2012 Survey of KSCRS and KOS Member: Current Trends in Cataract Surgery in Korea

PURPOSE: This study investigated the current trends and changes in the field of cataract surgery in Korea. METHODS: The members of the Korean Society of Cataract and Refractive Surgery (KSCRS) and the members of the Korean Ophthalmological Society (KOS) participated in a survey on cataract surgery in 2012, the 16th survey, consisting of 108 multiple-choice questions, mailed in July 2013 to 301 KSCRS and KOS members. Sixty two (20.6%) members answered the questions. Current data were compared with previous surveys performed in 2006 and 2009. RESULTS: Most of the respondents (46%) were in the fourth decade, 43% in the fifth decade and 10% in the sixth decade of life. The duration of hospital stay had decreased annually and the use of topical anesthesia (69%) was the most preferred. Self-sealing wound construction was the main wound closure technique in phacoemulsification (72%). The most preferred intraocular lens (IOL) for cataract surgery was hydrophobic acrylic (76%) which showed an increasing trend. The implantation of phakic IOL was performed by 41% of the respondents and interest in the value added IOLs such as presbyopia IOL and toric IOL had increased annually. In addition, to minimize astigmatism following cataract surgery, several methods were performed according to the degree of astigmatism. However, there was little interest in new cataract surgery techniques such as femtosecond laser and many respondents were skeptical whether to adopt the femtosecond laser cataract surgery system. CONCLUSIONS: This survey summarized current trends and changes in the field of cataract surgery in Korea.

Antibiotics Susceptibility in Bacterial Keratitis and Proper Initial Treatment

PURPOSE: The present study aims to determine the common pathogens involved in the etiology of bacterial keratitis and to analyze not only the antibiotic susceptibility of bacterial isolates from patients with bacterial keratitis but also the propriety of initial treatment. METHODS: A retrospective study of 161 eyes in 161 patients with bacterial keratitis, who were diagnosed by cultures from 2000 to 2011, was performed. Causative bacteria and antibiotic susceptibility were evaluated in consecutive 6-year periods. RESULTS: The most common bacteria was the pseudomonas species in the 2 time periods tested and cefazolin with tobramycin was the most commonly used antibiotic (125 cases, 77.6%) for initial treatment of bacterial keratitis. In vitro testing showed gram-negative susceptibility to tobramycin and ciprofloxacin was over 70%, gram-positive susceptibility to cephalothin and vancomycin was 100% and there was no significant difference between the 2 time periods tested. Eight cases had resistance to the initial treatment, but only 1 case showed treatment failure. CONCLUSIONS: Antibiotics used for initial treatment of bacterial keratitis were able to obtain a proper effect but several cases showed bacterial resistance to antibiotics. Thus, continued testing is essential to monitor for antibiotic resistance.

Comparison of White-to-White Diameters Measured by IOLMaster, Lenstar, Orbscan, and a Manual Method

PURPOSE: To compare and evaluate device efficacy using white-to-white (WTW) diameter measurements by IOLMaster(R), Lenstar(R), Orbscan II(R), and a manual method with anterior segment photographs in normal eyes. METHODS: Three sets of WTW diameter measurements were obtained from 62 normal eyes of 31 patients, using the Orbscan II(R), Lenstar(R), IOLMaster(R), and a manual method with anterior segment photographs. Repeatability of each device was evaluated by coefficient of variation. ANOVA and Pearson's correlation were used to compare the differences among the devices. Bland Altman plot was performed to assess measurement agreement among the devices. RESULTS: The mean WTW distance was 11.79 +/- 0.46 mm with Orbscan II(R), 12.05 +/- 0.38 mm with Lenstar(R), 12.15 +/- 0.36 mm with IOLMaster(R), and 12.30 +/- 0.40 mm with a manual method. There were significant differences in the results among the methods (ANOVA, p 0.8, p < 0.05). The coefficient of variation of Orbscan II(R) was larger than those of Lenstar(R) and IOLMaster(R). CONCLUSIONS: The WTW measurement using Orbscan II(R) has low correlations with other devices and lower repeatability. Our findings suggest that partial coherence interferometry should be considered as a new standard.

Refractive Errors and Strabismus in Down's Syndrome in Korea

PURPOSE: The aims of this study were to examine the distribution of refractive errors and clinical characteristics of strabismus in Korean patients with Down's syndrome. METHODS: A total of 41 Korean patients with Down's syndrome were screened for strabismus and refractive errors in 2009. RESULTS: A total of 41 patients with an average age of 11.9 years (range, 2 to 36 years) were screened. Eighteen patients (43.9%) had strabismus. Ten (23.4%) of 18 patients exhibited esotropia and the others had intermittent exotropia. The most frequently detected type of esotropia was acquired non-accommodative esotropia, and that of exotropia was the basic type. Fifteen patients (36.6%) had hypermetropia and 20 (48.8%) had myopia. The patients with esotropia had refractive errors of +4.89 diopters (D, +/-3.73) and the patients with exotropia had refractive errors of -0.31 D (+/-1.78). Six of ten patients with esotropia had an accommodation weakness. Twenty one patients (63.4%) had astigmatism. Eleven (28.6%) of 21 patients had anisometropia and six (14.6%) of those had clinically significant anisometropia. CONCLUSIONS: In Korean patients with Down's syndrome, esotropia was more common than exotropia and hypermetropia more common than myopia. Especially, Down's syndrome patients with esotropia generally exhibit clinically significant hyperopic errors (>+3.00 D) and evidence of under-accommodation. Thus, hypermetropia and accommodation weakness could be possible factors in esotropia when it occurs in Down's syndrome patients. Based on the results of this study, eye examinations of Down's syndrome patients should routinely include a measure of accommodation at near distances, and bifocals should be considered for those with evidence of under-accommodation.

The Ocular Fatigue of Watching Three-Dimensional (3D) Images

PURPOSE: To compare ocular fatigue, non-ocular symptoms, and ocular surface changes, such as tear break-up time (BUT) and ocular surface temperature, after watching 2-dimensional (2D) and 3-dimensional (3D) images. METHODS: Fourteen volunteers were enrolled in the present study. Subjects watched 2D as well as 3D images and answered questions regarding ocular fatigue and general symptoms such as headache. Before and after watching images, the spherical equivalent, degree of conjunctival injection, tear BUT, and ocular surface temperature were measured and the amount of change was analyzed. While watching images, subjects answered questions regarding ocular fatigue and the time when they began to feel definitive symptoms. RESULTS: Watching 3D images induced a greater degree of ocular fatigue, headache, and decreasing concentration than watching 2D images (p = 0.038, 0.003, and 0.045, respectively). While watching images, 3D images induced a greater degree of ocular fatigue than 2D images and caused subjects to feel earlier ocular fatigue (3D: 54.86 min, 2D: 78.57 min, p = 0.002). Spherical equivalents became more myopic after watching 3D images. CONCLUSIONS: After watching 3D images, a greater degree of ocular fatigue, headache, and decreasing concentration was induced and a shorter time to feel definitive ocular fatigue was observed than after watching 2D images. In addition, spherical equivalents changed myopically after watching 3D images.

Prevalence and Risk Factors of Dry Eye Syndrome in the Incheon Area

PURPOSE: To investigate the prevalence, clinical manifestations, and risk factors of dry eye syndrome (DES) among people over 50 years old in the Incheon area. METHODS: A cross-sectional prevalence study was performed on 462 people over 50 years old in Dong-gu, Incheon. DES was defined as the constant or frequent presence of symptoms of both dryness and irritation. Symptoms and past medical history were assessed by a survey. Eye examination included slit lamp examination, Schirmer test, and tear break-up time (T-BUT). Age, sex, living habits, systemic and eye diseases were also analyzed to determine the risk factors of DES. RESULTS: The prevalence of DES was 26.2%. The major symptoms were as follows in descending order: dryness (77.9%), tearing (75.2%), and sandiness (72.7%). An average of 12.1 +/- 6.0 mm in the Schirmer test and 6.7 +/- 2.4 seconds in the T-BUT were significantly different in the DES group from the normal group (p < 0.001). Variables such as age, sex, living habits, and eye diseases were not related to the diagnosis of DES, whereas diabetes was the only risk factor of DES with statistical significance (p = 0.03). CONCLUSIONS: In the present study, the prevalence of DES among people over 50 years old in the Incheon area was 26.2%. Schirmer test and T-BUT were considered to be helpful tools for the diagnosis of DES, and diabetes was a significant risk factor of DES.

The Objective Methods to Evaluate Ocular Fatigue Associated With Computer Work

PURPOSE: To develop methods for the objective measurement of ocular fatigue. METHODS: Fifteen patients were enrolled in the present study. Subjects performed visual tasks on a computer for one hour. A survey of ocular fatigue was conducted with a questionnaire. Tear break-up time, blinking rate, ocular protection index, conjunctival injection, maximal blinking interval, temperature of the ocular surface, and visual evoked potential were evaluated before and immediately after the task. Surface electromyography of the orbicularis oculi muscle was performed before and during the task. RESULTS: The survey showed increases in subjective ocular fatigue in all subjects. Tear break-up time, ocular protection index and maximal blinking interval decreased, while temperature of the ocular surface increased after the task. Conjunctival injection showed a tendency to increase. Electromyography, and visual evoked potential did not change significantly. CONCLUSIONS: In the present study, tear break-up time, ocular protection index, maximal blinking interval, and temperature of the ocular surface changed as ocular fatigue increased. Therefore, these measures can be objectively used for the evaluation of ocular fatigue.

Clinical Outcome of Diffractive Multifocal Aspheric Intraocular Lens

PURPOSE: To compare the clinical outcome between Tecnis ZM900 and Tecnis ZA9003. METHODS: We reviewed 20 eyes of 11 patients implanted with Tecnis ZM900 and 20 eyes of 20 patients implanted with Tecnis ZA9003. The clinical outcomes of these two intraocular lenses were evaluated one month after operation and consisted of distant, intermediate, and near visual acuity; depth of focus; contrast sensitivity; wavefront aberration; and patient satisfaction. Six months after the operation a reevaluation was performed for the group who had received the Tecnis ZM 900 implant. RESULTS: Near and intermediate vision was better in the Tecnis ZM900 group. There were no statistical differences between the two groups with respect to distant vision and wavefront aberration. Contrast sensitivity was better in the Tecnis ZA9003 group and depth of focus was deeper in the Tecnis ZM900 group. There were no statically significant differences in the result between one month and six month after the operation. CONCLUSIONS: The Tecnis multifocal ZM900 IOL can be effective at improving patient satisfaction after cataract surgery as well as for correcting presbyopia.

Malignant Hyperthermia in a Patient with Partially Accommodative Esotropia

PURPOSE: Malignant hyperthermia is hypermetabolic disorder of skeletal muscle that manifests during general anesthesia. Strabismus and ptosis are important risk factors in ophthalmology field for malignant hyperthermia. We report a case of malignant hyperthermia in patient with partially accommodative esotropia. CASE SUMMARY: A 6-year-old patient was supposed to undergo a surgical correction for 20 prism diopters of right esotropia after correction of hypermetropia. Because the patient showed tachycardia and hyperthermia just after inhalation of sevoflurane, we interrupted general anesthesia and cancelled the surgery. The patient was transferred to the intensive care unit. In this case, no significant familial and past histories were found. Intractable tachycardia and hyperthermia that had not responded to conservative management improved after two administration of dantrolene sodium. The patient was returned to the ward three days later. As the patient showed no other complication, he was discharged. CONCLUSIONS: In malignant hyperthermia, early diagnosis, appropriate management, and prompt administration of dantrolene sodium are important factors for better prognosis. Preoperatively, full explanation of possible complication and history taking are needed. Careful observation is necessary during anesthesia and surgery.

The Effect of Autologous Dermis-fixation to Orbital Periosteum in Superior Sulcus Deformity

PURPOSE: To evaluate the efficacy of autologus dermis-fixation on the orbital periosteum in patients with superior sulcus deformity. METHODS: From September 2005 to February 2007, an appropriate amount of a rolled autologus dermis was added to the site of superior sulcus deformity by means of fixation to the orbital periosteum via lid crease incision. Four patients had superior sulcus deformity after undergoing evisceration or other ocular surgeries. RESULTS: Superior sulcus deformities in all patients could be corrected satisfactorily with bilateral symmetry. During the follow-up period, no complications such as mechanical ptosis and recurrence of superior sulcus deformity were observed. CONCLUSIONS: The authors believe that autologus dermis-fixation to the orbital periosteum might be a useful method to correct superior sulcus deformity without disturbing movement of the upper eyelid. A study with a larger series of patients and longer follow-up period might be necessary in the future to obtain more information about autologous dermis-fixation to the periosteum in patients with superior sulcus deformity.

Factors Associated with the Successful Separation of Corneal Epithelium in Epi-LASIK

PURPOSE: To determine the incidence and perioperative factors of flap-related complications from Epi-LASIK. METHODS: In this study, 122 eyes of 66 patients who had Epi-LASIK using Centurion SES(TM) epikeratome (Norwood Eye Care, Australia) were enrolled. Associations of pre-operative corneal curvature, white-to-white distance, central corneal thickness, refractive error, dry eye, punctate corneal erosion, pannus, and history of wearing contact lenses with flap-related complications were investigated. To decrease flap-related complications, surgeons pressed patients' eyelids with a speculum during epithelial separation, and the effect of this method was verified. RESULTS: Complete epithelial separation was achieved in 74 eyes (60.6%), incomplete separation in 29 eyes (23.8%), and free epithelial sheet in 19 eyes (15.6%). Thin corneas (P=.041), a history of wearing contact lenses (P=.008), and the duration of contact lens use (P=.003) significantly decreased the incidence of successful epithelial separation. Pressing down the eyelids with a speculum while separating the epithelial sheet increased the incidence of complete separation from 50.6% to 83.8% (P=.003). CONCLUSIONS: The risk of flap-related complications from Epi-LASIK may be higher in people who use contact lenses and in people who have thin corneas. The risk can be reduced by pressing the eyelids with a speculum during epithelial separation.

Bacteria-Filtering Effect of a Filtering System Used in Eye Drops

PURPOSE: A filtering system (ABAK system, Thea(R), France) was developed and has been used to prevent the abuse of preservatives and to decrease the complications that may result from them. However, the bacteria filtering effect of the system has not been reported yet. In this study, we attempt to verify its efficacy. METHODS: Staphylococcus epidermidis was diluted to two different concentrations, 10(7) and 10(5) CFU (Colony-Forming-Unit)/ml. To determine the inward-filtering effect of the system (reverse direction), 0.5 ml of each bacterial concentration was aspirated through the ABAK system, and the solutions that filtered through were cultivated. The results were compared with the controls in which the same amounts of bacterial solutions were dropped from a dropper by squeezing the bottle. For the outward-effect (forward direction), 1ml of bacterial solution from each concentration was put into the bottle with a syringe. Solutions were re-collected by filtering them out through the ABAK system by squeezing the bottle and also by aspirating them from the bottle with a syringe. Both solutions were cultivated, and the results were compared. Each test was repeated 5 times. RESULTS: In control solutions that did not pass through the filter, bacteria were cultivated consistently in repeated tests. However, bacteria were not cultivated in solutions that had passed the filter in both concentrations and in both directions. CONCLUSIONS: Filtering systems prevent solutions from contamination, and even if the bottles are polluted with Staphylococcus epidermidis initially, the bacteria would be filtered out. The effectiveness of the filtering systems was also demonstrated in high bacterial concentrations.