Incidence and characteristics of cataract surgery in South Korea from 2011 to 2015: A nationwide population-based study

Incidence of Acute Endophthalmitis after Secondary Intraocular Lens Implantation: A Nationwide Cohort Study

INTRODUCTION

In this study, we aimed to analyze the incidence of acute endophthalmitis after secondary intraocular lens (IOL) implantation in South Korea.

METHODS

This study used information from the National Health Insurance Service (NHIS)-National Health Information Database (NHID). We identified patients who underwent secondary IOL implantation or IOL exchange surgeries during 2002-2021 due to diagnoses of IOL dislocation or mechanical complication of IOL. Postoperative endophthalmitis (POE) was defined as patients having received intravitreal antibiotic injection or vitrectomy for acute endophthalmitis diagnosed within 42 days after the claim for secondary IOL surgeries. All statistical analyses were performed with a significance level p < 0.05, and we used the univariate and multivariate Cox proportional hazard model to identify risk factors.

RESULTS

From 2002 to 2021, 39,364 patients received secondary IOL implantation, and acute POE was diagnosed in 62 patients. The overall incidence of acute POE was 0.16% during the 20-year period. More than half of the patients were diagnosed with POE within the first week after surgery. In the univariate analysis, there was a higher incidence of endophthalmitis in the group with pre-existing glaucoma (hazard ratio [HR], 1.945; 95% confidence interval [CI], 1.036-3.652; p = 0.0385) and the group undergoing concurrent vitrectomy (hazard ratio [HR], 2.329; 95% confidence interval [CI], 1.003-5.405; p = 0.0491).

CONCLUSIONS

The incidence of acute endophthalmitis after secondary IOL implantation in South Korea was similar to that of other countries. This is the largest retrospective claims data-based study of acute endophthalmitis after secondary IOL implantation in patients in South Korea.

Myotonic dystrophy type 1 in South Korea: a comprehensive analysis of cancer and comorbidity risks

BACKGROUND AND PURPOSE

Myotonic dystrophy type 1 (DM1) is an inherited neuromuscular disorder characterized by myotonia and progressive muscle weakness. Beyond the primary symptoms, there is growing concern regarding a higher incidence of certain comorbidities in DM1 patients, including cancer, diabetes, thyroid dysfunction, and cataracts. This study was designed to examine the occurrence of these conditions among patients diagnosed with DM1 in South Korea, using data from the National Health Insurance Service database.

METHODS

The study undertook a comprehensive review of 3,842 patients diagnosed with DM1 between 2012 and 2018. We assessed the incidence of cancer and the prevalence of diabetes, thyroid dysfunction, and cataracts among these patients, comparing their rates to those in the general population.

RESULTS

In the study cohort, 463 out of 3,842 DM1 patients (12.04%) were diagnosed with cancer, indicating a substantial elevation in cancer risk with an overall standard incidence ratio of 1.9 (95% CI = 1.6-2.3, p < 0.01) when compared to the expected rates in the general population. Moreover, the prevalence of diabetes (15.2%) and thyroid dysfunction (17.6%) was noteworthy in the DM1 population. The mean age at which DM1 patients underwent cataract surgery was 55.07 years, noticeably younger than the mean age of 69.25 years for cataract surgery in the general population.

CONCLUSIONS

DM1 patients have a noteworthy occurrence of several comorbidities such as cancer, diabetes, thyroid dysfunction, and earlier cataract surgery. This highlights the importance of a comprehensive and integrative approach to the management and treatment of DM1, going beyond addressing only the primary neuromuscular symptoms. More research is required to understand the underlying mechanisms contributing to these comorbidities in DM1 patients, which may inform preventative measures and guide improvements in patient care.

Actual lens positions of three intraocular lenses in highly myopic eyes: an ultrasound biomicroscopy-based study

AIM

To evaluate the actual lens positions (ALPs) of three intraocular lenses (IOLs) in highly myopic eyes and to identify relevant factors using ultrasound biomicroscopy (UBM).

METHODS

Ninety-three highly myopic eyes (93 patients) that underwent uneventful cataract surgery were included: 36 eyes were implanted with Zeiss 409MP IOLs, 27 with Rayner 920H IOLs and 30 with HumanOptics MCX11 IOLs. The prediction error (PE), ALP determined by UBM and the factors associated with ALP at 3 months after surgery were evaluated.

RESULTS

The eyes in the MCX11 IOL group had a more hyperopic PE (0.67±0.45 diopters (D)) and greater ALP (4.86±0.39 mm) than those in the 409MP and 920H IOL groups at 3 months after surgery (PE: -0.25±0.54 and -0.16±0.65 D, respectively; ALP: 4.34±0.26 and 4.14±0.32 mm, respectively). The MCX11 IOLs showed more backward bending deformation after surgery than 409MP and 920H IOLs. The radius of curvature of the IOL was negatively correlated with ALP (r=-0.532, p=0.002) in the MCX11 IOL group, but not in the other two groups. Multivariate analysis showed that MCX11 IOLs were more prone to bending in highly myopic eyes with a smaller anterior capsular opening (β=0.236, p=0.023) and lower implanted power (β=0.542, p=0.001).

CONCLUSION

In highly myopic eyes, IOLs with good capsular support show less backward bending, which result in a more stable lens position and refractive status postoperatively. Severe capsular contraction and low implanted power are risk factors for bending of certain IOLs.

Relationship Between Tamsulosin Use and Surgical Complications of Cataract Surgery in Elderly Patients: Population-Based Cohort Study

Purpose

Although several previous studies have investigated the relationship between tamsulosin use and surgical complications of cataract surgery, no population-based cohort study has been conducted for the Asian population. We aimed to investigate the relationship between tamsulosin use and surgical complications of cataract surgery in the Korean elderly population.

Methods

This nationwide population-based retrospective cohort study included elderly patients (≥60 years) who had undergone cataract surgery in the period from 2003 to 2015. Baseline characteristics were age, sex, income, residence, and systemic, and ocular comorbidities (glaucoma, myopia, eye trauma, diabetes mellitus with ophthalmic manifestations, severe cataract, age-related macular degeneration). The exposure of interest was tamsulosin use within 1 year before cataract surgery. Logistic regression model was used to evaluate the relationship of tamsulosin use with surgical complications of cataract surgery.

Results

The rate of surgical complications of cataract surgery was 0.88% (375/42,539) in the non-tamsulosin group and 0.83% (71/8,510) in the tamsulosin group. The groups showed no significant difference in the risk of surgical complications of cataract surgery in the unadjusted model [odds ratio (OR) = 0.946; 95% confidence interval (CI):0.733–1.220; P = 0.669]. Additionally, tamsulosin use was not significantly associated with surgical complications of cataract surgery in the fully adjusted model accounting for age, income, residence, and systemic and ocular comorbidities (OR = 0.997; 95% CI: 0.749–1.325; P = 0.981).

Conclusions

The rate or risk of surgical complications of cataract surgery does not change with tamsulosin use. We suggest that better surgical techniques and surgeons' cognizance of the patient's tamsulosin use could improve surgical outcomes, without increasing surgical complications.

Vitrectomy and All-Cause and Cause-Specific Mortality in Elderly Patients With Vitreoretinal Diseases: A Nationwide Cohort Study

Purpose

To determine the all-cause and cause-specific mortality in elderly patients with vitreoretinal diseases based on vitrectomy status.

Methods

Elderly patients (aged ≥ 60 years) diagnosed with vitreoretinal diseases between 2003 and 2012 using the Korean National Health Insurance Service-Senior cohort (2002–2015) were included in this nationwide population-based retrospective cohort study. The exposure of interest was vitrectomy, and information on mortality from patient inclusion until December 2015 was obtained. Cox regression modeling was used to assess the association between vitrectomy and mortality. An additional subgroup analysis was performed to investigate the effects of the underlying retinal disease characteristics and comorbidities on mortality.

Results

The study cohort included 152,283 patients (3,313 and 148,970 in the vitrectomy and non-vitrectomy groups, respectively). The adjusted model showed vitrectomy was associated with a decreased risk of pulmonary-cause mortality [hazard ratio (HR), 0.51; P < 0.001]; however, no association was observed for all-cause mortality (HR, 0.93; P = 0.325). Vitrectomy was associated with increased mortality risk (all-cause: HR, 1.26; P < 0.001 and vascular causes: HR, 1.41; P = 0.003) among patients with retinal vascular diseases and decreased mortality risk (all-cause: HR, 0.64; P < 0.001 and pulmonary causes: HR, 0.35; P = 0.011) among patients with macular diseases. There were significant interactions between age and vitrectomy with respect to all-cause mortality among patients with either vitreoretinal disease.

Conclusions

In elderly patients with retinal diseases, the vitrectomy group showed the lower mortality from pulmonary causes with no association for all-cause mortality.

Lighting Standards Revisited: Introduction of a Mathematical Model for the Assessment of the Impact of Illuminance on Visual Acuity

Purpose

Primary objective of present study is to introduce a contemporary methodology for the lighting standards update addressing both normophakic and pseudophakic patients.

Methods

For the sake of our study, we theoretically estimated the intraocular-to-crystalline lens iIluminance ratio (ICIR) and the intraocular lens (IOL) luminous efficiency function V_IOL(λ) as a new lighting benefit metric. Then, in a sample of 24 pseudophakic patients (38 eyes) implanted with the trifocal diffractive IOL Panoptix (SG) and in a control group (CG) of 28 normophakic participants (50 eyes), uncorrected distance visual acuity (UDVA) was measured at illuminance of 550lx (optimal UDVA). Following dark adaptation, illuminance was gradually raised from 20 lx until illuminance level that the patient reached his/her optimal UDVA. This measured illuminance at this point was defined as the minimum required illuminance level (MRIL). MRIL and UDVA for illuminance levels between 20 and 550lx in SG were compared with the corresponding values in CG. MRIL calculation allowed the construction of a predictive mathematical model that estimates the impact of environmental lighting on UDVA.

Results

ICIR for Panoptix eyes ranged from 54.00% to 55.99%. Both groups had significantly higher UDVA at 550lx compared to 20lx (p < 0.05). CG had significantly higher UDVA than SG at 20lx (7.20 letters, p = 0.045), while no significant difference was detected at 550lx (0.40 letters, p = 0.883). SG required significantly more illuminance than CG to maintain their UDVA (MRIL_SG= 191.05lx, MRIL_CG= 122lx, p = 0.007). Our predictive model suggests suboptimal UDVA in a series of lighting directives for normophakic and Panoptix eyes.

Conclusion

This is the first study to introduce the V_IOL(λ) as a new lighting benefit metric and a mathematical model that quantifies the impact of illuminance on UDVA in normophakic and pseudophakic patients.

Clinicaltrials.gov Identifier

NCT04263636.

Relationship between Cataract Surgery and Mortality in Elderly Patients with Cataract: Nationwide Population-Based Cohort Study in South Korea

We aimed to investigate the relationship between cataract surgery and all-cause and cause-specific mortality in Korean elderly patients with cataract using the Korean National Health Insurance Service-Senior cohort database. Elderly patients (≥60 years) diagnosed with cataract from 2002 through 2012 were included. The baseline characteristics included demographics and systemic and ocular comorbidities. Adjusted Cox regression models with time-varying covariates for cataract surgery were used to assess the relationship between cataract surgery and mortality. The study cohort included 241,062 patients, of whom 127,941 were in the cataract surgery group and 113,121 were in the cataract diagnosis group. The incidence of all-cause mortality was 3.62 deaths/100 person-years and 3.19 deaths/100 person-years in the cataract surgery and cataract diagnosis groups, respectively. Cataract surgery was associated with a decreased hazard of all-cause mortality after adjusting for demographics as well as systemic and ocular comorbidities (hazard ratio (HR), 0.93; p < 0.001). A protective association was noted between cataract surgery and mortality from vascular (HR, 0.92; p < 0.001) or neurologic (HR, 0.64; p < 0.001) causes. Patients with cataract who were 85 years of age and older, women, those who had lower income, and a Charlson comorbidity index score of 5 or more, or those without glaucoma revealed the largest reductions in mortality hazards resulting from cataract surgery.

Outcomes of Re-fixation after the First Intraocular Lens Scleral Fixation

Purpose: To investigate the outcomes of re-fixation after the first intraocular lens (IOL) scleral fixation. Methods: We retrospectively reviewed the charts of patients who underwent second IOL scleral fixation and vitrectomy for dislocation of IOL after the first IOL scleral fixation. We compared the best-corrected visual acuity (BCVA) and spherical equivalent (SE) after 1 month of the first and second surgery, and noted the complications. Results: We included 21 eyes that underwent second IOL scleral fixation: 13 eyes (61.9%) with IOL exchange and eight (38.1%) with one-haptic fixation. Mean BCVAs (LogMAR) were 0.17 ± 0.25 and 0.11 ± 0.23 after the first and second surgery, respectively (<i>p</i> = 0.073); mean SEs were -0.94 ± 1.69 and -0.58 ± 1.46 diopters after the first and second surgery, respectively (<i>p</i> = 0.076). Postoperative complications occurred in eight eyes (38.1%), including temporarily increased intraocular pressure and suture knots exposure. However, none of the complications required re-operation. Conclusions: The outcomes of primary and secondary IOL fixation were similar, and there were no serious complications of the second surgery.