PURPOSE: Keratoconus is a bilateral noninflammatory ecstatic disease of cornea. Clinical manifestations and treatments are well-described , but the exact pathophysiology has many debates. There are many reports on pathologic abnormalities of keratoconus, but few reports on epithelial adhesion complex. The authors investigated the abnormalities in epithelial adhesion complex of keratoconus. METHODS: Using 4 corneas from 4 recipients of penetrating keratoplasty, examination was done with transmission electron microscope (Hitachi-600, Japan) after proper fixation and staining. Central and peripheral portion of each corneal tissues were examined. RESULTS: In two tissues, severe degeneration of basement membrane and Bowman's layer were found. Some degree of abnormalities was found in other tissues, which had minimal change. Some of hemidesmosomes, the most distinct part of adhesion complex, were found only in well-maintained tissue but the distribution was abnormal. CONCLUSIONS: The fact that basal plasma membrane had selectively more degenerations and changes than intercellular plasma membrane implies pathophysiology of keratoconus on adhesion complex, basal plasma membrane, basement membrane and Bowman's layer. Further study on this issue will reveal more information as to its pathophysiology.
Basement Membrane ; Cell Membrane ; Cornea ; Hemidesmosomes ; Keratoconus* ; Keratoplasty, Penetrating

PURPOSE: As computer and Internet are getting widely spread, people who use visual display terminal (VDT) are increasing. Especially as computer and Internet on line games are popular, more people are exposed to VDT than in the past. So we examined to explore the relationship between middle school students' computer using time and dry eye. METHODS: The subjects were 105 middle school male students in the same district. We surveyed them on the time of computer use weekly and ocular discomfort while using computer. We examined anterior segment of the eyes by slit lamp, and checked BUT and Shirmer test. RESULTS: The subjects who frequently use computer showed shorter BUT, dry eye related ocular findings (meniscus floater, corneal erosion.), and symptoms of dry eye. But there was no significant difference in Schirmer test. CONCLUSIONS: Students in middle school age may have symptoms and ocular findings of dry eye owing to increased time of computer use. So proper rest during computer use and adequate education for dry eye are thought to be necessary.
Education ; Humans ; Internet ; Male

To investigate the drug effect of topical Mitomycin C in various concentrations combined with steroid, we used 30 rabbits whose corneal epitheliums were abraded intentionally. They were divided into 5 groups. Using MMC in various concentrations and steroids, we instilled them into right eyes and saline into left eyes as control. We measured the healing rate at a interval of 12 hours. Three months later, we sacrificed one of them and examined the pathological changes from various ocular tissues. We found many complications such as corneal edema, ulcer, opacity and definite delay of wound healing when the concentration higher than 0.04%MMC was used. There were also decreased fibroblast cells in H-E staining. The steroids seemed not to pose any influence on the effect of MMC. In conclusion, we must take the great care in the use of MMC, and the concentration should be low when used. In addition, we still think there ought to be more studies as to the effect of steroids according to MMC levels.
Cornea* ; Corneal Edema ; Epithelium, Corneal ; Fibroblasts ; Intention ; Mitomycin* ; Ophthalmic Solutions* ; Rabbits ; Steroids ; Ulcer ; Wound Healing

To investigate the drug effect of topical Mitomycin C in various concentrations combined with steroid, we used 30 rabbits whose corneal epitheliums were abraded intentionally. They were divided into 5 groups. Using MMC in various concentrations and steroids, we instilled them into right eyes and saline into left eyes as control. We measured the healing rate at a interval of 12 hours. Three months later, we sacrificed one of them and examined the pathological changes from various ocular tissues. We found many complications such as corneal edema, ulcer, opacity and definite delay of wound healing when the concentration higher than 0.04%MMC was used. There were also decreased fibroblast cells in H-E staining. The steroids seemed not to pose any influence on the effect of MMC. In conclusion, we must take the great care in the use of MMC, and the concentration should be low when used. In addition, we still think there ought to be more studies as to the effect of steroids according to MMC levels.
Cornea* ; Corneal Edema ; Epithelium, Corneal ; Fibroblasts ; Intention ; Mitomycin* ; Ophthalmic Solutions* ; Rabbits ; Steroids ; Ulcer ; Wound Healing

Purpose: To compare the accuracy of nine intraocular lens (IOL) power calculation formulas. Methods: This study is retrospective consecutive case series. A total of 228 eyes of 228 patients who underwent uncomplicated cataract surgery between October 2015 and March 2021 were included. The accuracy of nine IOL calculation formulas (Kane, Emmetropia verifying optical version, Hill-radial basis function, Olsen, Barrett Universal II [Barrett II], Haigis, Holladay, Hoffer, and SRK/T) was compared and analyzed using differences between the predicted refractive power and actual refractive power at 2 months after cataract surgery. Mean prediction error (ME), mean absolute error (MAE), median absolute error (MedAE), and the percentage of eyes that were within ± 0.50 diopters (D), ± 0.75 D, and ± 1.00 D of the target refraction were calculated for each formula. Results: For all eyes, Haigis formula was the most accurate in MAE, followed by Barrett II formula. Comparing the probability of MAE within 0.50 D, Haigis formula showed the highest accuracy. A total of 20 eyes of 20 patients had more than 25 mm axial length. Regarding MAE, Hoffer Q was the most accurate, followed by the Olsen formula. Comparing the probability of MAE within 0.50 D, the Hoffer Q formula was the most accurate. A total of 24 eyes of 24 patients had more than 46 D keratometry. Regarding MAE and MedAE, Haigis was the most accurate, followed by the Barrett II formula. Comparing the probability of MAE within 0.5 D, Holladay formula was the most accurate. Conclusions Barrett II and Haigis formulas showed greater accuracy for all patients when we determined IOL power before cataract surgery. Hoffer Q, Olsen, and Barrett II formulas showed higher accuracy for long axial length. And Haigis and Barrett II were the most accurate for steep keratometry.

PURPOSE: To evaluate changes in intraocular pressure (IOP) according to position using a portable rebound tonometer. METHODS: We measured the IOP values of 20 healthy volunteers (40 eyes) in the sitting, supine, right lateral decubitus and left decubitus positions with a portable rebound tonometer, and then analyzed using the Wilcoxon signed rank test. IOP in sitting position was also measured with a non-contact tonometer and a Goldmann applanation tonometer, and analyzed with Kruskal-Wallis test and Spearman correlation analysis. Agreement among the 3 tonometers was calculated using the Bland-Altman method. RESULTS: The IOP measured with rebound tonometer in the supine position was significantly higher than in the sitting position (p = 0.002). However, there was no significant difference in IOP between the supine and decubitus positions. In the decubitus position, there was no significant difference in IOP between the dependent and non-dependent eyes. IOP measurement using the rebound tonometer showed positive correlation with that of the noncontact and Goldmann applanation tonometers. CONCLUSIONS: In normal subjects, IOP measurement obtained with a rebound tonometer in the supine position was significantly higher than in the sitting position, but there was no significant difference in IOP between the supine and decubitus positions. A rebound tonometer may be useful for patients whose intraocular pressure measurement with Goldmann applanation tonometer or non-contact tonometer is impossible. When using a portable rebound tonometer in bed-ridden or pediatric patients, we should pay attention to the interpretation of IOP in the supine position.
Healthy Volunteers ; Humans ; Intraocular Pressure* ; Iron-Dextran Complex* ; Supine Position

With the development of body sensor technology, wearable health monitoring systems have been an emerging information technology in the 'ubiquitous health care' system. Wearable sensors enable long-term continuous physiological monitoring important in health promotion and management of many chronic disorders. In this paper, we present several wearable health monitoring systems developed by different countries and discuss emerging opportunities, as well as, existing challenges such as standardization, administration, validation, and discrepancy issues between technology and clinical implication.
Health Promotion ; Monitoring, Physiologic ; Telemedicine

PURPOSE: To compare subjective quality of life (QOL) of a glaucoma group with a control group. METHODS: The Korean version of the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25) was completed by 105 glaucoma clinic patients including 54 glaucoma group and 56 control group. We compared questionnaire scores and previous performed visual field parameters between a glaucoma group and a control group. RESULTS: The glaucoma group results were: Mean age: 55.73 +/- 15.17 years; mean best corrected visual acuity (BCVA; log MAR) 0.05 +/- 0.09 in better eyes and 0.06 +/- 0.09 in worse eyes; and mean intraocular pressure (IOP) 15.94 +/- 2.93 mm Hg in better eyes and 15.49 +/- 3.18 mm Hg in worse eyes. Control group scores were: Mean age: 51.85 +/- 11.36 years; mean BCVA (log MAR) 0.04 +/- 0.07 in better eyes and 0.06 +/- 0.08 in worse eyes; and mean IOP 16.40 +/- 2.50 mm Hg in better eyes and 16.13 +/- 2.16 mm Hg in worse eyes. Age, BCVA, and IOP were not significantly different between groups, but visual field index (VFI) score and visual function questionnaire (NEI-VFQ-25) total score were significantly lower in the glaucoma group (p < 0.01). Additionally, visual field parameters and QOL had a significant relationship in the glaucoma group, especially in better eyes. CONCLUSIONS: The QOL of glaucoma patients was lower than that of normal controls regardless of visual acuity. The degree of visual field loss in the better eye may affect QOL more significantly.
Glaucoma* ; Humans ; Intraocular Pressure ; National Eye Institute (U.S.) ; Quality of Life* ; Surveys and Questionnaires ; Visual Acuity ; Visual Fields

PURPOSE: To compare subjective quality of life (QOL) of a glaucoma group with a control group. METHODS: The Korean version of the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25) was completed by 105 glaucoma clinic patients including 54 glaucoma group and 56 control group. We compared questionnaire scores and previous performed visual field parameters between a glaucoma group and a control group. RESULTS: The glaucoma group results were: Mean age: 55.73 +/- 15.17 years; mean best corrected visual acuity (BCVA; log MAR) 0.05 +/- 0.09 in better eyes and 0.06 +/- 0.09 in worse eyes; and mean intraocular pressure (IOP) 15.94 +/- 2.93 mm Hg in better eyes and 15.49 +/- 3.18 mm Hg in worse eyes. Control group scores were: Mean age: 51.85 +/- 11.36 years; mean BCVA (log MAR) 0.04 +/- 0.07 in better eyes and 0.06 +/- 0.08 in worse eyes; and mean IOP 16.40 +/- 2.50 mm Hg in better eyes and 16.13 +/- 2.16 mm Hg in worse eyes. Age, BCVA, and IOP were not significantly different between groups, but visual field index (VFI) score and visual function questionnaire (NEI-VFQ-25) total score were significantly lower in the glaucoma group (p < 0.01). Additionally, visual field parameters and QOL had a significant relationship in the glaucoma group, especially in better eyes. CONCLUSIONS: The QOL of glaucoma patients was lower than that of normal controls regardless of visual acuity. The degree of visual field loss in the better eye may affect QOL more significantly.
Glaucoma* ; Humans ; Intraocular Pressure ; National Eye Institute (U.S.) ; Quality of Life* ; Surveys and Questionnaires ; Visual Acuity ; Visual Fields

PURPOSE: To evaluate of the range and relationship between intraocular pressure (IOP), and central corneal thickness (CCT) in premature infants. METHODS: To investigate the correlation of IOP and CCT with gestational age and body weight, 58 premature infants 37 weeks-old or younger were examined. Under topical anesthesia, IOP was measured with Tono-Pen(R) XL (Medtronic Solan, Jacksonville, FL) and the CCT with pachymeter (SP-2000, TOMEY(R), Japan). The fundus was examined in infants with a risk of retinopathy of prematurity (ROP). RESULTS: Average gestational age of the subjects was 33 weeks and 6 days and body weight was 1506+/-520 grams (mean+/-standard deviation). Forty-five subjects had oxygen therapy, and 10 patients were found to have any one of the stages of ROP. Average IOP was 15.14+/-4.64 mmHg in the right eye and 15.29+/-3.70 mmHg in the left eye. CCT was 594.72+/-74.87 micrometer in the right eye and 599.78+/-74.17 micrometer in the left eye. No statistically significant correlation was found between IOP or CCT and gestational age or body weight. CONCLUSIONS: Gestational age and body weight did not appear to affect IOP or CCT in the gestational age between 26 and 37 weeks. The maturing eye in the neonate is known for fast development in the first year after birth. There are, however, few reports in the literature regarding the changes in dimensions of ocular structures in the premature neonate. These normative values may aid ophthalmologists in assessing IOP and CCT in premature infants.
Anesthesia ; Body Weight ; Diterpenes ; Eye ; Gestational Age ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Intraocular Pressure ; Oxygen ; Parturition ; Retinopathy of Prematurity ; Toluidines