Incidence, Long-Term Visual Outcomes, and Mortality in Retinopathy of Prematurity in Korea: A Nationwide Population-Based Study

Purpose

To evaluate the incidence, visual prognosis, and mortality in retinopathy of prematurity (ROP) in Korea.

Methods

We used the National Health Insurance and the Korean Disability Registry database, which covers the entire newborn population in 2006 to 2014 and includes information on all newborns diagnosed with ROP until 2016. Using these databases, we evaluated the incidence, rate of visual impairment (VI), and mortality in patients with ROP according to the birth weight categories and treatment modalities.

Results

The ROP incidence per 1000 newborns was 1.99, which broke down into 317.14 in the very low birth weight (VLBW) less than 1500 g population, 25.45 in the 1500 to 2499 g population, and 0.29 in the 2500 g or greater population. When assessed at age 10, the VI rate was 2.2 per 100 person-years, which was highest at 4.5 per 100 person-years in the VLBW population compared with the population in other birth weight categories. Among treated cases, the proportion of VI in patients undergoing laser photocoagulation or cryotherapy was 1.6% (42/2595), which was lower than the 2.9% (2/68) of patients treated with anti-vascular endothelial growth factor injection, and 32.2% (82/255) of patients undergoing vitrectomy or scleral buckling. The mortality rate was 4.8 per 1000 person-years, which was highest in the VLBW population, but similar across treatment modalities.

Conclusions

The ROP incidence in Korea was approximately 1 in 500 among all newborns, and 1 in 3 in the VLBW population. As the first nationwide population-based study of long-term visual prognosis in ROP, we report the higher VI rate in ROP than previously determined in other studies. Differences in visual outcomes and comparable mortality risks between treatment modalities require further verification.

Faden operation in consecutive esotropia

PURPOSE

To evaluate the efficacy of Faden procedure for correcting consecutive esotropia (ET).

METHODS

This retrospective study included 25 children who developed consecutive ET after primary bilateral lateral rectus (BLR) recession and underwent medial rectus (MR) recession with the Faden procedure (Faden group) or MR recession only (control group) between 2013 and 2018. Postoperative deviation angles were evaluated at each follow-ups until postoperative 6-month visit. Surgical motor and sensory outcomes were compared between Faden group and control group.

RESULTS

There were 10 children in the Faden group and 15 children in the control group. While the Faden group maintained orthotropia without any small deviation until postoperative 6-month visit, the control group showed wider distribution of postoperative deviation angles (1 patient with small angle esodeviation < 5 PD, 3 patients with esodeviation > 5 PD, and 3 patients with exodeviation < 5 PD). In the Faden group, seven patients have good stereopsis (60″ or better) and three patients demonstrated fair stereopsis (80-3000″) after surgery. In the control group, four, eight, and three patients showed good, fair, and nil stereopsis (P = 0.026), respectively.

CONCLUSION

MR recession combined with Faden operation could be a good surgical option for managing consecutive ET.

Effect of Ambient Light Exposure on Ocular Fatigue during Sleep

BACKGROUND

To investigate the influence of nocturnal ambient light on visual function and ocular fatigue.

METHODS

Sixty healthy subjects (30 men and 30 women) aged 19 through 29 years with no history of ocular disease were recruited. All subjects spent 3 consecutive nights in the sleep laboratory. During the first and second nights, the subjects were not exposed to light during sleep, but during the third night, they were exposed to ambient light, measuring 5 or 10 lux at the eye level, which was randomly allocated with 30 subjects each. The visual function and ocular fatigue were assessed at 7 a.m. on the 3rd and 4th mornings, using best-corrected visual acuity, refractive error, conjunctival hyperemia, tear break-up time, maximal blinking interval, ocular surface temperature, and subjective symptoms reported on a questionnaire.

RESULTS

Three men and three women subjects failed to complete the study (4 in the 5 lux; 2 from the 10 lux). For the entire 54 subjects, tear break-up time and maximal blinking interval decreased (P = 0.015; 0.010, respectively), and nasal and temporal conjunctival hyperemia increased significantly after sleep under any ambient light (P < 0.001; 0.021, respectively). Eye tiredness and soreness also increased (P = 0.004; 0.024, respectively). After sleep under 5 lux light, only nasal conjunctival hyperemia increased significantly (P = 0.008). After sleep under 10 lux light, nasal and temporal conjunctival hyperemia, eye tiredness, soreness, difficulty in focusing, and ocular discomfort increased significantly (P < 0.05).

CONCLUSION

Nocturnal ambient light exposure increases ocular fatigue. Avoiding ambient light during sleep could be recommended to prevent ocular fatigue.

Eye Drop Dispenser Type and Medication Possession Ratio in Patients With Glaucoma: Single-Use Containers Versus Multiple-Use Bottles

PURPOSE

To determine whether the consumption of topical glaucoma medication is influenced by the type of eye drop dispenser.

DESIGN

Retrospective cohort study.

METHODS

We examined 366 patients with open-angle glaucoma or ocular hypertension who were bilaterally treated with 0.0015% tafluprost or 2% dorzolamide/0.5% timolol fixed combination (DTFC). The patients were grouped by the type of dispenser and content of eye drops used: (1) tafluprost in bottles (T-Bottle group); (2) tafluprost in unit-dose pipettes (T-Unit group); (3) DTFC in bottles (C-Bottle group); and (4) DTFC in unit-dose pipettes (C-Unit group). We evaluated the medication possession ratio (MPR) among groups, and factors associated with over-consumption (MPR > 1.2) or under-consumption (MPR < 0.8) in multinomial logistic regression.

RESULTS

The mean MPR was 1.49 (range, 0.69-2.91) in the T-Bottle group, 0.91 (range, 0.32-1.27) in the T-Unit group, 1.25 (range, 0.51-2.60) in the C-Bottle group, and 0.96 (range, 0.36-1.60) in the C-Unit group. The Bottle groups demonstrated higher mean values and wider ranges of MPR compared to the Unit groups. The MPR interval at which the largest number of patients were found was 1.0-1.4 in the Bottle groups and 0.8-1.2 in the Unit groups. Bottle-type dispenser (odds ratio [OR] 64.02), tafluprost medication (OR 2.84), and older age (OR 1.03) were associated with over-consumption, whereas no factor was correlated with under-consumption.

CONCLUSIONS

The type of eye drop dispenser affects the consumption of glaucoma medication. Physicians should consider the type of eye drop dispenser when assessing glaucoma medication adherence.

Time and Factors Affecting the Direction of Re-drift in Essential Infantile Esotropia

PURPOSE

To investigate the development pattern and related factors of postoperative re-drift in infantile esotropia.

METHODS

A total of 112 patients with infantile esotropia who underwent surgery before 3 years of age were included. Surgical outcomes were divided into (1) consecutive exotropia: more than 8 prism diopters (PD) of exodeviation; (2) recurrent esotropia: more than 8 PD of esodeviation; and (3) monofixation syndrome: maintenance of deviations within 8 PD. The occurrence rate, time of onset, and associated factors of the re-drift were evaluated.

RESULTS

At a mean follow-up of 9.5 years, consecutive exotropia developed in 37 patients (33.0%) and recurrent esotropia in 43 patients (38.4%). Whereas 76.7% of total recurrent esotropia cases were identified within postoperative 1 year, consecutive exotropia occurred constantly over 10 years postoperatively. The mean time to consecutive exotropia development from surgery was 78.6 months, greater than that of recurrent esotropia development (8.9 months) (P < 0.001). In multinomial logistic regression using monofixation syndrome as the reference category, fixation preference before surgery (odds ratio [OR]: 6.64, 95% confidence interval [CI]: 2.07 to 21.32) and the rate of myopic progression (OR: 15.07 per -1.00 D/year, 95% CI: 1.23 to 184.86) were associated with consecutive exotropia, whereas increase in the angle of esodeviation on postoperative day 1 (OR: 1.15, 95% CI: 1.04 to 1.26) was correlated with recurrent esotropia.

CONCLUSIONS

This study demonstrates a difference between the development pattern of exotropic and esotropic drift after infantile esotropia surgery. Detailed preoperative assessment and close postoperative observation of deviations and refractive status will help to determine surgical outcomes of infantile esotropia. [J Pediatr Ophthalmol Strabismus. 2018;55(2):128-134.].

Prevalence, Age at Diagnosis, Mortality, and Cause of Death in Retinitis Pigmentosa in Korea-A Nationwide Population-based Study

PURPOSE

To determine the prevalence and mortality of retinitis pigmentosa (RP) patients in Korea.

DESIGN

Population-based retrospective cohort study.

METHODS

We used data covering the 2011-2014 period from the Rare Intractable Disease (RID) registry and Health Insurance Review and Assessment (HIRA) service, which include information on all patients diagnosed with RP based on predefined diagnostic criteria. Using the HIRA-RID database, we evaluated the prevalence and age at diagnosis of RP patients across the entire Korean population. We further linked the data from Statistics Korea to the HIRA-RID database to confirm mortality and causes of death.

RESULTS

The prevalence in the total population across all ages was 11.09 per 10⁵ people, and the prevalence in those over the age of 40 was 16.16 per 10⁵ people. The age at diagnosis ranged from 0 to 95 and, on average, was 44.8. The standardized mortality ratio (SMR) was 1.56 for all ages, peaking at 2.61 in men aged 40-59, which was attributed to 6.6-fold higher suicide rates than the same age group in the general male population.

CONCLUSIONS

This is the first nationwide epidemiologic study of RP patients covering the entire population of all ages. The results suggest that the prevalence of RP in Korea is about 1 in 9000 for all ages and 1 in 6000 for those over 40 years of age. The higher mortality of RP patients than that of the general population is attributable to a high suicide rate in male RP patients of working ages, which necessitates a careful attention to their mental health.

Effects of Head-Mounted Display on the Oculomotor System and Refractive Error in Normal Adolescents

PURPOSE

To investigate the clinical effects of head-mounted display on the refractive error and oculomotor system in normal adolescents.

METHODS

Sixty volunteers (age: 13 to 18 years) watched a three-dimensional movie and virtual reality application of head-mounted display for 30 minutes. The refractive error (diopters [D]), angle of deviation (prism diopters [PD]) at distance (6 m) and near (33 cm), near point of accommodation, and stereoacuity were measured before, immediately after, and 10 minutes after watching the head-mounted display. The refractive error was presented as spherical equivalent (SE). Refractive error was measured repeatedly after every 10 minutes when a myopic shift greater than 0.15 D was observed after watching the head-mounted display.

RESULTS

The mean age of the participants was 14.7 ± 1.3 years and the mean SE before watching head-mounted display was -3.1 ± 2.6 D. One participant in the virtual reality application group was excluded due to motion sickness and nausea. After 30 minutes of watching the head-mounted display, the SE, near point of accommodation, and stereoacuity in both eyes did not change significantly (all P > .05). Immediately after watching the head-mounted display, esophoric shift was observed (0.6 ± 1.5 to 0.2 ± 1.5 PD), although it was not significant (P = .06). Transient myopic shifts of 17.2% to 30% were observed immediately after watching the head-mounted display in both groups, but recovered fully within 40 minutes after watching the head-mounted display.

CONCLUSIONS

There were no significant clinical effects of watching head-mounted display for 30 minutes on the normal adolescent eye. Transient changes in refractive error and binocular alignment were noted, but were not significant. [J Pediatr Ophthalmol Strabismus. 2016;53(4):238-245.].

Comparison of Clinical Features and Long-term Surgical Outcomes in Infantile Constant and Intermittent Exotropia

PURPOSE

To evaluate the long-term surgical outcomes and the clinical features between infantile-onset constant and intermittent exotropia.

METHODS

The medical records of 67 patients diagnosed as having infantile exotropia before 12 months of age who underwent surgery were reviewed retrospectively. Patients were divided into intermittent exotropia and constant exotropia groups based on presentation before surgery. All patients underwent bilateral lateral rectus recession. Preoperative and postoperative clinical features were investigated.

RESULTS

There were 37 children in the intermittent exotropia group and 30 children in the constant exotropia group. The cumulative probabilities of success 3 years after bilateral lateral rectus recession were 91.9% in the intermittent exotropia group and 70% in the constant exotropia group. Constant deviation was more closely associated with both dissociated vertical deviation (DVD) and inferior oblique muscle overaction (IOOA) (P = .009 and P = .009, respectively) and related to poor stereopsis outcome (P = .002) and distance suppression (P = .029).

CONCLUSIONS

Constant deviation was associated with the development of recurrence, DVD/IOOA, and poor stereopsis after surgery. Constancy of exotropia is a reliable factor for predicting poor surgical outcomes in infantile exotropia at long-term follow-up.