Showing papers in "Journal of Cataract and Refractive Surgery in 2009"
TL;DR: Results indicate that changing the inclusion criteria may significantly reduce the complications and failures of CXL and restricting patient age to younger than 35 years may reduce the complication rate to 1%.
Abstract: Purpose To evaluate the complication rate of corneal crosslinking (CXL) for primary keratectasia and to develop recommendations for avoiding complications. Setting Institut fur Refraktive und Ophthalmo-Chirurgie, Zurich, Switzerland. Methods In a prospective study, eyes with verified progressive keratectasia had standard CXL. Preoperative and 6- and 12-month postoperative examinations included corrected distance visual acuity (CDVA), slitlamp evaluation, applanation tonometry, and Scheimpflug imaging (Pentacam). Statistical analysis included analysis of variance and the Mann-Whitney U test to detect risk factors for complications. Results The study evaluated 117 eyes of 99 patients; approximately 90% completed the 12-month follow-up. The complication rate (percentage of eyes losing 2 or more Snellen lines) was 2.9% (95% confidence interval, 0.6%-8.5%). The failure rate of CXL (percentage of eyes with continued progression) was 7.6%. Age older than 35 years and a preoperative CDVA better than 20/25 were identified as significant risk factors for complications. A high preoperative maximum keratometry (K) reading was a significant risk factor for failure. Sterile infiltrates were seen in 7.6% of eyes and central stromal scars, in 2.8%. Conclusions Results indicate that changing the inclusion criteria may significantly reduce the complications and failures of CXL. A preoperative maximum K reading less than 58.00 diopters may reduce the failure rate to less than 3%, and restricting patient age to younger than 35 years may reduce the complication rate to 1%.
519 citations
TL;DR: Corneal astigmatism less than 1.25 D was present in most cataract surgery candidates; it was higher in about 22%, with slight differences between the various age ranges, which is useful for intraocular lens manufacturers and surgeons to evaluate which age ranges concentrate the parameters most frequently needed in sphere and cylinder powers.
Abstract: Purpose To analyze the prevalence and presentation patterns of corneal astigmatism in cataract surgery candidates. Setting University of Valencia, Valencia, Spain. Methods Refractive and keratometric values were measured before surgery in patients having cataract extraction. Descriptive statistics of refractive and keratometric cylinder data were analyzed and correlated by age ranges. Results Refractive and keratometric data from 4540 eyes of 2415 patients (mean age 60.59 years ± 9.87 [SD]; range 32 to 87 years) differed significantly when the patients were divided into 10-year subsets. There was a trend toward less negative corneal astigmatism values, except the steepest corneal radius and the J 45 vector component, in older groups (Kruskal-Wallis, P Conclusions Corneal astigmatism less than 1.25 D was present in most cataract surgery candidates; it was higher in about 22%, with slight differences between the various age ranges. This information is useful for intraocular lens (IOL) manufacturers to evaluate which age ranges concentrate the parameters most frequently needed in sphere and cylinder powers and for surgeons to evaluate which IOLs provide the most effective power range.
372 citations
TL;DR: The current treatment protocol for advanced keratoconus is modified by preoperatively swelling thin corneas to a stromal thickness of at least 400 μm using hypoosmolar riboflavin solution.
Abstract: Corneal collagen crosslinking (CXL) with riboflavin and ultraviolet-A light is a method for treating progressive keratectasia. The currently accepted treatment parameters induce collagen crosslinking in the anterior 250 to 350 μm of corneal stroma. To protect the endothelium, CXL inclusion criteria require a minimum corneal thickness of 400 μm after removal of the epithelium. In advanced keratoconus, however, progressive corneal thinning often leads to a remaining stromal thickness of less than 400 μm. We have therefore modified the current treatment protocol by preoperatively swelling thin corneas to a stromal thickness of at least 400 μm using hypoosmolar riboflavin solution. This treatment protocol was performed in a case series of 20 patients, and no complications were observed. Preoperative swelling of the cornea safely broadens the spectrum of CXL indications to thin corneas that would otherwise not be eligible for treatment.
343 citations
TL;DR: Complaints of blurred vision and photic phenomena after multifocal IOL implantation were effectively managed with appropriate treatment and should be delayed until it has been determined that IOL exchange will not be necessary.
Abstract: Purpose To analyze the reasons for patient dissatisfaction after phacoemulsification with multifocal intraocular lens (IOL) implantation and the outcomes after intervention. Setting Emory Eye Center, Atlanta, Georgia, USA. Methods This retrospective review comprised eyes of patients dissatisfied with visual outcomes after multifocal IOL implantation. Outcomes analyzed included type of visual complaint, treatment modality for each complaint, and degree of clinical improvement after intervention. Results Thirty-two patients (43 eyes) reported unwanted visual symptoms after multifocal IOL implantation, including in 28 eyes (65%) with an AcrySof ReSTOR IOL and 15 (35%) with a ReZoom IOL. Thirty patients (41 eyes) reported blurred vision, 15 (18 eyes) reported photic phenomena, and 13 (16 eyes) reported both. Causes of blurred vision included ametropia (12 eyes, 29%), dry eye syndrome (6 eyes, 15%), posterior capsule opacification (PCO) (22 eyes, 54%), and unexplained etiology (1 eye, 2%). Causes of photic phenomena included IOL decentration (2 eyes, 12%), retained lens fragment (1 eye, 6%), PCO (12 eyes, 66%), dry-eye syndrome (1 eye, 2%), and unexplained etiology (2 eyes, 11%). Photic phenomena attributed to PCO also caused blurred vision. Thirty-five eyes (81%) had improvement with conservative treatment. Five eyes (12%) did not have improvement despite treatment combinations. Three eyes (7%) required IOL exchange. Conclusions Complaints of blurred vision and photic phenomena after multifocal IOL implantation were effectively managed with appropriate treatment. Few eyes (7%) required IOL exchange. Neodymium:YAG capsulotomy should be delayed until it has been determined that IOL exchange will not be necessary.
341 citations
TL;DR: Corneal crosslinking without epithelial debridement reduced the biomechanical effect by approximately one fifth compared with standard crossl linking, probably because of restricted and inhomogeneous stromal distribution of riboflavin.
Abstract: Purpose To test the biomechanical efficiency of corneal crosslinking with riboflavin without epithelial debridement (C3-R). Setting Moscow Helmholtz Research Institute of Eye Diseases, Moscow, Russia. Methods The left eyes of rabbits were crosslinked using standard crosslinking including epithelial removal (Group 1), using benzalkonium chloride–containing proxymetacaine eyedrops without epithelial removal (Group 2), or using preservative-free oxybuprocaine eyedrops without epithelial removal (Group 3). All left eyes received riboflavin solution and were irradiated with an ultraviolet-A double diode for 30 minutes (irradiance 3 mW/cm 2 ). The animals were killed 1 day after crosslinking. Biomechanical and histological analyses were performed. Results Fourteen eyes were evaluated. There was a statistically significant increase in Young's modulus in Group 1 (102.45%) and in Group 2 (21.30%). In Group 3, no biomechanical changes were measured. Histology showed complete cell loss of keratocytes and endothelium in Group 1 and inhomogeneous keratocyte loss down to 200.0 μm in Group 2. No changes were observed in Group 3. Conclusions Corneal crosslinking without epithelial debridement reduced the biomechanical effect by approximately one fifth compared with standard crosslinking, probably because of restricted and inhomogeneous stromal distribution of riboflavin. The cytotoxic damage was restricted to 200.0 μm stromal depth, which is an advantage over the standard method. Therefore, C3-R is not recommended for the routine treatment of keratoconus but primarily for cases with a corneal thickness less than 400.0 μm in which standard crosslinking cannot be used without serious risk to the endothelium.
312 citations
TL;DR: The HPLC quantitative study showed that stromal concentrations of rib oflavin increased with exposure time only if the epithelium was removed, and a theoretically safe and effective riboflavin concentration of 15 μg/g was obtained for ultraviolet A‐induced CXL only after the epithelial was removed and after at least 10 minutes of ribofavin application every 2 minutes.
Abstract: Purpose To evaluate intrastromal concentrations of riboflavin with and without epithelium to ensure the efficacy and safety of corneal crosslinking (CXL) by the standard and transepithelial procedures. Setting Department of Ophthalmology and Department of Pharmacology G. Segre, Siena University, Siena, Italy. Methods This study comprised keratoconic patients enrolled for penetrating keratoplasty (PKP) and warm-stored sclerocorneal rings unsuitable for transplantation. Half the PKP specimens were debrided, and half were left with the epithelium in situ. One of the latter and 1 debrided sample were not exposed to riboflavin (controls). Samples in both groups were soaked with 0.1% riboflavin–dextran 20% solution instilled every 2 minutes for 5, 15, and 30 minutes. Riboflavin concentrations were determined by high-performance liquid chromatography (HPLC). Results The study evaluated 14 PKP specimens and 16 sclerocorneal rings. Control samples did not show a riboflavin emission peak. In exposed samples with epithelium, the mean riboflavin concentration was 91.88 ng/g after 5 minutes of exposure, 95.60 ng/g after 15 minutes, and 94.92 ng/g after 30 minutes. In the debrided samples, the mean riboflavin concentration was 14.42 μg/g, 20.92 μg/g, and 24.06 μg/g, respectively. No differences were seen between the in vivo samples and the ex vivo samples. Conclusions The HPLC quantitative study showed that stromal concentrations of riboflavin increased with exposure time only if the epithelium was removed. A theoretically safe and effective riboflavin concentration of 15 μg/g was obtained for ultraviolet A-induced CXL only after the epithelium was removed and after at least 10 minutes of riboflavin application every 2 minutes.
209 citations
TL;DR: The IOP reductions were similar to previously reported reductions in nonglaucomatous eyes, indicating that the aging crystalline lens may be a major cause of ocular hypertension and glaucoma and that phacoemulsification with IOL implantation may help prevent and treat adult glau coma.
Abstract: Purpose To study the long-term effects of phacoemulsification with intraocular lens (IOL) implantation in nonglaucomatous and glaucomatous eyes. Setting Phillips Eye Institute, Minneapolis, Minnesota, and private practice, Savannah, Georgia, USA. Methods Intraocular pressure (IOP) after phacoemulsification with IOL implantation was retrospectively reviewed. Eyes were divided into 5 groups by preoperative IOP. Data were recorded preoperatively, 1 year postoperatively, and at the final check. Analysis included preoperative IOP versus IOP at 1 year and final IOP, percentage of eyes with elevated or reduced IOP postoperatively, patient age at surgery, and years of postoperative follow-up. Results The study comprised 124 eyes. The final mean IOP reduction was 8.5 mm Hg (34%) in the 29 to 23 mm Hg group, 4.6 mm Hg (22%) in the 22 to 20 mm Hg group, 3.4 mm Hg (18%) in the 19 to 18 mm Hg group, and 1.1 mm Hg (10%) in the 17 to 15 mm Hg group. In the 14 to 5 mm Hg group, IOP increased by 1.7 mm Hg (15%). Conclusions Intraocular pressure reduction was proportional to preoperative IOP; the highest preoperative IOPs decreased the most and the lowest increased slightly. One-year IOP reductions were sustained for 10 years and were similar in patients of all ages. The IOP reductions were similar to previously reported reductions in nonglaucomatous eyes, indicating that the aging crystalline lens may be a major cause of ocular hypertension and glaucoma and that phacoemulsification with IOL implantation may help prevent and treat adult glaucoma.
202 citations
TL;DR: The 9‐item Rasch‐scaled Catquest‐9SF was highly valid in measuring visual disability outcomes of cataract surgery and its brevity makes it suited to routine clinical use, and a raw‐data to Rasch•measure conversion simplifies application.
Abstract: Purpose To assess and optimize the Catquest questionnaire for measuring patient-reported outcomes of cataract surgery using Rasch analysis. Setting Fifty-eight ophthalmic surgical units in Sweden. Methods Catquest questionnaires (n = 21364) from the Swedish National Cataract Register were selected and randomized to 2 groups. Data from 10486 questionnaires were comprehensively Rasch analyzed using a 4-Andrich rating scale model in Winsteps software. A revised version of Catquest was developed (Catquest-9SF) and tested in 10886 patients for validity and responsiveness to cataract surgery. Results Only the visual disability subscale formed a valid measurement scale. This could be enhanced through the addition of the 2 global assessment items; however, the symptoms and frequency of performing the activities items did not contribute to the measurement. The 9-item short-form version (Catquest-9SF) had ordered response thresholds and good person separation (2.65) and was largely free from differential item functioning. All items fit a single overall construct (infit range, 0.75 to 1.29; outfit range, 0.70 to 1.39) and unidimensional by principal components analysis. The items were well targeted to the preoperative participants (0.34 logit difference in means). The score correlated with visual acuity ( r = 0.43 preoperatively; r = 0.48 postoperatively) and was highly responsive to cataract surgery (preoperatively −0.32 ± 2.15 logits; postoperatively −3.21 ± 2.50 logits ( P Conclusions The 9-item Rasch-scaled Catquest-9SF was highly valid in measuring visual disability outcomes of cataract surgery. Its brevity makes it suited to routine clinical use, and a raw-data to Rasch-measure conversion simplifies application.
195 citations
TL;DR: Stable BCVA, spherical equivalent, anterior and posteriorCorneal curvatures, and corneal elevation 1 year after crosslinking indicate that keratoconus did not progress.
Abstract: Purpose To evaluate changes in corneal curvature, corneal elevation, corneal thickness, lens density, and foveal thickness after corneal collagen crosslinking with riboflavin and ultraviolet-A (UVA) light in eyes with progressive keratoconus. Setting Grewal Eye Institute, Chandigarh, India. Methods Subjective refraction, best corrected visual acuity (BCVA), Scheimpflug imaging, and optical coherence tomography were performed preoperatively and 1 week, 1, 3, and 6 months, and 1 year after crosslinking. Results There were no significant differences ( P > 0.05) in mean values between preoperatively and 1 year postoperatively, respectively, in BCVA (0.22 ± 0.10 and 0.20 ± 0.10), spherical equivalent (−6.30 ± 4.50 diopters (D) and −4.90 ± 3.50 D), or cylinder vector (1.58 × 7 ° ± 3.8 D and 1.41 × 24 ° ± 3.5 D). There was no significant difference in mean measurements between preoperatively and 1 year postoperatively, respectively, for central corneal thickness (458.9 ± 40 μm and 455.2 ± 48.6 μm), anterior corneal curvature (50.6 ± 7.4 D and 51.5 ± 3.6 D), posterior corneal curvature (−7.7 ± 1.2 D and −7.4 ± 1.1 D), apex anterior ( P = .9), posterior corneal elevation ( P = .7), lens density ( P = .33), or foveal thickness (175.7 ± 35.6 μm and 146.4 ± 8.5 μm; P = .1). Conclusions Stable BCVA, spherical equivalent, anterior and posterior corneal curvatures, and corneal elevation 1 year after crosslinking indicate that keratoconus did not progress. Unchanged lens density and foveal thickness suggest that the lens and macula were not affected after UVA exposure during crosslinking.
178 citations
TL;DR: Intraocular lenses designed solely for the capsular bag should not be placed in the ciliary sulcus, and backup IOLs in appropriate powers, sizes, and designs should be available for every cataract procedure.
Abstract: Purpose To describe complications arising from sulcus placement of single-piece acrylic (SPA) intraocular lenses (IOLs), evaluate IOL options for eyes that lack adequate capsule support, and examine the appropriateness of various IOL designs for sulcus placement. Setting University and private anterior segment surgery practices. Methods Patients referred for complications of SPA IOLs in the ciliary sulcus from 2006 and 2008 were identified. Demographic information, examination findings, and complications of the initial surgery were recorded. Details of surgical interventions and the most recent corrected distance visual acuity (CDVA) were noted. A thorough review of the literature was undertaken to analyze options for IOL placement. Results Complications of sulcus SPA IOLs included pigment dispersion, iris transillumination defects, dysphotopsia, elevated intraocular pressure, intraocular hemorrhage, and cystoid macular edema. Two patients in the series of 30 patients experienced 1 complication; 8 experienced 2 complications; 13 experienced 3 complications; 4 experienced 4 complications; and 2 experienced 5 complications. Twenty-eight eyes (93%) required surgical intervention; IOL exchange was performed in 25 (83%). Postoperatively, the mean CDVA improved, with most eyes attaining 20/20. Conclusions Intraocular lenses designed solely for the capsular bag should not be placed in the ciliary sulcus. Backup IOLs in appropriate powers, sizes, and designs should be available for every cataract procedure. The development, investigation, and supply of IOLs specifically designed for placement in eyes that lack adequate capsule support represent clinically important endeavors for ophthalmology and the ophthalmic industry.
173 citations
TL;DR: This is the first report of a case of rare postoperative complication resulted in an avascularized corneal scar and permanent reduction of the visual acuity.
Abstract: We report a case of bacterial keratitis 3 days after corneal crosslinking for keratoconus. The patient complained of increasing pain and redness combined with blurred vision in the treated eye starting on the first postoperative day. Clinical examination showed multiple stromal infiltrations and moderate anterior chamber inflammation. Corneal scraping revealed an Escherichia coli infection, which was successfully treated with fortified tobramycin and cephazolin eyedrops for several weeks. This is the first report of a case of rare postoperative complication resulted in an avascularized corneal scar and permanent reduction of the visual acuity.
TL;DR: Scheimpflug and OCT CCT measurements were reproducible but always thinner than US pachymetry in normal and keratoconus‐suspect eyes, and in post–laser in situ keratomileusis (LASIK) eyes, OCTpachymetry maps were more accurate than Scheimp flug maps.
Abstract: Purpose To compare central (CCT) and peripheral corneal thickness (PCT) using Scheimpflug imaging (Pentacam), high-speed optical coherence tomography (Visante OCT), and ultrasound (US) pachymetry (Sonogage Corneo-Gage Plus) in normal, keratoconus-suspect, and post–laser in situ keratomileusis (LASIK) eyes Setting Department of Refractive Surgery, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA Methods The CCT and PCT were retrospectively measured using US pachymetry, Scheimpflug imaging, and high-speed OCT from January 2006 to March 2008 The influence of age and absolute magnitude of corneal thickness were also analyzed Analysis was by multivariate generalized estimating equations, multivariate linear regression, and linear regression plots Results One hundred sixty-three eyes were analyzed Ultrasound pachymetry CCT measurements were consistently higher than Scheimpflug and OCT measurements (mean difference 65 μm ± 18 [SD] and 75 ± 14 μm, respectively) (both P P >05) Scheimpflug measurements were significantly lower than US pachymetry in post-LASIK eyes ( P P >5), although Scheimpflug measurements were significantly lower in post-LASIK eyes ( P P = 017) Conclusions Scheimpflug and OCT CCT measurements were reproducible but always thinner than US pachymetry in normal and keratoconus-suspect eyes In post-LASIK eyes, OCT pachymetry maps were more accurate than Scheimpflug maps The influence of age on PCT requires further study
TL;DR: Implantation of ICRS followed by CXL resulted in greater improvement of keratoconus and there was more improvement in CDVA, SE, and mean K in Group 2 than in Group 1.
Abstract: Purpose To compare 2 sequences of combined intrastromal corneal ring segment (ICRS) implantation and ultraviolet/riboflavin–mediated corneal collagen crosslinking (CXL) in progressive keratoconus. Setting Dunya Eye Hospital, Istanbul, Turkey. Methods In this prospective comparative randomized consecutive study, CXL was followed by ICRS implantation (Group 1) or ICRS implantation was followed by CXL (Group 2). Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), manifest cylinder (cylinder), and mean keratometry (K) were compared preoperatively and postoperatively. Results The mean interval between treatments was 7 months ± 2 (SD) (mean follow-up, 13 ± 1 months). The mean UDVA and CDVA improved in both groups (UDVA: 0.07 ± 0.09 to 0.25 ± 0.12, Group 1, and 0.11 ± 0.09 to 0.32 ± 0.21, Group 2; CDVA: 0.24 ± 0.11 to 0.41 ± 0.20 and 0.22 ± 0.16 to 0.55 ± 0.2, respectively). The mean SE, cylinder, and mean K values decreased in both groups (SE: −7.13 ± 3.34 D to −2.98 ± 2.33 D, Group 1, and −7.05 ± 5.54 D to −2.81 ± 4.08 D, Group 2; cylinder: −4.38 ± 2.03 D to −2.62 ± 1.93 D and −4.68 ± 2.60 D to −2.20 ± 1.67 D, respectively; mean K: 52.47 ± 4.01 D to 48.31 ± 3.65 D and 52.06 ± 4.93 D to 48.08 ± 4.13 D, respectively). Overall, there was more improvement in CDVA, SE, and mean K in Group 2 than in Group 1. Conclusion Implantation of ICRS followed by CXL resulted in greater improvement of keratoconus.
TL;DR: The potential effects of deepithelialization, contact lens placement, instillation of topical nonsteroidal antiinflammatory drugs and anesthetic agents, and the possible role of apoptosis when performing CXL treatment for keratoconus are discussed.
Abstract: A 32-year-old man with keratoconus developed corneal melting 5 days after riboflavin/ultraviolet-A corneal collagen crosslinking (CXL). Corneal scraping was positive for Acanthamoeba. The patient was unaware that he was wearing a bandage contact lens and repeatedly rinsed his face and eyelids with tap water. Because of corneal perforation, a large therapeutic keratoplasty a chaud was performed. Although CXL is considered a safe procedure, this case emphasizes the potential risks. We discuss the potential effects of deepithelialization, contact lens placement, instillation of topical nonsteroidal antiinflammatory drugs and anesthetic agents, and the possible role of apoptosis when performing CXL treatment for keratoconus.
TL;DR: Canonoplasty was safe and effective in reducing IOP in adult patients with OAG and medication use results at all time points were statistically significant versus baseline (P <.001).
Abstract: Purpose To evaluate 2-year postsurgical safety and efficacy of canaloplasty (circumferential viscodilation and tensioning of the inner wall of Schlemm canal) to treat open-angle glaucoma (OAG) Setting Multicenter surgical sites Methods This international prospective study comprised adult OAG patients having glaucoma surgery or combined glaucoma–cataract surgery Qualifying preoperative intraocular pressure (IOP) was at least 16 mm Hg and historical IOP, at least 21 mm Hg The full circumference of the canal was viscodilated and a trabecular tensioning suture placed with a microcatheter Primary outcome measures included IOP and glaucoma medication use Results At 24 months, all 127 eyes (127 patients) had a mean IOP of 160 mm Hg ± 42 (SD) and mean glaucoma medication use of 05 ± 08 (baseline values 236 ± 48 mm Hg and 19 ± 08 medications) Eyes with canaloplasty alone had a mean IOP of 163 ± 37 mm Hg and 06 ± 08 medications (baseline values 232 ± 40 mm Hg and 20 ± 08 medications) Eyes with combined glaucoma–cataract surgery had a mean IOP of 134 ± 40 mm Hg and 02 ± 04 medications (baseline values 231 ± 55 mm Hg and 17 ± 10 medications) The IOP and medication use results at all time points were statistically significant versus baseline ( P Conclusion Canaloplasty was safe and effective in reducing IOP in adult patients with OAG
TL;DR: Implementation of a structured surgical curriculum for ophthalmology residents resulted in a statistically significant reduction in sentinel event complications, even after adjusting for surgical experience.
Abstract: Purpose To determine whether institution of a structured surgical curriculum for ophthalmology residents decreased the rate of sentinel surgical complications. Setting Veterans Affairs Medical Center, Des Moines, Iowa, USA. Methods A retrospective review was performed of third-year ophthalmic resident quality-assurance surgical outcomes data at a single residency-training site from 1998 to 2008. The primary outcome measure was defined as a sentinel event; that is, a posterior capsule tear (with or without vitreous loss) or vitreous loss (from any cause) occurring during a resident-performed case. The study population was divided into 2 groups. Group 1 comprised surgical cases of residents trained before the surgical curriculum change (academic years 1998 to 2003) and Group 2, surgical cases of residents trained with the enhanced curriculum (academic years 2004 to 2008). Data from 1 year (academic year 2003 to 2004) were excluded because the transition to the enhanced curriculum occurred during that period. The data were analyzed and adjusted for surgical experience. Results In Group 1 (before institution of surgical curriculum), there were 823 cases with 59 sentinel complications. In Group 2 (after institution of surgical curriculum), there were 1009 cases with 38 sentinel complications. There was a statistically significant reduction in the sentinel complication rate, from 7.17% before the curriculum changes to 3.77% with the enhanced curriculum ( P = .001, unpaired 2-tailed t test). Conclusion Implementation of a structured surgical curriculum resulted in a statistically significant reduction in sentinel event complications, even after adjusting for surgical experience.
TL;DR: Aberration‐correcting IOLs have the potential to provide diffraction‐limited imaging quality when perfectly aligned, and modern aspheric Iols provided better imaging quality than conventional spherical IOL designs.
Abstract: Purpose To determine the impact of decentration and tilt on the imaging quality of aspheric intraocular lens (IOL) designs in a schematic model eye. Setting Institute of Medical Physics, University of Erlangen-Nuremberg, Erlangen, Germany. Method A model eye was used to calculate the impact of misalignment on the imaging quality of 6 IOL designs. The crystalline lens in the model eye was replaced with IOL designs with 22.0 diopters nominal refractive power, and the anterior chamber depth (ACD) was set to the estimated ACD value provided by the manufacturer. The retinal position was optimized for the best image quality. The IOLs were decentered up to ±1.0 mm and tilted up to ±5 degrees relative to the line of sight. At each position, the modulation transfer function was recorded with 3.0 mm and 4.5 mm pupil diameters. The results between the IOL designs and those of the phakic model eye were then compared. Results Aberration-correcting IOLs were very sensitive to decentration and tilt. However, the impact of misalignment depended on IOL design. Aberration-free IOLs showed less sensitivity within a wide range of displacement but provided better results than the spherical IOL. Conclusions Overall, modern aspheric IOLs provided better imaging quality than conventional spherical IOL designs. Aberration-free IOLs were less sensitive to decentration and tilt than aberration-correcting IOLs but provided better image quality than spherical IOLs. Aberration-correcting IOLs have the potential to provide diffraction-limited imaging quality when perfectly aligned.
TL;DR: Toric IOL implantation achieved a slight enhanced effect over OCCIs in treating preexisting astigmatism in patients having cataract surgery.
Abstract: Purpose To compare toric intraocular lens (IOL) implantation with paired opposite clear corneal incisions (OCCIs) for astigmatism correction in patients having cataract surgery. Setting Ophthalmology Service, Donostia Hospital, San Sebastian, Spain. Methods This randomized prospective clinical study comprised eyes with more than 1.00 diopter (D) of preexisting corneal astigmatism. One group had AcrySof toric IOL implantation and the other, paired 2.75 mm/3.20 mm OCCIs in the steep axis with spherical IOL implantation. Uncorrected (UCVA) and best corrected (BCVA) visual acuity, refraction, corneal and total higher-order aberrations (HOAs), photopic and mesopic contrast sensitivity, and toric IOL axis were measured 3 months postoperatively. Results Forty eyes (40 patients) were evaluated. In the toric group, 95% of eyes achieved 20/40 or better UCVA and 70%, 20/25 or better. In the OCCI group, 80% of eyes achieved 20/40 or better UCVA and 50%, 20/25 or better. All eyes achieved 20/25 or better BCVA. Mean refractive cylinder decreased significantly from preoperatively to postoperatively (−1.75 ± 0.71 to −0.62 ± 0.46 D, toric group; −1.61 ± 0.67 to −0.97 ± 0.51 D, OCCI group) (P .1). Contrast sensitivity was similar except at the highest spatial frequency, being better in the toric group (P Conclusion Toric IOL implantation achieved a slight enhanced effect over OCCIs in treating preexisting astigmatism.
TL;DR: The results in this review were used in an attempt to understand whether there is a visual and/or optical benefit of implanting aspheric intraocular lenses over implanting spherical IOLs.
Abstract: We reviewed recently published studies that analyzed the visual and optical quality in eyes with different spherical and aspheric intraocular lenses (IOLs). Recent studies focused on visual quality metrics, such as visual acuity and contrast sensitivity, under photopic and mesopic lighting conditions and optical metrics, such as wavefront aberrations, especially spherical aberration. The results in this review were used in an attempt to understand whether there is a visual and/or optical benefit of implanting aspheric IOLs over implanting spherical IOLs.
TL;DR: Eyes with femtosecond flaps had a lower incidence of LASIK‐associated dry eye and required less treatment for the disorder, and other factors may be important because no correlation was found between flap thickness (or ablation depth) and the incidence ofLASik‐induced dry eye.
Abstract: Laser in situ keratomileusis (LASIK) remains the most commonly performed refractive surgical procedure1 Advances in techniques and instruments have reduced the incidence and severity of flap abnormalities and other potentially severe complications of LASIK One of the most common problems after surgery is LASIK-associated dry eye2–4 One condition that is thought to play an important role in dry eye after LASIK is LASIK-induced neurotrophic epitheliopathy (LINE), a term suggested by Wilson2 and Ambrosio et al3 to describe the neurotrophic component of LASIK dry eye and that results from damage to the nerves during flap formation and stromal ablation2–4
Corneal innervation is an integral component of the lacrimal gland–ocular surface functional unit,5 which coordinates basal and stimulated tear production, lid blinking, tear spreading, and tear clearance2–9 In addition, neurotrophic factors released from corneal nerves are important in the normal physiology of corneal epithelial cells10 Denervation of the central cornea after LASIK is the result of surgical amputation of the nerve fibers produced by flap cutting and stromal ablation2–4,6–9 The significant decrease in sensation in the area of the flap after LASIK normally recovers in a progressive manner from 3 to 9 months after LASIK3,8,11–13 This nerve recovery is best seen on confocal microscopy3 and generally correlates with resolution of, or at least marked improvement in, LASIK-induced dry eye3
Frequently, LINE is seen in LASIK patients who do not have underlying chronic dry-eye disease before surgery In other LASIK patients,4 a combination of chronic dry eye, albeit mild, and superimposed neurotropic epitheliopathy contribute to the symptoms and signs of the postoperative disorder In either case, the typical presentation involves corneal punctate epithelial erosions that are best seen using lissamine green or rose bengal staining as well as well as symptoms such as fluctuating vision, blurred vision, stinging, pain, photophobia, and visual fatigue2,3,11,14–16 Many patients with LINE have no symptoms or only mild fluctuations in vision2,3
The lamellar cut to fashion the flap for LASIK can be performed using a mechanical microkeratome or a femtosecond laser Our clinical experience with the IntraLase femtosecond laser (Abbott Medical Optics, Inc) over the past few years has given us the clinical impression that the incidence and severity of LASIK-associated dry eye is less with that mode of flap creation than with the Hansatome microkeratome (Bausch & Lomb) Thus, we performed a retrospective study to compare the incidence of LASIK-associated dry eye and the need for postoperative cyclosporine A treatment between femtosecond laser flap creation and mechanical microkeratome flap creation
TL;DR: Five years after ICRS implantation, the UDVA and CDVA were improved in eyes with keratoconus, and there was significant postoperative corneal flattening that remained stable over the follow‐up period.
Abstract: Purpose To report the long-term follow-up of Ferrara intrastromal corneal ring segment (ICRS) implantation for the management of keratoconus. Setting Private clinic, Belo Horizonte, Brazil. Methods This study comprised patients with keratoconus who completed at least 5 years of follow-up. One or 2 ICRS were inserted in the cornea, embracing the keratoconus area. Statistical analysis included preoperative and postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and keratometry (K) values. Results Thirty-five eyes of 28 patients were evaluated. The mean UDVA improved from 0.15 preoperatively to 0.31 postoperatively and the mean CDVA, from 0.41 to 0.62, respectively; the increases were statistically significant (P = .003 and P = .002, respectively). Corneal topography showed corneal flattening in all eyes. The mean minimum K value decreased from 48.99 D preoperatively to 44.45 D postoperatively and the mean maximum K value, from 54.07 D to 48.09 D, respectively; the decreases were statistically significant (both P = .000). Conclusions Five years after ICRS implantation, the UDVA and CDVA were improved in eyes with keratoconus. There was significant postoperative corneal flattening that remained stable over the follow-up period.
TL;DR: Collagen crosslinking with riboflavin-UVA is a minimally invasive method but traditionally requires epithelial removal, which could be a predisposing factor to bacterial keratitis.
Abstract: Several infiltrates appeared in the upper midperipheral cornea of a 29-year-old woman who had had uneventful corneal collagen crosslinking (CXL) with riboflavin and ultraviolet-A light (UVA) for the treatment of keratoconus in the right eye. Staphylococcus epidermidis keratitis was confirmed by microbiological studies, which guided treatment with topical fortified antibiotic agents. Before CXL, the best spectacle-corrected visual acuity (BSCVA) in the right eye was 20/25, the manifest refraction was -0.25 -0.25 x 125, and the anterior segment was normal under biomicroscopy. Five months after the procedure, the BSCVA was 20/22, the manifest refraction was +1.00 -2.50 x 40, and slitlamp examination revealed a mild residual haze in the upper midperipheral cornea. Collagen crosslinking with riboflavin-UVA is a minimally invasive method but traditionally requires epithelial removal, which could be a predisposing factor to bacterial keratitis.
TL;DR: This review provides a comprehensive assessment of intraocular pressure (IOP), phacoemulsification techniques, and intraocular lenses (IOLs) in pseudoexfoliation (PXF) eyes having cataract surgery with recommendations for the use of adjunctive pupil and zonule support devices.
Abstract: This review provides a comprehensive assessment of intraocular pressure (IOP), phacoemulsification techniques, and intraocular lenses (IOLs) in pseudoexfoliation (PXF) eyes having cataract surgery. Pseudoexfoliation is ubiquitous and the most common cause for open-angle glaucoma worldwide. Cataracts occur with increased frequency in PXF eyes, and surgery is potentially complicated by the presence of small pupils and zonule laxity and significantly affects IOP in these eyes. Preoperative evaluation and the options for intraoperative management of cataract are presented with recommendations for the use of adjunctive pupil and zonule support devices. Postoperative complications such as capsule contraction and IOL instability are discussed and laser and surgical options to manage these special problems presented.
TL;DR: The results suggest that repeatability and reproducibility are higher in Scheimpflug photography than in scanning‐slit topography.
Abstract: Purpose To evaluate the repeatability, reproducibility, and agreement in anterior, posterior, and in particular the total corneal power of 2 topography devices, rotating Scheimpflug photography and scanning-slit topography. Setting Department of Ophthalmology and Visual Science, Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan. Methods Seventeen eyes of 17 subjects (mean age 24.7 years ± 4.1 [SD]) were included in the study. The corneal shapes within the central 3.0 mm were measured with rotating Scheimpflug photography (Pentacam) and scanning-slit corneal topography (Orbscan II). The within-rater repeatability and reproducibility of 2 raters and the overall between-instrument agreement of the measurements were evaluated using intraclass correlation coefficients (ICCs) and the Bland-Altman method. Results The repeatability of Scheimpflug photography and scanning-slit corneal topography was high (ICC, 0.70 to 0.99). Scheimpflug photography outperformed scanning-slit corneal topography for anterior power, posterior power, and total corneal power. The reproducibility results were similar, with limits of agreement (LoA) consistently narrower for Scheimpflug photography. The between-instrument agreement was moderate, with LoA around the mean value of total corneal power of 0.46 diopter ranging from 0.032 to 0.889. Conclusions The results suggest that repeatability and reproducibility are higher in Scheimpflug photography than in scanning-slit topography. The agreement between rotating Scheimpflug photography and scanning-slit topography for total corneal power was moderate.
TL;DR: Bilateral apodized diffractive aspheric multifocal intraocular lenses with a +3.0 D add provided a broad range of optimum near vision, good intermediate visual acuity, and low rates of visual disturbances.
Abstract: Purpose To evaluate visual function after bilateral implantation of apodized diffractive aspheric multifocal intraocular lenses (IOLs) with a +3.0 diopter addition (add) power. Setting Multicenter study at 5 European sites. Methods Five surgeons prospectively enrolled patients to receive bilateral implantation of AcrySof IQ ReSTOR SN6AD1 IOLs. Assessments included defocus testing, uncorrected and corrected distance visual acuities at various distances, and patient questionnaires. Results Ninety-three patients were enrolled. The mean distance-corrected visual acuities at far, intermediate, and near distances were significantly better postoperatively. At 6 months, uncorrected visual acuity (logMAR) was −0.03 ± 0.13 (SD) at 4 m, 0.20 ± 0.14 at 70 cm, 0.13 ± 0.15 at 60 cm, 0.05 ± 0.18 at 50 cm, and 0.04 ± 0.11 at 40 cm. The mean patient-preferred near distance was 41 ± 4 cm, at which distance the mean visual acuity was −0.01 ± 0.11 logMAR. The defocus curve had a plateau of optimum near vision from 40 to 50 cm. Postoperatively, patients reported having minimal to no difficulty with 22 of 27 visual disturbances or visual activities; the other 5 items were ranked minimally to moderately difficult. The mean patient satisfaction with vision was 8.3 ± 1.6 (out of 10); 88% of patients were spectacle independent. Conclusions Bilateral apodized diffractive aspheric multifocal IOLs with a +3.0 D add provided a broad range of optimum near vision, good intermediate visual acuity, and low rates of visual disturbances. Patients were highly satisfied with their vision, and 88% were spectacle independent.
TL;DR: Diabetes mellitus affected biomechanical parameters of the human corneas, including increased CH, CRF, and CCT, which has implications in the clinical management and understanding of corneal ectasia and glaucoma requires further study.
Abstract: Purpose To compare parameters of biomechanical response of the human cornea measured as corneal hysteresis (CH) and corneal resistance factor (CRF) in patients with diabetes mellitus and healthy control subjects. Setting Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, Israel. Methods In the right eye of each participant, the CH, CRF, Goldmann-correlated intraocular pressure (IOPg), and corneal-compensated intraocular pressure (IOPcc) were measured with the Ocular Response Analyzer. Central corneal thickness (CCT) was measured by ultrasonic pachymetry and intraocular pressure by Goldmann applanation tonometry (IOP GAT). Findings were compared between the 2 groups (control and diabetic). Results Forty diabetic patients (17 women, 23 men) and 40 healthy subjects (19 women, 21 men) were prospectively recruited. The mean CH was 9.3 mm Hg ± 1.4 (SD) and 10.7 ± 1.6 mm Hg and the mean CRF was 9.6 ± 1.6 mm Hg and 10.9 ± 1.7 mm Hg in the control group and diabetic group, respectively (both P P = .019); the mean CCT was 530.3 ± 35.9 μm in the control group and 548.7 ± 33.0 μm in the diabetic group. The CH and CRF remained significantly different in multivariate analysis that included CCT. There was no statistically significant difference between the 2 groups in IOPcc, IOPg, or IOP GAT measurements. Conclusions Diabetes mellitus affected biomechanical parameters of the human corneas, including increased CH, CRF, and CCT. Whether this observation has implications in the clinical management and understanding of corneal ectasia and glaucoma requires further study.
TL;DR: The flap architecturecreated with the femtosecond laser was more regular and accurate than the flap architecture created with the microkeratome.
Abstract: Purpose To assess and compare the morphology of laser in situ keratomileusis flaps (LASIK) created by a 60 kHz femtosecond laser and a mechanical microkeratome. Setting Department of Ophthalmology, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany. Methods Anterior segment optical coherence tomography (AS-OCT) (Visante) was used to assess 1 week postoperatively the morphology of 20 LASIK flaps created with the IntraLase femtosecond laser or the Zyoptix XP microkeratome. The flap diameter and flap thickness were assessed at 20 measuring points across each flap. First, the repeatability of the AS-OCT flap measurement was evaluated. On this basis, the dimensions of femtosecond laser flaps and microkeratome flaps were tested and their regularity, reproducibility, and accuracy compared. Results The method was approved with a repeatability of maximum 8.9 μm. The femtosecond laser flaps were more regular than the microkeratome flaps (P = .02). The reproducibility of flap morphology was not different in the central 1.0 mm radius area (P = .26); however, the femtosecond laser was significantly more precise than the microkeratome in the peripheral area (P = .001). The mean thickness of the femtosecond laser flap was significantly more accurate than the mean thickness of the microkeratome flap (P = .01), with a mean deviation of +16.9 μm and 40.8 μm, respectively. Conclusions The flap architecture created with the femtosecond laser was more regular and accurate than the flap architecture created with the microkeratome.
TL;DR: Cross‐sectional and longitudinal data showed significant differences between groups in the 3 indices and use of this classification scheme might form a basis for detecting subclinical keratoconus.
Abstract: Purpose To determine in a longitudinal study whether there is correlation between videokeratography and clinical signs of keratoconus that might be useful to practicing clinicians. Setting Cornea-Genetic Eye Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA. Methods Eyes grouped as keratoconus, early keratoconus, keratoconus suspect, or normal based on clinical signs and videokeratography were examined at baseline and followed for 1 to 8 years. Differences in quantitative videokeratography indices and the progression rate were evaluated. The quantitative indices were central keratometry (K), the inferior–superior (I–S) value, and the keratoconus percentage index (KISA). Discriminant analysis was used to estimate the classification rate using the indices. Results There were significant differences at baseline between the normal, keratoconus-suspect, and early keratoconus groups in all indices; the respective means were central K: 44.17 D, 45.13 D, and 45.97 D; I–S: 0.57, 1.20, and 4.44; log(KISA): 2.49, 2.94, and 5.71 (all P Conclusions Cross-sectional and longitudinal data showed significant differences between groups in the 3 indices. Use of this classification scheme might form a basis for detecting subclinical keratoconus.
TL;DR: The amounts of tilt and decentration of both IOLs were not large enough to cause deterioration of optical quality, and they do not compromise the correction of spherical aberration by the aspheric IOL.
Abstract: Purpose To determine the impact of spherical and aspheric foldable intraocular lens (IOL) tilt and decentration on optical quality after cataract surgery in an intraindividual comparative study. Setting Department of Ophthalmology, Goethe-University, Frankfurt am Main, Germany. Methods Randomized implantation of a spherical IOL (Sensar AR40e) was performed in 1 eye and of an aspheric IOL with negative spherical aberration (Tecnis Z9000) in the contralateral eye. Three to 4 months postoperatively, the wavefront was measured and higher-order aberrations (HOAs) were calculated for virtual pupil diameters of 3.5 mm and 6.0 mm. Tilt and decentration of the IOLs were measured using Scheimpflug photography. The tilt and decentration, HOAs, and best corrected visual Strehl ratio of the optical transfer function (BCVSOTF) calculated from the wavefront aberration were compared. The effect of tilt and decentration on HOAs and optical quality was assessed using multiple regression analysis. Results The mean optic tilt was 2.89 degrees ± 1.46 (SD) for the spherical IOL and 2.85 ± 1.36 degrees for the aspheric IOL. The mean optic decentration was 0.19 ± 0.12 mm and 0.27 ± 0.16 mm, respectively. No significant intergroup differences in IOL tilt or decentration were found. Tilt and decentration did not significantly affect the BCVSOTF with either IOL. Conclusions The amounts of tilt and decentration of both IOLs were not large enough to cause deterioration of optical quality. Thus, when IOL tilt and decentration are within normal limits, they do not compromise the correction of spherical aberration by the aspheric IOL.
TL;DR: The modified sterilization and asepsis protocol adopted to facilitate high‐volume cataract surgery in a clinical setting appeared to be safe and effective in preventing postsurgical endophthalmitis.
Abstract: Purpose To report the incidence of postoperative endophthalmitis at a high-volume eye hospital in southern India using a modified cost-effective sterilization protocol. Setting Aravind Eye Hospital and Post Graduate Institute of Ophthalmology, Pondicherry, India. Methods In this retrospective observational series at a single eye hospital, records of patients who had cataract surgery using a modified sterilization protocol from January 2007 through August 2008 and developed postoperative endophthalmitis within the first 3 postoperative months were drawn from a computerized database. The patient's socioeconomic status, the surgeon's experience, and the type of cataract procedure performed were analyzed as possible risk factors using the chi-square test/Fischer exact test. Results During the study period, 42 426 cataract surgeries were performed. From these, 38 cases of presumed postoperative endophthalmitis were identified (incidence 0.09%). Thirty-five of the 38 cases were in the manual large- and small-incision extracapsular cataract extraction (ECCE) group, which had a statistically higher rate than the phacoemulsification group (P = .016). There was no statistical difference in the endophthalmitis rates between private patients and charity patients for either surgical method (manual ECCE or phacoemulsification). Conclusions The modified sterilization and asepsis protocol adopted to facilitate high-volume cataract surgery in a clinical setting appeared to be safe and effective in preventing postsurgical endophthalmitis. Despite a 3:1 ratio of manual ECCE to phacoemulsification and the elimination of certain traditional sterilization practices, the rate of endophthalmitis in this generally underserved patient population with multiple risk factors for infection was comparable to that reported in other modern settings.