سیدجواد هاشمیان

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 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. 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±0.162μ before surgery to 0.393±0.119μ 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. 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.

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. 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±0.80D. 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. 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. 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.

To evaluate the efficacy, safety, predictability and stability of Implantable Collamer Lens (ICL) and toric ICL for the treatment of high myopia and high myopic astigmatism, one year prospective study. In this prospective nonrandomized clinical trial, 95 eyes of 51 patients that had ICL (31 eyes) and toric ICL (64 eyes) were participate in Eye Research Center, Department of Ophthalmology, Rasoul Akram Hospital, Iran University of Medical Sciences and Negah Eye Hospital, Tehran, Iran. Uncorrected visual accuity (UCVA), best spectacle corrected visual acuity (BSCVA), manifest refraction, adverse events and complications were evaluated at 5th day and 2, 6 and 12 months postoperation. The preoperative mean manifest refractive spherical equivalent (MRSE) were 11.75±4.63 D (diopter) (-5.0 to -22.0) in ICL group and -11.67±3.99 D (-3.0 to -21.0) in toric ICL group. Mean residual refractive spherical equivalent were -0.68±1.07 D at 5th day, -0.86±1.07 D at 2 months, 0.65±0.72 D at 6 months, -0.71±0.78 D at one year in ICL group and -0.69±1.03 D, -0.59±0.84 D, -0.71±0.76 D and 0.89±0.68 D in toric ICL group, respectively. Preoperative cylinder in toric ICL group was -3.25±1.29 D (-2.0 to -6.0) and after operation was - 0.81±0.63D, -0.75±0.67 D, -0.93±0.70 D, -0.94±0.61 D, respectively. At 2 months after operation, the UCVA was 20/40 or better in 74.3% in ICL group and 74.6 % in toric ICL group (efficacy=1.092 and 1.154, respectively). 71.0% and 68.2% were within ±0.5 D and 77.5% and 85.7% were within ±1.0 D of emmetropia, respectively. 58.1% and 63.6% gained one or more lines (safety=1.18 and 1.24) two months after operation. At 2 months after operation, 81%, of eyes in toric ICL group had <1.0 D and 95.3% <1.5 D cylinder. No operative and postoperative complications or adverse events were observed. Asymptomatic (trace) anterior sub capsular opacities were seen in one eye (1.05%). ICL and toric ICL were effective, predictable, and safe procedures for the treatment of high myopia and high myopic astigmatism.

To study the distribution of ocular higher-order aberrations (HOAs) and mesopic pupil size in individuals screened for refractive surgery. Ocular HOAs and mesopic pupil size were studied in 2458 eyes of 1240 patients with myopia, simple myopic astigmatism and compound myopic astigmatism and 215 eyes of 110 patients with hyperopia, simple hyperopic astigmatism and compound hyperopic astigmatism using the Zywave aberrometer (Busch& Lomb). All patients had correctable refractive errors without a history of refractive surgery or underlying diseases. Root-mean-square values of HOAs, total spherical aberration, and total coma aberration and mesopic pupil size were analyzed. Ocular HOAs were measured across a ≥ 6.0 mm pupil. Mean values of HOAs, total spherical aberration and total coma aberration in the myopic group were 0.369±0.233 μm, 0.133±0.112 μm and 0.330±0.188 μm, respectively. The corresponding values in the hyperopic group were 0.418±0.214 μm, 0.202±0.209 μm and 0.343±0.201 μm, respectively. The hyperopes showed greater total HOAs (P<0.01) and total spherical aberration (P<0.01) as compared to the myopes. In agematched analysis, only the amount of total spherical aberration was higher in the hyperopic group (P=0.05). Mesopic pupil size was significantly larger in the myopic group than in the hyperopic group (P=0.05). Significant levels of HOAs were found in both groups which are important for planning refractive surgeries. There were significantly higher levels of total spherical aberration in hyperopes compared to myopes. Mesopic pupil size was larger in the latter group.

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 keratoconusaffected patients. 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. 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. 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.