Efficacy of 4-Haptic Bitoric Intraocular Lens Implantation in Asian Patients with Cataract and Astigmatism.

PURPOSE: To determine the efficacy of 4-haptic bitoric intraocular lens (IOL) implantation in Asian patients with cataract and astigmatism. METHODS: A total of 19 eyes with ≤25.0 mm axial length and ≥0.75 diopters (D) corneal astigmatism were included in this prospective non-comparative study. All subjects underwent phacoemulsification with implantation of an AT Torbi 709M IOL. Visual and refractive outcomes as well as toric IOL axis were evaluated during a 3-month follow-up. Errors in predicted residual spherical equivalent were calculated by subtracting predicted residual spherical equivalent from postoperative refraction. RESULTS: Uncorrected and corrected distance visual acuity improved significantly 3 months after surgery, from 0.43 to 0.05 and from 0.24 to -0.05, respectively. Mean refractive cylinders also decreased significantly, from -1.91 preoperatively to -0.54 D 3 months after surgery. Mean J0 and J45 decreased 3 months postoperatively, from 0.26 to 0.03 D and from 0.24 to -0.06 D, respectively. After 3 months, mean absolute IOL rotation was 1.81°. Errors in predicted residual spherical equivalent showed a hyperopic shift of 0.35 D. CONCLUSIONS: Implantation of 4-haptic bitoric IOL proved to be effective for correcting astigmatism in Asian eyes during cataract surgery.

Comparative Efficacy of the New Optical Biometer on Intraocular Lens Power Calculation (AL-Scan versus IOLMaster).

PURPOSE: To evaluate the agreement in axial length (AL), keratometry, and anterior chamber depth measurements between AL-Scan and IOLMaster biometers and to compare the efficacy of the AL-Scan on intraocular lens (IOL) power calculations and refractive outcomes with those obtained by the IOLMaster. METHODS: Medical records of 48 eyes from 48 patients who underwent uneventful phacoemulsification and IOL insertion were retrospectively reviewed. One of the two types of monofocal aspheric IOLs were implanted (Tecnis ZCB00 [n = 34] or CT Asphina 509M [n = 14]). Two different partial coherence interferometers measured and compared AL, keratometry (2.4 mm), anterior chamber depth, and IOL power calculations with SRK/T, Hoffer Q, Holladay2, and Haigis formulas. The difference between expected and actual final refractive error was compared as refractive mean error (ME), refractive mean absolute error (MAE), and median absolute error (MedAE). RESULTS: AL measured by the AL-Scan was shorter than that measured by the IOLMaster (p = 0.029). The IOL power of Tecnis did not differ between the four formulas; however, the Asphina measurement calculated using Hoffer Q for the AL-Scan was lower (0.28 diopters, p = 0.015) than that calculated by the IOLMaster. There were no statistically significant differences between the calculations by MAE and MedAE for the four formulas in either IOL. In SRK/T, ME in Tecnis-inserted eyes measured by AL-Scan showed a tendency toward myopia (p = 0.032). CONCLUSIONS: Measurement by AL-Scan provides reliable biometry data and power calculations compared to the IOLMaster; however, refractive outcomes of Tecnis-inserted eyes by AL-Scan calculated using SRK/T can show a slight myopic tendency.

Comparison of two Nd:YAG laser posterior capsulotomy: cruciate pattern vs circular pattern with vitreous strand cutting.

AIM: To investigate the effects and safety of neodymium: yttrium-aluminium-garnet (Nd:YAG) laser posterior capsulotomy with vitreous strand cutting. METHODS: A total of 40 eyes of 37 patients with symptomatic posterior capsular opacity (PCO) were included in this prospective randomized study and were randomly subjected to either cruciate pattern or round pattern Nd:YAG posterior capsulotomy with vitreous strand cutting (modified round pattern). The best corrected visual acuity (BCVA), intraocular pressure (IOP), refractive error, endothelial cell count (ECC), anterior segment parameters, including anterior chamber depth (ACD) and anterior chamber angle (ACA) were measured before and 1mo after the laser posterior capsulotomy. RESULTS: In both groups, the BCVA improved significantly (P<0.001 for the modified round pattern group, P=0.001 for the cruciate pattern group); the IOP and ECC did not significantly change. The ACD significantly decreased (P<0.001 for both) and the ACA significantly increased (P=0.001 for the modified round pattern group and P=0.034 for the cruciate group). The extent of changes in these parameters was not significantly different between the groups. CONCLUSION: Modified round pattern Nd:YAG laser posterior capsulotomy is an effective and safe method for the treatment of PCO. This method significantly changes the ACD and ACA, but the change in refraction is not significant. Modified round pattern Nd:YAG laser posterior capsulotomy can be considered a good alternative procedure in patients with symptomatic PCO.

Unexpected potential protective associations between outdoor air pollution and cataracts.

Air pollution is one of the biggest public health issues, and the eye is continuously exposed to multiple outdoor air pollution. However, to date, no large-scale study has assessed the relationship between air pollutants and cataracts. We investigated associations between outdoor air pollution and cataracts in the Korean population. A population-based cross-sectional study was performed using data from the Korea National Health and Nutrition Examination Survey, including 18,622 adults more than 40 years of age. The presence of cataracts and their subtypes were evaluated by ophthalmologists. Air pollution data (levels of particulate matter, ozone, nitrogen dioxide, and sulfur dioxide) for the 2 years prior to the ocular examinations were collected from national monitoring stations. The associations of multiple air pollutants with cataracts were assessed by multivariate logistic regression analyses. Sociodemographic factors and previously known risk factors for cataracts were controlled as covariates (model 1 included sociodemographic factors, sun exposure, and behavioral factors, while model 2 further included clinical factors). Higher ozone concentrations were protectively associated with overall cataract which included all subtypes [single pollutant model: 0.003 ppm increase-model 1 (OR 0.89, p = 0.014), model 2 (OR 0.87, p = 0.011); multi-pollutant model: 0.003 ppm increase-model 1 (OR 0.80, p = 0.002), model 2 (OR 0.87, p = 0.002)]. Especially, higher ozone concentrations showed deeply protective association with nuclear cataract subtype [0.003 ppm increase-single pollutant model: model 2 (OR 0.84, p = 0.006), multi-pollutant model: model 2 (OR 0.73, p < 0.001)]. Higher tropospheric ozone concentrations showed protective associations with overall cataract and nuclear cataract subtype in the Korean population.

Effect of Histocompatibility Y Antigen Matching on Graft Survival in Primary Penetrating Keratoplasty.

PURPOSE: To investigate the influence of histocompatibility Y (H-Y) antigen matching on corneal graft survival in primary penetrating keratoplasty (PK). METHODS: Medical records of patients who underwent primary PK at Seoul National University Bundang Hospital between June 2005 and October 2015 were retrospectively analyzed. The eyes were classified into 2 groups: H-Y-compatible (115 eyes) and H-Y-incompatible (23 eyes). The H-Y-compatible group included donor/recipient combinations of male/male (57 eyes), female/male (44 eyes), and female/female (14 eyes). The H-Y-incompatible group included the male/female (23 eyes) combination alone. A subgroup analysis of low- and high-risk patients according to preoperative diagnoses was also performed. Survival analysis was conducted using the Kaplan-Meier method; differences between groups were assessed with a log-rank test. RESULTS: A total of 138 eyes from 136 patients (age: 58 ± 18 years) were enrolled. Rejection-free graft survival and graft survival were not significantly different between H-Y-compatible and H-Y-incompatible groups (χ = 0.4, P = 0.548; χ = 1.9; P = 0.17, respectively). Preoperative diagnoses of high-risk cases included those with corneal perforation or thinning (8.7%) and infectious keratitis (7.2%). Low-risk cases included corneal opacity (50.0%), bullous keratopathy (25.4%), keratoconus (5.8%), and corneal dystrophy (2.9%). In the high-risk group, rejection-free graft survival rate was significantly higher in the H-Y-compatible group (χ = 3.9, P = 0.049). CONCLUSIONS: H-Y antigen matching does not influence graft rejection and failure in cases of primary PK. However, matching the H-Y antigen could help reduce graft rejection, especially in preoperatively high-risk patients.

Mooren Ulcer in a Child Wearing Orthokeratology Contact Lenses.

PURPOSE: To report a case of Mooren ulcer that developed in a pediatric patient wearing orthokeratology overnight contact lenses. METHODS: Case report. RESULTS: A 10-year-old boy was referred to our clinic because of progressive peripheral corneal ulcer in the right eye, despite the intensive use of fortified antibiotic eye drops. The patient had been using overnight orthokeratology lenses for 4 months before presentation of corneal ulcer. There was no other history of ocular or systemic trauma and disorders. Microbiological tests of the lesion were negative. Systemic evaluation showed no sign of rheumatologic disease. Under a diagnosis of Mooren ulcer, the patient was treated with topical and systemic corticosteroids. After four weeks of treatment, the patient's symptoms rapidly disappeared, and corneal ulcer was healed. The vision recovered to normal with the correction of with-the-rule astigmatism. CONCLUSIONS: Mooren ulcer can develop in pediatric patients wearing orthokeratology contact lenses. Given rapid progression of Mooren ulcer in a young population, early diagnosis and proper treatment are essential to prevent a devastating outcome.

Effect of Iris registration on visual outcome in wavefront-guided LASEK for myopic astigmatism.

PURPOSE: This study aimed to investigate the effect of iris registration (IR) on visual outcomes in wavefront-guided LASEK for myopic astigmatism. METHODS: The retrospective chart review was performed for wavefront-guided LASEK using VISX Star S4 in patients with myopic astigmatism (cylinder ≥ 1.00 diopter[D]). Eyes were divided into IR group (LASEK with IR at the time of surgery) and Non-IR group (LASEK without IR system + failed-IR engagement during LASEK). Visual acuity (VA), astigmatism, higher-order aberration (HOA), and contrast sensitivity were assessed preoperatively and 3 months postoperatively. The IR and Non-IR groups were subcategorized depending on the spherical equivalent (lower myopia ≤-5.00 D vs. higher myopia >-5.00 D) for the comparison of HOA changes. RESULTS: Postoperative uncorrected VAs showed no differences between IR (n = 30) and Non-IR (n = 46). In astigmatic vector analyses, no differences were noted in the mean magnitude of error and the mean angle of error between two groups. There were no differences in postoperative total HOA, spherical aberration (SA), coma, and trefoil between the groups, either. The total HOA and SA increased in both groups, while coma increased only in Non-IR. In higher myopia, ΔRMS of coma was smaller in IR. Preoperative and postoperative total HOA were linearly correlated in Non-IR, but not for IR. Contrast sensitivity of 12 cycles per degree improved in both groups. CONCLUSION: IR had similar outcomes to conventional trackers in wavefront-guided LASEK, with less tendency of inducing coma, especially in higher myopia.

Prospective Clinical Trial of Corneal Reconstruction With Biomaterial-Free Cultured Oral Mucosal Epithelial Cell Sheets.

PURPOSE: To investigate the efficacy and safety of transplantation with biomaterial-free cultured oral mucosal epithelial cell sheets (COMECs) for ocular reconstruction in subjects with total limbal stem cell deficiency. METHODS: A prospective clinical trial (NCT02149732) was conducted in 8 subjects with total limbal stem cell deficiency after approval from the institutional review board of Seoul National University Hospital (H-0707-043-213) and the Ministry of Food and Drug Safety of Korea. COMECs were prepared in a culture system without the use of any temperature-sensitive polymers or carriers. The COMECs were transplanted without suture fixation. Four subjects underwent penetrating keratoplasty after stabilization of the COMEC transplant. Stable epithelialization, changes in visual acuity, and postoperative complications were evaluated for 6 months. Corneal cytokeratins (K) of 4 subjects who underwent penetrating keratoplasty were stained with an immunofluorescent agent. RESULTS: The ocular surface was successfully reconstructed in 6 eyes. Complete stable epithelialization was achieved within a mean of 53.6 days. Visual improvement (≥2 lines) was achieved in 62.5% of the eyes. K12 (corneal phenotype), K4, and K13 (mucosal phenotype) were well expressed in grafts after keratoplasty, whereas K1, K8, and K19 were barely expressed. No ocular infections, local tumor formation, or remarkable systemic complications were observed. Ocular reconstruction using COMECs failed in 2 eyes, which had full symblepharon in 4 quadrants. CONCLUSIONS: Transplanting biomaterial-free COMECs seems to be an efficient and safe procedure to reconstruct the ocular surface in patients who are completely limbal stem cell deficient without a full symblepharon.

Sex differences in the effect of aging on dry eye disease.

PURPOSE: Aging is a major risk factor in dry eye disease (DED), and understanding sexual differences is very important in biomedical research. However, there is little information about sex differences in the effect of aging on DED. We investigated sex differences in the effect of aging and other risk factors for DED. METHODS: This study included data of 16,824 adults from the Korea National Health and Nutrition Examination Survey (2010-2012), which is a population-based cross-sectional survey. DED was defined as the presence of frequent ocular dryness or a previous diagnosis by an ophthalmologist. Basic sociodemographic factors and previously known risk factors for DED were included in the analyses. Linear regression modeling and multivariate logistic regression modeling were used to compare the sex differences in the effect of risk factors for DED; we additionally performed tests for interactions between sex and other risk factors for DED in logistic regression models. RESULTS: In our linear regression models, the prevalence of DED symptoms in men increased with age (R=0.311, P=0.012); however, there was no association between aging and DED in women (P>0.05). Multivariate logistic regression analyses showed that aging in men was not associated with DED (DED symptoms/diagnosis: odds ratio [OR] =1.01/1.04, each P>0.05), while aging in women was protectively associated with DED (DED symptoms/diagnosis: OR =0.94/0.91, P=0.011/0.003). Previous ocular surgery was significantly associated with DED in both men and women (men/women: OR =2.45/1.77 [DED symptoms] and 3.17/2.05 [DED diagnosis], each P<0.001). Tests for interactions of sex revealed significantly different aging × sex and previous ocular surgery × sex interactions (P for interaction of sex: DED symptoms/diagnosis - 0.044/0.011 [age] and 0.012/0.006 [previous ocular surgery]). CONCLUSION: There were distinct sex differences in the effect of aging on DED in the Korean population. DED following ocular surgery also showed sexually different patterns. Age matching and sex matching are strongly recommended in further studies about DED, especially DED following ocular surgery.

Intraocular Lens Power Calculation after Refractive Surgery: A Comparative Analysis of Accuracy and Predictability.

PURPOSE: To compare the accuracy of intraocular lens (IOL) power calculation using conventional regression formulae or the American Society of Cataract and Refractive Surgery (ASCRS) IOL power calculator for previous corneal refractive surgery. METHODS: We retrospectively reviewed 96 eyes from 68 patients that had undergone cataract surgery after keratorefractive surgeries. We calculated the formula with two approaches: IOL powers using the ASCRS IOL power calculator and IOL powers using conventional formulae with previous refractive data (Camellin, Jarade, Savini, and clinical history method) or without prior data (0, 2 and, 4 mm total mean power in topography, Wang-Koch-Maloney, Shammas, Seitz, and Maloney). Two conventional IOL formulae (the SRK/T and the Hoffer Q) were calculated with the single K and double K methods. Mean arithmetic refractive error and mean absolute error were calculated at the first postoperative month. RESULTS: In conventional formulae, the Jarade method or the Seitz method, applied in the Hoffer Q formula with the single K or double K method, have the lowest prediction errors. The least prediction error was found in the Shammas-PL method in the ASCRS group. There was no statistically significant difference between the 10 lowest mean absolute error conventional methods, the Shammas-PL method and the Barrett True-K method calculated with using the ASCRS calculator, without using preoperative data. CONCLUSIONS: The Shammas-PL formula and the Barrett True-K formula, calculated with the ASCRS calculator, without using history, were methods comparable to the 10 most accurate conventional formulae. Other methods using the ASCRS calculator show a myopic tendency.