Prevalence of and risk factors associated with dry eye: the Korea National Health and Nutrition Examination Survey 2010-2011.

PURPOSE: To investigate the prevalence of and risk factors associated with dry eye syndrome (DES) in South Korea. DESIGN: Cross-sectional study. METHODS: In 2010 and 2011, 11,666 subjects, ranging in age from 19 to 95, were randomly selected as nationally representative participants in the Korea National Health and Nutrition Examination Survey (KNHANES). Subjects were divided into 2 groups: 1 with clinically diagnosed DES and 1 with symptoms of dry eye. We determined the prevalence of and risk factors for dry eyes in a Korean population. Health-related quality of life (HRQoL), measured by the EuroQoL-5 dimension (EQ-5D), was evaluated in patients with dry eyes. RESULTS: The mean age was 49.9 years. The overall prevalence of diagnosed DES was 8.0% (95% confidence interval [CI], 7.3% to 8.7%), and of dry eye symptoms the prevalence was 14.4% (95% CI, 13.1 to 15.7). Age (adjusted odds ratio [aOR] = 1.8, 1.6), female (aOR = 2.8, 1.9); history of eye surgery (aOR = 2.6, 2.2); stress (aOR = 1.7, 1.6); thyroid disease (aOR = 1.7, 1.5); and high education level (aOR = 1.6, 1.5) were common risk factors in the groups. Subjects who had undergone ptosis, cataract or refractive surgery were more likely to have dry eye than subjects with no history of eye surgery. Means of pain and anxiety dimensions in the EQ-5D and the Euro Quality of Life Visual Analog Scale (EQ-VAS) were significantly higher in the group with diagnosed DES than in the normal group. CONCLUSIONS: The risk factors were mostly similar in both groups. It is thought there are more patients with DES who have not been diagnosed by doctors. Doctors should identify whether a patient has any risk factors for dry eye. Patients need to be educated about the modifiable factors of DES.

Evaluation of optical quality parameters and ocular aberrations in multifocal intraocular lens implanted eyes.

PURPOSE: We investigated the correlations between optical quality parameters obtained from the double-pass system and ocular aberrations obtained from the ray-tracing aberrometer in multifocal intraocular lens (IOL) implanted eyes. MATERIALS AND METHODS: Twenty eyes from 20 patients were enrolled in this study. Modulation transfer function cutoff frequency, The Strehl ratio, objective scatter index, and objective pseudo-accommodation obtained from the double-pass system were compared with root mean square (RMS) total aberration, RMS higher-order aberration, and spherical aberration obtained from the ray-tracing aberrometer. Additionally, parameters of the double-pass system and ray-tracing aberrometer were compared with manifested refraction values and subjective visual acuity, respectively. RESULTS: There was no statistically significant correlation between optical quality parameters obtained from the double-pass system and ocular aberrations, except between the Strehl ratio and RMS total aberration (r=-0.566, p=0.018). No significant correlations were found between the parameters of both devices, and manifested refraction values or subjective visual acuity. CONCLUSION: Optical quality parameters, especially the Strehl ratio, in multifocal IOL implanted eyes were affected by RMS total aberration. Further studies based on accurate measurements of ocular aberrations and additional optical quality parameters are needed to delineate relationships between optical quality parameters and ocular aberrations in multifocal IOL implanted eyes.

Evaluation of dry eye and meibomian gland dysfunction after cataract surgery.

PURPOSE: To evaluate dry eye and meibomian gland dysfunction after cataract surgery. DESIGN: Prospective observational case series. METHODS: We studied 58 eyes of 48 patients who underwent phacoemulsification and evaluated them preoperatively and at 1 month and 3 months postoperatively. Ocular symptom scores, lid margin abnormalities, superficial punctate keratopathies (SPKs), tear film break-up time (TBUT), Schirmer test, lower tear meniscus height, depth, and area using Fourier domain optical coherence tomography, meibum expressibility and images of the meibomian glands using meibography were measured. RESULTS: The ocular symptom scores were worse at 1 month and 3 months postoperatively (P < 0.001 and P < 0.001, respectively). Lid margin abnormalities were significantly increased (P < 0.001 and P < 0.001, respectively) and TBUT decreased postoperatively (P < 0.001 and P < 0.001, respectively). Meibum expressibility decreased at 3 months postoperatively (P = 0.016); however, meibography score, SPK, lower tear meniscus height, depth and area and the Schirmer test did not change significantly postoperatively (all P values >0.05). CONCLUSION: Meibomian gland function may be altered without accompanying structural changes after cataract surgery.

Double-pass system assessing the optical quality of pseudophakic eyes.

PURPOSE: To compare the optical quality measurements obtained from the double-pass system and ocular aberrations, subjective visual acuity, and contrast sensitivity score in pseudophakic eyes. METHODS: Three months after cataract surgery, modulation transfer function (MTF) cutoff frequency, Strehl ratio, objective scatter index, and objective pseudoaccommodation obtained from the double-pass system were compared with total aberration, higher-order aberration, and spherical aberration obtained from ray-tracing aberrometer. In addition, parameters of the double-pass system were compared with subjective visual acuity and the contrast sensitivity score. RESULTS: Forty eyes of 40 patients were included. The MTF cutoff frequency and Strehl ratio were negatively correlated with total aberration (r = -0.503, p = 0.003; r = -0.509, p = 0.003, respectively) and subjective visual acuity (r = -0.453, p = 0.007; r = -0.354, p = 0.040, respectively). The objective scatter index was positively correlated with total aberration (r = 0.451, p = 0.024) and subjective visual acuity (r = 0.516, p = 0.008). The MTF cutoff frequency showed a correlation with contrast sensitivity score under photopic and mesopic conditions. CONCLUSIONS: Optical quality parameters obtained from the double-pass system were correlated with ocular aberrations, subjective visual acuity, and contrast sensitivity score in pseudophakic eyes.

Surgical approach with high-frequency radiowave electrosurgery for superior limbic keratoconjunctivitis.

PURPOSE: The aim was to introduce the application of a simple technique using high-frequency radiowave electrosurgery in the management of superior limbic keratoconjunctivitis (SLK). METHODS: This study is a prospective, noncomparative, interventional case series analysis. Seven patients (9 eyes) with SLK were recruited from the outpatient clinic of the Department of Ophthalmology, Severance Eye Hospital and Kangbuk Samsung Hospital, Seoul, Korea. On the superior bulbar conjunctiva, multiple ablations were performed using a high-frequency radiowave electrosurgical unit (Ellman Surgitron Dual Frequency RF; Ellman International, Inc, Hewlett, NY) with the lowest power setting of 1 (of 100) in the cutting mode. The operation was completed when the operator found no redundant portion on the superior bulbar conjunctiva. RESULTS: After the surgery was performed, all the patients had mild to moderate superior conjunctival injection and swelling at the operating area. One month postoperatively, slit-lamp examinations revealed a smooth conjunctival surface without remarkable hyperemia. The symptoms were significantly improved in all eyes. Follow-up Fourier domain optical coherence tomography images showed a decrease of the space between subconjunctival tissue and sclera. No notable complications were observed. CONCLUSIONS: This study demonstrated that high-frequency radiowave electrosurgery is a simple, safe, and effective first-line surgical treatment modality for refractory SLK patients with conjunctivochalasis.

Analysis of tear cytokines and clinical correlations in Sjögren syndrome dry eye patients and non-Sjögren syndrome dry eye patients.

PURPOSE: To compare concentrations of tear cytokines in 3 groups composed of Sjögren syndrome (SS) dry eye, non-Sjögren syndrome (non-SS) dry eye, and normal subjects. Correlations between ocular surface parameters and tear cytokines were also investigated. DESIGN: Prospective cross-sectional study. METHODS: SS dry eye patients (n = 24; 40 eyes) were diagnosed with primary SS according to the criteria set by the American-European Consensus Group. Non-SS dry eye patients (n = 25; 40 eyes) and normal subjects (n = 21; 35 eyes) were also enrolled. Tear concentrations of interleukin (IL)-17, IL-6, IL-10, IL-4, IL-2, interferon γ (IFN-γ), and tumor necrosis factor α (TNF-α) were measured by a multiplex immunobead assay. Ocular Surface Disease Index (OSDI), tear film breakup time (TBUT), Schirmer I test, and fluorescein staining scores were obtained from dry eye patients. RESULTS: All cytokine levels except for IL-2 were highest in the SS group, followed by non-SS dry eye group and control subjects. Concentrations of IL-17, TNF-α, and IL-6 were significantly different among the 3 groups (IL-17: SS > control P < .001, non-SS > control P = .042, SS > non-SS P < .001; TNF-α: SS > control P = .006, non-SS > control P = .034, SS > non-SS P = .029; IL-6: SS > control P = .002, non-SS > control P = .032, SS > non-SS P = .002). IL-17 was significantly correlated with TBUT (R = -0.22, P = .012) and Schirmer I test (R = -0.36, P = .027) scores in the SS group. IL-6 was significantly correlated only with TBUT (R = -0.38, P = .02) in the non-SS group. CONCLUSIONS: Differences in tear cytokine levels and correlation patterns between SS dry eye and non-SS dry eye patients suggest the involvement of different inflammatory processes as causes of dry eye syndrome.

Comparison of optical quality parameters and ocular aberrations after wavefront-guided laser in-situ keratomileusis versus wavefront-guided laser epithelial keratomileusis for myopia.

BACKGROUND: To compare optical quality, ocular scattering, and higher-order aberrations (HOAs) after laser in-situ keratomileusis (LASIK) versus laser epithelial keratomileusis (LASEK). METHODS: A total of 47 eyes from 47 participants who had undergone LASIK (group I) or LASEK (group II) procedure at least 6 months prior were enrolled. Ocular aberrations and modulation transfer function (MTF) values measured using iTrace, a ray-tracing type aberrometer, were compared to MTF (modulation transfer function) cut-off values, Strehl ratio, and objective indices of scattering obtained using the Objective Quality Analysis System II (OQAS II). RESULTS: There was no significant correlation between the postoperative optical quality parameters and the HOAs between both groups. In group I, the MTF cut-off value was significantly correlated with cylinder refraction (p = 0.037), and the objective scattering index (OSI) was positively correlated with spherical equivalent (p = 0.023). In group II, there was a statistically significant correlation between the OSI and achieved refractive correction (p = 0.001). Regression analysis showed that the OSI was the most significant predictor of MTF cut-off values after refractive surgery. Additionally, MTF values measured by OQAS were significantly lower than those measured by iTrace without correlation. CONCLUSION: Optical quality after refractive surgery may be influenced by not only ocular aberrations but also by scattering. Even though the accuracies of the machines used in this study to measure optical quality have yet to be proven, this study showed limited correlation among the values measured using the two different machines after refractive surgery. Therefore, for more generalized evaluation of visual function after refractive surgery, more advanced optical devices still need to be developed.

Three different aspheric treatment algorithms of laser-assisted sub-epithelial keratectomy in patients with high myopia.

PURPOSE: To compare visual outcomes and quality in high myopia patients treated using one of three aspheric treatment algorithms based on the NIDEK Advanced Vision Excimer Laser System. METHODS: Sixty eyes of 60 high myopia patients (>-6 diopter) underwent topography-guided (CATz) (20 eyes), wavefront-guided (OPDCAT) (20 eyes), or topography and wavefront-guided (OPA) (20 eyes) laser-assisted sub-epithelial keratectomy. Visual acuity, manifest refraction spherical equivalent (MRSE), ocular and corneal higher order aberrations, corneal asphericity, point spread function (Strehl ratio) and modulation transfer function (MTF) were compared preoperatively and 1, 3 and 6 months postoperatively. RESULTS: Six months after surgery, logMAR uncorrected visual acuity was 0.02 ± 0.09 in the CATz group, 0.02 ± 0.07 in the OPDCAT group and 0.02 ± 0.08 in the OPA group, and there were no statistically significant differences (P = 0.5355). No statistical differences were found among the three groups in MRSE (P = 0.3541). Induced spherical aberrations and the change of corneal asphericity were less in the OPA group than in the others (P < 0.0001). The MTF was slightly better in the OPA group than in the others. The Strehl ratio showed no statistically significant differences among the three groups. CONCLUSIONS: All three aspheric treatment algorithms were safe and effective in correcting high myopia. Among them, the OPA algorithm maintained optical quality and physiologic cornea longer than the others.

Health-related quality of life and emotional status of anophthalmic patients in Korea.

PURPOSE: To evaluate the health-related quality of life and emotional status of anophthalmic patients. DESIGN: Prospective, cross-sectional study. METHODS: The study included 134 monocular anophthalmic patients and 48 healthy volunteers who visited the department of Ophthalmology at the Yonsei University College of Medicine, Seoul, Korea, between July and December 2008. Surveys were administered to participants to evaluate their sociodemographic characteristics and disease-related factors. Data collected from the Short-Form 36-Item Health Survey (SF-36) and the Hospital Anxiety and Depression Scale survey instruments were analyzed to identify significant differences and correlations between categories. RESULTS: Anophthalmic patients scored lower in all categories of SF-36 compared with controls. Married females and participants with children generally had lower scores on the SF-36, and some of the differences were statistically significant. There were significant negative correlations between all SF-36 scores and participant self-evaluations on whether they had negative feelings regarding their social interpersonal relationships as a result of wearing prostheses. Those who scored higher on the Hospital Anxiety and Depression Scale anxiety and depression scales tended to evade social interrelations significantly. CONCLUSIONS: Anophthalmic patients had lower health-related quality-of-life scores than healthy individuals. This finding was particularly evident in terms of the patients' own perceptions of their social relationships, which were negatively affected by their use of prosthetic eyes. Such perceptions reduced their quality of life and heightened their anxiety and depression. Therefore, it is important to evaluate both the physical and emotional well-being of anophthalmic patients to identify those patients who will need additional physical and mental support.

Concentration of cytokines in age-related macular degeneration after consecutive intravitreal bevacizumab injection.

BACKGROUND: To evaluate the changes in aqueous humor cytokine levels following consecutive intravitreal bevacizumab (Avastin, Genentech Inc., San Francisco, CA, USA) injections in eyes with choroidal neovascularization (CNV) due to age-related macular degeneration (AMD). METHOD: Aqueous humor samples were collected at the time of intravitreal injection of 1.25 mg of bevacizumab every 7.0 (+/-2.0) weeks from ten eyes with AMD for the AMD group and during cataract surgery in nine eyes for the control group. Visual acuity with Early Treatment of Diabetic Retinopathy Study (ETDRS) letters and central macular thickness (CMT) using optical coherence tomography were measured before each injection in the AMD group. Aqueous cytokine levels were determined by immunoassay using multi-analyte biochip array technology (Evidence investigator cytokine and growth factor biochip array, RANDOX laboratories Ltd., Crumlin, UK). RESULT: In the AMD group, mean +/- standard deviation(SD) aqueous VEGF levels decreased from 68.0 +/- 32.1 pg/ml at baseline to 26.3 +/- 19.0 pg/ml after the first injection (p = 0.028) and to 25.2 +/- 12.8 pg/ml after the second injection (p = 0.005). While CMT decreased from 307.7 +/- 102.0 mum to 206.8 +/- 141.5 microm (p = 0.037), ETDRS visual acuity increased from 17.6 +/- 11.7 letters to 22.0 +/- 15.6 letters after three consecutive injections (p = 0.017). CONCLUSION: Significantly decreased VEGF levels were noted after the first injection of bevacizumab. These levels were maintained after the second injection, which paralleled the change in visual acuity and CMT.