Read by QxMD icon Read

IOL power calculation

Rick Potvin, Brent A Kramer, David R Hardten, John P Berdahl
PURPOSE: To analyze intraocular lens (IOL) orientation data from an online toric back-calculator ( for determining if differences were apparent by lens type. METHODS: A retrospective review of toric back-calculations that included IOL identification and intended orientation axis. RESULTS: Of 12,812 total validated calculation records, 8,229 included intended orientation and lens identification data. Of the latter, 5,674 calculations (69%) involved lenses oriented 5° or more from their intended position...
2016: Clinical Ophthalmology
Pelin Özyol, Erhan Özyol, Ercan Baldemir
PURPOSE: Since age-related changes in lens elasticity and ciliary muscle contractility can affect how ocular parameters respond to cycloplegia, intraocular lens (IOL) power measurements calculated by formulas using anterior chamber depth (ACD), lens thickness (LT) or white-to-white (WtW) for effective lens position prediction can vary. In response, using swept-source optical biometry in pre-presbyopic and presbyopic eyes, we investigated changes in ocular parameters and IOL power calculations due to cycloplegia...
October 1, 2016: American Journal of Ophthalmology
Bin Zhang, Jing-Xue Ma, Dan-Yan Liu, Cong-Rong Guo, Ying-Hua Du, Xiu-Jin Guo, Yue-Xian Cui
AIM: To evaluate the effects of posterior corneal surface measurements on the accuracy of total estimated corneal astigmatism. METHODS: Fifty-seven patients with toric intraocular lens (IOL) implantation and posterior corneal astigmatism exceeding 0.5 diopter were enrolled in this retrospective study. The keratometric astigmatism (KA) and total corneal astigmatism (TA) were measured using a Pentacam rotating Scheimpflug camera to assess the outcomes of AcrySof IOL implantation...
2016: International Journal of Ophthalmology
Tomasz Choragiewicz, Robert Rejdak, Andrzej Grzybowski, Katarzyna Nowomiejska, Joanna Moneta-Wielgoś, Małgorzata Ozimek, Anselm G M Jünemann
Purpose. To evaluate the indications, refraction, and visual and safety outcomes of iris-claw intraocular lens implanted retropupillary with sutureless technique during primary or secondary operation. Methods. Retrospective study of case series. The Haigis formula was used to calculate intraocular lens power. In all cases the wound was closed without suturing. Results. The study comprised 47 eyes. The mean follow-up time was 15.9 months (SD 12.2). The mean preoperative CDVA was 0.25 (SD 0.21). The final mean CDVA was 0...
2016: Journal of Ophthalmology
Ahmet Kirgiz, Kurşat Atalay, Havva Kaldirim, Kubra Serefoglu Cabuk, Mehmet Orcun Akdemir, Muhittin Taskapili
The purpose of this study was to compare the keratometry (K) values obtained by the Scheimpflug camera combined with placido-disk corneal topography (Sirius) and optical biometry (Lenstar) for intraocular lens (IOL) power calculation before the cataract surgery, and to evaluate the accuracy of postoperative refraction. 50 eyes of 40 patients were scheduled to have phacoemulsification with the implantation of a posterior chamber intraocular lens. The IOL power was calculated using the SRK/T formula with Lenstar K and K readings from Sirius...
September 1, 2016: International Ophthalmology
Ken Hayashi, Soichiro Ogawa, Motoaki Yoshida, Koichi Yoshimura
PURPOSE: To examine whether intraocular lens (IOL) power prediction error (PE) after cataract surgery differs according to patient age. DESIGN: Prospective cohort study. METHODS: We consecutively enrolled 75 eyes of 75 patients 59 years of age or younger, and 150 eyes of 150 patients in each of 3 age groups (60-69, 70-79, and 80-89 years), for whom phacoemulsification and implantation of a single-piece acrylic IOL was planned. The IOL power was calculated using the optimized SRK/T formula...
October 2016: American Journal of Ophthalmology
Douglas D Koch
PURPOSE: To review the progress and challenges in obtaining accurate corneal power measurements for intraocular lens (IOL) calculations DESIGN: Personal perspective, review of literature, case presentations, and personal data METHODS: Using literature review findings, case presentations, and data from the author's center, the types of corneal measurement errors that can occur in IOL calculation are categorized and described, along with discussion of future options to improve accuracy...
August 22, 2016: American Journal of Ophthalmology
Jia-Kang Wang, Shu-Wen Chang
The aim of this study was to compare the refractive errors after uneventful phacoemulsification and intraocular lens implantation in the cases of vitrectomized eyes and non-vitrectomized eyes. Vitrectomized eyes were divided into 2 groups: vitrectomy alone as Group 1, vitrectomy with gas tamponade as Group 2. Normal-controlled eyes were categorized as Group 3. Intraocular lens (IOL) power calculation and the measurements of axial length (AL) and keratometric value (K) were performed using the IOLMaster and the Haigis and SRK/T formula as subgroup A and B...
August 25, 2016: International Ophthalmology
Bharkbhum Khambhiphant, Suganlaya Sasiwilasagorn, Nattida Chatbunchachai, Krit Pongpirul
PURPOSE: The purpose of this study was to evaluate the effect of pupillary dilation on the Haigis formula-calculated intraocular lens (IOL) power and ocular biometry measurements by using IOLMaster(®). METHODS: A prospective study was performed for biometry measurements of 373 eyes of 192 healthy subjects using the IOLMaster at the outpatient department of King Chulalongkorn Memorial Hospital from February 2013 to July 2013. The axial length (AL), anterior chamber depth (ACD), keratometry (K), and IOL power were measured before and after 1% tropicamide eye drop instillation...
2016: Clinical Ophthalmology
Youngsub Eom, Dongok Ryu, Dae Wook Kim, Seul Ki Yang, Jong Suk Song, Sug-Whan Kim, Hyo Myung Kim
BACKGROUND: To evaluate the toric intraocular lens (IOL) calculation considering posterior corneal astigmatism, incision-induced posterior corneal astigmatism, and effective lens position (ELP). METHODS: Two thousand samples of corneal parameters with keratometric astigmatism ≥ 1.0 D were obtained using bootstrap methods. The probability distributions for incision-induced keratometric and posterior corneal astigmatisms, as well as ELP were estimated from the literature review...
October 2016: Graefe's Archive for Clinical and Experimental Ophthalmology
Kenneth J Hoffer, Peter C Hoffmann, Giacomo Savini
PURPOSE: To investigate agreement between the IOLMaster 700 based on swept-source optical coherence tomography (SS-OCT) and the Lenstar LS 900 based on optical low-coherence reflectometry (OLCR). SETTING: Private practice, Castrop-Rouxelle, Germany. DESIGN: Prospective evaluation of diagnostic test. METHODS: Axial length (AL), keratometry (K), anterior chamber depth (corneal epithelium to lens) (ACD), lens thickness, and central corneal thickness (CCT) were measured in 183 eyes of 183 patients...
August 2016: Journal of Cataract and Refractive Surgery
David L Cooke, Timothy L Cooke
PURPOSE: To evaluate the accuracy of 9 intraocular lens (IOL) calculation formulas using 2 optical biometers. SETTING: Private practice, Saint Joseph, Michigan, USA. DESIGN: Retrospective consecutive case series. METHODS: Nine IOL power formula predictions with observed refractions after cataract surgery were compared using 1 IOL platform. The performance of each formula was ranked for accuracy by machine and by axial length (AL)...
August 2016: Journal of Cataract and Refractive Surgery
V Vasavada, S K Shah, V A Vasavada, A R Vasavada, R H Trivedi, S Srivastava, S A Vasavada
PurposeTo evaluate and compare the accuracy of modern intraocular lens (IOL) power calculation formulae in pediatric eyes and compare prediction error (PE) obtained with manufacturer's vs personalized lens constant.Patients and methodsAn observational case study was conducted in 117 eyes (117 patients) undergoing pediatric cataract surgery with IOL implantation. PE was calculated as predicted refraction minus actual postoperative refraction, and absolute PE as absolute difference independent of the sign, (APE)=predicted refraction minus actual postoperative refraction...
September 2016: Eye
Rubina Rahman, Simon Kolb, Chun Xiao Bong, John Stephenson
PURPOSE: To evaluate the accuracy of user-adjusted axial length (AL) measured by optical biometry for intraocular lens (IOL) calculations in eyes having combined phacovitrectomy for macula-off rhegmatogenous retinal detachment (RRD). SETTING: Ophthalmology Department, Calderdale Royal Hospital, Halifax, United Kingdom. DESIGN: Retrospective case series. METHODS: Consecutive eyes having phacovitrectomy for macula-off RRD were evaluated...
July 2016: Journal of Cataract and Refractive Surgery
C Samarawickrama, Y-C Li, N Kanapathipillai, J R Grigg
PurposeTo present longer-term refractive and ocular health outcomes for patients who had primary intraocular lens (IOL) insertion following infant cataract surgery.Patients and methodsA retrospective review of all infant cataract cases at a tertiary children's hospital between 2003 and 2006 was conducted. Surgery was performed before 12 months of age. IOL power was calculated using the SRK/T formula targeting hyperopia based on the child's age; children under 3 months were targeted at +9.0 D, between 3 and 6 months at +6...
September 2016: Eye
Jack X Ma, Maolong Tang, Li Wang, Mitchell P Weikert, David Huang, Douglas D Koch
PURPOSE: To evaluate the accuracy of the optical coherence tomography-based (OCT formula) and Barrett True K (True K) intraocular lens (IOL) calculation formulas in eyes with previous radial keratotomy (RK). METHODS: In 95 eyes of 65 patients, using the actual refraction following cataract surgery as target refraction, the predicted IOL power for each method was calculated. The IOL prediction error (PE) was obtained by subtracting the predicted IOL power from the implanted IOL power...
July 1, 2016: Investigative Ophthalmology & Visual Science
Yunus Karabela, Mustafa Eliacik, Faruk Kaya
BACKGROUND: The SRK/T formula is one of the third generation IOL calculation formulas. The purpose of this study was to evaluate the performance of the SRK/T formula in predicting a target refraction ±1.0D in short and long eyes using ultrasound biometry after phacoemulsification. METHODS: The present study was a retrospective analysis, which included 38 eyes with an AL < 22.0 mm (short AL), and 62 eyes ≥24.6 mm (long AL) that underwent uncomplicated phacoemulsification...
2016: BMC Ophthalmology
Michael Schultz, Uwe Oberheide, Omid Kermani
PURPOSE: To test whether keratometry (K) and astigmatism measurements provided by the Verion Reference Unit (an image-guided system) compared well with the Tonoref II automated tonometer-refractometer, IOLMaster partial coherence interferometry (PCI) biometer, AL-Scan optical biometer, Pentacam rotating Scheimpflug camera, and OPD Scan III wavefront aberrometer. SETTING: Augenklinik am Neumarkt, Cologne, Germany. DESIGN: Retrospective case series...
June 2016: Journal of Cataract and Refractive Surgery
Leonie J van der Geest, Martin J Siemerink, Marco Mura, Maarten P Mourits, Ruth Lapid-Gortzak
PURPOSE: To evaluate the refractive accuracy of intraocular lens (IOL) power calculation after phacovitrectomy. SETTING: Eye Hospital Zonnestraal and Department of Ophthalmology Academic Medical Center, Amsterdam, the Netherlands. DESIGN: Retrospective comparative case series. METHODS: Refraction results 1 month after phacovitrectomy or phacoemulsification were compared with predicted refractions calculated using the IOLMaster 500 and the Haigis formula...
June 2016: Journal of Cataract and Refractive Surgery
Michael G Woodcock, Robert Lehmann, Robert J Cionni, Michael Breen, Maria C Scott
PURPOSE: To compare astigmatic outcomes in patients with bilateral cataracts having toric intraocular lens (IOL) implantation with intraoperative aberrometry measurements in 1 eye and standard power calculation and a toric IOL calculator with inked axis marking in the contralateral eye. SETTING: Twelve sites in the United States. DESIGN: Prospective cohort study. METHODS: The eye with the more visually significant cataract was randomized to intraoperative aberrometry measurements (Ocular Response Analyzer with Verifeye) or standard preoperative biometry and use of a toric calculator with the contralateral eye automatically assigned to the other group...
June 2016: Journal of Cataract and Refractive Surgery
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"