigmatic eyes (median of cylinder diopters equal with -1.5 D). The mean refractive spherical equivalent (MRSE) on patients with myopic eyes reduced from -4.25D (median) to -0.5D at one month follow-up, -0.25 D at 6 and 12 months. The mean refractive spherical equivalent (MRSE) on patients with astigmatic myopic eyes reduced from-6.25 D to -0.67 D at one month, -0.62 D at six and twelve months. The value of sphere decreased postoperatively on myopic eyes with a median of -0.25D at one, six and twelve months. The value of cylinder decreased postoperatively on myopic astigmatic eyes with a median of -0.50 D at one month, -0.25 D at six months and -0.50 D at 12 months. At 6 and 12 months, 20 (80.0%) of myopic eyes were maintained within ±0.5 D and 22 (88.0%) with ±1D. On both groups (myopic eyes and myopic astigmatic eyes), statistically significant differences were observed when the keratometric baseline values were compared to each follow-up (P-values < 0.0001), without any significant differences between follow-ups (P-values>0.15). At 1-month follow-up, uncorrected distance visual acuity (UDVA) was better than or equal to 0.5 in 88.0% of myopic eyes and 82.1% of myopic astigmatic eyes. UDVA remained stable in all cases of myopic eyes at six months and the percentage increased at 92.0% in myopic eyes. UDVA slightly increased at 6-months (85.1%) and remained at the same value at 12-months in myopic astigmatism eyes. Conclusions SMILE proved an effective and safe refractive corneal procedure and provided a predictable and stable correction of myopia and myopic astigmatism. SMILE technique demonstrated very good outcomes in terms of keratometric, cylinder, spherical measurements.

Corneal densitometry in patients with keratoconus undergoing intrastromal Ferrara ring implantation

2021 ◽  
pp. 112067212110206
Author(s):  
Pablo Felipe Rodrigues ◽  
Bernardo Kaplan Moscovici ◽  
Guilherme Ferrara ◽  
Luciano Lamazales ◽  
Marcela Mara Silva Freitas ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Medical Records ◽  
Spherical Equivalent ◽  
Interventional Study ◽  
Data Comparison ◽  
Corneal Densitometry ◽  
Corrected Visual Acuity ◽  
Ring Segment ◽  
The Mean

Objective: Evaluation of central corneal densitometry changes following Ferrara corneal ring segment implantation in patients with keratoconus, especially the correlation between corneal densitometry and keratometry. Methods: Retrospective, non-comparative, interventional study based on the review of medical records of patients diagnosed with keratoconus who underwent Ferrara corneal ring segment implantation. Pre and post-operative corneal densitometry measurements obtained with Pentacam HR (Oculus, Wetzlar, Germany) were analyzed. The follow-up time was 3 months, and data comparison was made, using specific statistical analysis, with the data of 3 months postoperatively. Results: The study sample consisted of 43 eyes of 36 patients. The mean corrected visual acuity improved from 0.82 LogMAR preoperatively (SD ± 0.33) to 0.19 LogMAR (SD ± 0.13) postoperatively. The mean spherical equivalent varied from −4.63 (SD ± 3.94) preoperatively to −2.16 (SD ± 2.63) postoperatively. Asphericity varied from −0.69 (SD ± 0.32) preoperatively to −0.27 (SD ± 0.31) postoperatively. The mean maximum K was 54.01D (SD ± 3.38) preoperatively and 51.50D (SD ± 2.90) postoperatively. The mean anterior densitometric value was 18.26 (SD ± 2.03) preoperatively and 17.66 (SD ± 1.84) postoperatively. Conclusion: Corneal densitometry is an interesting technology that should be studied in keratoconus patients. Our results suggest that the corneal densitometry in the cornea’s anterior layer reduces after ICRS implantation and correlates with corneal keratometry. Further studies should be performed to increase the knowledge in this field.

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.

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