scholarly journals Reversal of Myopic Correction for Patients Intolerant to LASIK

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Amr A. Gab-Alla
Keyword(s):  
Refractive Surgery ◽  
Average Duration ◽  
Corneal Thickness ◽  
Case Series ◽  
Spherical Equivalent ◽  
Efficacy And Safety ◽  
Effective Option ◽  
Optical Zone ◽  
The Mean ◽  
One Year

Purpose. To evaluate the outcome of the reversal of myopia correction in patients intolerant to LASIK. Methods. This study is a retrospective and case series of patients who decided to reverse their previous myopic LASIK correction between July 2012 and July 2020. It was conducted at a private refractive surgery centre, Ismailia, Egypt. The patients were followed up after reversal treatment for one year. Primary LASIK and reversal treatment were performed by a 500 kHz Amaris excimer laser platform. The main outcomes included refractive predictability, stability, efficacy, and safety and any reported complications. Results. This study included 48 eyes of 24 patients (6 male and 18 female patients). The average duration between the primary LASIK surgery and reversal treatment was 3.20 ± 0.30 months (range 3 to 4 months). Reversal treatment was bilateral in all patients. The mean age of the patients was 38 ± 1.9 years (range 37 to 45 yrs). After reversal, the mean postreversal cycloplegic refraction spherical equivalent was −1.82 ± 0.34 D (range −1.50 to −3.00 D). The mean ablation depth was 34.10 ± 7.36 μm (range 20 to 46 μm), and the mean of the central corneal thickness 12 months after reversal treatment was 510.2 ± 14.4 μm (range 515 to 487 μm). The mean keratometric reading was 42.6 ± 1.6 (range 42.5 to 44.8). The mean of CDVA was 0.2 ± 0.03 log MAR (range −0.10 to 0.4 log MAR). The mean optical zone of reversal treatment was 6.1 ± 0.3 mm (range 5.9 to 6.2 mm). UDVA was 0.4 log MAR in 87.5% of the patients, 0.5 log MAR in 8.3% of the patients, and 0.6 log MAR in 4.2% of the patients. CDVA remained unchanged in 83.3% of patients; 2.1% of the patients gained one line of CDVA (Snellen); 8.3% of the patients lost one line of CDVA; 6.3% of the patients lost two lines of CDVA. No cases of corneal ectasia were recorded. The only postoperative complications were flap microfolds in 3 eyes (6.25%). Conclusion. In conclusion, this study demonstrates that reversal of myopic LASIK treatment is a safe, stable, and effective option for intolerant patients.

Detecting subclinical keratoconus by biomechanical analysis in tomographically regular keratoconus fellow eyes

2021 ◽  
pp. 112067212110637
Author(s):  
Victor A Augustin ◽  
Hyeck-Soo Son ◽  
Isabella Baur ◽  
Ling Zhao ◽  
Gerd U Auffarth ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Case Series ◽  
Biomechanical Analysis ◽  
Corvis St ◽  
Corrected Visual Acuity ◽  
The Mean ◽  
Best Corrected Visual Acuity ◽  
Fellow Eyes

Purpose To analyze the tomographically non-affected second eyes of keratoconus patients using the Corvis ST to detect any biomechanical abnormalities or subclinical keratoconus. Methods In this retrospective, single-center, consecutive case series 244 eyes of 122 keratoconus patients were analyzed between November 2020 and February 2021. Fourteen fellow eyes fulfilled the inclusion criteria and showed no clinical or tomographic signs of keratoconus. Main outcome measures included best-corrected visual acuity, tomographic and biomechanical analyses using Scheimpflug imaging: Pentacam and Corvis ST (Oculus, Wetzlar, Germany). Tomographic analyses included anterior and posterior simulated keratometry, K-Max, central corneal thickness, thinnest corneal thickness, Belin/Ambrosio Ectasia Display, and the ABCD grading system. For biomechanical analyses, the corneal biomechanical index (CBI) and tomographic biomechanical index were used. Results The mean best-corrected visual acuity was 0.01 ± 0.10 logMAR. Mean K-Max was 43.79 ± 1.12 D, mean central corneal thickness 529 ± 25 µm, mean thinnest corneal thickness 524 ± 23 µm, and mean Belin/Ambrosio Ectasia Display 1.0 ± 0.32. The mean CBI was 0.30 ± 0.21. Regular CBI values were found in six of 14 patients. The mean tomographic biomechanical index was 0.47 ± 0.22 with regular values observed in only two of 14 patients. No signs of tomographic or biomechanical abnormalities were shown in only one of 14 keratoconus fellow eyes, with regular ABCD, Belin/Ambrosio Ectasia Display, CBI and tomographic biomechanical index values. Conclusions Tomographically normal fellow eyes of keratoconus patients are rare. In these cases, a biomechanical analysis of the cornea may help detect a subclinical keratoconus. The tomographic biomechanical index was the most sensitive index to verify a mild ectasia.

scholarly journals Correlation between Central Corneal Thickness and Degree of Myopia among Malaysian Patients Undergoing Laser Keratorefractive Surgery

2020 ◽  
pp. 52-58
Author(s):  
Sagili Chandrasekhara Reddy ◽  
Mohd Mansor Shariff ◽  
Aina Malindri Dasrilsyah
Keyword(s):  
Optical Coherence Tomography ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Military Hospital ◽  
Moderate Degree ◽  
Optical Coherence ◽  
Corneal Refractive Surgery ◽  
The Mean

Purpose: To determine the central corneal thickness in myopic adult patients scheduled for laser corneal refractive surgery and to explore its correlation with degree of refractive error. Materials and Methods: The case records of 130 myopic patients who underwent laser corneal refractive surgery in a military hospital over a period of two years were reviewed to determine the central corneal thickness. All patients had 6/6 vision with best correction, and did not have any other anterior segment or fundus diseases in both eyes. The central corneal thickness was measured with Visante Carl Zeiss anterior segment optical coherence tomography instrument.                                                                                                                        Results: Out of 130 patients, males were more (73, 56.2%); mean age of patients was 33.8 years (range 18-60 years) and majority were Malays (110, 84.6%).  The spherical power of myopia ranged from – 0.5 to – 10.00 D, and the cylindrical power ranged from – 0.25 to – 3.25 D. The mean central corneal thickness of both eyes was 528.2 µm (range 331- 615 µm); in the mild degree of myopia (- 0.50 to - 2.00 D) 527.9 µm, moderate degree (- 2.25 to -5.00 D) 529.4 µm, and high degree (-5.25 to -11.00 D) 523.9 µm. Conclusion: The anterior segment optical coherence tomography provides noncontact, rapid, pachymetry mapping of the corneal thickness. In Malaysian patients, the mean central corneal thickness of both eyes in myopia was 528.1 µm (range 331- 615 µm). There was no correlation between the mean central corneal thickness and degree of myopia, different genders, age groups, ethnic groups and two eyes.

scholarly journals A formula for expressing the decrement of human life. In a letter addressed to Sir Edward Hyde East, Bart. M. P. F. R. S. By Thomas Young, M. D. For. Sec. R. S

1833 ◽  
Vol 2 ◽  
pp. 275-276
Keyword(s):  
Average Duration ◽  
Human Life ◽  
Annual Average ◽  
Prolongation Of Life ◽  
The Mean ◽  
Full Life ◽  
One Year

The author first observes that an opinion is generally prevalent, of a decided increase in the average duration of human life in many parts of Europe ; but he yet regards it as probable that this improvement has been much exaggerated, partly on account of the limited number of persons on whom the observations have been made, and partly from erroneous views respecting the profits of assurance companies. He then examines the evidence on which this opinion rests, and gives a comparative statement of the annual average of mortality, the mean term of full life, and the mean age of mankind, according to a great number of different authorities ; and considers that a prolongation of life to the extent of one year in eight, is a much fairer estimate than one in three, which some have maintained, even on the limited grounds of the experience on which they have reasoned.

Significance of dynamic contour tonometry in evaluation of progression of glaucoma in patients with a history of laser refractive surgery

2019 ◽  
Vol 104 (2) ◽  
pp. 276-281 ◽  
Author(s):  
Sang Yeop Lee ◽  
Eun Woo Kim ◽  
Wungrak Choi ◽  
Chan Keum Park ◽  
Sangah Kim ◽  
...  
Keyword(s):  
Refractive Surgery ◽  
Open Angle Glaucoma ◽  
Corneal Thickness ◽  
Significant Risk ◽  
Applanation Tonometry ◽  
Dynamic Contour Tonometry ◽  
Significant Difference ◽  
History Of ◽  
The Mean ◽  
Laser Refractive Surgery

AimsIn this study, we tested the hypothesis that intraocular pressure (IOP) parameters measured by dynamic contour tonometry (DCT) would be more relevant in progression of glaucoma when there is a history of laser refractive surgery (LRS) than the IOP parameters measured by Goldmann applanation tonometry (GAT) or calculated by correction formulae.MethodsNinety-eight eyes in 54 patients with open-angle glaucoma and a history of LRS were included in this retrospective study. IOP was measured by both GAT and DCT during follow-up. Baseline, mean, and peak IOP, IOP fluctuation, and IOP reduction were measured by each tonometry method. Corrected IOP parameters using central corneal thickness and mean keratometry values were also analysed. Clustered logistic regression was used to identify variables correlated with progression of glaucoma. Areas under the curve (AUCs) for correlated variables were also compared.ResultsThe mean DCT value (OR 1.36, p=0.024), peak DCT value (OR 1.19, p=0.02) and pattern SD (OR 1.10, p=0.016) were significant risk factors for progression. There was a significant difference in the predictive ability of the mean DCT and GAT values (AUC 0.63 and 0.514, respectively; p=0.01) and of the peak DCT and GAT values (0.646 and 0.503, respectively, p=0.009). The AUCs for corrected IOP did not exceed those of DCT.ConclusionsIOP measurements were more associated with progression of glaucoma when measurements were obtained by DCT than by GAT or correction formulae in eyes with a history of LRS.

Corneal biomechanical outcome of collagen cross-linking in keratoconic patients evaluated by Corvis ST

2020 ◽  
pp. 112067212094479
Author(s):  
Mahmoud Jabbarvand ◽  
Zahra Moravvej ◽  
Kianoush Shahraki ◽  
Hessam Hashemian ◽  
Hamed Ghasemi ◽  
...  
Keyword(s):  
Amplitude Ratio ◽  
Corneal Thickness ◽  
Case Series ◽  
Cross Linking ◽  
Corvis St ◽  
Significant Difference ◽  
Biomechanical Changes ◽  
The Mean ◽  
Prospective Case Series ◽  
Collagen Cross Linking

Purpose: A 6-month evaluation of the topographic and biomechanical changes induced by corneal collagen cross-linking (CXL) in keratoconic eyes using Pentacam and Corvis ST. Design: Longitudinal prospective case series. Methods: In this study, 67 eyes of 67 patients with progressive keratoconus (KCN) treated with “Epithelium-off” CXL were evaluated. Patients with stages 1 or 2 of KCN and a corneal thickness of at least 400 μm at the thinnest point were included. Standard ophthalmologic examinations were carried out for all patients. The topographic and biomechanical measurements of the cornea were obtained by Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) and Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) preoperatively and 6-month postoperatively. Results: The mean age of the participants was 21.68 ± 4.23 years. There was significant difference in mean spherical equivalent (SE) before and 6 months after CXL. Uncorrected and best corrected visual acuity improved postoperatively, although not statistically significant. The mean and maximum keratometry showed a significant decrease 6 months after CXL (0.93 ± 0.38 D and 1.43 ± 0.62 D, respectively p < 0.001). Among Corvis ST parameters, first applanation length and velocity (AL1 and AV1) showed statistically significant changes. The radius at highest concavity changed significantly (0.13 ± 0.37 mm mean increase after CXL; p < 0.001). A significant increase was observed in stiffness parameter A1 (SP-A1; p < 0.001) and significant decreases were noted in integrated radius (IR) and deformation amplitude ratio (DAR; p < 0.001). Conclusion: Analyzing biomechanical changes after corneal cross-linking can provide basis for efficient KCN treatment. Corvis ST parameters demonstrated changes in corneal biomechanical characteristics indicative of stiffing after CXL.

Correlation between refractive state, corneal thickness, and keratometry in ametropic patients

2019 ◽  
Vol 30 (5) ◽  
pp. 891-896
Author(s):  
Amir Rosenblatt ◽  
Michael Mimouni ◽  
Tzahi Sela ◽  
Gur Munzer ◽  
David Varssano ◽  
...  
Keyword(s):  
Retrospective Analysis ◽  
Refractive Error ◽  
Refractive Surgery ◽  
Corneal Thickness ◽  
Spherical Equivalent ◽  
Moderate Correlation ◽  
Male And Female ◽  
Tel Aviv ◽  
Refractive State ◽  
Patient Demographics

Purpose: To analyze the correlation between age, gender, refractive error, keratometry, and corneal thickness in a large group of subjects. Methods: This study is a retrospective analysis of patients who underwent refractive surgery between January 2000 and February 2015 at Care Vision Refractive Clinic, Tel Aviv, Israel. Patient demographics, subjective refraction, pachymetry, and average keratometry were collected. Results: Overall, 51,113 eyes of patients averaging 28.8 ± 9.3 years of which 53.9% were males were included. Average keratometry, spherical equivalent and cylindrical error differed significantly between male and female subjects (p < 0.001), while pachymetry did not (p = 0.332). In myopic eyes, correlations between age, pachymetry, average keratometry, spherical equivalent, and cylindrical error were all statistically significant except for the correlation between age and either pachymetry (p = 0.462) or spherical equivalent (p = 0.016). All correlations found were negligible or small (|r|= 0.003 to 0.141). In hyperopic eyes, correlations between age, pachymetry, average keratometry, spherical equivalent, and cylindrical error were all statistically significant except for the correlation between average keratometry and either pachymetry or cylindrical error (p = 0.344 or p = 0.274, respectively). All correlations found were negligible or small, except for a moderate correlation found between age and cylindrical error (r = 0.365). Conclusion: Refractive state, pachymetry, and keratometry of refractive surgery candidates are mostly weakly correlated.

scholarly journals Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and Transpalpebral Tonometry

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Isabel Cacho ◽  
Juan Sanchez-Naves ◽  
Laura Batres ◽  
Jesús Pintor ◽  
Gonzalo Carracedo
Keyword(s):  
Intraocular Pressure ◽  
Refractive Surgery ◽  
Corneal Thickness ◽  
Laser In Situ Keratomileusis ◽  
Spherical Equivalent ◽  
Transpalpebral Tonometry ◽  
Spherical Equivalent Refraction ◽  
Before And After ◽  
Noncontact Tonometry

Purpose. To compare the intraocular pressure (IOP) before and after Laser In Situ Keratomileusis (LASIK), measured by Diaton, Perkins, and noncontact air pulse tonometers.Methods. Fifty-seven patients with a mean age of 34.88 were scheduled for myopia LASIK treatment. Spherical equivalent refraction (SER), corneal curvature (K), and central corneal thickness (CCT) and superior corneal thickness (SCT) were obtained before and after LASIK surgery. IOP values before and after surgery were measured using Diaton, Perkins, and noncontact air pulse tonometers.Results. The IOP values before and after LASIK surgery using Perkins tonometer and air tonometers were statistically significant (p<0.05). However, no significant differences were found (p>0.05) for IOP values measured with Diaton tonometer. CCT decreases significantly after surgery (p<0.05) but no statistical differences were found in SCT (p=0.08). Correlations between pre- and postsurgery were found for all tonometers used, withp=0.001andr=0.434for the air pulse tonometer,p=0.008andr=0.355for Perkins, andp<0.001andr=0.637for Diaton.Conclusion. Transpalpebral tonometry may be useful for measuring postsurgery IOP after myopic LASIK ablation because this technique is not influenced by the treatment.

scholarly journals Efficacy and Safety of Timolol-Dorzolamide Fixed-Combination Three Times a Day Versus Two Times a Day in Newly Diagnosed Open Angle Glaucoma

2018 ◽  
Author(s):  
Mohammad Pakravan ◽  
Afsaneh Naderi Beni ◽  
Shahin Yazdani ◽  
Hamed Esfandiari
Keyword(s):  
Blood Pressure ◽  
Primary Open Angle Glaucoma ◽  
Fixed Combination ◽  
Open Angle Glaucoma ◽  
Case Series ◽  
Open Angle ◽  
Newly Diagnosed ◽  
Efficacy And Safety ◽  
The Mean

Purpose: To compare the therapeutic efficacy and safety of dorzolamide/timolol fixed-combination in newly diagnosed primary open angle glaucoma patients. Methods: In this prospective, interventional case series, newly diagnosed primary open angle glaucoma (POAG) patients that had not been treated for glaucoma were included. Patients were started on Cosopt twice a day (BID) for 1 month and then switched to three times a day (TDS) for additional 1 month. Patients underwent comprehensive ophthalmic examination, diurnal intraocular pressure (IOP), blood pressure (BP) and 24-hours heart rate (HR) measurements at baseline, month 1( BID), and month 2( TDS). IOP, systolic and diastolic pressures were measured at 8:00 AM,12:00 AM, 4:00 PM, 8:00 PM and 12:00 PM. Throughout the study, all adverse events were recorded and monitored by the investigators. Results: In 31 POAG patients that completed the study ,mean baseline IOP was 23.1&plusmn;3.15 mmHg . IOP was decreased significantly 16.5 &plusmn; 2.21 at 1 month (P &lt; 0.0001) and 13.9 &plusmn; 2.23 mmHg at 1 and 2 month follow up. (P &lt; 0.0001) IOP was significantly lower in month 2 compared to month 1 (P = 0.0004). While Cosopt BID significantly reduced the mean 24-hour systolic BP and mean 24-hour HR from baseline (P &lt; 0.0001), the mean 24-hour systolic BP and HR remained unchanged 2ith Cosopt TDS compared to BID (P = 0.62). Conclusions: Cosopt TDS has a superior IOP-lowering effect than Cosopt BID in POAG patients with comparable safety profile.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;

scholarly journals Safety and effectiveness of intrastromal corneal ring segment implantation at Al-Dharan Eye Specialist Hospital, Al-Dharan, Saudi Arabia

2019 ◽  
Vol 6 (4) ◽  
pp. 1295
Author(s):  
Abdulaziz Alaqsam ◽  
Mohanna AL-Jindan ◽  
Ammar Almahmod ◽  
Ibrahim Gosadi
Keyword(s):  
Visual Acuity ◽  
Saudi Arabia ◽  
Case Series ◽  
Applanation Tonometry ◽  
Retrospective Case ◽  
Intrastromal Corneal Ring ◽  
Case Series Study ◽  
Ring Segment ◽  
The Mean ◽  
One Year

Background: Intrastromal corneal ring segment (ICRS) implantation is one of the treatment options of keratoconus. This study is aiming to evaluate safety and effectivness of ICRS implantation at Al-Dharan Eye Specialist Hospital.Methods: This study is a descriptive retrospective case series study. The target population of this study is patients diagnosed with corneal ectasia who underwent ICRS implantation in Al-Dharan Eye Specialist Hospital, Al-Dharan, Saudi Arabia. Preoperative and postoperative data about uncorrected visual acuity (UCVA), best spectacle–corrected visual acuity (BSCVA), manifest refraction, keratometry, applanation tonometry, corneal topography, and slit-lamp biomicroscopy and indirect ophthalmoscopy were retrieved from medical records of department of Medical Archive. Paired students t-test was used to compare preoperative and postoperative means of study variables.Results: The total number of recruited patients in this study was 57 patients where 62% of them were males. Sixty-six treated eyes were included in this study where no intra-operative complications were recorded. Upon comparing the mean preoperative data to the mean postoperative data at three months, six months and one year intervals, an overall improvement in the measured outcomes was witnessed. UCVA, BSCVA, and keratometric readings exhibited a statistically significant improvement when comparing preoperative with one-year postoperative findings (p<0.001).Conclusions: The findings of this study indicate that ICRS implantation is a safe and effective treatment for keratoconus.

scholarly journals The Study of Ocular Parameters in Low to Moderate Myopic Chinese Children Age Between Eight to Eighteen-Year-Old

2021 ◽  
Author(s):  
Zhengxuan Li ◽  
Lu Sun ◽  
Hongxin Song
Keyword(s):  
Retrospective Study ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Corneal Endothelial Cell ◽  
Spherical Equivalent ◽  
Corneal Endothelial Cell Density ◽  
The Mean ◽  
Beijing China ◽  
Corneal Diameter

Abstract Purpose: The primary aim of this study was to analyze the distribution of ocular parameters of children aged from eight to eighteen-year-old with low to moderate myopia as well as offer useful information for the design and clinical fitting of ortho-k lens in China.Methods: In this retrospective study, we collected data of 300 subjects (600 eyes) age between eight to eighteen-year-old from the myopic control outpatient clinic at Beijing Tongren Hospital, Beijing, China. The spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), corneal endothelial cell density (CECD)，corneal diameter (CD), simulated K (Sim K) were collected from all the subjects and analyzed. Results: The mean of SE for all subjects was -3.12 ± 1.21D, the median was -3.16D. The mean of AL for all subjects was 24.72 ± 0.83 mm, the median was 24.72 mm. The mean of CCT for all subjects was 537.8 ± 29.82 μm, the median was 538.17 μm. The mean of CECD for all subjects was 3340.3 ± 352.6 cells/mm2, the median was 3357.77 cells/mm2. The mean of ACD for all subjects was 3.71 ± 0.21 mm, the median was 3.69 mm. The mean of CD for all subjects was 12.15 ± 1.67 mm, the median was 12.05 mm. The mean of flat K was 42.80 ± 1.29, the median was 42.81. The mean of steep K was 43.76 ± 1.37, the median was 43.76.Conclusions: This study provided the distribution of ocular parameters to offer useful information for diagnosis of many eye conditions. Meanwhile, the distribution of ocular parameters of children aged from eight to eighteen-year-old with low to moderate myopia is beneficial to make the application of overnight orthokeratology lens more appropriate and effective.

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