BCLA CLEAR presbyopia: Management with intraocular lenses.

Cataract surgery including intraocular lens (IOL) insertion, has been refined extensively since the first such procedure by Sir Harold Ridley in 1949. The intentional creation of monovision with IOLs using monofocal IOL designs has been reported since 1984. The first reported implantation of multifocal IOLs was published in 1987. Since then, various refractive and or diffractive multifocal IOLs have been commercialised. Most are concentric, but segmented IOLs are also available. The most popular are trifocal designs (overlaying two diffractive patterns to achieve additional focal planes at intermediate and near distances) and extended depth of focus designs which leave the patient largely spectacle independent with the reduced risk of bothersome contrast reduction and glare. As well as mini-monovision, surgical strategies to minimise the impact of presbyopia with IOLs includes mixing and matching lenses between the eyes and using IOLs whose power can be adjusted post-implantation. Various IOL designs to mimic the accommodative process have been tried including hinge optics, dual optics, lateral shifts lenses with cubic-type surfaces, lens refilling and curvature changing approaches, but issues in maintaining the active mechanism with post-surgical fibrosis, without causing ocular inflammation, remain a challenge. With careful patient selection, satisfaction rates with IOLs to manage presbyopia are high and anatomical or physiological complications rates are no higher than with monofocal IOLs.

Cataract surgical outcomes, visual function and quality of life in four rural districts in Vietnam.

BACKGROUND: To evaluate cataract surgical outcomes in four rural districts of Ha Tinh Province, Vietnam. DESIGN: Cross-sectional study. PARTICIPANTS: Post-cataract surgery patients sampled randomly from facilities in four rural districts of Ha Tinh Province >3 months after surgery. MAIN OUTCOME MEASURES: Postoperative visual acuity (VA), visual function and quality of life. RESULTS: Among 412 patients, the mean age was 74.5 ± 9.4 years, 67% (276) were female, and 377 (91.5%) received intraocular lenses (IOL). Nearly two-thirds of patients had no postoperative visits after discharge. Postoperatively, more than 40% of eyes had presenting VA <6/18, while 20% remained <6/60. The mean self-reported visual function and quality of life for all patients were 68.7 ± 23.8 and 73.8 ± 21.6, respectively. Most patients (89.5%) were satisfied with surgery and the majority (94.4%) would recommend surgery to others. One-third of patients paid ≥$US50 for surgery. In multiple regression modelling, older age (P < 0.01), intraoperative complications (P < 0.01) and failure to receive an IOL (P < 0.01) were associated with postoperative VA <6/60. CONCLUSION: Satisfaction with surgery was high, and many patients were willing to pay for their operations. Poor visual outcomes were common; however, and better surgical training is needed to reduce complications and their impact on visual outcomes. More intensive postoperative follow-up may also be beneficial.

A 10-year prospective audit of LASIK outcomes for myopia in 37,932 eyes at a single institution in Asia.

PURPOSE: This study evaluates the efficacy, predictability and safety of LASIK surgery as a treatment for myopia performed as part of a large-scale, prospective clinical audit spanning 10 years in an Asian study population and to evaluate the outcomes and trends. DESIGN: Prospective, nonrandomized, single-center, multisurgeon study. PARTICIPANTS: We included 37,932 eyes of 19,753 patients that underwent myopic LASIK at the Singapore National Eye Centre between 1998 and 2007. METHODS: All eyes underwent LASIK as a treatment for myopia. Pre- and postoperative refractions, uncorrected visual acuity (UCVA), and best-corrected visual acuity (BCVA) were documented. MAIN OUTCOMES MEASURES: Safety, efficacy, refractive predictability, treatment trends, retreatment rates, and complications for mild, moderate, and high myopia according to spherical equivalence (SE) of less than -5.00 diopters (D), -5.00 D or more to less than -10.0 D, and -10.00 D or more, respectively. RESULTS: Patients' median age was 32 years (mean, 33.0+/-7.9 years); there were 6832 males (34.6%) and 12,921 females included. Patients were predominantly ethnic Chinese (90.5%). Mean follow-up time was 68.8 days. The mean spherical error corrected was -5.90+/-2.57 D (median, -5.625 D), and outcomes were categorized into low, moderate, or high myopia. The UCVA achieving > or =20/40 has been consistently above 90% since 2000, with 72.8% achieving > or =20/20. More than 93.0% of eyes achieved within +/-1.00 D target in the last 4 years. An improvement in safety was observed since the start of the study, with the best outcomes observed in 2007; loss of 1 and 2 Snellen line BCVA postoperatively was 2.4% and 0.1%, respectively. The overall retreatment rate was 3.8%; 91% of retreated eyes achieved UCVA of > or =20/30. Between 1998 and 2007, there was a significant improvement in postoperative UCVA and BCVA (P<0.001). CONCLUSIONS: Myopic LASIK performed in Asian eyes within a comprehensive LASIK clinical program with appropriate clinical audit governance can be safe and effective, with high refractive predictability. Improvements in the nomograms to prevent undercorrection and to compensate for myopic regression have led to better efficacy after LASIK, with an increasing percentage of patients achieving 20/15 visual acuity postoperatively.

Correcting post-keratoplasty anisometropia with the implantable collamer phakic intraocular lens.

BACKGROUND: We evaluate the Visian Implantable Collamer Lens (Staar, Monrovia, CA, USA) phakic intraocular lens for treating post-keratoplasty anisometropia. METHODS: Case series of three eyes (2 phakic and 1 pseudophakic). RESULTS: The mean age was 47.3 years (range 30-73 years), with a minimum of 3-month follow up. The mean preoperative spherical equivalent was -8.75 ± 5.17 D (-4.00 to -14.25 D) improving to -0.29 ± 1.21 D postoperatively (range 0.75 to -1.625 D). Mean logMAR uncorrected visual acuity improved from 1.66 ± 0.60 (6/240) preoperatively to 0.41 ± 0.52 (6/15(2) ). Mean logMAR best spectacle-corrected visual acuity improved from 0.32 ± 0.15 (6/12) preoperatively to 0.10 ± 0.11 (6/7.5). Anisometropia improved from a difference of 6.37 ± 2.59 D preoperatively to 2.09 ± 1.37 D postoperatively, and there were no complications. CONCLUSION: Our technique for this clinical indication shows that the Visian Implantable Collamer Lens is a safe and effective alternative for treating post-keratoplasty anisometropia.

Comparison of the Visian ICL and Verisyse phakic intraocular lenses for myopia from 6.00 to 20.00 diopters.

PURPOSE: To compare visual and refractive outcomes between the Visian Implantable Collamer Lens (ICL) and Verisyse phakic intraocular lens. METHODS: Comparative interventional case series for myopia between 6.00 and 20.00 diopters (D). Thirty consecutive eyes of 16 patients had a Visian ICL implanted and 31 consecutive eyes of 19 patients had the Verisyse lens implanted. Outcomes measured at 3 months postoperatively included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and refractive predictability as well as adverse events. Preoperatively, the groups were no different in regard to age (P=.72) and spherical equivalent refraction (P=.38). RESULTS: Postoperative UCVA of 20/20 or better and 20/25 or better in the Visian ICL group was 67% and 96%, respectively, compared to 63% and 79%, respectively, in the Verisyse lens group (P=.10). Binocular UCVA of 20/20 or better and 20/25 or better in the Visian ICL group was 92% and 100%, respectively, and in the Verisyse group, 70% and 80%, respectively (P=.007). One and two lines gain of postoperative BSCVA in the Visian ICL group was 40% and 10%, respectively, which was statistically significantly better than the Verisyse group of 16% and 6%, respectively (P=.025). Postoperative deviation from target refraction was 0.038+/-0.39 D in the Visian ICL group and -0.38+/-0.89 D in the Verisyse lens group (P=.018). CONCLUSIONS: Monocular UCVA was similar for both groups, whereas binocular UCVA was better in the Visian ICL group. The Visian ICL group had more accurate refractive outcomes than the Verisyse lens group.

Two cases of Z syndrome with the Crystalens after uneventful cataract surgery.

We report 2 cases of Z syndrome with the Crystalens AT50SE and AT52SE intraocular lenses (Eyeonics, Inc.) after uneventful cataract surgery. Both patients had subsequent neodymium:YAG laser capsulotomy treatment that remedied the complication. To our knowledge, these are the first reported cases of Z syndrome with the Crystalens AT50SE and AT52SE, a unique complication with this type of hinged accommodating intraocular lens.

Effect of nepafenac sodium 0.1% on delayed corneal epithelial healing and haze after photorefractive keratectomy: retrospective comparative study.

PURPOSE: To assess delayed epithelialization and corneal haze related to nepafenac ophthalmic suspension 0.1% (Nevanac) use after photorefractive keratectomy (PRK). SETTING: Private practice, Beverly Hills, California, USA. METHODS: This retrospective comparative chart review comprised 69 eyes (44 patients) that were divided into 2 treatment groups that were not statistically significantly different in age or preoperative spherical equivalent. The nepafenac group consisted of 34 eyes (22 patients) that received nepafenac 0.1%, moxifloxacin, and fluorometholone postoperatively. The non-nepafenac group included 35 eyes (22 patients) that received moxifloxacin and fluorometholone only. Patients were seen between 1 day and 5 days postoperatively for evaluation of epithelial healing and haze formation. Delayed epithelialization was defined as healing after day 5. All patients were followed for haze formation for a minimum of 3 months. RESULTS: Statistical analysis showed no difference between the nepafenac and non-nepafenac groups in delayed epithelialization (P = .61, chi-square test). Neither group had significant corneal haze. CONCLUSION: Nepafenac did not appear to delay corneal epithelial healing or contribute to haze formation after PRK.

The DNA double-stranded break repair protein endo-exonuclease as a therapeutic target for cancer.

DNA repair mechanisms are crucial for the maintenance of genomic stability and are emerging as potential therapeutic targets for cancer. In this study, we report that the endo-exonuclease, a protein involved in the recombination repair process of the DNA double-stranded break pathway, is overexpressed in a variety of cancer cells and could represent an effective target for developing anticancer drugs. We identify a dicationic diarylfuran, pentamidine, which has been used clinically to treat opportunistic infections and is an inhibitor of the endo-exonuclease as determined by enzyme kinetic assay. In clonogenic and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays as well as in the in vivo Lewis lung carcinoma mouse tumor model, pentamidine is shown to possess the ability to selectively kill cancer cells. The LD50 of pentamidine on cancer cells maintained in vitro is correlated with the endo-exonuclease enzyme activity. Tumor cell that has been treated with pentamidine is reduced in the endo-exonuclease as compared with the untreated control. Furthermore, pentamidine synergistically potentiates the cytotoxic effect of DNA strand break and cross-link-inducing agents such as mitomycin C, etoposide, and cisplatin. In addition, we used the small interfering RNA for the mouse homologue of the endo-exonuclease to down-regulate the level of endo-exonuclease in the mouse myeloma cell line B16F10. Down-regulation of the endo-exonuclease sensitizes the cell to 5-fluorouracil. These studies suggested the endo-exonuclease enzyme as a novel potential therapeutic target for cancer.

Outcomes of the Haigis-L formula for calculating intraocular lens power in Asian eyes after refractive surgery.

PURPOSE: To report outcomes using the Haigis-L formula to calculate intraocular lens (IOL) power in Asian eyes with long axial lengths (ALs) that had previous myopic laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK). SETTING: Singapore National Eye Centre, Singapore. DESIGN: Retrospective case series. METHODS: Patients with ALs greater than 25.0 mm and previous myopic LASIK or PRK who had phacoemulsification were analyzed. The emmetropic IOL power was back-calculated using the 1-month postoperative manifest refraction and compared with the emmetropic IOL power calculated with the Haigis-L formula. The primary outcome measure was the mean arithmetic prediction error, defined as the difference between the actual postoperative refractive error and the intended formula-derived refractive target. RESULTS: Sixty-two eyes (52 patients) were analyzed. The mean arithmetic prediction error was -0.44 diopter (D) ± 0.98 (SD) and the mean absolute error, 0.87 ± 0.62 D. The mean arithmetic prediction error was -0.52 ± 0.96 D in eyes with an AL less than 27.0 mm and -0.36 ± 1.00 D in eyes with an AL of 27.0 mm or greater (P = .463). The predictability of being within ±0.50 D and ±1.00 D of target was 35.7% and 63.1%, respectively, overall; 31.6% and 60.5%, respectively, in eyes with an AL less than 27.0 mm; and 39.1% and 65.2%, respectively, in eyes with an AL of 27.0 mm or greater (P = .772). CONCLUSION: The Haigis-L formula was acceptably accurate in predicting and achieving target outcomes after phacoemulsification in Asian eyes with a long AL that had previous myopic LASIK or PRK. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Predisposing Factors, Microbial Characteristics, and Clinical Outcome of Microbial Keratitis in a Tertiary Centre in Hong Kong: A 10-Year Experience.

Purpose. To study the risk factors, microbial profile, antibiotic susceptibility pattern, and outcome for microbial keratitis over the past 10 years in a tertiary center in Hong Kong. Methods. All cases with corneal scraping performed in Queen Mary Hospital, Hong Kong from January 2004 to December 2013 were included. Clinical outcome was defined as poor if the final visual acuity (VA) was abnormal or worse than presenting VA, a major complication occurred, or therapeutic keratoplasty was required. Results. 347 scrapes were performed in the 10-year period growing 130 microorganisms (32.3% culture positive rate). Contact lens use was the commonest risk factor. The commonest isolates were coagulase-negative Staphylococcus and Pseudomonas aeruginosa. Fluoroquinolone susceptibility was tested in 47 Gram-negative bacteria with 93.6% susceptibility (100% for Pseudomonas). 90.7% of cases had good visual outcome. Multivariate logistic regression showed age (p = 0.03), trauma (p = 0.006), and ulcer size >3 mm (p = 0.039) to be independently associated with poor outcome. Conclusion. There was no shifting trend in the isolate distribution or emergence of resistant strains in our study. Contact lens wear was the commonest risk factor, with Pseudomonas being the most frequent isolate in this group. It remained 100% susceptible to fluoroquinolones and 97% cases had good visual outcome.

Matched comparison of rotational stability of 1-piece acrylic and plate-haptic silicone toric intraocular lenses in Asian eyes.

PURPOSE: To evaluate and compare the postoperative rotational stability of a 1-piece acrylic toric intraocular lens (IOL) (Acrysof) and a plate-haptic silicone toric IOL (Staar) in Asian eyes. SETTING: Singapore National Eye Centre, Singapore. DESIGN: Prospective randomized control trial. METHODS: Eyes of Chinese patients having cataract surgery were randomized to receive the acrylic toric IOL or the silicone toric IOL. Postoperatively, patients returned at 1 day, 1 week, and 1 and 3 months. The eyes were dilated and slitlamp retroillumination photography of the toric IOL was performed to assess rotational stability. RESULTS: The acrylic IOL was implanted in 24 eyes and the silicone IOL in 26 eyes. The mean age of the patients was 68.2 years (range 42 to 82 years). The mean IOL rotation from baseline to 3 months postoperatively was 4.23 ± 4.28 degrees in the acrylic IOL group and 9.42 ± 7.80 degrees in the silicone IOL group; the difference was statistically significant (P=.01). Of the acrylic IOLs, 73% were rotated less than 5 degrees at 3 months; none was rotated more than 15 degrees at 3 months. The silicone toric IOLs showed greater rotational movement, with 37% being rotated less than 5 degrees and 21% being rotated more than 15 degrees. CONCLUSION: The acrylic toric IOL had better rotational stability than the silicone toric IOL.

Anterior segment optical coherence tomography study of the cornea and anterior segment in adult ethnic South Asian Indian eyes.

PURPOSE: To report normative results of anterior segment and corneal biometric parameters and their associations in ethnic South Asian Indian adults. METHODS: The Singapore Indian Eye Study is a cross-sectional, population-based study of ethnic South Asian Indians ranging in age from 40 to 80 years. Subjects underwent ophthalmic and systemic examination, including imaging with anterior segment optical coherence tomography. Parameters were derived using the Zhongshan Assessment Program: anterior chamber depth (ACD), central corneal thickness (CCT), and anterior and posterior corneal curvatures (ACC and PCC). Posterior corneal arc length (PCAL) is a novel parameter defined as the arc distance between scleral spurs on the posterior border of the cornea. The authors studied correlations between PCAL with various anterior segment parameters and systemic parameters using univariate and multivariate analyses. RESULTS: The authors studied 438 subjects whose mean age was 58.5 ± 9.9 years and of whom 50.7% were male. Parameters (mean ± SD) included central ACD 2.72 ± 0.37 mm, PCC 6.45 ± 0.35 mm, CCT 561.4 ± 34.1 µm, ACC 7.17 ± 0.35 mm, and PCAL 13.85 ± 0.54 mm. The authors found significant correlations between PCAL and ACD (r = 0.46, P < 0.001), PCC (r = 0.31, P < 0.001), and ACC (r = 0.16, P < 0.001), whereas they found poor correlations between PCAL and age, height, weight, blood pressure, and glucose levels. Multivariate analysis showed a significant association between PCAL and both ACD (P < 0.001) and PCC (P < 0.001). CONCLUSIONS: The authors have described useful baseline anterior segment parameters from this population-based study of ethnic South Indian adults. These data may be useful for corneal and anterior segment procedures such as endothelial keratoplasty and anterior chamber intraocular lens insertion.

Anterior chamber dimensions and posterior corneal arc length in Malay eyes: an anterior segment optical coherence tomography study.

PURPOSE: We provided normative data of corneal and anterior segment dimensions, and a novel parameter, posterior corneal arc length (PCAL), in an adult Malay population. METHODS: The current analysis is a substudy of the Singapore Malay Eye Study (SiMES), a population-based, cross-sectional study of urban Malay adults aged 40 to 80. Subjects underwent ophthalmic and systemic examination, including imaging with anterior segment optical coherence tomography (AS-OCT). Ocular parameters subsequently were measured with the Zhongshan Assessment Program (ZAP), and included anterior chamber depth (ACD), central corneal thickness (CCT), anterior and posterior corneal curvature (ACC and PCC, respectively), and PCAL, which is a novel parameter defined as the arc-distance of the posterior corneal border between the scleral spurs. Age- and sex-adjusted analyses, and multivariate analyses were performed to determine correlations of PCAL with other ocular and systemic components. RESULTS: We studied 237 subjects, among whom the mean age was 56.6 ± 10.4 years and 50.2% were women. Ocular parameters (mean ± SD) included central ACD 2.78 ± 0.34 mm, CCT 550.23 ± 37.12 mm, ACC 7.43 ± 0.37 mm, PCC 6.75 ± 0.37 mm, and PCAL 13.95 ± 0.51 mm. There was moderate correlation between PCAL and ACD (r = 0.476, P < 0.001), but poor correlation with PCC (r = 0.243, P < 0.001), ACC (r = 0.251, P < 0.001), and systemic parameters, like age, body mass index (BMI), blood pressure, blood glucose levels, hemoglobin A1c (HbA1c), and refractive parameters. Multivariate analysis showed a significant association between PCAL and ACD (P < 0.001), PCC (P < 0.001), and height (P < 0.05). CONCLUSIONS: Our study, to our knowledge, provides the largest baseline anterior segment parameters in an adult Asian Malay population. PCAL correlated moderately with ACD. These data are applicable clinically for assessment and surgical management of patients requiring anterior segment or corneal surgery.

Hemi-automated lamellar keratoplasty (HALK).

AIM: To describe a hybrid technique for anterior lamellar keratoplasty in corneas with topographical irregularities that circumvents the limitations of the microkeratome, namely reproduction of surface irregularities in the lamellar cut when creating the recipient flap. METHOD: Hemi-automated lamellar keratoplasty, a procedure that combines manual recipient bed lamellar dissection with automated donor preparation using a microkeratome, was performed on 14 eyes of 14 patients with heterogeneous causes of anterior stromal scarring. RESULTS: There was an overall improvement in uncorrected visual acuity (UCVA) in 78.6% (11/14) eyes and in best-corrected visual acuity (BCVA) in 78.6% (11/14) eyes at a mean of 9 months postoperatively. Mean preoperative and postoperative logMAR UCVAs were 1.31 ± 0.74 and 0.83 ± 0.46 (p=0.04), respectively. Mean preoperative and postoperative logMAR BCVAs were 0.72 ± 0.58 and 0.38 ± 0.23 (p=0.05). Mean preoperative and postoperative manifest refractive spherical equivalents were -0.76 ± 3.61 D and -0.52 ± 3.44 D (p=0.872). There was no difference in preoperative and postoperative sphere and cylinder (p=0.871 and 0.965, respectively). In a subset of six eyes with longer follow-up >12 months, the UCVA and BCVA show continuing improvement. All grafts remained clear at the final appointment. CONCLUSIONS: Hemi-automated lamellar keratoplasty is an effective and safe surgical procedure in the treatment of corneas with irregular topographic profiles with varying depths of anterior stromal scarring. It combines the benefits of smooth microkeratome lamellar dissection of the donor with customised lenticule thickness and diameter together with a manual lamellar dissection technique for the recipient providing encouraging visual outcomes that show continuing improvement with time.

Reproducibility of cornea measurements in anterior segment OCT images of normal eyes and eyes with bullous keratopathy analyzed with the Zhongshan Assessment Program.

PURPOSE: To determine the interobserver and intraobserver measurement reproducibility of cornea parameters of both normal eyes and eyes with bullous keratopathy (BK) obtained with the Zhongshan Assessment Program (ZAP) on anterior segment optical coherence tomography (AS-OCT) images. METHODS: A comparative study was carried out on 24 healthy volunteers and 25 subjects with BK. AS-OCT images were independently analyzed by two examiners. Parameters examined: anterior chamber depth (ACD), central corneal thickness (CCT), posterior corneal curvature (PCC), and posterior corneal arc length (PCAL). Interobserver and intraobserver reproducibility of these parameters was calculated in terms of limits of agreement (mean of differences ± 1.96SD of differences). RESULTS: In the normal group, both horizontal and vertical ACD were successfully measured in 23 of 24 (96%) images. The mean bias for two measurements by two different observers ranged from 0.003 to 0.117 mm for ACD, PCC, and PCAL measurements and from 0.013 to 2.25 µm for CCT measurements, and there were no differences between the two observers (P > 0.05). Mean bias for two measurements by the same grader ranged from 0.005 to 0.327 mm for ACD, PCC, and PCAL measurements and 1.46 to 2.53 µm for CCT measurements. There was no difference between the two observations (P > 0.05). Similar results were found in the BK group. CONCLUSIONS: There was high inter- and intraobserver reproducibility for normal and pathologic corneas using the ZAP software. The ZAP software may serve as a new investigatory tool for accurately evaluating the anterior segment and corneal parameters for corneal procedures.

Biometry of the cornea and anterior chamber in chinese eyes: an anterior segment optical coherence tomography study.

PURPOSE. To investigate the normative data of corneal and anterior segment biometric parameters and their associations in Chinese adults, for use in preoperative assessment for corneal and anterior segment surgery. METHODS. This cross-sectional, population-based study included 750 subjects aged > or =50 years. The subjects underwent an ophthalmic examination including imaging with anterior segment optical coherence tomography (AS-OCT). Dimensions were subsequently measured with the Zhongshan Assessment Program (ZAP). Also measured was posterior corneal arc length (PCAL), a novel parameter defined as the arc distance between scleral spurs on the posterior border of the cornea. Correlations with age, sex, height, weight, body mass index (BMI), refractive sphere and cylinder, and intraocular pressure were also measured. RESULTS. The subjects' mean age was 63.3 +/- 7.9 years and 349 (46.5%) were men. Corneal parameters (mean +/- SD) included PCAL (12.924 +/- 0.544 mm), anterior chamber depth (ACD; 2.684 +/- 0.309 mm), central corneal thickness (562.39 +/- 31.85 microm), anterior chamber curvature (7.35 +/- 0.37 mm), and posterior corneal curvature (6.65 +/- 0.34 mm). A moderate correlation was observed between PCAL and ACD (R = 0.55, P < 0.001) and a poor correlation between PCAL and age, height, weight, and BMI. Multivariate analysis showed a significant association between PCAL and ACD, ACC, PCC, and cylinder (P < 0.05). CONCLUSIONS. In this Chinese population, PCAL was found to correlate moderately with ACD. The data may be useful for corneal and anterior segment procedures such as Descemet's stripping automated endothelial keratoplasty (DSAEK).