Objectives: Sleep misperception is the underestimation of perceived total sleep time compared to actual total sleep time. It is observed in approximately 50% of patients with insomnia. Insomnia patients with sleep misperception report significantly higher depression than those without sleep misperception. Depression is one of the most consistent risk factors for predicting insomnia. Therefore, this study attempted to confirm the mediating effect of depression in exacerbating insomnia. Methods: This study included 77 male and female aged 18–40 years who met diagnostic criteria for insomnia disorder based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Depression and insomnia severity were measured using self-report questionnaires, and actigraphy data were collected for 1 week. The sleep misperception index was calculated using the sleep diary and actigraphy. Results: The Pearson correlation analysis was performed to examine the relationships between sleep misperception, insomnia, and depression. Sleep misperception was positively associated with depression (r=0.399, p<0.01). There was also a significant positive correlation between depression and insomnia severity (r=0.591, p<0.01). However, there was no significant correlation between sleep misperception and insomnia severity (r=0.210, p=0.07). Depression was found to have a full mediating effect on the relationship between sleep disturbance and severity of insomnia (n=77, B=6.1688, 95% confidence interval=2.9960, 10.4562). Conclusions This study verified the mediating effect of depression on the relationship between sleep misperception and insomnia severity. The results highlight the importance of considering depression and sleep misperception in insomnia treatment.

Nightmares are vivid, unpleasant dreams that result in awakening during sleep. According to previous studies, the prevalence of nightmare disorder is 2–5% of the general population and is associated with other medical conditions and mental illnesses. Imagery rehearsal therapy (IRT) is an evidence-based treatment for nightmare disorder. The current study is a case study with a 35-year-old female who was diagnosed with nightmare disorder and posttraumatic stress disorder, and participated in IRT for five sessions. Prior to treatment, the patient reported difficulties initiating and maintaining sleep, and reported suffering from nightmares more than 2–3 times per week. After treatment, the patient reported no longer experienced nightmares, accompanied by improvements in both sleep and clinical indicators.
Adult ; Dreams ; Female ; Humans ; Prevalence ; Sleep Initiation and Maintenance Disorders ; Stress Disorders, Post-Traumatic

OBJECTIVE: This study aimed to evaluate psychometric properties of the Munich ChronoType Questionnaire (MCTQ) in a sample of Korean older adults. METHODS: One-hundred ninety two participants aged 65 and over completed interview-based questionnaires about chronotype, insomnia, depression, and anxiety. Additionally, a small subset of subjects completed a 7-day sleep diary and actigraphy measurements. RESULTS: Morningness-Eveningness Questionnaire (MEQ) scores were significantly negatively correlated with Midpoint of sleep on free days corrected for sleep debt accumulated through weekdays (MSFsc) (r=-0.45, p < 0.01) assessed by the MCTQ. MSFsc using the MCTQ was significantly positively correlated with MSFsc assessed by both the sleep diary (r=0.74, p < 0.05) and actigraphy (r=0.76, p < 0.05). Additionally, MSFsc assessed by the MCTQ was significantly positively correlated with insomnia (r=0.26, p < 0.01), depression (r=0.25, p < 0.01), and anxiety (r=0.18, p < 0.05). Finally, based on MEQ scores, we derived a cut-off score for the MCTQ that distinguishes morning type and other types (intermediate/evening types) in older adults. CONCLUSION: The results of these studies supported the validity of the MCTQ in Korean older adults. Additionally, while sleep rhythms in elder adults may be more advanced, eveningness tendency may be still important and indicative of sleep and psychological disturbance.
Actigraphy ; Adult* ; Anxiety ; Circadian Rhythm ; Depression ; Geriatric Assessment ; Geriatric Psychiatry ; Humans ; Psychometrics ; Sleep Initiation and Maintenance Disorders ; Sleep Wake Disorders

Objectives: Sleep misperception is the underestimation of perceived total sleep time compared to actual total sleep time. It is observed in approximately 50% of patients with insomnia. Insomnia patients with sleep misperception report significantly higher depression than those without sleep misperception. Depression is one of the most consistent risk factors for predicting insomnia. Therefore, this study attempted to confirm the mediating effect of depression in exacerbating insomnia. Methods: This study included 77 male and female aged 18–40 years who met diagnostic criteria for insomnia disorder based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Depression and insomnia severity were measured using self-report questionnaires, and actigraphy data were collected for 1 week. The sleep misperception index was calculated using the sleep diary and actigraphy. Results: The Pearson correlation analysis was performed to examine the relationships between sleep misperception, insomnia, and depression. Sleep misperception was positively associated with depression (r=0.399, p<0.01). There was also a significant positive correlation between depression and insomnia severity (r=0.591, p<0.01). However, there was no significant correlation between sleep misperception and insomnia severity (r=0.210, p=0.07). Depression was found to have a full mediating effect on the relationship between sleep disturbance and severity of insomnia (n=77, B=6.1688, 95% confidence interval=2.9960, 10.4562). Conclusions This study verified the mediating effect of depression on the relationship between sleep misperception and insomnia severity. The results highlight the importance of considering depression and sleep misperception in insomnia treatment.

Background: and Purpose The Karolinska Sleepiness Scale (KSS) is widely used for assessing current level of sleepiness, but it has not been validated in South Korea. This study aimed to validate the KSS using the Stanford Sleepiness Scale (SSS), polysomnography (PSG), and electroencephalography (EEG). Methods: The sample consisted of 27 adult participants in this study aged 40.5±7.7 years (mean±standard deviation) and included 22 males. They completed questionnaires and underwent EEG recording and overnight PSG. The KSS was completed from 18:00 to 24:00 every 2 hours and following PSG (at 07:00). KSS scores changed over time and in particular increased with the time since waking, with the score peaking at 24:00. Results: Convergent validity of the KSS was verified by performing a Spearman correlation analysis between the KSS and SSS (r=0.742, p<0.01). Concurrent validity of the KSS was verified by performing a Spearman correlation analysis between the KSS administered before sleep and the sleep onset latency measured using PSG (r=-0.456, p<0.05). Alpha waves were measured 5 minutes before administering the KSS, and the KSS scores were compared with these alpha waves. There were no significant correlations observed between the KSS scores and alpha waves measured in the left occipital area (O1), left frontal area (F3), or left central area (C3). In addition, Spearman correlation analyses of the difference between KSS scores and alpha waves measured at O1, F3, and C3 produced no significant results. Conclusions This study verified the convergent validity and concurrent validity of the KSS, and confirmed the capabilities of this scale in assessing sleepiness changes over time.

Purpose: To compare and analyze the performance of dual pneumatic ultra-high-speed vitreous cutters based on their cut rates, vacuum levels, and diameters in terms of flow rate and cutting time. Methods: The Constellation Vision System was used to remove egg white for 30 seconds, after which we calculated the flow rate by measuring the change in weight. We then measured the time required to remove 4 mL of egg white. We tested the UltraVit (UV) 7,500 cuts per minute (cpm) probe and the Advanced UltraVit (AUV) 10,000 cpm probe in biased open duty cycle mode, using 23-, 25-, and 27-gauge probes, respectively. Results: In biased open duty cycle, the flow rate tended to decrease as the cut rates increased for all three gauges. At the same cut rates, the flow rate increased as the vacuum level increased (p < 0.05), and as the diameter increased (p < 0.05). Among cutters with the same diameter, the AUV cutter showed higher flow rates than the UV cutter, with increases of 0.267 mL/min (18.5%) at 27 gauge, 0.627 mL/min (20.8%) at 25 gauge, and 1.000 mL/min (20.7%) at 23 gauge (all p < 0.05). The times required to remove 4 mL of egg white took longer with the UV cutter than the AUV cutter for all three gauges (all p < 0.05). Conclusions The use of a smaller gauge vitreous cutter may reduce the flow rate and increase the time required for vitrectomy, but this can be partially compensated for by increasing the vacuum level as well as using a vitreous cutter with a higher maximum cut rate, improved port size, and improved duty cycle.

Purpose: Various vitrectomy probes are currently being used commercially, and there are ongoing efforts toward developing probes with higher cutting rates and smaller gauges. This study aimed to compare the efficiency and safety of various commercially available small gauge ultrahigh-speed dual pneumatic vitrectomy probes. Methods: We retrospectively analyzed the medical records of patients and recorded intraoperative videos while they underwent microincision three-port vitrectomy surgery for idiopathic epiretinal membrane at Soonchunhyang University Seoul Hospital. The patients were categorized into four groups based on the vitrectomy probe used during surgery: 23-7500 (UltraVit 23-gauge 7,500 cuts per minute [CPM]), 23-7500 (UltraVit 25-gauge 7,500 CPM), 25-10K (Advanced UltraVit 25-gauge 10,000 CPM), and 27-10K (Advanced UltraVit 27-gauge 10,000 CPM). Results: In total, 82 eyes from 82 patients were included in this work, with 16, 11, 26, and 29 eyes in groups 23-7500, 25-7500, 25-10K, and 27-10K, respectively. The corresponding vitrectomy times were 295.56 ± 53.55, 293.09 ± 50.28, 299.92 ± 59.42, and 349.38 ± 67.23 seconds, respectively. There was a significant difference in the vitrectomy time between the groups (p = 0.004). The mean number of sutures was 3, 3, 2.96, and 0.83, respectively. In the 23-7500 group, there was one case of iatrogenic retinal break, while in the 27-10K group, there was one case of postoperative hypotony. Conclusions Although advancements have been made in the 27-gauge vitrectomy probe, it still takes more vitrectomy time than it does when using the 23- and 25-gauge probes. However, the delay was within an average of 1 minute, and considering the significantly reduced need for sutures, there is a substantial benefit in terms of postoperative discomfort. Therefore, when choosing a probe for epiretinal membrane surgery among the four options, it is reasonable to select the 27-gauge probe according to the surgeon’s preference.

Background: and Purpose The Karolinska Sleepiness Scale (KSS) is widely used for assessing current level of sleepiness, but it has not been validated in South Korea. This study aimed to validate the KSS using the Stanford Sleepiness Scale (SSS), polysomnography (PSG), and electroencephalography (EEG). Methods: The sample consisted of 27 adult participants in this study aged 40.5±7.7 years (mean±standard deviation) and included 22 males. They completed questionnaires and underwent EEG recording and overnight PSG. The KSS was completed from 18:00 to 24:00 every 2 hours and following PSG (at 07:00). KSS scores changed over time and in particular increased with the time since waking, with the score peaking at 24:00. Results: Convergent validity of the KSS was verified by performing a Spearman correlation analysis between the KSS and SSS (r=0.742, p<0.01). Concurrent validity of the KSS was verified by performing a Spearman correlation analysis between the KSS administered before sleep and the sleep onset latency measured using PSG (r=-0.456, p<0.05). Alpha waves were measured 5 minutes before administering the KSS, and the KSS scores were compared with these alpha waves. There were no significant correlations observed between the KSS scores and alpha waves measured in the left occipital area (O1), left frontal area (F3), or left central area (C3). In addition, Spearman correlation analyses of the difference between KSS scores and alpha waves measured at O1, F3, and C3 produced no significant results. Conclusions This study verified the convergent validity and concurrent validity of the KSS, and confirmed the capabilities of this scale in assessing sleepiness changes over time.

Background: and Purpose The Karolinska Sleepiness Scale (KSS) is widely used for assessing current level of sleepiness, but it has not been validated in South Korea. This study aimed to validate the KSS using the Stanford Sleepiness Scale (SSS), polysomnography (PSG), and electroencephalography (EEG). Methods: The sample consisted of 27 adult participants in this study aged 40.5±7.7 years (mean±standard deviation) and included 22 males. They completed questionnaires and underwent EEG recording and overnight PSG. The KSS was completed from 18:00 to 24:00 every 2 hours and following PSG (at 07:00). KSS scores changed over time and in particular increased with the time since waking, with the score peaking at 24:00. Results: Convergent validity of the KSS was verified by performing a Spearman correlation analysis between the KSS and SSS (r=0.742, p<0.01). Concurrent validity of the KSS was verified by performing a Spearman correlation analysis between the KSS administered before sleep and the sleep onset latency measured using PSG (r=-0.456, p<0.05). Alpha waves were measured 5 minutes before administering the KSS, and the KSS scores were compared with these alpha waves. There were no significant correlations observed between the KSS scores and alpha waves measured in the left occipital area (O1), left frontal area (F3), or left central area (C3). In addition, Spearman correlation analyses of the difference between KSS scores and alpha waves measured at O1, F3, and C3 produced no significant results. Conclusions This study verified the convergent validity and concurrent validity of the KSS, and confirmed the capabilities of this scale in assessing sleepiness changes over time.