Corneal Diseases

The Korean Corneal Disease Study Group (KCDSG) is an independent, non-profit, academic society whose members comprise the most active corneal subspecialists in Korea. In 2009, the initial survey on the definition, diagnosis, severity grading, and management of dry eye disease was conducted among the members of the KCDSG. In this survey, we found that 78.8% of KCDSG members use the DEWS classification [3 (link)] as diagnostic guidelines of dry eye disease, while 21.2% use guidelines proposed by the DTS group [2 (link)]. KCDSG members also responded that they consider subjective symptoms, tear film breakup time (TBUT), and signs of ocular surface inflammation of more diagnostic value than other parameters. Based on the results of this survey, along with a review of the contemporary literature with regard to definition, classification, and treatment recommendations for dry eye, the subcommittees held face-to-face meetings to reach a consensus on the issues related to the definition, diagnosis, severity grading, and treatment recommendations for dry eye disease. New guidelines for the diagnosis and management of dry eye disease were adopted as shown in Tables 1 and 2. These guidelines were based on DEWS guidelines and modified to simplify the grading scheme so that they could be used more easily in clinical practice.
Dry eye disease was defined as "a disease of the ocular surface that is associated with tear film abnormalities." We agreed that a patient should be diagnosed with dry eye disease when he or she has at least one symptom and one objective sign. In the diagnosis guidelines, dry eye symptoms included ocular symptoms (such as dryness, discomfort, foreign body sensation, and pain) and visual symptoms (such as blurring or vision fluctuation). Ocular surface staining score by the Oxford system [9 (link)], TBUT, and Schirmer-1 test score were used as objective signs for diagnosing dry eye disease. Conjunctival injection, lid problems such as blepharitis, trichiasis, keratinization, or symblepharon, and tear film abnormalities such as debris, decreased tear meniscus, and mucus clumping, were considered signs of ocular surface inflammation, but these findings were not considered during the grading of disease severity. The severity level of the disease was determined when both designated symptoms and signs were present at a certain level. If there was a discrepancy between the patients' symptoms and signs, the severity level was determined according to the severity level of the objective signs. When several objective signs were present at different levels, the severity level of the disease was determined following ocular surface staining. In addition, we introduced a provisional category of "dry eye suspect," which is not listed on the grading scheme. The patient was diagnosed with suspected dry eye when he or she had only dry eye symptoms without any objective signs. This was to evaluate the distribution of disease severity at the initial visit, and the treatment recommendation did not include the category of "dry eye suspect."
Detailed treatment options for each particular level from level I to level IV were recommended as shown in Table 2.

In this prospective, cross-sectional, and comparative investigation, 64 right eyes of 64 participants were evaluated at The University, Medical Faculty, Department of Ophthalmology. The University-Local Ethics Committee approved the study protocol (Protokol Number; 2016-58-09.03). The study was conducted in accordance with the ethical principles of the Declaration of Helsinki, and all of the participants provided written informed consent.
The study groups were selected from patients who have been diagnosed with OSAS by PSG in the Sleep Disorder Laboratory of the Department of Thoracic Medicine but have not yet been treated. The control group was selected from healthy volunteers who applied to the ophthalmology outpatient clinic with presbyopic complaints. Both the Berlin questionnaire (9 (link)) was applied and a complete physical examination was performed by a thoracic medicine specialist (FE) to the participants to be included in the control group to exclude possible OSAS cases. The subjects who had a total score of <2 in the Berlin questionnaire and had no additional ocular and systemic diseases except controlled HT were included in the control group.
The patients who were <18 years old, who had any corneal diseases, ocular diseases requires continued medication (diseases such as glaucoma, uveitis, dry eyes, etc.), previous operation history of the eye in the past 6 months, contact lens use within last 4 weeks, the best corrected visual acuity (BCVA) <20/30 with spherical and cylindrical refraction exceeding ±3 diopter were excluded from the study. Patients who have systemic diseases that may affect the biomechanics of the cornea, such as Sjögren’s Disease, chronic renal failure, diabetes mellitus (DM), liver diseases, chronic obstructive pulmonary diseases, rheumatic, and oncological disorders were also excluded from the study.
The study group was selected according to their AHI value. While mild OSAS cases (AHI <15) were excluded, 32 eyes of 32 patients with moderate to severe OSAS (AHI ≥15; number of moderate case=16 and number of severe case=16) were included in the study (Group 1). The control group was determined as “Group 0” and 32 eyes of 32 patients were recruited in Group 0. Only the right eyes of the subjects were evaluated in both groups.

A retrospective and chart review was conducted on patients with epiphora, who were referred to the oculoplastic surgery clinic of the tertiary ophthalmology hospital between January 2014 and July 2021. Due to the retrospective nature of the study, an informed consent form was not obtained from the patients. The study was planned in accordance with the Declaration of Helsinki and ethics committee approval has been obtained (March 09, 2022, E22–922).
This study included patients over the age of 18 who complained of epiphora and was followed up in the oculoplastic surgery clinic for at least 6 months. Patients with epiphora due to congenital nasolacrimal duct obstruction (NLDO), tumor-induced NLDO, and trauma-related eyelid or canaliculi injury were not included in this study.
Data regarding age, gender, etiology, duration of symptoms, and follow-up periods of all patients were retrospectively recorded. In our clinic, a routine approach is applied to determine all etiological causes for the evaluation of epiphora. For every tearing patient referred to oculoplastic sugery clinic, lacrimal irrigation is performed to analyze for functional/anatomical obstructions of the punctum, canaliculi, lacrimal system, and Schirmer test, tear break-up time, corneal and conjunctival staining is performed to evaluate for dry eye. Furthermore, we assessed eyelid diseases such as entropion, ectropion, and trichiasis. These patients were categorized into lacrimal system diseases (e.g., punctal stenosis, canaliculitis, canaliculi obstruction, and NLDO, eyelid malpositions (e.g., entropion and ectropion), and hypersecretory causes (e.g., dry eye, superficial corneal diseases, allergy, and inflammation).
Statistiscal analyses were performed with Statistical Package for the Social Sciences (SPSS Inc., Chicago, Illionis, USA) version 22.0. Continuous variables were presented as the mean±standart deviation, and quantitative variables were presented as frequency (%). For categorical variables, the Chi-square test was used. The mean age, follow-up period, and symptom duration of more than two groups were compared using analysis of variance (ANOVA), Independent-t test was used to compare between two groups. P<0.05 was considered statistically significant.