New Korean guidelines for the diagnosis and management of dry eye disease were developed based on literature reviews by the Korean Dry Eye Guideline Establishment Committee, a previous dry eye guideline by Korean Corneal Disease Study Group, a survey of Korean Dry Eye Society (KDES) members, and KDES consensus meetings. The new definition of dry eye was also proposed by KDES regular members. The new definition by the regular members of the KDES is as follows: “Dry eye is a disease of the ocular surface characterized by tear film abnormalities and ocular symptoms.” The combination of ocular symptoms and an unstable tear film (tear breakup time <7 seconds) was considered as essential components for the diagnosis of dry eye. Schirmer test and ocular surface staining were considered adjunctive diagnostic criteria. The treatment guidelines consisted of a simplified stepwise approach according to aqueous deficiency dominant, evaporation dominant, and altered tear distribution subtypes. New Korean guidelines can be used as a simple, valid, and accessible tool for the diagnosis and management of dry eye disease in clinical practice.

Purpose: To compare the clinical outcomes of intrascleral fixation of the three-piece intraocular lenses (IOLs) 2.5 mm posterior to the limbus with ciliary sulcus implantation and transscleral fixation 2.5 mm posterior to the limbus. Methods: Sixty-five eyes of 65 patients who underwent ciliary sulcus implantation or transscleral or intrascleral fixation of the AMO Sensar AR40e IOL were retrospectively reviewed. The postoperative refractive prediction error, back-calculated effective lens position (ELP), corrected distance visual acuity (CDVA), and postoperative residual cylinder were compared. Results: There were significant differences in the median (interquartile range) postoperative refractive prediction error (diopters [D]) among the three groups (p < 0.001): for ciliary sulcus implantation (33 eyes), −0.89 D (−1.21 to −0.56 D); for transscleral fixation (10 eyes), −0.40 D (−0.78 to −0.22 D); and for intrascleral fixation (22 eyes), 0.01 D (−0.28 to 0.34 D). Significant differences (p < 0.001) were observed in the median back-calculated ELP: for ciliary sulcus implantation, 4.35 mm (3.95 to 4.55 mm); for transscleral fixation, 4.51 mm (4.34 to 4.76 mm); and for intrascleral fixation, 4.90 mm (4.56 to 5.35 mm). There were no differences in the median postoperative CDVA (0, 0.10, and 0 logarithm of the minimum angle of resolution, respectively; p = 0.083) and the residual cylinder (−0.75, −1.50, and −0.63 D, respectively; p = 0.074) among three groups. Conclusions Intrascleral fixation showed no myopic shift and the most posterior lens position, while ciliary sulcus implantation induced the greatest myopic shift and the most anterior lens position. However, there was no significant difference in the postoperative CDVA or astigmatism among the eyes with different IOL insertion methods, demonstrating good IOL stability and vision outcomes.

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.

Background: Obesity, the prevalence of which is increasing due to the lack of exercise and increased consumption of Westernized diets, induces various complications, including ophthalmic diseases. For example, obesity is involved in the onset of cataracts. Methods: To clarify the effects and mechanisms of midodrine, an α1-adrenergic receptor agonist, in cataracts induced by obesity, we conducted various analytic experiments in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a rat model of obesity. Results: Midodrine prevented cataract occurrence and improved lens clearance in OLETF rats. In the lenses of OLETF rats treated with midodrine, we observed lower levels of aldose reductase, tumor necrosis factor-α, and sorbitol, but higher levels of hexokinase, 5’-adenosine monophosphate-activated protein kinase-alpha, adenosine 5´-triphosphate, peroxisome proliferator-activated receptordelta, peroxisome proliferator-activated receptor gamma coactivator 1-alpha, superoxide dismutase, and catalase. Conclusion The ameliorating effects of midodrine on cataracts in the OLETF obesity rat model are exerted via the following three mechanisms: direct inhibition of the biosynthesis of sorbitol, which causes cataracts; reduction of reactive oxygen species and inflammation; and (3) stimulation of normal aerobic glycolysis.

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: To derive the optimized intraocular lens (IOL) constants from automated and manifest refraction after cataract surgery in Korean patients, and to evaluate whether there is a difference in optimized IOL constants according to the refraction method. Methods: This retrospective multicenter cohort study enrolled 4,103 eyes of 4,103 patients who underwent phacoemulsification and in-the-bag IOL implantation at 18 institutes. Optimized IOL constants for the SRK/T, Holladay, Hoffer Q, and Haigis formulas were calculated via autorefraction or manifest refraction of samples using the same biometry and IOL. The IOL constants derived from autorefraction and manifest refraction were compared. Results: Of the 4,103 eyes, the majority (62.9%) were measured with an IOLMaster 500 followed by an IOLMaster 700 (15.2%). A total of 33 types of IOLs were used, and the Tecnis ZCB00 was the most frequently used (53.0%). There was no statistically significant difference in IOL constants derived from autorefraction and manifest refraction when IOL constants were optimized with a large number of study subjects. On the other hand, optimized IOL constants derived from autorefraction were significantly smaller than those from manifest refraction when the number of subjects was small. Conclusions It became possible to use the IOL constants optimized from Koreans to calculate the IOL power. However, if the IOL constant is optimized using autorefraction in a small sample group, the IOL constant tends to be small, which may lead to refractive error after surgery.

Purpose: To describe current cataract surgery practice patterns and trends among Korean ophthalmologists. Methods: A survey was conducted among members of the Korean Society of Cataract and Refractive Surgery in October 2020. Of the 998 questionnaires, 262 (26.3%) were received for analysis. Data were analyzed using descriptive statistics and compared with those of previous surveys. Results: The largest percentage of respondents (39%) had <5 years of practical experience, and 40% had >11 years of practical experience. The average, median, and mode monthly volumes of cataract surgeries performed by the Korean Society of Cataract and Refractive Surgery members were 31, 20, and 10 cases, respectively. Topical anesthesia was administered by 85% of the respondents. For intraocular lens (IOL) calculations, 96% of the respondents used optical biometry. The proportion of surgeons providing femtosecond laser-assisted cataract surgery increased significantly from 5% in 2018 to 29% in 2020. This increase was accompanied by an increase in the multifocal IOLs. Those who implant multifocal IOL for >10% of their cases increased from 16% (2018) to 29% (2020). Topical nonsteroidal anti-inflammatory drugs were prescribed postoperatively by 76% of the respondents. Most respondents (70%) prescribed these anti-inflammatory drugs for 4 weeks. Conclusions This survey provided a comprehensive update on current cataract surgery practice in the Republic of Korea. The results highlighted the increasing use of premium IOLs, femtosecond laser-assisted cataract surgery, optical biometry, and topical anesthesia to better meet the patients’ needs.

Purpose: To compare eyelid heating efficacy according to the type and the method of use of eyelid warm compress products commercially available in South Korea. Methods: For six healthy adults, three types of eyelid warm compresses were worn for 10 minutes and the temperature of the product surface, external upper lid, external lower lid, and internal lower lid were measured every 2 minutes. The average of the measured values was divided into four groups according to the type of product (Moist Heat Eye Compress®, Megrythm Steam Eye Mask®, Nurieye-5900®-High Temperature Mode [H], Nurieye-5900®-Low Temperature Mode [L]) and were compared. Results: Eyelid temperature showed a significant difference between each group after the first 2 minutes of treatment (p < 0.000). In the Moist Heat Eye Compress® group, the temperature of the external upper lid was maintained above 38°C until 6 minutes and the remaining groups did not exceed 38°C. The temperature of the inner lower lid was maintained at 37°C or higher for 10 minutes in the Moist Heat Eye Compress® use group and exceeded 37°C at 6 minutes in the Megrythm Steam Eye Mask® use group. The remaining groups did not exceed 37°C. Conclusions For the external eyelid, only the Moist Heat Eye Compress® group were heated above 38°C. For the inner lower lid, Moist Heat Eye Compress® and Megrythm Steam Eye Mask® groups were heated above 37°C, showing a higher heating effect. Further studies are required on the effects of the three warm compress products in patients with Meibomian gland dysfunction.

Purpose: To describe current cataract surgery practice patterns and trends among Korean ophthalmologists. Methods: A survey was conducted among members of the Korean Society of Cataract and Refractive Surgery in October 2020. Of the 998 questionnaires, 262 (26.3%) were received for analysis. Data were analyzed using descriptive statistics and compared with those of previous surveys. Results: The largest percentage of respondents (39%) had <5 years of practical experience, and 40% had >11 years of practical experience. The average, median, and mode monthly volumes of cataract surgeries performed by the Korean Society of Cataract and Refractive Surgery members were 31, 20, and 10 cases, respectively. Topical anesthesia was administered by 85% of the respondents. For intraocular lens (IOL) calculations, 96% of the respondents used optical biometry. The proportion of surgeons providing femtosecond laser-assisted cataract surgery increased significantly from 5% in 2018 to 29% in 2020. This increase was accompanied by an increase in the multifocal IOLs. Those who implant multifocal IOL for >10% of their cases increased from 16% (2018) to 29% (2020). Topical nonsteroidal anti-inflammatory drugs were prescribed postoperatively by 76% of the respondents. Most respondents (70%) prescribed these anti-inflammatory drugs for 4 weeks. Conclusions This survey provided a comprehensive update on current cataract surgery practice in the Republic of Korea. The results highlighted the increasing use of premium IOLs, femtosecond laser-assisted cataract surgery, optical biometry, and topical anesthesia to better meet the patients’ needs.

Purpose: To compare optical coherence tomography (OCT) and histological findings of Meibomian glands in rats. Based onthese results, the histological findings of the structures seen using OCT were clarified. Methods: En bloc excision was performed on the upper and lower eyelids in two rats. The axis of the Meibomian gland was verticallyscanned with three-dimensional (3D) OCT and reconstructed into 3D images. The samples were fixed in 10% formalinagain and stained with hematoxylin and eosin. The findings of the OCT and histological examinations were then compared to determinethe histological characteristics of the structures observed in the OCT. Results: The surface of the acinus was well-delineated in the Meibomian glands of rats using OCT. However, no deep acini wereobserved in the central ducts. Conclusions The structure of Meibomian glands imaged by OCT in rats was limited to the surface of the acinus. The structureof the reconstructed Meibomian gland ex vivo was similar to that of the human Meibomian gland. The possibility of developing anin vivo meibography system was therefore confirmed in animals.