PURPOSE: To describe the clinical features of Korean patients with contact lens-induced limbal stem cell deficiency (CL-LSCD).METHODS: Medical records of 22 patients who were diagnosed with CL-LSCD between 2014 and 2019 were reviewed retrospectively. Outcome measures included demographics, clinical presentation, treatment, clinical course, and pattern of contact lens (CL) wear.RESULTS: Forty-two eyes of 22 patients were found to have typical changes associated with CL-LSCD. Twenty (91%) patients were women and mean age was 36 ± 12 years. All patients had myopia with mean spherical equivalent of −7.52 ± 3.2 diopter. Twenty (91%) patients had bilateral disease and the location of limbal involvement was diffuse in 20 eyes (47.6%) and partial in 22 eyes (52.4%, superior in 20 eyes and inferior in 2 eyes). Fourteen (63.6%) patients complained of decreased visual acuity. Average period of CL wear was 14 ± 9 years. Four patients used cosmetic colored CLs and four patients had a history of overnight CL wear. All 12 patients who completed follow-up (28 ± 42 weeks) showed improvement in visual acuity and ocular surface condition after cessation of CL wear and medical treatment. Of them, five (42%) patients showed full recovery while seven (58%) showed partial recovery.CONCLUSIONS: If a patient with a history of CL wear for an extended period of time presents with decreased visual acuity, practitioners should perform detailed examinations with suspicion of CL-LSCD, including fluorescein staining. CL-LSCD is usually reversible and close follow-up with conservative treatment is recommended as the initial treatment option.
Contact Lenses, Hydrophilic ; Demography ; Female ; Fluorescein ; Follow-Up Studies ; Humans ; Medical Records ; Myopia ; Outcome Assessment (Health Care) ; Retrospective Studies ; Stem Cells ; Visual Acuity

PURPOSE: This study aimed to evaluate the influence of varying concentrations of sodium hyaluronate (SH) eye drops on corneal aberrations in normal individuals wearing silicone hydrogel contact lenses. METHODS: Normal individuals wearing silicone hydrogel contact lenses were enrolled in this study. Subjects were classified into two groups depending on the concentration of the preservative-free SH used (group 1, 0.1% SH; group 2, 0.3% SH). All subjects were asked to blink five times after instillation of the SH eye drop and before the Galilei measurements. Corneal aberrations were measured over the contact lenses before and after SH eye drop instillation. Visual acuity (VA) over the contact lenses was also measured both before instillation of the SH eye drop and after the subjects completed the five blinks. RESULTS: There was no change in VA after SH instillation in group 1; however, group 2′s VA significantly deteriorated after SH instillation. Changes in VA after SH instillation compared to baseline were significantly higher in group 2 than in group 1. Similarly, the increase in corneal aberrations after SH instillation was significant in group 2 but not significant in group 1. Among the significantly increased corneal aberration parameters, defocus was the main type in group 2. Changes in corneal aberrations after SH instillation compared to baseline were significantly higher in group 2 than in group 1. CONCLUSIONS: A 0.3%-concentration of SH increases corneal aberration and decreases VA in soft contact lens wearers. Defocus is the main type of aberration that increased in the 0.3% SH instillation group.
Contact Lenses ; Contact Lenses, Hydrophilic* ; Hyaluronic Acid* ; Hydrogel ; Ophthalmic Solutions ; Silicon ; Silicones ; Sodium* ; Visual Acuity

PURPOSE: To investigate the change of retinal volume according to anterior segment refractive power using contact lens by spectral domain optical coherence tomography (SD-OCT). METHODS: The retinal volume was measured using a SD-OCT (Heidelberg retinal angiography Spectralis + OCT, Heidelberg Engineering, Heidelberg, Germany) in 60 subjects without any underlying disease. The same examiner performed a 31-section macular volume-scan at 240 µm intervals, re-measured the same area by changing the refractive power of the anterior segment by wearing soft contact lenses of +6.0 diopters and −6.0 diopters. By using the ImageJ software to calculate the cross-sectional area and of the cross-sectional area and the volume was measured. RESULTS: The mean age of the participants was 25.6 ± 1.5 years and the mean axial length was 25.7 ± 1.57 mm. The volume of the posterior pole retina measured without the contact lens was 13.48 ± 0.05 and the mean volume of the retina measured with +6.0 diopter and −6.0 diopter contact lens in the same patient was 13.47 ± 0.07 mm³ and 13.48 ± 0.05 respectively. The mean volume was significantly lower(p = 0.036) in the measurement with the +6.0 diopter lens than in the measurement without the lens, and the mean volume was significantly higher in the measurement with the +6.0 diopter lens (p = 0.042). The change in retinal thickness was increased with longer axial length (r = 0.32, p < 0.05), but the central foveal thickness did not correlate with anterior corneal power (p = 0.463). CONCLUSIONS: The volume of the retina measured using the SD-OCT is affected by the refractive power of the anterior segment and the axial length. Therefore, it is necessary to consider the change of refractive index because it can change the retinal volume measured by SD-OCT.
Angiography ; Contact Lenses, Hydrophilic ; Humans ; Refractometry ; Retina ; Retinaldehyde ; Tomography, Optical Coherence

PURPOSE: To analyze the Paecilomyces keratitis cases in Korea and compare cases from foreign literature. METHODS: The records of 3 patients diagnosed with Paecilomyces keratitis at our hospital and other reported cases in Korea were evaluated to examine the predisposing factors, clinical aspects, antifungal therapy, therapeutic surgery, and visual outcome and compared with previously reported foreign cases. RESULTS: In Korea, 1 patient was female, 4 patients were male and had predisposing factors including prior corneal trauma or surgery, except 1 spontaneous occurrence. All 5 eyes of 5 patients had poor initial visual acuity, less than finger count, and deep corneal infiltration. The patients were treated with multiple topical and systemic antifungal treatments such as intracameral or intrastromal voriconazole injections and required evisceration and penetrating keratoplasty. However, the final outcomes were unsatisfactory. Previously reported cases from foreign literature also had predisposing factors such as corneal surgery, trauma, and soft contact lens use. They were resistant to antifungal therapy and eventually led to surgeries such as penetrating keratoplasty and the final outcomes were poor. CONCLUSIONS: Frequently, Paecilomyces keratitis has direct risk factors and is resistant to many topical and systemic antifungal agents. In the majority of cases, therapeutic surgery was required and the final visual outcomes were poor. When Paecilomyces keratitis is suspected, we suggest aggressive therapy including intracameral and intravitreal injections of voriconazole in the initial treatment.
Antifungal Agents ; Causality ; Contact Lenses, Hydrophilic ; Corneal Ulcer ; Female ; Fingers ; Humans ; Intravitreal Injections ; Keratitis* ; Keratoplasty, Penetrating ; Korea* ; Male ; Paecilomyces* ; Risk Factors ; Visual Acuity

Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100. 7 µV/µm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 µV/mm Hg under the ideal condition.
Contact Lenses, Hydrophilic ; Dimethylpolysiloxanes ; Glaucoma ; Humans ; Intraocular Pressure ; Tonometry, Ocular ; instrumentation

OBJECTIVEA method for determined oxygen permeability (Dk) of finished soft contact lens.

METHODSOxygen permeability(Dk) of 10 group finished soft contact lens was determined by polarographic method, and the values were linearly calibrated using the measured and established Dk values of the specified reference materials.

RESULTSOnly one Dk value fell outside of the requirement of GB 11417.3-2012 tolerance for Dk (± 20%).

CONCLUSIONIt is great practicability when determined the oxygen permeability (Dk) of finished soft contact lens by polarographic method which were linearly calibrated using the measured and established Dk values of the specified equal thickness reference materials without the measured lens customized 4 different thickness.

PURPOSE: In this study we investigated the safety level of the national standard for tinted soft contact lenses by comparing the standards in various countries. METHODS: To evaluate the current guidelines for tinted soft contact lenses such as form and appearance, diameter, curvature radius, vertex power, cylindrical refractivity and cylindrical axis, luminous/ultraviolet ray (UV) transmittance, moisture content, oxygen permeability coefficient, extractables, elution test, cytotoxicity, sensitization, eye irritation test, acute systemic/subchronic/subacute toxicity, genotoxicity and biocompatibility safety test using rabbit eyes and sterility test. We compared the standards of International Organization for Standardization (ISO), Food and Drug Administration (FDA) of the United States, Ministry of Health, Labor and Welfare (MHLW) of Japan and Ministry of Food and Drug Safety (MFDS) of Korea. RESULTS: The guidelines for tinted soft contact lenses of ISO, FDA and MFDS are similar to soft contact lenses but MHLW of Japan classifies these lenses and sets specific guidelines. First, the oxygen permeability coefficient measured at 6mm from the center should be maintained over 80%. Also, coloring should not affect the oxygen permeability coefficient significantly. Regarding the physical (form and appearance, diameter, curvature radius, moisture content) and optical (vertex power, cylindrical refractivity and cylindrical axis, luminous/UV transmittance, oxygen permeability coefficient) characteristics, no differences were found between ISO and MFDS. However, several differences were found in chemical characteristics (extractables, elution test) and biological stability (cytotoxicity, sensitization, eye irritation test, acute systemic/subchronic/subacute toxicity test, genotoxicity, biocompatibility safety test using rabbit eyes, sterility test). For example, the elution test is required only by MFDS. CONCLUSIONS: The reinvestigation into the effectiveness of the elution test is needed and new evaluation measures including scanning electron microscopy and atomic force microscopy designed for tinted soft contact lenses to evaluate the size of the optical area, the location and roughness of the pigmented layer are required.
Axis, Cervical Vertebra ; Contact Lenses* ; Contact Lenses, Hydrophilic ; Infertility ; Japan ; Korea ; Microscopy, Atomic Force ; Microscopy, Electron, Scanning ; Oxygen ; Permeability ; Radius ; Toxicity Tests ; United States ; United States Food and Drug Administration

PURPOSE: The present study was conducted to gather valid data for promoting public eye health among adolescent contact lens wearers by investigating the current practices of contact lenses wearers. METHODS: A questionnaire regarding use and care of contact lenses was distributed to middle and high school students. A total of 920 students (472 males, 448 females) were enrolled and the purpose of the study was explained to the students. RESULTS: Among all student, 49% had myopia (male 44%, female 54%) and 12% hyperopia (male 12%, female 13%). In addition, 70% of the subjects chose to wear glasses for vision correction, 27% (male 4%, female 50%) reported they have worn contact lenses and 64% of those were soft contact lenses. The age for starting contact lenses was between 14-16 years of age (63%). Most students (95%) purchased their contact lenses from an optical store. Many (89%) cleaned the contact lenses with cleaning solution on a daily basis, however, only 25% of the students received instructions on how to clean the lens properly. Common complaints associated with use in descending order were hyperemia (31%), foreign body sensation (19%), tearing (16%), pruritis (13%), and keratitis (9%). The subjects reported that the main cause of complications was due to the users' lens handling (93%). CONCLUSIONS: The present study findings showed many adolescents have misleading knowledge regarding use of contact lenses. There is a need for better education of young contact lens users regarding the contact lens care.
Adolescent* ; Contact Lenses ; Contact Lenses, Hydrophilic ; Education ; Eyeglasses ; Female ; Foreign Bodies ; Glass ; Humans ; Hyperemia ; Hyperopia ; Keratitis ; Male ; Myopia ; Pruritus ; Surveys and Questionnaires ; Sensation ; Tears

PURPOSE: To investigate the biometric risk factors for corneal surface complications associated with hydrogel soft contact lens (SCL) fitting in myopic patients in Korea. METHODS: This is a retrospective case-control study. The records of 124 subjects (124 eyes) who wore SCLs on a daily basis were reviewed. Thirty-one patients (31 eyes) who were diagnosed with corneal neovascularization (NV) while wearing SCLs were included in the complication group. Ninety-three age- and sex-matched patients (93 eyes) who wore SCLs, who did not have corneal NV and who visited our clinic for correction of refractive errors were included in the control group. The degree of spherical equivalent, astigmatism and corneal base curve radius (BCR) were compared in both groups. RESULTS: Patients with NV exhibited poorer best corrected visual acuity and more myopia than controls (p = 0.008 and 0.006, respectively). In univariate analysis, highly myopic patients (-9 diopters [D] or higher) were more likely to experience NV (odds ratio [OR], 2.232; 95% confidence interval [CI], 1.602 to 3.105). High astigmatism (> or =2 D) increased the risk of complications (OR, 2.717; 95% CI, 1.141 to 6.451). Steep cornea, in which BCR was <7.5 mm, also raised the risk of complications (OR, 4.000; 95% CI, 1.661 to 9.804). Flat cornea was not a risk factor for the development of NV. CONCLUSIONS: High myopia, high astigmatism, and steep cornea seemed to be risk factors in the development of corneal NV in SCL wearers.
Adult ; Astigmatism/diagnosis ; Biometry ; Case-Control Studies ; Contact Lenses, Hydrophilic/*adverse effects ; Corneal Neovascularization/diagnosis/*etiology ; Female ; Humans ; Hydrogel ; Male ; Myopia/diagnosis/*therapy ; Prosthesis Fitting ; Retrospective Studies ; Risk Factors ; Visual Acuity

PURPOSE: To investigate the clinical features and compliance of cosmetic contact lens (CL)-related complications compared with soft CL-related complications. METHODS: We performed a retrospective chart review of 97 patients (194 eyes) regarded as having CL-related complications at the outpatient clinic. The portion of complications, gender, age, and chief complaints at the initial visit were analyzed, as was compliance to cosmetic and soft CL-related guidelines for use. RESULTS: A total of 97 patients (49 patients with cosmetic CL-related complications and 43 patients with soft CL-related complications) were evaluated. The mean age of the subjects using cosmetic CL was 19.8 years (14-31 years), and all the patients were female. The chief complaints at the initial visit included ocular pain, injection, blurred vision, dryness, itching and foreign body sensation. The main complications included corneal erosion, sterile corneal infiltrate, allergic disease, neovascularization, corneal ulcer and dry eye syndrome. No statistical difference was found regarding chief complaints or complications. The proportion of patients lost to follow-up was 47% in cosmetic CL-related and 20% in soft CL-related complications, a significant difference (p = 0.015). CONCLUSIONS: Because young females are the most common CL patients and do not always fully comply with the guidelines for use, ophthalmologists need to warn these patients about the risk of serious complications.
Ambulatory Care Facilities ; Compliance* ; Contact Lenses, Hydrophilic ; Corneal Neovascularization ; Dry Eye Syndromes ; Female ; Foreign Bodies ; Humans ; Lost to Follow-Up ; Pruritus ; Retrospective Studies ; Sensation ; Ulcer