scholarly journals Quantification of Ocular Parameters To Create An Anatomical Eye Model for The Japanese Population

Author(s):  
Takushi Kawamorita ◽  
Hiroshi Uozato ◽  
Tetsuro Oshika ◽  
Kazuno Negishi ◽  
Takashi Fujikado ◽  
...  

Abstract This prospective observational study aimed to evaluate the eye shape and visual function of Japanese people through a multicenter approach and to create a Japanese model eye. Uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) in the log minimum angle of resolution (logMAR), subjective and objective spherical equivalent values (SE) of ocular refraction, anterior and posterior corneal curvature (ACC and PCC, respectively), anterior and posterior corneal asphericity (ACA and PCA, respectively), central corneal thickness (CCT), anterior chamber depth (ACD), and ocular axial length (AL) were measured in the eyes of 250 participants (mean age = 46.5 ± 18.0 years, range: 20–90 years) across five institutions in Japan. The mean UDVA, CDVA, subjective SE, objective SE, ACC, PCC, ACA, PCA, CCT, ACD, and AL were 0.68, -0.08, -2.42 D, -2.66 D, 7.77 mm, 6.33 mm, -0.31, -0.39, 0.55 mm, 2.92 mm, and 24.78 mm, respectively. Age-related changes and sex-based differences were observed in the visual acuity, refraction, corneal shape, ACD, and AL. Although the sample size needs to be increased, the results of this study can be applied to the development of refractive correction methods and various vision-related fields.

2021 ◽  
pp. 112067212110528
Author(s):  
Abdelrahman Salman ◽  
Ali Ali ◽  
Shaaban Rafea ◽  
Rana Omran ◽  
Buraa Kubaisi ◽  
...  

Aim To evaluate the long-term outcomes of corneal cross-linking (CXL) in patients with progressive keratoconus. Method In this retrospective non-comparative study, forty-five eyes of 31 patients with progressive keratoconus were treated with 30 min “epi-off” corneal cross-linking. The visual, refractive, topographic and tomographic outcomes were evaluated preoperatively and at least 10 years after cross-linking. Results Ten years post-corneal cross-linking, the mean anterior maximum keratometry decreased (−2.10 ± 3.25 D, P = 0.0001). Conversely, the posterior maximum keratometry increased (6.38 ± 9.79 D, P = 0.065). Both uncorrected and corrected distance visual acuity improved (LogMAR −0.08 ± 0.30) and (LogMAR −0.05 ± 0.21), respectively (P > 0.05, both). A statistically significant hyperopic shift was observed postoperatively (0.70 ± 1.31 D, P = 0.0009). The anterior topographic cylinder values revealed no change (−0.17 ± 1.31 D, P = 0.3), whereas the mean posterior cylinder values decreased (absolute value increased) significantly compared to baseline from −1.31 ± 0.97 D to −1.82 ± 1.78 D, (P < 0.05). The minimum corneal thickness values decreased significantly (−35.11 ± 48.63 µm, P = 0.0001). Four eyes (8.8%) showed more than 1 D increase in the anterior maximum keratometry. Conclusion This protocol and duration of Epi-off corneal cross-linking was found to be effective in halting keratoconus progression over the follow up period (10 years). Anterior corneal flattening and a hyperopic shift were observed. A statistically significant increase in the posterior corneal cylinder was observed. Although, not reaching statistical significance, the logMAR uncorrected and corrected visual acuity were improved.


2021 ◽  
Vol 7 (3) ◽  
pp. 466-470
Author(s):  
Sharah Rahman ◽  
Jalal Ahmed ◽  
Anisur Rahman ◽  
Ishtiaque Anwar ◽  
Tarzia Asma Zafrullah ◽  
...  

: To assess the impact on intraocular pressure (IOP) after Phacoemulsification (PE) with Posterior Chamber Intraocular Lens (PCIOL) implantation and its relation with ocular biometric parameters. The study was a prospective observational study included 524 eyes with normal IOP (11-21 mmHg) who underwent uneventful Phacoemulsification with PCIOL Implantation surgery for age-related cataract. IOP, Central Corneal Thickness (CCT), Anterior Chamber Depth (ACD), Axial Length (AL) were measured pre-operatively and one month post-operatively by Goldman Applanation Tonometer, Corneal Pachymeter and Optical Coherence Biometer, respectively. The post-operative IOP change and its relation with preoperative biometric parameters were determined.: The mean pre-operative and post-operative IOP was 13.44±1.98 & 11.54±1.66mmHg, respectively, with an average IOP reduction after one month of 1.90±0.61mmHg. The mean pre-operative and post-operative ACD was 3.27±0.24 and 3.66±0.27 mm, respectively, with an average increase of 0.39 ±0.3 mm. Paired t-test showed post-operative IOP reduction was significantly associated with preoperative IOP (p&#60;0.001) and ACD (p&#60;0.001). But CCT and AL were not significantly associated. The linear regression analysis confirmed the proportional reduction of post-operative IOP, r 0.921. So 92.1% of the preoperative IOP is proportional to post-operative IOP reduction. The graphical representation shows more the pre-operative IOP, more the post-operative IOP reduction.: IOP is significantly reduced, and ACD increased after PE with PCIOL implantation surgery and is associated with post-operative IOP reduction. The post-operative IOP reduction is proportional to pre-operative IOP, and more the preoperative IOP, more the post-operative IOP reduction.


2020 ◽  
pp. bjophthalmol-2019-315260 ◽  
Author(s):  
Mi Tian ◽  
Weijun Jian ◽  
Xiaoyu Zhang ◽  
Ling Sun ◽  
Xingtao Zhou

PurposeTo investigate the long-term safety and efficacy of accelerated transepithelial corneal cross-linking (ATE-CXL) in children with progressive keratoconus.MethodsFifty-three eyes of 41 paediatric patients (34 boys, 7 girls; mean age 14.81±1.96 years) undergoing ATE-CXL were enrolled in the study. Corrected distance visual acuity (CDVA) and manifest refraction were assessed preoperatively and 36 months postoperatively. Corneal keratometry, corneal thickness and posterior elevation were measured using Pentacam preoperatively and 1, 6, 12 and 36 months postoperatively. Pachymetry and epithelial thicknesses were measured using optical coherence tomography preoperatively and 6, 12, and 36 months postoperatively.ResultsThirty-six months postoperatively, CDVA improved from 0.32±0.28 to 0.26±0.25 in logarithm of the minimum angle resolution (p=0.025). Maximum keratometry was 58.73±9.70 D preoperatively and 59.20±10.24, 58.28±9.33, 57.88±9.99 and 58.98±10.79 D at 1, 6, 12 and 36 months postoperatively throughout the 36-month follow-up period (p>0.05). Similarly, corneal central thickness, which was 492.42±33.83 µm postoperatively, also remained stable during the 36-month follow-up (p>0.05). Both posterior central elevation and posterior highest elevation were stable at 12 months after ATE-CXL (p>0.05), but increased at 36 months postprocedure (p<0.05). Corneal pachymetry and epithelial thicknesses remained stable throughout the follow-up period (p>0.05).ConclusionsATE-CXL is a safe and effective treatment in paediatric progressive keratoconus patients, leading to stable keratometry and corneal thickness throughout the 36-month follow-up.


Author(s):  
Paulo Ferrara ◽  
Leonardo Torquetti ◽  
Guilherme Ferrara

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.


2018 ◽  
Vol 29 (6) ◽  
pp. 615-620
Author(s):  
Medine Yilmaz Dag ◽  
Filiz Afrashi ◽  
Serhad Nalcaci ◽  
Jale Mentes ◽  
Cezmi Akkin

Purpose: To evaluate the efficacy of the IOL-Vip Revolution telescopic intraocular lens in age-related macular degeneration patients. Methods: A total of 13 eyes of 12 age-related macular degeneration patients with senile cataract were enrolled. Selection of the patients was done by means of a low vision diagnostic and rehabilitative program (IOL-Vip software) that evaluates residual visual function. After standard phacoemulsification surgery, the incision site was enlarged and the IOL-Vip Revolution system was implanted in the capsular bag. The outcome measures were best corrected visual acuity, contrast sensitivity, anterior chamber depth, endothelial cell density, central corneal thickness, and quality-of-life questionnaire. Results: The mean age of the subjects was 72.3 ± 8.5 years. The mean positive power of the intraocular lens was 59 ± 2 D and the negative intraocular lens power was standard (–46 D). Pre- and postoperative best corrected visual acuity were 1.08 ± 0.14 and 0.81 ± 0.16 logMAR in the operated eye and 1.13 ± 0.36 and 1.01 ± 0.40 logMAR in the unoperated eye, respectively. The best corrected visual acuity was increased significantly in both operated and unoperated eyes (p = 0.005 and 0.021, respectively). Quality of life and anterior chamber depth increased significantly (p = 0.018 and 0.008, respectively), while endothelial cell density decreased (p = 0.002). No significant differences were detected in central corneal thickness or contrast sensitivity (p = 0.133 and 0.684, respectively). Conclusion: The results showed that IOL-Vip Revolution telescopic intraocular lens is a promising treatment option in age-related macular degeneration patients. The rehabilitation program may have an important role in the restored clinical results, which also provided visual improvement in the unoperated eyes.


Author(s):  
Pablo F Rodrigues ◽  
Wagner G Dias

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.


2017 ◽  
Vol 27 (4) ◽  
pp. 454-459 ◽  
Author(s):  
Behrad Samadi ◽  
Mats Lundström ◽  
Maria Kugelberg

Purpose To identify and evaluate possible causes of poor patient-reported visual function after cataract surgery. Methods We obtained retrospective data from the Swedish National Cataract Register on patient self-assessed visual function before and after cataract surgery based on the Catquest-9SF questionnaire. We identified patients who self-reported similar or more difficulties postoperatively than preoperatively, and looked at possible causative variables such as sex, age, preoperative and postoperative corrected distance visual acuity (CDVA) and refractive errors, and ocular comorbidity. Results Nearly 75% of the 119 patients identified had a better postoperative CDVA; the mean CDVA increased by over 0.2 logarithm of the minimum angle of resolution visual acuity. Patients with low or high preoperative CDVA had poor self-assessed outcomes postoperatively. Younger patients (52-68 years) had a lower self-assessed outcome than more elderly patients. Surgical complications and poor near vision yielded lower outcomes. Anisometropia, ocular comorbidity, and sex did not significantly affect the outcome in this specific group. Conclusions Patients content with their visual function despite the presence of a cataract should defer surgery. This may also include patients younger than 68 years with good visual function. Detailed information given to the patients about their ophthalmic condition, the surgical procedure and risks, and the eventual need for reading glasses postoperatively may result in higher self-assessed visual function outcomes among patients.


2021 ◽  
pp. 112067212110183
Author(s):  
Yasin Cinar ◽  
Cagla Cilem Han ◽  
Alparslan Sahin ◽  
Zeba A Syed

Purpose: To evaluate the long term visual, refractive, and corneal tomographic outcomes of epithelium-off accelerated corneal collagen cross-linking (ACXL) in the management of pediatric keratoconus (KC). Methods: This retrospective study included patients under 18 years old with progressive KC who underwent ACXL between 2012 and 2019 at Dicle University Hospital. Complete ophthalmic examination was performed including uncorrected distance visual acuity (UDVA), best spectacle-corrected distance visual acuity (CDVA), manifest refraction, and corneal tomography. Evaluations were performed preoperatively and at 6 months intervals postoperatively. Results: Forty-nine eyes of 49 patients were included in the study. The mean age of patients at the time of ACXL was 14.2 ± 1.8 (range: 9.5–17.3) years. Mean follow up was 4.61 ± 1.90 (range: 2.0–8.1) years. The mean LogMAR UDVA improved from 0.94 ± 0.41 to 0.81 ± 0.43, 0.69 ± 0.41, and 0.67 ± 0.33 after 1, 3, and 5 years respectively ( p = 0.001). The mean LogMAR CDVA improved from 0.58 ± 0.36 to 0.46 ± 0.31, 0.34 ± 0.23, and 0.39 ± 0.27 after 1, 3, and 5 years respectively ( p = 0.015). The mean refractive cylinder improved significantly from 6.01 ± 2.07 diopters (D) to 5.46 ± 1.87, 5.38 ± 2.18, and 5.02 ± 2.31 D after 1, 3, and 5 years respectively ( p = 0.005). As compared to preoperative values, steep keratometry and maximum keratometry were not significantly different ( p = 0.805 and 0.448, respectively) following ACXL, while flat keratometry significantly improved after ACXL ( p = 0.012). Although central corneal thicknesses decreased significantly ( p = 0.029), the decrease in thinnest corneal thickness was not statistically significant ( p = 0.205). Conclusion: Epithelium-off ACXL seems to be effective for halting KC progression with long term clinical benefits in pediatric patients.


2021 ◽  
pp. 112067212110206
Author(s):  
Iliya Simantov ◽  
Lior Or ◽  
Inbal Gazit ◽  
Biana Dubinsky-Pertzov ◽  
David Zadok ◽  
...  

Background: Retrospective cohort study evaluating long term keratoconus progression amongst cross-linking (CXL) treated pediatric patients in the treated and the fellow untreated eyes. Methods: Data on 60 eyes of 30 patients, 18 years old or younger, who underwent CXL in at least one eye was collected and analyzed. Follow-up measurements taken from the treated and untreated eye up to 7 years after CXL treatment, were compared to baseline measurements. Parameters included uncorrected distance visual acuity (UCDVA), best-corrected spectacle visual acuity (BCSVA), manifest refraction, pachymetry, corneal tomography, and topography. Results: Mean age of patients was 16 ± 2.1 years. For the treated eyes, during follow-up period mean UCDVA had improved (from 0.78 ± 0.22 at baseline to 0.58 ± 0.26 logMAR at 7 years; p = 0.13), as well as mean BCSVA (from 0.23 ± 0.107 at baseline to 0.172 ± 0.05 logMAR at 7 years; p = 0.37). The mean average keratometry showed a significant flattening (from 49.95 ± 4.04 to 47.94 ± 3.3 diopters (D); p < 0.001), However there was no change in the mean maximal keratometry. The mean minimal corneal thickness (MCT) showed a significant mild reduction of 26 µm ( p = 0.006). Although statistically insignificant, the mean manifest cylinder was also reduced to 2D ( p = 0.15). During the follow-up period, eight untreated eyes (26.6%) deteriorated and underwent CXL, while only one treated eye (3.33%) required an additional CXL. Conclusion: CXL is a safe and efficient procedure in halting keratoconus progression in the pediatric population, the fellow eye needs to be carefully monitored but only a 25% of the patients will require CXL in that eye during a period of 7 years.


2021 ◽  
pp. 112067212110637
Author(s):  
Victor A Augustin ◽  
Hyeck-Soo Son ◽  
Isabella Baur ◽  
Ling Zhao ◽  
Gerd U Auffarth ◽  
...  

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.


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