Background: One of the reasons that the power of intraocular lens (IOL) after Photorefractive keratectomy (PRK) report lower than the actual amount is an error of measurement of refractive power of cornea by corneal topography system and keratometers. There are Different devices with different accuracy for postoperative keratometry. It is necessary to use a more accuare device. This study aimed to compare IoL-Master keratometer with Zhaval keratometer.Methods: This clinical trial was a prospective study on patients referred for PRK. 35 patients aged 20 to 30, were randomly chosen. Keratometery was done by Zhaval (, china GM300) and the IOL Master system. Three months after PRK another keratometry was done for all of the patients with both devices by an 5 minutes interval. The differences between postoperative clinical history method with IOL Master keratometry and Zhaval keratometry was calculated. SPSS version 16 was used for data analysis and paired t-test and student t-test were performed.Finding: 70 eyes of 35 patients included 10 males and 25 females were studied. The mean age of patients was 23.45±1.55 years. The difference between postoperative keratometry using IOL Master with keratometry from CHM compared with the difference between Zhaval keratometer from CHM was statistically significant. There was a Significant direct relationship between IOL master keratometry and CHM method (0.86 but Zhaval keratometry had not a significant correlaton with CHM.Conclusion: The result of this study showed that the method obtained by IOL Master are much closer to the CHM, therfor is recommended that for postoperative PRK keratometry IOL Master device should be used.

Purpose: To evaluate anterior chamber depth (ACO) measurement validity by Orbscan II and IOL Master in comparison to A-scan as a standard and to determine ACO measurement repeatability with Orbscan II.Materials & Methods: Forty-four myopic patients (88 eyes), scheduled for refractive surgery, were enrolled in this prospective study. In all eyes, the ACO was measured with A-Scan (EchoScan US-3300, Nidek), Orbscan II (Orbtek), and IOL Master (Carl Zeiss) by three independent technicians. The mean (±SO) age and spherical equivalent were 30.2±8.5 years and -4.98±2.67 0 (range, -1.00 to -15.00), respectively. The female percentage was 56.8%. To evaluate the validity, Orbscan II and IOLMaster readings were compared with those of A-scan as a standard. To evaluate Orbscan II reliability, each eye was examined twice consecutively and the reliability coefficient was calculated.Results: The mean difference between Orbscan II and A-scan ACO measurements was -0.025±0.12mm, with 95% limits of agreement from -0.25 to +0.20 mm. Corresponding figures for IOL Master and A-scan measurements were +0.093±0.14mm with 95% limits of agreement from -0.18 to +0.36mm. Based on these results, Orbscan II readings were lower and those of IOLMaster were higher than A-scan readings on average. Both Orbscan II and IOLMaster had acceptable agreement with A-Scan in measuring ACO, although the agreement between IOL Master and A-Scan was lower.The Pearson coefficient of Orbscan measuring ACO was 0.994 (P<0.001), which shows quite good reliability.Conclusion: Orbscan II ACO measurements in myopic patients showed better agreement with ultrasonic values than IOL Master. Both Orbscan II and IOL Master provide advantages of a non-contact method and their ACO measurements seem valid enough to consider them suitable devices for measuring the ACO.

Purpose: To investigate the differences and limits of agreement in measuring corneal thickness using Pentacam, Corvis, and intraocular lens (IOL)‑, Master 700 devices. Methods: This study was conducted on 37 right eyes of 21 males and 16 females (n = 37) with a mean age of 52. 11 ±,6. 30 years. The central corneal thickness was measured using three optical biometric devices, including Pentacam, Corvis, and IOL‑, Master 700. The inclusion criteria were normal eyes without any ophthalmological abnormalities, history of ocular pathology, or ocular surgery. The data obtained from these three devices were compared two by two. The correlation and agreement limits among them were analyzed using statistical techniques. Results: The mean standard deviation differences between Pentacam and Corvis, Pentacam and IOL‑, Master 700, as well as Corvis and IOL‑, Master 700 regarding the corneal thickness measurement, were 22. 13 ±,8. 05, 7. 91 ±,8. 02, and 14. 21 ±,9. 85 µ, m, respectively, which were statistically significant (P < 0. 0001). Based on the investigation of the limits of agreement according to the Bland Altman method, the corresponding values between Pentacam and Corvis, Pentacam and IOL‑, Master 700, and Corvis and IOL‑, Master 700 were ‑, 16. 2 to +15. 4, ‑, 15. 8 to +16. 3, and ‑, 20. 1 to +20. 0 µ, m, respectively. Furthermore, the correlation coefficients of the measurements obtained by Pentacam and Corvis, Pentacam and IOL‑, Master 700, as well as Corvis and IOL‑, Master 700 were determined 0. 957, 0. 964, and 0. 948, respectively (P < 0. 0001). Conclusion: The results from this study indicate that the interchangeable use of these three devices is not appropriate due to statistically significant differences and broad limits of agreement among the three devices, especially between Corvis and IOL‑, Master 700.

Purpose: To compare AcrySof IQ and Sensar intraocular lens (IOLs) in terms of spherical aberration and contrast sensitivity.Methods: Thirty-four eyes of 34 patients undergoing phacoemulsification cataract surgery were randomly assigned for implantation of AcrySof IQ or Sensar IOLs. Three months postoperatively, bestcorrected visual acuity (BCVA), spherical aberration (with 4 and 6 mm pupil diameters) and contrast sensitivity under photopic and mesopic conditions at spatial frequencies of 1, 2, 5, 10 and 20 cycles per degree (cpd) were determined.Results: Patients included 21 male (61.8%) and 13 female (38.2%) subjects. Mean BCVA was 0.083±0.071 logMAR in the IQ group and 0.145±0.097 logMAR in the Sensar group (P=0.079). Spherical aberration with both 4 and 6 mm pupil diameters in the IQ group was less than in the Sensar group (0.183±0.107 mm vs 0.354±0.138mm, P<0.001 and 0.26±0.096mm vs 0.435±0.152mm, p=0.002; respectively). Contrast  sensitivity was higher in the IQ group at 1, 2, 5, 10 and 20 cpd under photopic conditions and at 1, 10 and 20 cpd under mesopic conditions (P<0.02).Conclusion: AcrySof IQ aspheric IOL seems to have better visual outcomes regarding spherical aberration and contrast sensitivity as compared to spheric Sensar IOL.

Purpose: To assess Hoffer correction factor in measurement of axial length (AL) in eyes with phakic IOL implants. Methods: In this descriptive historical cohort study, axial length was measured by ultrasound (US) and IOL Master in both phakic and pseudophakic modes in 24 eyes of 14 patients with Artisan intraocular lenses (IOLs) implanted for refractive purposes, Hoffer's suggested formula for correcting ultrasound AL was applied to the data (cor-US) and all four datasets were compared to preoperative ultrasound AL values as standards.Results: The mean difference between preoperative ultrasound measurements and postoperative readings by US (ALpo), IOLMaster in phakic mode (AL IOLMp), IOL Master in pesudophakic mode (AL IOLMpp) and US corrected with Hoffer factor (ALhc), were 0.01, 0.022, 0.13, and 0.61mm, with mean absolute differences of 0.23, 0.23, 0.26, and 0.25mm, respectively. In these readings, respectively 42.3%, 37.5%, 57.5%, and 46.2% of differences were greater than 0.2 mm, which is considered to be clinically important. Discussion: Use of the Hoffer correction factor has no clinical application for a more accurate biometry in patients with an Artisan implant. The most reliable method in this type of patients is making an accurate record of their preoperative AL measured with ultrasound or IOL Master.

Purpose: To compare the results of the current gold standard, laser interferometry, and keratometry by the IOL-Master, with a newly developed Galilei G6 using raytracing software Okulix for intraocular lens (IOL) power calculations. Methods: For comparison of the IOL-power calculation of both devices, we analyzed the difference between the actual one-month postoperative subjective refraction and the theoretically calculated target refraction before cataract surgery. The IOL was selected according to the IOL Master recommendation aiming for emmetropia after surgery. We analyzed the differences of the measurements of the basic biometric data in 205 healthy eyes by each device. Results: Our study included 205 healthy, unoperated eyes from 117 patients (61 women, 56 men) aged 20 to 75 years. Twenty-two eyes of cataract patients were also included in this retrospective study design. The mean difference between the prediction of the postoperative refraction and the refraction actually achieved was 0. 03 D for the IOL Master and –0. 23 D for the Galilei G6. The difference was not statistically significant (P = 0. 059). The difference between the IOL power calculation of the IOL Master and the calculation of the G6 was not statistically significant (P = 0. 064). The difference between the predicted refraction of the G6 and the refraction achieved after one month was also not statistically significant (P = 0. 12) and neither was the difference between the predicted refraction of the IOL Master and the achieved refraction (P = 0. 39). The mean axial length was calculated as 24. 21 ± 0. 80 mm using the IOL Master and 24. 27 ± 0. 82 mm using the Galilei G6 device. The mean value regarding anterior chamber depth (ACD) of the IOL master was 3. 46 ± 0. 23 mm and for the Galilei was G6 3. 51 ± 0. 25 mm. When comparing the white to white (WTW) values of the IOL master, it showed mean values of 12. 32 ± 0. 31 and Galilei showed mean values of G6 12. 21 ± 0. 28. All of these differences (between Galileo and IOL Master measurements) were statistically significant (P < 0. 001). Conclusion: Both the laser interferometry/keratometry performed by the IOL Master and the interferometry/raytracing biometry strategy performed by the Galilei G6 demonstrated equal results when executing the IOL power calculation before cataract surgery in eyes with no prior ocular surgery.

Introduction & Objective: The age related cataract surgery is most common ophthalmic surgery. Today the method of choice for cataract surgery is phacoemulsification. This study was conducted to compare the visual acuity, pre-operation and post operation ECCE & Phacemulsification complication in patients referring to Khalili & Oastgheib Hospital in Shiraz during 1380-1381. Materials & Methods: This prospective non randomized concurrent Control study was conducted on 100cases (52 case of ECCE and 48 case Pre-operative evaluation included age, sex, visual acuity, astigmatism according to keratometry difference and type of cataract. The patients were evaluated during the operation for size, site of incision, posterior capsular rupture, vitreous loss and nucleus dropped in vitreous. Then in 1, 5, 14, 90,180 days post operation, they were examined for BCVA, UNCVA, astigmatism (keratometry and refraction), Inflammation, Comeal edema, posterior capsular opacity and clinical CME. Results: In this study 100 cases (48 phacemulsification, 52 ECCE) aged 48-76 for cataract surgery were included. Patients were followed for 6 months after operation. Mean age in phacemulsification was 58.27 ±7.26 was 64.71±6.84. On the fifth day after ECCE, UNCVA≥30.60 was 15.3% and in phaco was 62.5%. On the fifth day mean UNCVA in phaco was 30.60 and in ECCE, 20.60. Mean astigmatism on the first day post-operation according to keratometry difference in ECCE was 4.84±2.08D and in phaco was 2.27±1.67D and according to refraction in ECCE was 3.62±2.08D and in phaco was1.91±1.34D. Posterior capsular rupture in ECCE was 7.6% and in phacor was 12.5%. Vitreous loss in ECCE was 5.7% and in phaco was 0.7%.Cornealedema in the first day post-operation in ECCE was 19.2% and in phaco was 43.8%. Two weeks after operation in all patients who underwent phacoemulsification, corneal edema was cleared but in ECCE 3.8% corneal edema continued for 6 months after operation. Nucleus dropped in vitreous occurred only in phaco (2.1%). lOL dislocation after  phacoemulsification was 4.1% and 2.1%(1 case) need to lOL removal but this complication was not visible in  ECCE. Conclusion: Success rate, Intra operative& post-operative complications in phacoemulsification in comparison to other studies were in an acceptable range. We recommend further study In this case for more documented results.