Association of Patient Satisfaction with Cataract Grading in Five Types of Multifocal IOLs.

INTRODUCTION: This study investigated patient satisfaction levels in five premium intraocular lenses (IOLs). A secondary aim was to determine whether patient satisfaction was associated with the cataract grade before lens surgery. METHODS: In this multicenter prospective comparative study, 164 patients from diverse backgrounds underwent cataract surgery and were assigned for identical bilateral implantation of multifocal IOLs. In addition to visual performance, quality of life was measured using the National Eye Institute Refractive Error Quality Of Life Instrument (NEI-RQL 42) scoring questionnaire. The Sirius Scheimpflug Analyzer was used to evaluate the posterior cornea and aberrations. Finally, the association of patient satisfaction reports with the Pentacam Cataract Grading Scale (PCGS) and Lens Opacities Classification System (LOCS III) was evaluated. RESULTS: A considerable subjective improvement was observed in uncorrected far, near (40 cm), and intermediate (60 cm) visual acuity in the five groups (P values < 0.001). A significant difference was observed in mesopic and photopic contrast sensitivity between Symfony, Trinova, and AT LISA at the spatial frequency of 12 cycles per degree, favoring Symfony (P < 0.001). PanOptix users had considerably lower mean coma values (P < 0.001), while AT LISA users had lower mean spherical aberrations (P = 0.009) compared to the other groups. No additional safety concerns relating to IOLs were recorded. Mean satisfaction had a high correlation with LOCS and Pentacam Nuclear Staging (PNS) in each lens group, e.g., correlation coefficient and P value for AT LISA were respectively r = 0.99, P < 0.001 and r = 0.97, P = 0.004. CONCLUSION: Despite discrepancies between groups of lenses, most patients who received multifocal IOLs reported satisfaction at more than 3 years after the initial operation. A growing number of patients with cataracts are seeking spectacle-free vision with presbyopia-correcting IOLs. Hence, the high satisfaction rate among patients with cataract could indicate the value of offering a wider range of available lenses.

Optical coherence tomography angiography parameters after cataract surgery.

PURPOSE: To evaluate the changes in macular blood flow after cataract surgery through optical coherence tomography angiography (OCT-A). METHODS: In this prospective case series, 50 patients who underwent uncomplicated cataract surgery by the resident were included. OCT-A images and complete ocular examinations were performed at baseline, 1 and 3 months postoperatively. The changes in OCT-A parameters including foveal avascular zone (FAZ) area, vessel density (VD) of superficial and deep plexus, and central macular thickness were assessed before and after surgery. Cataract grading, intraocular inflammation, and duration of surgery were analyzed. RESULTS: FAZ was significantly reduced from 0.36 ± 0.13 mm2 at baseline to 0.32 ± 0.12 mm2 at month 1 (P < 0.001) and this reduction continued until month 3. In the superficial layer, vessel density of the fovea, parafovea, and whole image significantly increased from 13.9 ± 6.8, 43.7 ± 4.7, and 43.2 ± 4.4 at baseline to 18.4 ± 7.9, 45.7 ± 4.9, and 44.9 ± 4.5 at month 1. The increase in the vessel density of the deep layer was similar to the superficial layer. Accordingly, CMT at the fovea was significantly increased from 240.5 ± 21.99 µm at baseline to 253.1 ± 23.2 microns at month 1 (P < 0.001) and the increase significantly continued and reached 259.5 ± 22.6 µm at month 3 (P < 0.001). Accordingly, the FAZ area significantly reduced one month postoperatively. In regression analysis, CMT changes positively correlated with cataract grading. FAZ area negatively correlated with intraocular inflammation on the first postoperative day. CONCLUSION: The present study shows that CMT and vessel density of the macula significantly increase after uncomplicated cataract surgery, while the FAZ area reduces. Postoperative inflammation could be the possible explanation for the findings of this study.

Systemic supplemental oxygen therapy during accelerated corneal crosslinking for progressive keratoconus: randomized clinical trial.

PURPOSE: To investigate the potential additive effect of systemic supplemental oxygen administered during accelerated corneal crosslinking (CXL) for progressive keratoconus (KC). SETTING: Academic center. DESIGN: Randomized clinical trial. METHODS: Eyes with progressive KC randomized to 3 different CXL protocols were included. The first group (OA-CXL) included 19 eyes that underwent an accelerated CXL protocol (9 mW/cm2 for 10 minutes) while receiving systemic oxygen at a rate of 5 L/min for 10 minutes. The second group consisted of 14 eyes undergoing the same accelerated CXL protocol without supplemental oxygen therapy (A-CXL). The third group (C-CXL) comprised 14 eyes undergoing conventional CXL according to the Dresden protocol. All subjects were followed up for at least 6 months. Visual acuity, keratometry and corneal biomechanical parameters including corneal hysteresis and corneal resistance factor (CRF) were measured preoperatively and 6 months postoperatively. RESULTS: Reduction in maximum keratometry (Kmax) was significantly greater in the OA-CXL group (P = .01). At baseline, the mean Kmax was 54.31 ± 3.64 diopters (D) in the OA-CXL group, 54.66 ± 4.99 D in the A-CXL group, and 56.03 ± 5.28 D in the C-CXL group (P = .58), which reached 53.58 ± 3.24 D, 54.59 ± 4.65 D, and 55.87 ± 4.73 D at 6 months in the 3 study groups, respectively (P = .115). The mean CRF increased significantly only in the OA-CXL group from a baseline value of 6.32 ± 2.12 mm Hg to 7.38 ± 1.88 mm Hg at 6 months (P = .009). CONCLUSIONS: This study suggests superior efficacy of an accelerated CXL protocol coupled with systemic oxygen supplementation when compared with the accelerated CXL protocol and the conventional protocol in eyes with progressive KC. In addition to greater reduction in Kmax as the primary outcome, improvement in corneal biomechanics was also observed at 6 months.

Topical Umbilical Cord Serum for Corneal Epithelial Defects after Diabetic Vitrectomy.

PURPOSE: To evaluate the role of topical umbilical cord serum (TUCS) therapy in treating corneal epithelial defects (CEDs) after diabetic vitrectomy. METHODS: In this double-masked, randomized clinical trial, we included 80 eyes of 80 patients who were candidates for vitrectomy due to proliferative diabetic retinopathy complications. In cases of corneal edema obscuring the fundus view during surgery, the corneal epithelium was removed using a 6-mm trephine and a blade no.15. The day after the surgery, patients were randomly divided into two groups: (1) the TUCS group that received 20% TUCS six times/day in addition to the conventional treatment of CED and (2) the control group, which was prescribed artificial tears as placebo in addition to the conventional treatment of CED. The rate of healing of CEDs was measured via two maximum linear dimensions perpendicular to each other at the start of therapy and on postoperative days 1-5, 7, and 12. RESULTS: Of 80 eyes, 40 were assigned to each treatment group. The mean times to complete CED healing were 2.4 ± 0.7 and 3.8 ± 2.1 days in the TUCS and control groups, respectively (P < 0.001). Persistent CED occurred in two eyes in the control group but in no eyes in the TUCS group. CONCLUSION: TUCS therapy may be safe and effective in healing CEDs after vitrectomy in patients with diabetes.

Lower- and higher-order aberrations after photorefractive keratectomy with and without compensation of pupil centroid shift: fellow eye comparison.

PURPOSE: To study the effect of pupil centroid shift (PCS) compensation on lower- and higher-order aberrations (HOAs) after photorefractive keratectomy (PRK). SETTING: Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. DESIGN: Prospective intrasubject fellow eye study. METHODS: One hundred twelve eyes of 56 patients with simple myopia or myopic astigmatism scheduled for PRK were enrolled. Preoperatively, the amount of PCS was measured in the horizontal and vertical directions. All eyes received wavefront-optimized treatment with static cyclotorsion compensation. PCS compensation was turned on for the right eye of each subject (PCS-on group), and turned off for the left eye (PCS-off group). Postoperatively, refraction and corneal HOAs were compared between the study groups at 6 months. RESULTS: Mean preoperative myopia was -3.84 diopters (D) ± 2.41 (SD) vs -3.75 ± 2.27 D (P = .408), whereas mean preoperative cylinder was -1.18 D ± 1.15 (SD) vs -1.14 ± 1.16 D (P = .769) in the PCS-on and PCS-off groups, respectively. Mean absolute PCS values were 62.25 µm ± 41.82 (SD) vs 55.92 ± 37.47 µm (P = .45) in the horizontal direction and 65.04 ± 47.16 µm vs 58.40 ± 45.44 µm in the vertical direction (P = .29) in the PCS-on and PCS-off groups, respectively. The study groups were comparable in terms of postoperative refraction and root mean square of total corneal HOAs. CONCLUSIONS: Compensation of PCS did not affect lower- and higher-order aberrations after wavefront-optimized PRK with static cyclotorsion compensation in myopic or myopic astigmatic eyes.

Trans-iris fixation of dislocated in-the-bag intraocular lenses.

PURPOSE: The aim of this article is to describe the safety and efficacy of trans-iris suture fixation for the management of late dislocation of in-the-capsular-bag intraocular lenses following uncomplicated cataract surgery. PATIENTS AND METHODS: Eleven eyes of 11 patients with late in-the-capsular-bag intraocular lens dislocation following uneventful phacoemulsification cataract surgery were recruited in the study. The dislocated intraocular lens-capsular bag complex was sutured to the iris at two points 180° apart using 9-0 polypropylene sutures on long needles. RESULTS: Mean patient age was 67 ± 6 years. Seven eyes had pseudoexfoliation syndrome, one eye had Marfan syndrome, and another eye had a traumatic cataract; no risk factor was identified for intraocular lens dislocation in two eyes. A capsular tension ring had been implanted during cataract surgery in four eyes. In six eyes, the posterior chamber intraocular lenses were one-piece foldable while the remaining were three-piece intraocular lenses. Compared to the preoperative value, corrected distance visual acuity was significantly improved postoperatively (p < 0.005). Intraoperative hyphema occurred in two eyes. Pupil ovalization was observed in all eyes. Mean endothelial cell count decreased by 4 ± 1.7% after intraocular lens fixation. The capsular bag-intraocular lens complex was stable and well-centered in the pupillary area in all eyes at the final follow-up examination which was performed 16 ± 4 months postoperatively. CONCLUSION: Trans-iris fixation is a simple and effective procedure for management of late intraocular lenses-capsular bag complex dislocation, without major complications.

Goldmann applanation tonometer versus ocular response analyzer for measuring intraocular pressure after congenital cataract surgery.

PURPOSE: To compare intraocular pressure measured using the Goldmann applanation tonometer with that measured using the ocular response analyzer after congenital cataract surgery. METHODS: This study included 113 eyes of 64 patients who underwent lensectomy and vitrectomy. In all, 36 eyes remained aphakic after surgery. Intraocular lens implantation was performed at the time of surgery in 47 eyes and secondarily in 30 eyes. Corneal hysteresis, corneal resistance factor, and cornea-compensated intraocular pressure were measured. The influences of independent factors on the difference between the cornea-compensated intraocular pressure and intraocular pressure measured with Goldmann applanation tonometer were investigated using linear regression analyses. Agreement between the two tonometers was investigated using the Bland and Altman and 95% limits of agreement analysis. RESULTS: Central corneal thickness, corneal hysteresis, and corneal resistance factor were 591.2 ± 53.3 µm, 10.83 ± 2.27 mmHg, and 11.36 ± 2.14 mmHg, respectively. Cornea-compensated intraocular pressure (16.75 ± 4.82 mmHg) was significantly higher than intraocular pressure measured with Goldmann applanation tonometer (14.41 ± 2.27 mmHg, p < 0.001). Central corneal thickness (p = 0.02) and corneal hysteresis (p < 0.001) were identified as the main predictors of difference between cornea-compensated intraocular pressure and intraocular pressure measured with Goldmann applanation tonometer readings. A 95% limits of agreement for cornea-compensated intraocular pressure and intraocular pressure measured with Goldmann applanation tonometer was between -4.86 and 9.53 mmHg in the entire group. Cornea-compensated intraocular pressure showed the best agreement with intraocular pressure measured with Goldmann applanation tonometer in the primary pseudophakic subgroup as compared to the other subgroups. CONCLUSION: The Goldmann applanation tonometer and ocular response analyzer cannot be used interchangeably for measuring intraocular pressure after congenital cataract surgery. The difference between the cornea-compensated intraocular pressure and intraocular pressure measured with Goldmann applanation tonometer was primarily affected by central corneal thickness and corneal hysteresis. Among the subgroups, the primary pseudophakic subgroup had the thinnest cornea and the highest corneal hysteresis values and demonstrated the best agreement between the two tonometers.

Accuracy of Various Intraocular Lens Power Calculation Formulas in Steep Corneas.

PURPOSE: To compare the accuracy of four different intraocular lens (IOL) power calculation formulas for eyes with mean keratometry values greater than 46 diopters (D). METHODS: Forty five eyes from 45 patients who were candidates for senile cataract surgery with mean keratometry values greater than 46 D were included. Calculation of the IOL power was performed by the Lenstar. The implanted IOL in all cases was Acrysof SA60AT. The average absolute value of the differences between the actual and predicted spherical equivalent (SE) of the postoperative refractive error (mean absolute error: MAE) was calculated using 4 formulas (Haigis, Holladay 1, Hoffer Q, and SRK/T) with optical IOL constants from the User Group for Laser Interference Biometry constants. RESULTS: The MAE was smallest in the SRK/T formula (0.39 D ± 0.35) followed by those of the Holladay 1 (0.44 D ± 0.32), Haigis (0.45 D ± 0.35) and Hoffer Q (0.5 D ± 0.38) formulas. However, there was no statistically significant difference between the MAE among different formulas. The SRK/T formula predicted more eyes within ± 0.5 D of the SE (77.8%) compared to other formulas. CONCLUSION: In eyes with steep corneas, there were no statistically significant differences among the accuracies of the four common IOL power calculation formulas.

Factors influencing intraocular pressure, corneal thickness and corneal biomechanics after congenital cataract surgery.

AIMS: This study aims to compare intraocular pressure (IOP), central corneal thickness (CCT) and corneal biomechanics among patients with aphakia, patients with primary and secondary pseudophakia and matched controls following congenital cataract surgery and to investigate the factors influencing these variables. METHODS: This study included 36 aphakic eyes, 47 primary pseudophakic eyes and 30 secondary pseudophakic eyes. Thirty-four normal eyes of matched volunteers were recruited for comparisons. Postoperative IOP measured with a Goldmann applanation tonometer (IOPGAT), CCT, corneal hysteresis (CH), corneal resistance factor (CRF) and cornea-compensated IOP (IOPCC) were compared among the groups. Univariate analyses and multiple linear regression analyses were used to investigate the influences of independent factors on IOPGAT, CCT, CH, CRF and IOPCC, considering all the operated eyes as one group. RESULTS: IOPGAT was 12.5±0.92, 14.7±1.9, 13.4±2.3 and 15.7±2.0 mm Hg in normal, aphakic, primary pseudophakic and secondary pseudophakic eyes, respectively (p<0.001). CCT was 559.5±42.7, 628.0±61.7, 566.8±35.3 and 585.2±41.1 µm, respectively (p<0.001). CH was 10.87±2.47, 10.42±2.20, 11.84±2.13 and 9.74±1.94 mm Hg, respectively (p=0.019). IOPCC was 15.91±3.74, 18.40±4.35, 14.58±4.36 and 19.05±4.54 mm Hg, respectively (p<0.001). There was no significant difference in CRF among the groups (p=0.06). Regression analyses revealed that the type of operation was significantly associated with IOPGAT (p=0.04), CCT (p<0.001) and CH (p=0.006). CONCLUSIONS: IOPGAT, CCT, CH and IOPCC were significantly different in treated eyes compared with normal eyes after congenital cataract surgery. These variables were primarily affected by the type of surgery. Primary intraocular lens implantation preserved corneal structure and function of the anterior chamber angle.

Aspheric versus wavefront-guided aspheric photorefractive keratectomy in eyes with significant astigmatism.

PURPOSE: To compare the refractive and higher-order aberrations (HOAs) outcomes after photorefractive keratectomy (PRK) in patients with significant astigmatism using aspheric versus wavefront-guided aspheric profiles. SETTING: Ophthalmic Research Center and Department of Ophthalmology, Shahid Beheshti University of Medical Sciences, Negah Eye Hospital, Tehran, Iran. DESIGN: Prospective randomized case series. METHODS: One eye of each patient with a refractive astigmatism more than 2.00 diopters (D) randomly received aspheric PRK. In the other eye, wavefront-guided and aspheric treatment was performed using a personalized treatment advanced algorithm. Visual acuity, refractive errors, and HOAs were compared between the 2 groups preoperatively and 12 months postoperatively. RESULTS: The study comprised 32 patients (64 eyes). The mean preoperative refractive astigmatism was -4.07 D ± 1.64 (SD) and -4.02 ± 1.55 D in the aspheric group and wavefront-guided aspheric group, respectively (P = .2). The mean postoperative astigmatism was -0.46 ± 0.37 D and -0.82 ± 0.53 D in the aspheric group and wavefront-guided aspheric group, respectively (P = .02). Postoperatively, the root mean square of total HOAs was significantly increased in both groups. However, compared with wavefront-guided aspheric PRK, aspheric PRK induced fewer HOAs (P = .003). CONCLUSIONS: In eyes with high astigmatism, post-PRK residual astigmatism was lower in the aspheric group than in the wavefront-guided aspheric group. The increase in HOAs was significantly higher in the wavefront-guided aspheric group than in the aspheric group.

A technique to fixate dislocated lenticules in complicated Descemet stripping automated endothelial keratoplasty.

PURPOSE: To describe a technique to fixate a dislocated donor lenticule following complicated Descemet stripping automated endothelial keratoplasty (DSAEK) when lenticule attachment has not been successful following previous attempts employing air tamponade due to iris defects and posterior capsule ruptures. METHODS: In this technique, we fixate the DSAEK lenticule at 2 points using partial-thickness sutures buried in the recipient corneal stroma. RESULTS: Three complicated DSAEK cases were operated by this technique. The lenticules were totally attached and the corneas remained clear up to the last visit, 6 months after the last procedure. CONCLUSIONS: Our technique is easy to perform and efficient for fixation of detached lenticules and may also be performed primarily to prevent lenticule detachment in complicated DSAEK eyes.

Modified big-bubble deep anterior lamellar keratoplasty using peripheral air injection.

PURPOSE: To introduce a modification to big-bubble deep anterior lamellar keratoplasty (DALK) which can decrease the risk of Descemet membrane (DM) perforation during air injection. METHOD: In Anwar's big-bubble technique, a 27-guage needle is inserted from the trephination site and advanced into the corneal stroma up to the centre. The technique we introduce modifies the original technique in the following fashion. After trephination to approximately 80% of corneal thickness, a 27-guage needle is inserted into the stroma peripherally from the trephination site towards the limbus. Air is injected gently into the deep stroma until a big bubble is formed. This technique was performed in 16 consecutive keratoconic eyes undergoing DALK. Additionally, peripheral air injection was carried out in 27 eye-bank corneas using a peripheral approach. RESULTS: In all (100%) eye-bank and 13 (81.3%) live corneas, a successful big bubble was easily achieved following peripheral air injection. In these 13 live corneas, all bubbles were formed at the central (n=10) or paracentral (n=3) cornea and extended centrifugally (type 1 bubble). In one of these corneas, an additional three bubbles were noted in the periphery between the DM and the pre-Descemet posterior stromal layer (Dua's layer, type 2) after a type 1 bubble was formed. In two live corneas in which peripheral air injection failed, a big bubble was successfully formed after air was injected inside the trephination site. CONCLUSIONS: Air injection peripheral to the trephination site is a reproducible modification to the standard technique which can decrease the risk of DM perforation during air injection.

Limbal stem cell-sparing lamellar keratoplasty for the management of advanced keratoglobus.

PURPOSE: To describe the technique and outcomes of limbal stem cell-sparing lamellar keratoplasty (LSCS-LKP) for the management of advanced keratoglobus (KGB). METHODS: In a sequential interventional case series from March 2010 to December 2012, 8 eyes of 6 patients with advanced KGB underwent an LSCS-LKP. Three patients had isolated KGB, 2 were affected with the Ehlers-Danlos syndrome, and the other subject had osteogenesis imperfecta. Epithelial healing, anatomical results (corneal thickness and keratometry), and visual outcomes were evaluated after this intervention. RESULTS: Three of the 6 patients were male. Complete epithelial healing occurred in 7 eyes during 2 weeks. Refractory persistent epithelial defect and graft melting occurred in 1 eye. Corneal thickness increased and central keratometry decreased after the LSCS-LKP was performed in all the patients. The patients were followed up for at least 6 months. Visual acuity improved in all eyes except 1. CONCLUSIONS: LSCS-LKP is an effective procedure for preserving ocular integrity and for improving visual acuity in patients with advanced KGB. Early surgical intervention can be considered before the occurrence of vision-threatening traumatic corneal rupture.

Central anterior chamber depth changes after prophylactic laser iridotomy.

PURPOSE: To evaluate the effect of laser peripheral iridotomy (LPI) on biometric parameters including central anterior chamber depth (CACD) in primary angle closure suspect eyes. METHODS: Eyes classified as primary angle closure suspect were enrolled in this interventional case series. Biometry with Lenstar (Haag-Streit AG, Koeniz, Switzerland) was performed before LPI and 6 weeks afterward. Central anterior chamber depth, lens thickness, axial length, and central corneal thickness were measured before and after the intervention. RESULTS: Forty eyes of 40 patients with mean age of 56.5 ± 5.5 years were studied. Mean central anterior chamber depth was 2.07 ± 0.21 mm before and 2.08 ± 0.19 mm after LPI (p = 0.8). There was no significant change in lens thickness, axial length, and central corneal thickness after LPI. CONCLUSIONS: Central anterior chamber depth "measured by Lenstar" does not change after LPI in primary angle closure suspect eyes.

Subconjunctival bevacizumab injection for ocular surface squamous neoplasia.

PURPOSE: To determine the efficacy and safety of perilesional/subconjunctival bevacizumab injections in the management of ocular surface squamous neoplasia (OSSN). METHODS: Ten eyes of 10 patients with an OSSN diagnosis confirmed by impression cytology received 2 perilesional/subconjunctival injections of bevacizumab at a 2-week interval. Patients were evaluated for 3 months, during which time, changes in the lesions were documented using digital photography. After this period, excisional biopsy of the remaining tumor and cryotherapy of the conjunctival borders were performed if deemed necessary. RESULTS: The mean age of the patients was 65 ± 12 years (± SD). All of the tumors were nasal in origin and had varying degrees of vascularization. The mean lesion area before treatment was 16 ± 6.9 mm2. Two weeks after the first injection, the mean reduction observed in the tumor area was 25% ± 5.65% and ranged from 17% to 33% (P = 0.001). Two weeks after the second injection, the mean tumor area was further decreased (42% ± 33%, ranging from 15% to 100%, P = 0.049). Corneal extension of the tumor was not affected significantly in 8 of the eyes with concomitant conjunctival and corneal involvement. Complete disappearance of the tumor was demonstrated by impression cytology and occurred in 2 cases involving lesions clinically confined to the conjunctiva. No systemic or ocular side effects occurred during the study period. CONCLUSIONS: Perilesional/subconjunctival injections of bevacizumab decrease the size and vascularity of OSSN and may be curative in lesions limited to the conjunctiva. However, this treatment has no significant effect on the corneal extension of OSSN.

Corneal endothelial cell loss during phacoemulsification: bevel-up versus bevel-down phaco tip.

PURPOSE: To compare corneal endothelial cell loss during cataract extraction by phacoemulsification with 2 different phaco-tip positions. SETTING: Ophthalmic Research Center and Department of Ophthalmology, Labbafinejad Medical Center, Shahid Beheshti Medical University, Tehran, Iran. DESIGN: Randomized clinical trial. METHODS: Eyes scheduled for cataract extraction were randomly assigned stop-and-chop phacoemulsification with the phaco tip in the conventional bevel-up position or with the phaco tip in the bevel-down position. During surgery, the effective phacoemulsification time (EPT) was recorded. Preoperative endothelial cell parameters were compared with measurements taken 3 months postoperatively. RESULTS: Each group comprised 30 eyes (30 patients). There were no statistically significant differences in age, sex, anterior chamber depth, axial length, or EPT between the 2 groups. The mean preoperative endothelial cell density (ECD) was 2544 cells/mm(2) ± 64 (SD) in the bevel-up group and 2471 ± 59 cells/mm(2) in the bevel-down group (P=.610). Postoperatively, both groups had a significant decrease in ECD. The mean endothelial cell loss was 5.9% in the bevel-up group and 13.6% in the bevel-down group (P=.012). The percentage of hexagonal cells and coefficient of variation in cell size were not different between the 2 groups preoperatively or postoperatively; however, after surgery, there was a significant decrease in the percentage of hexagonal cells in both groups. CONCLUSION: Corneal endothelial cell loss during phacoemulsification was significantly higher when the phaco tip was in the bevel-down position than in the conventional bevel-up position. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Comparison of corneal tomography measurements using Galilei, Orbscan II, and Placido disk-based topographer systems.

PURPOSE: To evaluate agreement in keratometry readings and anterior and posterior elevation map measurements among the Galilei V4.01 (Ziemer), Orbscan IIz (Bausch & Lomb), and Corneal Map topographer (Costruzione Strumenti Oftalmici) systems. METHODS: This prospective comparative study comprised 184 eyes of 92 consecutive refractive surgery candidates who were simultaneously examined with the Galilei (dual Scheimpflug), Orbscan II (scanning-slit), and Corneal Map topographer (Placido disk-based) systems. Keratometry readings and anterior and posterior elevation map measurements were compared using analysis of variance and paired t test, respectively. RESULTS: Mean keratometry reading was 44.30 ± 1.49 diopters (D), 44.11 ± 1.47 D, and 44.60 ± 1.56 D with the Galilei, Orbscan, and Corneal Map topographer, respectively. Despite a significant difference in mean keratometry (P<.001), the correlation among these three systems was strong. The maximum mean difference between two sets in simulated keratometry and astigmatism was <0.50 D. In the evaluation of anterior best-fit-sphere (BFS) and posterior BFS, the correlation between Galilei and Orbscan II was found to be 0.960 and 0.947, respectively. Maximum anterior central elevation measured by Orbscan II and Galilei was 9.2 ± 5.1 µm and 3.2 ± 1.8 µm, respectively. Maximum posterior central elevation by Orbscan II and Galilei was 33.8 ± 9.3 µm and 6.8 ± 3.8 µm, respectively. CONCLUSIONS: Despite significant differences in mean keratometry readings and anterior and posterior elevation measurements among the three systems, the keratometry readings can be used interchangeably, as this difference is not clinically significant.

Changes in central corneal thickness after congenital cataract surgery.

PURPOSE: To evaluate central corneal thickness (CCT) changes after congenital cataract surgery with or without intraocular lens (IOL) implantation. SETTING: Ophthalmic Research Center, Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. DESIGN: Comparative case series. METHODS: Anterior lensectomy and anterior vitrectomy were performed in eyes with congenital cataract. Eyes had IOL implantation (pseudophakic group) or remained aphakic (aphakic group). The CCT and intraocular pressure were measured in all cases preoperatively and 1 and 6 months postoperatively. Age-matched normal eyes served as a control group. RESULTS: The study evaluated 47 eyes (30 patients), 32 pseudophakic and 15 aphakic. The mean preoperative CCT was 540 µm ± 34 (SD) in the pseudophakic group, 548 ± 61 µm in the aphakic group, and 558 ± 36 µm in the control group (P = .207). The mean CCT in the aphakic group was significantly greater than in the pseudophakic group (587 ± 65 µm versus 539 ± 37 µm) 1 month postoperatively (P = .018) and at 6 months (602 ± 65 µm versus 540 ± 36 µm) (P = .012). Although the CCT values in the pseudophakic group at 1 month and 6 months were similar to preoperative values (P = .463 and P = 1.00, respectively), both postoperative CCT values in the aphakic group were significantly greater than preoperatively (P<.001). CONCLUSIONS: The CCT in eyes with congenital cataract was similar to that in normal age-matched eyes. However, shortly after cataract removal, the CCT was significantly greater in aphakic eyes than in pseudophakic eyes.

Central corneal thickness measurements after myopic photorefractive keratectomy using Scheimpflug imaging, scanning-slit topography, and ultrasonic pachymetry.

PURPOSE: To compare central corneal thickness (CCT) measurements obtained with a dual Scheimpflug camera system (Galilei), a scanning-slit topographer (Orbscan II), and an ultrasound (US) pachymeter (SP-2000) after photorefractive keratectomy (PRK) for myopia. SETTING: Ophthalmic Research Center, Labbafinejad Medical Center, Tehran, Iran. METHODS: This prospective study enrolled patients who had PRK to correct myopia or myopic astigmatism and a postoperative follow-up of at least 5 months. The CCT was measured in a single session using Scheimpflug imaging, scanning-slit topography, and US pachymetry. Data were analyzed with paired t tests, linear regression, and Bland-Altman plots. RESULTS: The mean CCT in the 100 eyes (50 patients) was 524.06 microm +/- 38.56 (SD) with Scheimpflug imaging, 505.92 +/- 47.35 microm with scanning-slit topography, and 496.97 +/- 42.74 microm with US pachymetry. The lower to upper 95% limits of agreement (LoA) with US pachymetry were 2.4 to 51.8 microm for Scheimpflug imaging and -22.2 to 40.1 microm for scanning-slit topography. After application of a correction factor (0.95), the mean corrected Scheimpflug CCT measurement was 497.33 +/- 36.59 microm and the lower to upper 95% LoA with US pachymetry were -25.9 to 25.5 microm. The acoustic factor for scanning-slit topography was 0.94. CONCLUSIONS: The CCT measurements in eyes that had PRK were thicker with Scheimpflug imaging than with US pachymetry or scanning-slit topography in the late postoperative period. With application of a correction factor, the Scheimpflug measurements were closer to US pachymetry values and had better agreement than scanning-slit topography.