Purpose: To evaluate the safety, efficacy, stability and predictability of posterior chamber collagen copolymer phakic intraocular lens (PIOL) implantation to correct myopia and MYOPIC ASTIGMATISM in keratoconus-affected patients.Methods: Uncorrected (UCVA) and best-corrected (BCVA) distance visual acuity, refraction and complications were evaluated in 22 keratoconic eyes of 14 patients who underwent Implantable Collamer Lens (ICL) (STAAR Surgical Inc.) implantation. The outcomes were evaluated during a 6-month follow up.Results: Mean preoperative spherical equivalent (SE) and cylinder decreased from -4.98±2.63 and -2.77±0.99 diopters (D) preoperatively to -0.33±0.51 and -1.23±0.65 D at the end of 6-month follow up, respectively. Preoperatively, the mean Snellen decimal BCVA was 0.63±0.20. The mean UCVA was 0.76±0.23 and BCVA was 0.85±0.21 at the final follow up. The mean safety and efficacy indices were 1.40±0.32 and 1.24±0.34, respectively. No line of BCVA was lost; 17 eyes (77.3%) gained 1 or more lines. Fifteen (68.2%) of the eyes were within±0.50 D and 20 (90.9%) were within±1.00 D of the desired spherical equivalent refraction. There was a change in manifest refraction of 0.09±0.21 (range, -0.25 to +0.75) from week 1 to month 6 postoperatively.Conclusion: Toric ICL was safe, effective, and predictable to correct myopia and MYOPIC ASTIGMATISM associated with keratoconus. The achieved refraction remained stable during the course of the study.

Purpose: To investigate the changes in aberrations induced by implantation of Implantable Collamer Lenses (ICL and Toric ICL; STAAR Surgical, Nidau, Switzerland) in eyes with HIGH myopia. and HIGH MYOPIC ASTIGMATISM Methods: We investigated thirty-three eyes of 18 consecutive patients, with spherical equivalent errors of-6. 00 to-21. 09 diopters (D) and cylindrical errors of-0. 5 to-4. 75 D, who underwent ICL and toric ICL implantation. Before and 5 days, 2 and 6 months after surgery, the uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), defocus and adverse events of the surgery were assessed. Ocular HIGHer order aberrations also were evaluated by Hartmann-Shack aberrometry ((Technolas PV, Rochester, New York, USA) before and 6 months after surgery. Results: 6. 0 month after surgery, the uncorrected and best corrected visual acuity respectively in 40% and 66. 7% of eyes were 20/20. Six month post-operation, mean defocus refraction and ASTIGMATISM reduced to-0. 66 and 0. 65 D from-12. 79 and 2. 18 at baseline respectively. For a 6-mm pupil, HIGHer order aberrations were not significantly changed, merely from 0. 417± 0. 162􀀀 before surgery to 0. 393± 0. 119􀀀 after surgery (P = 0. 45). Spherical aberration (Z400) increased significantly (P= 0. 00). Surgical induced ASTIGMATISM was lower than 0. 25 D and there were no changes in trefoils and coma aberration. No vision-threatening complications occurred during the observation period. Conclusion: This study shows, the ICL and toric ICL performed well in correcting HIGH MYOPIC ASTIGMATISM without significant changes in HOAs during a 6. 0 months observation period, although the spherical aberration (Z400) increased significantly.

Purpose: To evaluate the results of laser in situ keratomileusis (LASIK) retreatment in patients with postoperative regression.Methods: In a retrospective interventional case series, 153 eyes of 113 patients who had undergone LASIK retreatment for postoperative regression were evaluated. Both initial LASIK and retreatment were performed with a Nidek: EC 5000 excimer laser and flap was made with a Moria microkeratome.Results: Mean age was 29.63 ± 2.2 yr (range, 20 to 54 yr) and mean follow–up was 11 months (range, 3 to 34mth) after the initial surgery and 13.1 months (range, 12 to 18mth) after retreatment. Retreatment was performed 3-34 months after the primary LASIK. Mean spherical equivalent (SE) was -5.39 ± 2.69 diopters (D) (range, -1.50 to -14.00 D) before initial LASIK and -1.76 ± 1.08 D (range, -0.50 to -5.00 D) before retreatment. Mean ASTIGMATISM was -1.38 ± 1.07 D (range, -0.50 to -5.00 D) before initial LASIK and -1.12 ± 0.50 D (range, -0.50 to -2.50 D) before retreatment. One year after retreatment, mean UCVA was 20/25, and mean SE was -0.29 ± 0.02 D. Best corrected visual acuity (BCVA) improved in all eyes. Two eyes received more than one retreatment. Twenty eyes had flap wrinkling, 2 eyes had diffuse lamellar keratitis (DLK), and 2 eyes had epithelial in growth after the initial LASIK. Four eyes had epithelial in growth and 2 eyes developed mild keratectasia after retreatment.Conclusions: LASIK retreatment is a safe and effective option with small amounts of myopia and MYOPIC ASTIGMATISM regression. The rate of retreatment is HIGHer in patients with MYOPIC ASTIGMATISM and in patients with less than 40 years of age; also the risk of complications in retreatment is HIGHer than the initial LASIK. Refractive changes are more stable after retreatment. The risk of keratectasia is HIGHer in final residual stromal bed thickness less than 250 mm after the reoperation.

Purpose: To investigate the changes in HIGHer-order aberrations (HOAs) induced by the implantation of implantable collamer lenses (ICLs) and Toric ICL (TICL) in eyes with HIGH myopia and HIGH MYOPIC ASTIGMATISM. Methods: We investigated 33 eyes of 18 consecutive patients (in a prospective, interventional case series study), with spherical equivalent errors of
6. 00 to
21. 09 diopters (D) and cylindrical errors of
0. 5 to
4. 75 D, who underwent ICL and TICL implantation. Before and after 5 days, 2 and 6 months of surgery, the uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), defocus and adverse events of the surgery were assessed. Ocular HOAs were also evaluated by Hartmann-Shack aberrometry (Technolas PV, Rochester, New York, USA) before and after 6 months of surgery. Results: At 6. 0 months after surgery, the UCVA and BCVA in 40% and 66. 7% of eyes were 20/20, respectively. Mean defocus refraction and ASTIGMATISM was reduced to
0. 66 and 0. 65 D from
12. 79 and 2. 18 at baseline, respectively. For a 6 mm pupil, HOAs were not significantly changed, merely from 0. 417 ± 0. 162 m before surgery to 0. 393 ± 0. 119 m after surgery (P ¼ 0. 45). Spherical aberration (Z400) increased significantly (P ¼ 00. 0). Surgical induced ASTIGMATISM was lower than 0. 25 D, and there were no changes in trefoils and coma aberration. No vision-threatening complications occurred during the observation period. Conclusion: This study shows that the ICL and TICL performed well in correcting HIGH MYOPIC ASTIGMATISM without significant changes in HOAs during a 6-month observation period, although the spherical aberration (Z400) increased significantly.

Purpose: To compare the safety, efficacy, predictability, stability and complications of wavefront-guided laser-assisted subepithelial keratectomy (LASEK) in low myopia, MYOPIC ASTIGMATISM and HIGH myopia correction.Methods: In his retrospective study, 416 eyes were divided to 3 groups: 159 eyes with low myopia (LM) and mean refractive spherical equivalent (MRSE) of -3.68±1.33 (SD) diopter (D); 161 eyes with MYOPIC ASTIGMATISM (MA) and MRSE of -5.99±2.24 D and mean cylinder of 2.41±1.07 D; and 96 eyes with HIGH myopia (HM) and MRSE of -7.41±0.80 D. After an epithelial flap creation, a Wavefront-based excimer laser ablation was performed. Safety, efficacy, predictability, and stability were evaluated at day 10, months 2, 6 and 12 postoperatively.Results: The MRSE were -0.36±0.31 D in LM group, 0.15±0.41 D in MA group and 0.58±0.68 D in HM group. The uncorrected visual acuity (UCVA) were 20.20 in 90.60% of patients in LM group, 78.90% in MA group and 67% in HM group. Efficacy indices were 0.98, 1.04 and 0.92 in LM, MA and HM groups, respectively. Safety indices were 1.00, 1.07 and 1.05 in LM, MA and HM respectively. Five eyes (3.1%) in the LM group improved 1 line. Forty-four eyes (27.3%) in MA gained 1-3 lines and 19.2 % of HM group gained 1-2 lines of BSCVA. Only 2 eyes in LM group developed corneal haze. There were not significant statistically differences in efficacy and safety indices between three groups.Conclusion: Wavefront-guided LASEK is an effective and safe procedure for the treatment of LM, MA, and HM. Although predictability, efficacy and safety indices improved in MYOPIC ASTIGMATISM.

Purpose: To evaluate the safety, efficacy, predictability, and visual results of laser in situ keratomileusis (LASIK) using the Bausch & Lomb Technolas 217 for the treatment of compound MYOPIC ASTIGMATISM.Setting: Standard LASIK center, Nemazi Hospital, Shiraz, IRAN.Methods: In a prospective study, 60 eyes of 37 MYOPIC astigmatic patients with a mean pre-op spherical equivalent (SE) of -5.6 diopters (0) :!:2.15(SO) (range -2.37 to- 13.5 0) and mean pre-op ASTIGMATISM of -2.27 0 (range -1 to -6 0) underwent LASIK using the Technolas 217 system. The patients were followed 1 day, 1 week, 1 month, 3 months and 6 months after the procedure.Results: Mean SE refraction reduced significantly, 91% reduction at 1st wk (-0.52 0), 90% reduction at 1st month (-0.59 0), 89% reduction at 3rd month (-0.63 0) and 85% at 6th month (-0.87 0). Mean pre-op ASTIGMATISM (-2.27 0) reduced, too. At first wk 77% reduction (mean=-0.520), at 1st month 71% reduction (mean=-0.65 0), at 3rd month 68% reduction (mean=-0.72 0), and at 6th month 60% reduction (mean = -0.92 0).Pre-op best corrected visual acuity (BCVA) of 10/10 was seen in 55% of patients that increased post operatively to 72% at 6 months.Post-op uncorrected visual acuity (UCVA) was 10/10 or better, in 43% at 1st wk, in 45% at 1st month, in 55% at 3rd month, and in 48% at 6th month.Post-op decrease in BCVA (1or 2 lines) was seen in 4 eyes (6%), but no decrease in BCVA more than 2 lines was seen in any eye.Conclusion: The Technolas 217 system yielded acceptable post-pp UCVA and BCVA.lt is safe and effective in treatment of MYOPIC ASTIGMATISM. But long term follow-up is needed to assess stability of the procedure.

Purpose: To determine the safety of LASIK according to decreased BSCVA in myopia and MYOPIC ASTIGMATISM.Methods: In this pre and post non-randomized clinical trial, 736 eyes from 369 patient who had LASIK surgery for myopia and MYOPIC ASTIGMATISM were evaluated. Mean pre and postoperation visual acuity were measured based on Snellen and Log MAR systems. Results: This study included 62.6% female and 37.4% male patients with a mean age of 30±8 years. Follow up period was 9 months. Preoperative spherical equivalent was -5.2±2.6 diopters. Nine months after surgery this value decreased to -0.28±0.62 diopters. Nine months after operation, 83.7% of the eyes were within ±0.50 diopter of emmetropia. Uncorrected visual acuity was 20/20 or more in 55.8% and 20/40 or more in 97.8% of the eyes. Mean BSCVA before operation was 0.052±0.095and 9 months after operation increased to 0.034±0.069 (P<0.001). Nine months after operation, BSCVA decreased 2 lines in two eyes, 3 lines in one eye, and 4 lines in another eye. Overall the incidence of decreased BSCVA was 0.5%. Conclusion: Regarding decreased BSCVA, LASIK is a safe procedure for myopia and MYOPIC ASTIGMATISM.

Purpose: To determine and evaluate the visual acuity (VA) and refracion of correcting compound severe MYOPIC ASTIGMATISM with the Artisan toric intraocular lenses (IOLs).Methods: In this noncontrolled clinical trial, 15 patients with severe ASTIGMATISM and at least 2.0 diopters (D) of ASTIGMATISM were enrolled. All patients met the inclusion criteria. Artisan toric IOL implantation was recommended to them, while the procedure and its possible complications were discussed. Preoperative examinations included refraction, uncorrected visual acuity (UCVA), and best corrected visual acuity (BCVA) tests, endothelial cell count (ECC), and anterior chamber depth (ACD) measurement. Results: Mean UCVA was 1.57 logMAR preoperatively, and increased to 0.21 logMAR 18 months after surgery (P<0.001). Mean sphere was -7.84 ±3.1D (range, -3 to -15) preoperatively, and changed to 0.04±0.47 D (range, 0.75 to -1.5) 18 months after surgery (P<0.001). Cylinder error showed a statistically significant change from -3.53±1.32 D (range, -1.5 to -6.5) to -0.90±0.90 D (range, 0 to -4.5) during the same period (P<0.001). Mean ECC was 3257.8 cell/mm2 before surgery, and 2761.7 cell/mm2 18 months later (P<0.001). Mean ACD showed reduction from 3.7±0.23 mm preoperatively to 2.9±0.23 mm after surgery (P<0.001). Conclusion: When laser refractive surgery is not an option, correcting severe myopia and ASTIGMATISM with the Artisan toric IOL has acceptable results, but it’s possible complications must be kept in mind.

Purpose: Evaluation of corneal topographic changes after LASIK with quantitative and qualitative methods.Materials and Methods: A semiexperimental clinical trial was done in 80 eyes of 41 patients from 1380-1382 (2001-2003) in Tabriz. In this study eyes with myopia and MYOPIC ASTIGMATISM undergo LASIK with Nidek EC-5000.Computerized video keratography was made before, 5days after and in the last visit following LASIK with Eye sys corneal analysis system and Holladay diagnostic summary programs. Findings are comparised and differences was analysed with T-test and Wilcoxon statistical methods. Results: Mean age of Patients was 30±10 (SD) Year. Mean duration of follow up was 12 months. Mean level of best corrected visual acuity before operation was 0.1 LogMar (20/25) and mean uncorrected visual acuity after operation in the last visit was 0.2 LogMar (20/30). Mean Level of best corrected visual acuity in the last visit was 0.35 LogMar (20/22).Mean amount of refractive error before operation in the spectacle plan was -5.75±3 (SD) that reached to -0.35±0.62 (SD) after operation.Mean amount of corneal asphericity (Q) before operation was -0.105 (min -1.04 and max +0.35) that raised to +1.07 (min +0.01 and max +1.99) in the last visit after LASIK. Mean corneal uniformity index (CUI) before operation was 97.25%, that reached to 85.37% in the last visit after LASIK.Mean predicted corneal acuity (P.C.A) before operation was 20/14 that reduced to 20/25 in the last visit after LASIK.Mean decentration of corneal center before and after LASIK in the horizontal axis was 0.03 mm and 0.045 mm (respectively) and in the vertical axis was 0.037mm and 0.024mm (respectively).Mean amount of effective refractive power before operation was 43.83±1.63 (SD) that reduced to 38.98±2.05 (SD) in the last visit after LASIK.Topographic profiles after LASIK were: Circular (C) in 53 eyes (66.25%), circular with central bowtie (CCB) in 25 eyes (31.25%) and assymetric bowtie (ASB) in 2 eyes (2.5%).Conclusion: This study shows that LASIK with Nidek-EC 5000 causes corneal topographic change from prolate to oblate with resultant correction of myopia and MYOPIC ASTIGMATISM but, CU index and PCA are reduced after LASIK that causes unwanted effects on visual quality.