Rigid gas permeable (RGP) contact lenses are made of materials with excellent oxygen permeability and wettability, so they not only improve oxygen permeability compared to existing lenses, but also provide correction of refractive errors and improved vision in irregular corneas such as keratoconus. However, the hard material of the lens along with hypoxia and hypercapnia of the cornea caused by wearing RGP contact lenses cause various physiological changes in the cornea. Physiological changes in the cornea that may occur when wearing RGP contact lenses include mucin balls, decreased corneal epithelial thickness and increased size, decreased epithelial barrier function, corneal erosion and staining, decreased keratocyte density, decreased corneal sensitivity, and stromal opacities, contact lens‐induced peripheral ulcers, endothelial blebs, increased endothelial polymegethism, and changes in corneal shape. It is necessary to know the performance of the RGP contact lenses being prescribed, be aware of the physiological changes in the cornea caused by wearing RGP contact lenses, and provide the correct lens prescription along with appropriate education to the patient.

Rigid gas permeable (RGP) contact lenses are made of materials with excellent oxygen permeability and wettability, so they not only improve oxygen permeability compared to existing lenses, but also provide correction of refractive errors and improved vision in irregular corneas such as keratoconus. However, the hard material of the lens along with hypoxia and hypercapnia of the cornea caused by wearing RGP contact lenses cause various physiological changes in the cornea. Physiological changes in the cornea that may occur when wearing RGP contact lenses include mucin balls, decreased corneal epithelial thickness and increased size, decreased epithelial barrier function, corneal erosion and staining, decreased keratocyte density, decreased corneal sensitivity, and stromal opacities, contact lens‐induced peripheral ulcers, endothelial blebs, increased endothelial polymegethism, and changes in corneal shape. It is necessary to know the performance of the RGP contact lenses being prescribed, be aware of the physiological changes in the cornea caused by wearing RGP contact lenses, and provide the correct lens prescription along with appropriate education to the patient.

Rigid gas permeable (RGP) contact lenses are made of materials with excellent oxygen permeability and wettability, so they not only improve oxygen permeability compared to existing lenses, but also provide correction of refractive errors and improved vision in irregular corneas such as keratoconus. However, the hard material of the lens along with hypoxia and hypercapnia of the cornea caused by wearing RGP contact lenses cause various physiological changes in the cornea. Physiological changes in the cornea that may occur when wearing RGP contact lenses include mucin balls, decreased corneal epithelial thickness and increased size, decreased epithelial barrier function, corneal erosion and staining, decreased keratocyte density, decreased corneal sensitivity, and stromal opacities, contact lens‐induced peripheral ulcers, endothelial blebs, increased endothelial polymegethism, and changes in corneal shape. It is necessary to know the performance of the RGP contact lenses being prescribed, be aware of the physiological changes in the cornea caused by wearing RGP contact lenses, and provide the correct lens prescription along with appropriate education to the patient.

Rigid gas permeable (RGP) contact lenses are made of materials with excellent oxygen permeability and wettability, so they not only improve oxygen permeability compared to existing lenses, but also provide correction of refractive errors and improved vision in irregular corneas such as keratoconus. However, the hard material of the lens along with hypoxia and hypercapnia of the cornea caused by wearing RGP contact lenses cause various physiological changes in the cornea. Physiological changes in the cornea that may occur when wearing RGP contact lenses include mucin balls, decreased corneal epithelial thickness and increased size, decreased epithelial barrier function, corneal erosion and staining, decreased keratocyte density, decreased corneal sensitivity, and stromal opacities, contact lens‐induced peripheral ulcers, endothelial blebs, increased endothelial polymegethism, and changes in corneal shape. It is necessary to know the performance of the RGP contact lenses being prescribed, be aware of the physiological changes in the cornea caused by wearing RGP contact lenses, and provide the correct lens prescription along with appropriate education to the patient.

PURPOSE: To investigate systemic factors associated with central serous chorioretinopathy (CSC). METHODS: We retrospectively reviewed the medical records of 113 Korean patients who were diagnosed with CSC and who underwent history taking with a specialized questionnaire for CSC. They were matched for age and gender at a ratio of 1 : 3 to 339 normal controls. Normal controls were consecutively selected from a database at the Health Promotion Center. General characteristics and medical histories were compared between the two groups. The statistical analyses used included independent t-test, Mann-Whitney test, Fisher's exact test, and multivariate logistic regression analysis. RESULTS: There were 90 men and 23 women in the CSC group, and the male-female ratio for both groups was 3.9 : 1. The mean age of the patients was 45.6 years. In multivariate analysis, hypertension (odds ratio [OR], 2.327; 95% confidence interval [CI], 1.349-4.013), use of medicinal plants (OR, 2.198; 95% CI, 1.193-4.049), sleep disturbances (OR, 1.732; 95% CI, 1.096-2.739), and snoring (OR, 1.727; 95% CI, 1.058-2.820) were strongly associated with CSC. CONCLUSIONS: Hypertension, sleep disturbance, snoring, and medicinal plant use were identified as factors associated with CSC. Expanded history taking, including systemic factors and culture-specific behavior related to stress or fatigue such as use of medicinal plants, will be helpful in identifying Korean patients at an increased risk for CSC.
Asian Continental Ancestry Group ; Case-Control Studies ; Central Serous Chorioretinopathy/*epidemiology/*etiology ; Female ; Humans ; Logistic Models ; Male ; Middle Aged ; Questionnaires ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Factors ; Statistics, Nonparametric

PURPOSE: To investigate the effects of cataract grade based on wide-field fundus imaging on macular thickness measured by spectral domain optical coherence tomography (SD-OCT) and its signal-to-noise ratio (SNR). METHODS: Two hundred cataract patients (200 eyes) with preoperative measurements by wide-field fundus imaging and macular SD-OCT were enrolled. Cataract severity was graded from 1 to 4 according to the degree of macular obscuring by cataract artifact in fundus photo images. Cataract grade based on wide-field fundus image, the Lens Opacity Classification System III, macular thickness, and SD-OCT SNR were compared. All SD-OCT B-scan images were evaluated to detect errors in retinal layer segmentation. RESULTS: Cataract grade based on wide-field fundus imaging was positively correlated with grade of posterior subcapsular cataracts (rho = 0.486, p < 0.001), but not with nuclear opalescence or cortical cataract using the Lens Opacity Classification System III. Cataract grade was negatively correlated with total macular thickness (rho = −0.509, p < 0.001) and SD-OCT SNR (rho = −0.568, p < 0.001). SD-OCT SNR was positively correlated with total macular thickness (rho = 0.571, p < 0.001). Of 200 eyes, 97 (48.5%) had segmentation errors on SD-OCT. As cataract grade increased and SD-OCT SNR decreased, the percentage of eyes with segmentation errors on SD-OCT increased. All measurements of macular thickness in eyes without segmentation errors were significantly greater than those of eyes with segmentation errors. CONCLUSIONS: Posterior subcapsular cataracts had profound effects on cataract grade based on wide-field fundus imaging. As cataract grade based on wide-field fundus image increased, macular thickness tended to be underestimated due to segmentation errors in SD-OCT images. Segmentation errors in SD-OCT should be considered when evaluating macular thickness in eyes with cataracts.
Artifacts ; Cataract* ; Classification ; Fundus Oculi ; Humans ; Iridescence ; Retinaldehyde ; Signal-To-Noise Ratio ; Tomography, Optical Coherence

PURPOSE: To compare the effect of posterior corneal astigmatism on the estimation of total corneal astigmatism using anterior corneal measurements (simulated keratometry [K]) between eyes with keratoconus and healthy eyes. METHODS: Thirty-three eyes of 33 patients with keratoconus of grade I or II and 33 eyes of 33 age- and sex-matched healthy control subjects were enrolled. Anterior, posterior, and total corneal cylinder powers and flat meridians measured by a single Scheimpflug camera were analyzed. The difference in corneal astigmatism between the simulated K and total cornea was evaluated. RESULTS: The mean anterior, posterior, and total corneal cylinder powers of the keratoconus group (4.37 ± 1.73, 0.95 ± 0.39, and 4.36 ± 1.74 cylinder diopters [CD], respectively) were significantly greater than those of the control group (1.10 ± 0.68, 0.39 ± 0.18, and 0.97 ± 0.63 CD, respectively). The cylinder power difference between the simulated K and total cornea was positively correlated with the posterior corneal cylinder power and negatively correlated with the absolute flat meridian difference between the simulated K and total cornea in both groups. The mean magnitude of the vector difference between the astigmatism of the simulated K and total cornea of the keratoconus group (0.67 ± 0.67 CD) was significantly larger than that of the control group (0.28 ± 0.12 CD). CONCLUSIONS: Eyes with keratoconus had greater estimation errors of total corneal astigmatism based on anterior corneal measurement than did healthy eyes. Posterior corneal surface measurement should be more emphasized to determine the total corneal astigmatism in eyes with keratoconus.
Astigmatism* ; Cornea ; Humans ; Keratoconus* ; Meridians

Purpose: We used anterior segment optical coherence tomography (AS-OCT) to measure the pterygial subepithelial invasion length and thickness before and after surgery, and to evaluate the corneal epithelium and the extent of astigmatism. Methods: This was a retrospective study. Ten eyes that underwent pterygial excision surgery were analyzed. We used corneal topographic data to assess astigmatism before surgery and employed AS-OCT to measure corneal epithelial thickness and the length of subepithelial invasion. We measured the relative pterygial length, width, and area on anterior segment photographs. Corneal topographic assessment and AS-OCT were repeated 1 month after surgery. Multiple regression and Pearson correlation analyses were used to analyze the relationships between normalization of astigmatism and the size and thickness of the excised pterygium. Results: The mean With-the-Rule proportion of preoperative astigmatism was 2.9 ± 2.3 D and the mean corneal epithelial thickness 269.60 ± 84.17 µm. The mean thickness of the excised pterygia was 210.73 ± 80.36 µm. Pterygial thickness was significantly associated with the extent of preoperative With-the-Rule astigmatism and the normalized With-the-Rule astigmatism after pterygial excision. These correlations were stronger than those of the relative pterygial length, width, and area. The mean subepithelial invasion length was 595.00 ± 310.32 µm. Conclusions An increase in pterygial epithelial thickness influenced the extent of With-the-Rule astigmatism to a much greater extent than did the relative pterygial length, width, and area. AS-OCT measurement of the subepithelial invasion length identifies the required excisional area prior to surgery.

Purpose: We compared the cataract grades with slit lamp examination and anterior segment photography using the Lens Opacities Classification System (LOCS) III criteria. We also explored the effect of a yellow filter on the photographic results. Methods: Eighty eyes with cataracts were examined by three inspectors (1, 2, and 3). Anterior segment photographs taken by inspector 1 were divided into two groups depending on whether cortical opacity or nuclear sclerosis predominated. In each group, the cataract grades determined by inspector 1 on slit lamp examination and anterior segment photography were compared. Also, after randomly assigning the anterior segment photographs taken by inspector 1 to inspectors 2 and 3, the cataract grades of these photographs were compared to the grades of photographs taken by all inspectors using a yellow filter. Results: The average cortical opacity evaluated by inspector 1 on slit lamp examination (3.48 ± 0.91) was significantly higher than that apparent on anterior segment photographs (2.35 ± 0.77) (p < 0.001). In the photographs, the average cortical opacity when a yellow filter was used was significantly higher for both inspectors 1 (p < 0.001) and 2 (p = 0.022) than when the filter was absent. The average extent of nuclear sclerosis evaluated by inspector 1 on slit lamp examination (4.08 ± 0.94) was significantly higher than that of anterior segment photography (3.73 ± 1.24) (p = 0.042). Conclusions Cataract evaluation via anterior segment photography underestimates the extent of damage compared to direct slit lamp examination. However, use of a yellow filter during photography aids cataract evaluation, especially cortical opacity.

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.
Cataract ; Contrast Sensitivity ; Eye ; Humans ; Lenses, Intraocular ; Patient Satisfaction ; Presbyopia ; Vision, Ocular ; Visual Acuity