scholarly journals A comparison of axial length measurement by using applanation A- Scan and IOL master for accuracy of predicting postoperative refraction

2021 ◽  
Vol 7 (3) ◽  
pp. 477-481
Author(s):  
Harish R Trivedi ◽  
Bhavik C Zala ◽  
Nitesh S Pancholi

The higher cost of IOL master is an issue in developing countries and hence it cannot be widely used for calculation of IOL power in such countries. Thus, the aim of the current study is to evaluate a cheaper alternative for the calculation of IOL power by comparing the axial length measurement obtained using applanation A-scan with that of IOL Master for accuracy of predicting postoperative refraction.A prospective, randomized, comparative study was done with 100 patients who were posted for cataract surgery. The patients were randomly divided into two groups of 50 patients each using computerized random number method. In Group A (n=50) axial length was measured with applanation A-scan and in Group B (n=50) axial length was measured with IOL Master. Before cataract surgery keratometry reading was taken with auto keratometer and intraocular lens (IOL) power calculation was done using SRK 2 formula in all patients. All patients were operated for cataract surgery by phacoemulsification and foldable intraocular lens were implanted in the bag. Postoperatively, best accepted refraction at 8th week was taken and mean spherical equivalent was calculated. 100 patients of cataract were subjected for cataract surgery by phacoemulsification.Corrected spherical equivalent on 8th postoperative week showed: 88% patients in Group A and 96% patients of Group B were within ± 1.00 D.56% patients of Group A and 76% patients of Group B were within ± 0.50 D.There was no statistically significant difference (p > 0.05) in axial length and corrected spherical equivalent between the two groups. There is no extra advantage of IOL Master over applanation A-scan for measuring Axial Length between 21 and 24.50 and predicting post-operative refractive outcome.

2019 ◽  
Vol 34 (2) ◽  
Author(s):  
Sidra Anwar, Atif Mansoor Ahmad, Irum Abbas, Zyeima Arif

Purpose: To compare post-operative mean refractive error with SandersRetzlaff-Kraff/theoretical (SRK-T) and Holladay 1 formulae for intraocular lens (IOL) power calculation in cataract patients with longer axial lengths. Study Design: Randomized controlled trial. Place and Duration of Study: Department of Ophthalmology, Shaikh Zayed Hospital Lahore from 01 January 2017 01 January, 2018. Material and Methods: A total of 80 patients were selected from Ophthalmology Outdoor of Shaikh Zayed Hospital Lahore. The patients were randomly divided into two groups of 40 each by lottery method. IOL power calculation was done in group A using SRK-T formula and in group B using Holladay1 formula after keratomery and A-scan. All patients underwent phacoemulsification with foldable lens implantation. Post-operative refractive error was measured after one month and mean error was calculated and compared between the two groups. Results: Eighty cases were included in the study with a mean age of 55.8 ± 6.2 years. The mean axial length was 25.63 ± 0.78mm, and the mean keratometric power was 43.68 ± 1.1 D. The mean post-operative refractive error in group A (SRK/T) was +0.36D ± 0.33D and in group B (Holladay 1) it was +0.68 ± 0.43. The Mean Error in group A was +0.37D ± 0.31D as compared to +0.69D ± 0.44D in group B. Conclusion: SRK/T formula is superior to Holladay 1 formula for cases having longer axial lengths. Key words: Phacoemulsification, intraocular lens power, longer axial length, biometry.


2018 ◽  
Vol 2018 ◽  
pp. 1-4 ◽  
Author(s):  
Takayuki Baba ◽  
Tomohiro Nizawa ◽  
Toshiyuki Oshitari ◽  
Shuichi Yamamoto

Purpose. To compare the visual and surgical outcomes after a reuse or a replacement of a dislocated in-the-bag intraocular lens (IOL). Methods. This was a retrospective, nonrandomized case series at a single ophthalmological institution. Cases with an in-the-bag dislocation of an IOL were treated by pars plana vitrectomy and the reuse or the replacement of the IOL. The lens was held by intrascleral fixation of the haptics of the IOL under both conditions. The same dislocated IOL was reused in 6 eyes (group A) or it was replaced with another IOL in the other 9 eyes (group B). The pre- and postoperative parameters analyzed included the visual acuity, refractive error, corneal endothelial cell density, and intraocular pressure (IOP). Results. There was no significant difference between the two groups in the postoperative visual acuity (P=0.388), refractive error (P=0.955), IOP (P=0.529), and endothelial cell loss (P=0.940). A breakage or a tilting of the IOL was observed and required replacement in three eyes in the reuse group (P=0.044). Conclusions. Half of the cases with reused in-the-bag dislocated IOL had a breakage or a tilting of the IOL. The replacement of the in-the-bag dislocated IOL is better than the reuse of the IOL with intrascleral haptics fixation.


2020 ◽  
Vol 12 ◽  
pp. 251584142092430
Author(s):  
Carlo Cagini ◽  
Adriana Pellegrino ◽  
Alessia Iannone ◽  
Alessio Cerquaglia ◽  
Antonella Modugno ◽  
...  

Aim: The aim of this study is to compare the efficacy of different dexamethasone eye drops formulations in controlling postoperative inflammation. Methods: Cataract surgery was carried out in 72 patients (35 males) divided into two groups: group A (36 patients, mean age = 78.0 ± 5.6) received four times daily for 2 weeks a suspension containing tobramycin 0.3% mg/ml + dexamethasone 0.1% mg/ml, and group B (36 patients, mean age = 76.2 ± 6.8) a solution containing tobramycin 0.3% mg/ml + dexamethasone 0.1% mg/ml. Both groups received ofloxacin 0.5% four times daily for 7 days, and nepafenac 0.1% three times daily for 3 weeks. Best-corrected visual acuity, intraocular pressure, corneal thickness, endothelial cells count, aqueous flare and macular thickness were evaluated preoperatively and at 1 day, 15 days, 1 and 2 months. Results: In group A, intraocular pressure, corneal thickness and aqueous humour flare values preoperatively and at the end of follow-up were 14.3 ± 1.8 and 13.2 ± 1.8 mmHg, 546.4 ± 34.6 and 539.6 ± 36.1 µm, 11.84 ± 4.44 and 13.52 ± 5.54 ph/ms, respectively, with no statistically significant difference. In group B, intraocular pressure, corneal thickness and aqueous humour flare values preoperatively and at the end of follow-up were 14.3 ± 1.5 and 13.1 ± 1.7 mmHg, 552.9 ± 37.4 and 548.1 ± 39.3 µm, 11.45 ± 4.06 and 13.73 ± 4.99 ph/ms, respectively, with no statistically significant difference. No difference was detected in the macular thickness values in the parafoveal area preoperatively and at 2 months follow-up in group A (332.18 ± 16.19 and 337.71 ± 16.33 µm) and group B (329.11 ± 18.28 and 334.37 ± 20.86 µm), respectively. Conclusion: The two different formulations of dexamethasone eye drops reached the same anti-inflammatory effects.


2018 ◽  
Vol 9 (2) ◽  
pp. 264-268
Author(s):  
Tao Ming Thomas Chia ◽  
Hoon C. Jung

We report a case of patient dissatisfaction after sequential myopic and hyperopic LASIK in the same eye. We discuss the course of management for this patient involving eventual cataract extraction and intraocular lens (IOL) implantation with attention to the IOL power calculation method used.


2021 ◽  
Author(s):  
Beatriz Gargallo-Martinez ◽  
Amanda Ortiz-Gomariz ◽  
Ana Maria Gomez-Ramirez ◽  
Angel Ramon Gutiérrez-Ortega ◽  
Jose Javier Garcia-Medina

Abstract Fuchs endothelial dystrophy (FED) is a bilateral, asymmetric, progressive corneal endothelium disorder that causes corneal edema. Resolution of corneal edema is only possible by corneal transplantation. Cataract surgery is a common surgery that replaces the natural lens of the eye by an artificial intraocular lens (IOL). The IOL-power calculation depends mainly on the anterior corneal keratometry and the axial length. In patients with FED, anterior keratometry may be affected by corneal edema and calculations may be less accurate. Therefore, the aim of this study is to establish the theorical postoperative refractive error due to corneal edema resolution after Descemet stripping endothelial keratoplasty combined with cataract surgery and IOL implantation. For this, anterior keratometry was measure preoperatively with edematous cornea and postoperatively after corneal edema resolution. Both keratometries were compared and used to calculate the respective theorical IOL-powers. The difference between target IOLs was used to establish the theorical refractive error due to corneal edema resolution. The results showed that corneal edema resolution induces a change in anterior keratometry, which affects IOL-power calculations and causes a hyperopic shift. The patients with moderate-to-severe preoperative corneal edema had higher theorical refractive error so their target selection should be adjusted for additional − 0.50D.


2021 ◽  
Vol 17 (2) ◽  
pp. 179
Author(s):  
Eva Imelda ◽  
Feti Karfiati ◽  
Maya Sari Wahyu ◽  
Irawati Irfani ◽  
Primawita Oktarima ◽  
...  

Abstract: Cataract is one of the leading treatable causes of visual impairment in children. Visual rehabilitation is crucial for the development of good visual function after cataract surgery in children. The research aimd to describe post-operative Predictive Refractive Error (PRE) in congenital and developmental cataracts in Cicendo National Eye Hospital from January 2017 to December 2018. This is a retrospective analytic observational study from medical records. We found 107 eyes of 62 children with congenital and developmental cataracts had had cataract surgery and primary implantation of Intraocular Lens (IOL) in Pediatric Ophthalmology and Strabismus Unit, Cicendo National Eye Hospital. The patients were divided into two groups, with axial length (AXL) of ≤ 24 mm and > 24 mm. The paired t-test was used to compare Predictive Error (PE) in SRK/T, SRK II, and Showa SRK formula. Mean age at surgery was 6.7 ± 4.0 years.  Ninety-five eyes had AXL ≤ 24 mm, and 12 eyes had AXL > 24 mm. Prediction Error from patients with AXL ≤ 24 mm was 0.29 D, and from patients with AXL > 24 mm was 2.40 D in SRK/T formula (P < 0.05). There was no significant difference between PE and Absolute Predictive Error (APE) in SRK/T, SRK II, and Showa SRK in patients with AXL > 24 mm (P > 0.05). SRK/T is the most predictable formula in patients with AXL ≤ 24 mm. There is no significant difference in patients with AXL > 24 mm in all formulas. Keywords: congenital and developmental cataract, axial length, Prediction Error, intraocular lens


2019 ◽  
Vol 3 (2) ◽  

Objective: Aim of the study is to Compare the astigmatism induced by a reduced temporal sclerocorneal tunnel incision manual small incision cataract surgery with an extended temporal clear corneal Phacoemulsification of similar width . Methods: A Prospective, randomised controlled study was carried out in 224 selected patients who were again divided into two groups - Group A (112 patients) and Group B (112 patients). Group A patients underwent temporal manual small incision cataract surgery with a 5.5 mm sclerocorneal incision and Group B underwent phacoemulsification by a 2.8 mm clear corneal temporal incision which was extended to 5.5 mm before IOL implantation. In both groups, a 5.25 mm rigid PMMA IOL was implanted in the bag. UCVA and BCVA of both group of patients was quantified and analyzed at 1 week and at 6 weeks Observation: It was seen that the mean surgically Induced astigmatism in group A (N=112) was 0.5625D , which was slightly lesser than that in Group B (N=112) which was 0.65D, although the p-value of 0.26 indicated that there was statistically no significant difference in visual outcomes between the two groups of patients. Here, a p-value of < 0.05 was considered statistically significant. Conclusion: In Skilled and Safe hands, refractive outcomes following performing a 5.5mm temporal sclerocorneal frown-incision manual small incision cataract surgery and a phacoemulsification procedure by a 2.8mm temporal clear corneal incision extended to 5.5mm for implanting a 5.25mm rigid PMMA IOL , are comparable.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jinsoo Kim ◽  
Mee Kum Kim ◽  
Yuseung Ha ◽  
Hae Jung Paik ◽  
Dong Hyun Kim

Abstract Background To evaluate the effects of pretreatment for dry eye disease (DED) on the accuracy of intraocular lens (IOL) power calculation. Methods Patients who underwent uneventful cataract surgery were included in the study. IOL power was determined using the SRK/T and Barrett Universal II (Barrett) formulas. The patients were divided into non-pretreatment and pretreatment groups, and those in the pretreatment group were treated with topical 0.5% loteprednol etabonate and 0.05% cyclosporin A for 2 weeks prior to cataract surgery. Ocular biometry was performed in all groups within 2 days before surgery. The mean prediction error, mean absolute error (MAE), and proportions of refractive surprise were compared between the non-pretreatment and pretreatment groups at 1 month postoperatively. Refractive surprise was defined as MAE ≥ 0.75D. Results In a total of 105 patients, 52 (52 eyes) were in the non-pretreatment group and 53 (53 eyes) in the pretreatment group. The MAE was 0.42 ± 0.33, 0.38 ± 0.34 (SRK/T, Barrett) and 0.23 ± 0.19, 0.24 ± 0.19 in the non-pretreatment and pretreatment groups, respectively (p < 0.001/=0.008). The number of refractive surprises was also significantly lower in the pretreatment group. [non-pretreatment/pretreatment: 9/2 (SRK/T); 8/1 (Barrett); p = 0.024/0.016]. Pretreatment of DED was related to a reduction in postoperative refractive surprise. [SRK/T/Barrett: OR = 0.18/0.17 (95% CI: 0.05–0.71/0.05–0.60), p = 0.014/0.006]. Conclusions The accuracy of IOL power prediction can be increased by actively treating DED prior to cataract surgery.


2020 ◽  
Vol 17 (2) ◽  
pp. 233-242
Author(s):  
Juanita Noeline Chui ◽  
Keith Ong

Purpose: Achieving the desired post-operative refraction in cataract surgery requires accurate calculations for intraocular lens (IOL) power. Latest-generation formulae use anterior-chamber depth (ACD)—the distance from the corneal apex to the anterior surface of the lens—as one of the parameters to predict the post-operative IOL position within the eye, termed the effective lens position (ELP). Significant discrepancies between predicted and actual ELP result in refractive surprise. This study aims to improve the predictability of ELP. We hypothesise that predictions based on the distance from the corneal apex to the mid-sagittal plane of the cataractous lens would more accurately reflect the position of the principal plane of the non-angulated IOL within the capsular bag. Accordingly, we propose that predictions derived from ACD + ½LT (length thickness) would be superior to those from ACD alone. Design: Retrospective cohort study, comparing ELP predictions derived from ACD to aproposed prediction parameter. Method: This retrospective study includes data from 162 consecutive cataract surgery cases, with posterior-chamber IOL (AlconSN60WF) implantation. Pre- and postoperative biometric measurements were made using the IOLMaster700 (ZEISS, Jena, Germany). The accuracy and reliability of ELP predictions derived from ACD and ACD + ½LT were compared using software-aided analyses. Results: An overall reduction in average ELP prediction error (PEELP) was achieved using the proposed parameter (root-mean-square-error [RMSE] = 0.50 mm), compared to ACD (RMSE = 1.57 mm). The mean percentage PEELP, comparing between eyes of different axial lengths, was 9.88% ± 3.48% and −34.9% ± 4.79% for predictions derived from ACD + ½LT and ACD, respectively. A 44.10% ± 5.22% mean of differences was observed (p < 0.001). Conclusion: ACD + ½LT predicts ELP with greater accuracy and reliability than ACD alone; its use in IOL power calculation formulae may improve refractive outcomes.


2021 ◽  
Vol 12 (9) ◽  
pp. 126-129
Author(s):  
Kabindra Bajracharya ◽  
Anjita Hirachan ◽  
Kriti Joshi ◽  
Bimala Bajracharya

Background: In congenital and developmental cataract primary undercorrection of intraocular lens (IOL) power is a common practice. However, long-term refractive status of these children is largely unknown. Aims and Objective: To analyse refractive status after cataract surgery with undercorrected IOL power implantation in congenital and developmental cataract. Materials and Methods: This study was descriptive, retrospective conducted for three years from 1st January 2013 to 31st December 2015. The children (> 6 months to <=7 years of age) who underwent cataract surgery for congenital and developmental cataract with a primary IOL implantation and had reached the age of 8 years were studied. The data were collected in terms of demography, axial length, biometry, IOL implanted, hyperopic correction and postoperative refractive status at 8 years. Results: Total numbers of children operated were 181 with total eyes 288. Unilateral cases were 74 (40.88%) and bilateral 107 (59.12%). Male were 121 (66.85%) and female were 60 (33.15%) with male is to female ratio of 2:1. Right eye was involved in 152 (52.8%) and left eye 136 (47.2%). The mean axial length at the age of one year was 20.75 mm, and gradually increased as age increased which was 22.47 mm at 6 years. The mean biometry was 27.9 diopter (D) at the age of one year which gradually decreased as age increased. Of the total 288 congenital cataract operated, complete follow-up documents were available for 77 (26.74%) eyes up to 8 years which showed emmetropia achieved in 25.97%, myopia in 28.57% and hypermetropia in 45.45%. Conclusion: Primary IOL implantation with hyperopic correction is accepted practice in congenital and developmental cataract. Emmetropia can be achieved however some hyperopic or myopic refractive status at the age of 8 years is not a surprise. Myopic shift continues as the age increases. Parent awareness for early detection and surgery, optical correction and regular follow-up are essential for good outcome.


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