Biomechanical changes in keratoconus after customized stromal augmentation.

PURPOSE: To verify corneal biomechanical changes, poststromal augmentation using myopic small-incision lenticule extraction's (SMILEs) lenticules in advanced keratoconus (KCN) through Corvis ST (Oculus, Wetzlar, Germany). MATERIALS AND METHODS: A clinical trial enrolled 22 advanced KCN patients. We implanted lenticules exceeding 100 µ according to a nomogram and evaluated biomechanical factors through Corvis ST at 3-, 6-, and 24-month postimplantation. We examined parameters during the first applanation (A1), second applanation (A2), highest concavity (HC)/max concavity events, and Vinciguerra screening parameters, as recently established criteria derived from the ideal blend of diverse biomechanical and ocular factors and formulated through the application of logistic regression. Regression analyses explored relationships with age, mean keratometry value, thickness, sphere, cylinder, and best-corrected visual acuity. RESULTS: Patients were well matched for age, intraocular pressure, and central corneal thickness (CCT). The mean spherical equivalent decreased from -13.48 ± 2.86 Diopters (D) to -8.59 ± 2.17 D (P < 0.007), and mean keratometry decreased from 54.68 ± 2.77 D to 51.95 ± 2.21 D (P < 0.006). Significant increases were observed in HC time (HCT), Radius-central curvature radius at the HC state-, peak distance (PD) during HC state, CCT, first applanation time, and stiffness parameter (A1T and SP-A1), whereas HC deformation amplitude, maximum deformation amplitude ratio at 2 mm, Corvis Biomechanical Index (CBI), integrated radius (IR), second applanation deformation amplitude (A2DA), first applanation velocity and deflection amplitude (A1V and A1DeflA) significantly decreased postlenticule implantation. Multivariable regression revealed age positively correlated with SP-A1 (P = 0.003) and negatively with HC delta Arc length (P = 0.007). Mean K positively correlated with CCT (P = 0.05) and negatively with CBI (P = 0.032). Best-corrected visual acuity positively correlated with HCT (P = 0.044), and the cylinder positively correlated with PD (P = 0.05) and CCT (P = 0.05) whereas negatively with IR (P = 0.025). CONCLUSIONS: Stromal augmentation using myopic SMILE lenticules induces significant corneal biomechanical changes in KCN.

Supracor Multifocal Corneal Laser-Assisted In Situ Keratomileusis Procedure for the Correction of Presbyopia in Hyperopic Eyes.

Purpose: To investigate the outcomes of unilateral Supracor treatment to enhance near vision while maintaining good distance vision in hyperopic eyes. Methods: This prospective interventional study includes consecutive hyperopic patients with presbyopia. All eyes underwent femtosecond laser-assisted in situ keratomileusis treatment for hyperopia with an additional Supracor multifocal treatment algorithm in nondominant eyes. Monocular and binocular uncorrected and spectacle-corrected distance visual acuity (UCDVA and SCDVA), monocular and binocular uncorrected near visual acuity (UNVA), and distance-corrected near visual acuity at 40 cm and high-order aberration changes and complications were evaluated for 6 months. Results: Sixty-four patients with a mean age of 51.91 ± 3.64 were enrolled. After 6-month follow-up, the mean binocular UCDVA and UNVA were 0.03 ± 0.05 and 0.04 ± 0.06 logMAR, respectively. UCDVA (logMAR) of nondominant and dominant eyes was 0.30 ± 0.18 and 0.03 ± 0.05, respectively. Preoperative and postoperative mean ± standard deviation manifest refraction spherical equivalent was +1.84 ± 0.75 and -0.48 ± 0.57, respectively, in nondominant eyes and +1.77 ± 0.69 and +0.12 ± 0.33, respectively, in dominant eyes. No complications were observed. Conclusion: Supracor procedure in nondominant eyes may improve functional near, intermediate, and distance vision without significant photic phenomena in presbyopic patients with low and moderate hyperopia.

Ocular Biometric Values and Prevalence of Corneal Astigmatism in Patients Candidate for Cataract Surgery.

Purpose: To analyze the biometric values and the prevalence of corneal astigmatism in cataract surgery candidates. Methods: This is a prospective study. Ocular biometric values and corneal keratometric astigmatism were measured by optical low-coherence reflectometry (Lenstar LS 900) before surgery in patients who were candidates for cataract extraction surgery. Descriptive measurements of biometric dimensions and keratometric cylinder data and their correlations with sex and age were evaluated. Results: Ocular biometric and keratometric values from 2084 eyes of 2084 patients (mean age 66.43, range 19-95 years) were analyzed. The mean values were as follows: corneal astigmatism 0.89 diopter (D), mean corneal keratometry 44.29 D, central corneal thickness 534 µ, internal anterior chamber depth (ACD) 3.11 mm, lens thickness 4.50 mm, and axial length 23.35 mm. Corneal astigmatism was <1.25 D in 1660 (79.5%) of eyes. Astigmatism was with-the-rule in 976 (46.8%) of eyes, against-the-rule (ATR) in 702 (33.7%), and oblique in 406 (19.5%). Analysis of corneal astigmatism revealed a change toward "ATR" with age which was not statistically significant. The ACD was correlated with age. The amount of corneal astigmatism had no correlation with age and sex. Conclusion: Corneal astigmatism was higher than 1.25 D in about 21% of cataract surgery candidates with slight differences between the various age ranges and had no correlation with age and sex.

Outcomes of a Single-Segment Intrastromal Corneal Ring in Early Keratoconus and Early Pellucid Marginal Degeneration.

PURPOSE: To determine the effect of a single-segment intrastromal corneal ring segment (ICRS; Intacs SK) on early keratoconus (KCN) and pellucid marginal degeneration (PMD). METHODS: It is a prospective interventional study. One hundred twenty-four eyes (99 patients) with KCN and 36 eyes (26 patients) with PMD at early stage (the maximum keratometric reading less than 55 diopters) were included to ICRS implantation using femtosecond laser at a tertiary university-based hospital and a private outpatient center. The uncorrected distance and spectacle-corrected visual acuity (UDVA and SCDVA), manifest spherical and cylindrical refractions, and keratometry indices were measured preoperatively and postoperatively, 1 week, 2 and 6 months. RESULTS: One week after surgery, significant improvements were observed in UDVA, SCDVA, cylinder and keratometry readings of both KCN and PMD groups (all P < 0.05) with no significant changes afterward. No significant change occurred in the sphere refraction of PMD group (P = 0.10) in contrast to KCN group (P < 0.001). Corneal irregularity of KCN group in central 3 and 5 mm zones increased at 1 week (both P < 0.001) and then started to decrease up to 6 months. However, the corneal irregularity of PMD group had significant reduction only at 1 week in 5-mm zone (P = 0.02) and 2 months in 3-mm zone (P = 0.01) postoperatively. The final efficacy indexes were 1.44 ± 0.71 and 0.87 ± 0.40 in KCN and PMD groups, respectively. CONCLUSION: Visual acuity, refractive errors and keratometry values have been improved after one-segment Intacs SK implantation in early KCN and PMD patients.

Long-Term Visual and Refractive Stability and Ocular Biometric Changes after Laser-Assisted Subepithelial Keratomileusis for Correction of Myopia: An 8-Year Follow-Up.

PURPOSE: To assess the long-term visual and refractive stability and ocular biometric changes in low to moderate myopic subjects treated by laser-assisted subepithelial keratomileusis (LASEK). METHODS: It is a prospective, interventional study. Included were 70 eyes of 35 patients who underwent LASEK for correction of ≤6 diopters (D) myopia. The uncorrected and corrected distance visual acuity (UDVA and CDVA), manifest refractions, and ocular biometric indices (by Lenstar-LS900, Haag-Streit AG, Koeniz, Switzerland) including keratometry, anterior chamber depth (ACD), aqueous depth (AD), axial length (AL), central corneal thickness (CCT), and lens thickness (LT) were assessed preoperatively and after 6 months and 8 years. RESULTS: Mean preoperative spherical equivalent was -3.99 (standard deviation [SD] =1.38) D which improved to 0.02 (SD = 0.27, P < 0.001) D and -0.10 (SD = 0.31, P < 0.001) D at 6 months and 8 years, respectively. The preoperative AL was not different from postoperative measures at 6 months (P = 0.15) and 8 years (P = 0.47). The ACD and AD decreased during 8 years, while LT increased (all P ≤ 0.001). The changes of LT inversely correlated with changes of ACD (rs = -0.67, P = 0.001 at 6 months and rs = -0.87, P < 0.001 at 8 years) and AD (rs = -0.76, P < 0.001 at 6 months and rs = -0.86, P < 0.001 at 8 years). The CCT and keratometry values reduced at 6 months postoperatively (all P < 0.001) and then did not change up to 8 years (0.21 ≤ P ≤ 0.87). CONCLUSIONS: The post-LASEK myopic regression is 0.1 D over 8 years. Ocular biometric values like keratometry, CCT, ACD, AD, and LT have been changed for a long period after LASEK in low to moderate myopia except AL.

Efficacy of complete rings (MyoRing) in treatment of Keratoconus: a systematic review and meta-analysis.

PURPOSE: We aimed to systematically review the existing evidence and determine the efficacy of MyoRing as a novel method for treatment of keratoconus using meta-analysis. METHODS: Online electronic search of Medline, ISI Web of Science, Embase, Scopus, and Cochrane Library databases was performed with reference lists of relevant articles for pre-post trials published through August 2017. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), sphere, cylinder, spherical equivalent (SE), maximum, minimum, and mean keratometry were considered as the visual acuity outcomes. Weighted mean difference (WMD) with 95% confidence interval was used as pooled estimation of intervention efficacy using random-effects meta-analysis. Heterogeneity was measured with the Cochran Q statistic and quantified with the I2 statistic using Stata software. RESULTS: Of the 47 potentially related studies, 21 eligible studies were included in the meta-analysis. The mean of uncorrected distance visual acuity (UDVA) based on LogMAR in patients with keratoconus had a significant change 3 months after implantation/embedding of the complete ring (WMD =  - 0.73 (CI = - 0.88 to - 0.58), I2 = 79.9%, p < 0.001). Results support a statistically significance improvement in CDVA, SE, sphere, cylinder, and maximum keratometry after surgical intervention. Range of reported safety index, stability, and efficacy index by included studies was 1.7-2.7, 74-100%, and 0.9-1.96, respectively. CONCLUSIONS: MyoRing is an appropriate treatment option for keratoconus. Findings of this meta-analysis demonstrated that main visual outcomes have been improved 3, 6, and 12 months after the implantation of the complete ring (MyoRing).

Visual and Refractive Outcomes and Tomographic Changes after Femtosecond Laser-assisted Intrastromal Corneal Ring Segment Implantation in Patients with Keratoconus.

PURPOSE: To evaluate the visual, refractive, and tomography changes after femtosecond laser-assisted intrastromal corneal ring segment (ICRS; Intacs® SK) implantation in patients with keratoconus. METHODS: In this prospective interventional case series, Intacs SK ICRSs were inserted using a femtosecond laser into eyes with stage I-IV keratoconus. Visual, refractive, and corneal tomography changes, along with surgical complications, were analyzed 1 week, 2 months, and 6 months postoperatively. RESULTS: The study evaluated 71 eyes of 52 patients (mean age: 27.5 years). Six months postoperatively, the spherical equivalent, mean sphere, and mean cylinder were decreased by 2.07, 1.47, and 1.13 diopters (D), respectively. The mean preoperative uncorrected distance visual acuity (UDVA) increased from 0.87 ± 0.26 to 0.46 ± 0.19 LogMAR and the mean preoperative corrected distance visual acuity (CDVA) increased from 0.55 ± 0.21 to 0.28 ± 0.17 LogMAR (P < 0.001). Flat and steep keratometry decreased by a mean corneal power in the 3-mm zone, and mean anterior elevation decreased by 0.91 D, 2.52 D, and 1.03 microns (P < 0.001), respectively. Among all eyes, 93.0% gained one or more lines of CDVA. Mean internal anterior chamber depth decreased from 3.25 ± 0.33 to 3.14 ± 0.45 mm (P = 0.001), and mean irregularity in the 3-mm zone decreased from 5.63 ± 1.71 to 5.24 ± 1.82 (P = 0.006). However, mean posterior elevation and irregularity in the 5-mm zone did not change significantly. CONCLUSION: Implantation of one or two Intacs SK segments is safe and effective to treat keratoconus, leading to significant improvement in UDVA, CDVA, and refractive error.

Adjustment formulae to improve the correlation of white-to-white measurement with direct measurement of the ciliary sulcus diameter by ultrasound biomicroscopy.

PURPOSE: This study evaluates the correlation between horizontal white-to-white (WTW) distance using Caliper and Orbscan IIz with the ciliary sulcus diameter measured by high frequency ultrasound biomicroscopy (UBM) and presents an adjustment formula to improve the correlation. METHODS: We measured horizontal sulcus-to-sulcus (STS) dimension of 273 right eyes of 273 high myopic patients with 35 MHz UBM and horizontal WTW using Orbscan IIz and Caliper. Mean WTW diameter, differences, and the correlation of measurement methods were evaluated. RESULTS: The mean spherical equivalent was -8.79 ± 4.87 diopters. Mean horizontal STS dimension with UBM was 12.13 ± 0.45 mm (range, 10.81-13.42 mm). Mean WTW diameter in the Caliper method was 11.70 ± 0.40 mm (range, 10.6-12.8 mm) and 11.70 ± 0.40 mm (range, 10.5-13.1 mm) in the Orbscan method. Mean difference of UBM STS and WTW with Caliper was 0.48 ± 0.28 mm (range, -0.19 to 1.37 mm). Mean difference of UBM STS diameter and Orbscan WTW was 0.38 ± 0.31 mm (range, -0.64 to 1.29 mm). The Pearson correlations of WTW diameter measured by Caliper and Orbscan with UBM's STS diameter were 0.778 and 0.773, respectively. This difference diminished after adjustment. The 95% limit of agreement was almost the same in Caliper and Orbscan (-0.07 to 1.03 compared with -0.23 to 0.99). CONCLUSION: There is a significant difference in measurements between STS diameter using UBM and WTW diameter utilizing Caliper and Orbscan. This difference diminished after our recommended adjustment.

Ocular higher-order aberrations changes after implantable collamer lens implantation for high myopic astigmatism.

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 µ before surgery to 0.393 ± 0.119 µ after surgery (P = 0.45). Spherical aberration (Z400) increased significantly (P = 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.

Long-term outcomes of posterior chamber phakic intraocular lens implantation in keratoconus.

BACKGROUND: In this retrospective observational case series study, the aim was to evaluate the long-term safety, efficacy, stability and predictability of posterior chamber phakic intraocular lens (pIOL) implantation to correct myopia and myopic astigmatism associated with keratoconus. METHODS: Uncorrected distance visual acuity (UDVA), best spectacle-corrected distance visual acuity (BSCDVA), refraction and adverse effects were evaluated in 23 keratoconic eyes of 13 patients after five years with Visian ICMV4 pIOL (STAAR Surgical). RESULTS: The mean pre-operative spherical equivalent and cylinder changed from -5.35 ± 2.82 D and -3.14 ± 1.58 D to -0.78 ± 1.31 D and -1.56 ± 1.53 D, respectively, five years post-operatively. Before the surgery the mean Snellen decimal BSCDVA was 0.60 ± 0.20. The mean UDVA and BSCDVA changed to 0.74 ± 0.22 and 0.88 ± 0.16, respectively. A total of 82.5 per cent of eyes achieved 6/12 or better UDVA post-operatively. The mean safety and efficacy indices were respectively, 1.47 ± 0.32 and 1.24 ± 0.34. No eye lost a line of visual acuity and 19 eyes gained one or more lines. An endothelial cell loss of 7.88 per cent occurred. No significant changes were seen in intraocular pressure, steep, flat and mean keratometry. The crystalline lens was clear. CONCLUSION: The clinical outcomes of the current study demonstrate the safety, efficacy and predictability of the implantable collamer lens (toric and non-toric) in the correction of myopia and myopic astigmatism associated with keratoconus. The patients' refractions achieved early stability and remained stable during the course of the study.

Combined cataract extraction and trabeculotomy by the internal approach for coexisting cataract and open-angle glaucoma.

PURPOSE: To provide efficacy and safety of surgery with Trabectome combined with phacoemulsification in primary open-angle glaucoma. METHODS: In this interventional case series, 30 consecutive eyes that have had combined phacoemulsification with Trabectome were included. The main outcome measures were change in intraocular pressure (IOP), glaucoma medication use, and the rate of complications. RESULTS: Mean IOP was 18.25 ± 3.28 mmHg preoperatively which decreased to 13.50 ± 2.53 mmHg at 1 year. (P < 0.05). There was a corresponding drop in glaucoma medications from 2.52 ± 0.60 at baseline to 1.40 ± 0.53 at 12 months (P < 0.01). The preoperative BCVA (Log Mar) was improved from 0.68 ± 0.26 pre-operatively to 0.26 ± 0.19, 0.18 ± 0.13, 0.17 ± 0.13, 0.11 ± 0.12, at 5 days and 2, 6, and 12 months, respectively (P < 0.01). The only frequent complication was transient blood reflux resolving spontaneously within a few days. No vision-threatening complication occurred. CONCLUSION: Combined phacoemulsification and Trabectome significantly lowered IOP and medication use, with early visual rehabilitation in the majority of patients.

Three Methods for Correction of Astigmatism during Phacoemulsification.

PURPOSE: To compare the safety and efficacy of three methods for correcting pre-existing astigmatism during phacoemulsification. METHODS: This prospective, comparative, non-randomized study was conducted from March 2010 to January 2011, and included patients with keratometric astigmatism ≥1.25 D undergoing cataract surgery. Astigmatism was corrected using the following approaches: limbal relaxing incisions (LRI) on the steep meridian, extension and suturing of the phaco incision created at the steep meridian (extended-on-axis incision, EOAI), and toric intraocular lens (tIOL) implantation. Keratometric and refractive astigmatism were evaluated 1, 8, and 24 weeks postoperatively. RESULTS: Eighty-three eyes of 72 patients (35 male and 37 female) with mean age of 62.4 ± 14.3 (range, 41-86) years were enrolled. The astigmatism was corrected by using the LRI, EOAI and tIOL implantation methods in 17, 33 and 33 eyes, respectively. Postoperative uncorrected distance visual acuity (UDVA) was significantly improved in all three groups. The difference in postoperative UDVA was not statistically significant among the study groups throughout follow-up except at week 24, when UCVA was significantly better in the tIOL group as compared to the EOAI group (P = 0.024). There is no statistically significant difference of correction index and index of success between three groups at week 24 (P = 0.085 and P = 0.085 respectively). CONCLUSION: There was no significant difference in astigmatism reduction among the three methods of astigmatism correction during phacoemulsification. Each of these methods can be used at the discretion of the surgeon.

Customized Clinical Practice Guidelines for Management of Adult Cataract in Iran.

PURPOSE: To customize clinical practice guidelines (CPGs) for cataract management in the Iranian population. METHODS: First, four CPGs (American Academy of Ophthalmology 2006 and 2011, Royal College of Ophthalmologists 2010, and Canadian Ophthalmological Society 2008) were selected from a number of available CPGs in the literature for cataract management. All recommendations of these guidelines, together with their references, were studied. Each recommendation was summarized in 4 tables. The first table showed the recommendation itself in clinical question components format along with its level of evidence. The second table contained structured abstracts of supporting articles related to the clinical question with their levels of evidence. The third table included the customized recommendation of the internal group respecting its clinical advantage, cost, and complications. In the fourth table, the internal group their recommendations from 1 to 9 based on the customizing capability of the recommendation (applicability, acceptability, external validity). Finally, customized recommendations were sent one month prior to a consensus session to faculty members of all universities across the country asking for their comments on recommendations. RESULTS: The agreed recommendations were accepted as conclusive while those with no agreement were discussed at the consensus session. Finally, all customized recommendations were codified as 80 recommendations along with their sources and levels of evidence for the Iranian population. CONCLUSION: Customization of CPGs for management of adult cataract for the Iranian population seems to be useful for standardization of referral, diagnosis and treatment of patients.

Comparison of three phakic intraocular lenses for correction of myopia.

PURPOSE: To compare the visual outcomes and complications of three different types of phakic intraocular lenses (PIOLs), for correction of moderate to high myopia. METHODS: We reviewed 112 myopic eyes undergoing PIOL implantation using Artisan (40 eyes), Artiflex (36 eyes), and implantable collamer lens (ICL, 36 eyes). Best corrected visual acuity (BCVA), intraocular pressure (IOP), pachymetry, corneal endothelial cell (CEC) loss, and higher order aberrations (HOA) were compared. RESULTS: Mean follow-up period was 30 ± 11 months. Preoperatively, spherical equivalent (SE) refractive error was -11.6 ± 3.7, -9.59 ± 1.97, and -12.3 ± 4.8 D in the Artisan, Artiflex and ICL groups, respectively. SE was comparable among the study groups at final follow-up (P = 0.237). Mean astigmatic reduction was 0.31 ± 0.72, 0.45 ± 0.62, and 0.0 ± 0.57 in the Artisan, Artiflex and ICL groups, respectively (P = 0.007). Emmetropia (±1 D) was achieved in 60%, 91.7% and 77.8% of eyes in the Artisan, Artiflex and ICL groups, respectively, the difference was significant between the Artisan and Artiflex groups (P = 0.017). BCVA improvement more than one line occurred in 25%, 19.4% and 38.9% of eyes (P = 0.158); pachymetric changes were minimal with no difference among the three groups (P = 0.754), and mean CEC loss was 10 ± 9%, 9 ± 6% and 9 ± 10% in the Artisan, Artiflex and ICL groups, respectively (P = 0.694). HOAs (P = 0.039), vertical trefoil (P = 0.032) and spherical aberration (P = 0.001) were higher with Artisan group as compared to ICL. Total aberrations (P = 0.028) and spherical aberration (P = 0.001) was also higher with Artisan group as compared to Artiflex. CONCLUSION: Visual and refractive outcomes were comparable with Artisan, Artiflex and ICL. In terms of HOAs and quality of vision, ICL and Artiflex seem to be better choices in highly myopic eyes.

Toric implantable collamer lens for high myopic astigmatism in keratoconic patients after six months.

BACKGROUND: The aim was to evaluate the safety, efficacy, stability and predictability of posterior chamber collagen copolymer phakic intraocular lens (pIOL) implantation to correct myopia and myopic astigmatism associated with keratoconus. METHODS: The unaided vision and visual acuity, refraction and adverse events were measured in 22 keratoconic eyes of 14 patients after using an implantable collamer lens (ICL) (STAAR Surgical Inc.) to correct refractive error. The outcome was evaluated over six months. RESULTS: The mean pre-operative spherical equivalent (SE) and cylinder changed from -4.98 ± 2.63 DS and -2.77 ± 0.99 DC to -0.33 ± 0.51 DS and -1.23 ± 0.65 DC, respectively at the end of six months. Before the surgery the mean Snellen decimal visual acuity was 0.63 ± 0.20. The mean unaided vision and visual acuity changed to 0.76 ± 0.23 and 0.85 ± 0.21, respectively at the end of six months. The mean safety and efficacy indices were 1.40 ± 0.32 and 1.24 ± 0.34, respectively. No eye lost a line of visual acuity and 17 eyes (77.3 per cent) gained one or more lines. Fifteen eyes (68.2 per cent) were within 0.50 D and 20 (90.9 per cent) were within 1.00 D of the desired spherical equivalent refraction. There was a change in manifest refraction of 0.09 ± 0.21 (ranging from -0.25 to +0.75) from one week to six months after the surgery. CONCLUSION: The clinical outcomes of the current study demonstrate the safety, efficacy and predictability of toric implantable collamer lens in the correction of myopia and myopic astigmatism associated with keratoconus. The patients' refractions achieved early stability and remained stable during the course of the study.

Ocular higher-order aberrations and mesopic pupil size in individuals screened for refractive surgery.

AIM: To study the distribution of ocular higher-order aberrations(HOAs) and mesopic pupil size in individuals screened for refractive surgery. METHODS: Ocular HOAs and mesopic pupil size were studied in 2 458 eyes of 1 240 patients with myopia, myopic astigmatism and compound myopic astigmatism and 215 eyes of 110 patients with hyperopia, 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, total coma and mesopic pupil size were analyzed. Ocular HOAs were measured across a ≥ 6.0 mm pupil, and pupil size measurements were performed under the mesopic condition. RESULTS: The mean values of HOAs, total spherical aberration and total coma in the myopic group were 0.369µm, ±0.233, 0.133± 0.112µm and 0.330±0.188µm, respectively. In the hyperopic group the mean values of HOAs, total spherical aberration and total coma were 0.418µm ±0.214, 0.202±0.209µm and 0.343±0.201µm, respectively. Hyperopes showed greater total HOAs (P<0.01) and total spherical aberration (P<0.01) compared to myopes. In age-matched analysis, only the amount of total spherical aberration was higher in the hyperopic group (P=0.05). Mesopic pupil size in the myopic group was larger (P≤0.05). CONCLUSION: The results suggested that significant levels of HOAs were found in both groups which are important for planning refractive surgeries on Iranians. There were significantly higher levels of total spherical aberration in hyperopes compared to myopes. Mesopic pupil size was larger in myopic group.

Management of intracorneal epithelial cysts with ethanol irrigation and cyst wall excision: A clinicopathologic report.

PURPOSE: The clinical and pathologic characteristics and the surgical treatment of 2 patients with intrastromal corneal epithelial cysts are described. METHODS: This interventional case report presents 2 young patients with decreased vision and cosmetic impairment caused by intracorneal epithelial cysts. The first patient had history of strabismus surgery, and the second patient had undergone corneal laceration repair. The cysts had enlarged gradually and dissected into the cornea, threatening the visual axis. Both patients were treated with drainage of cyst contents, chemical cytodestruction with 96% ethanol for 1 minute in a closed system, followed by cyst wall excision. RESULTS: Corneal clarity and appearance improved significantly after surgery. In the first patient, best-corrected visual acuity was 20/20 before the operation and remained stable. In the second patient, best-corrected visual acuity improved from 20/400 to 20/60 after the procedure. Histopathologic findings revealed that the cyst walls were composed of nonkeratinized stratified squamous epithelium. No recurrence was noted up to 8 and 3 months in the first and second patients, respectively. No complication occurred during the follow-up period. CONCLUSION: Intracorneal epithelial cysts may be treated safely and effectively with a combination of drainage of cyst contents, irrigation with 96% ethanol, and cyst wall excision with good visual and cosmetic results.