The Incidence of Strabismus After Upper and Lower Blepharoplasty in the United States.

PURPOSE: To compare the incidence of strabismus after upper and lower blepharoplasty in the United States. METHODS: Retrospective cohort study of adults (age ≥18 years) in the IRIS Registry (Intelligent Research in Sight) who underwent blepharoplasty between January 1, 2013 and December 31, 2020. The primary outcome was the Kaplan-Meier estimated cumulative incidence of strabismus diagnosis and surgery within 3 years of blepharoplasty. Multivariable Cox regression was used to determine the association of blepharoplasty type with strabismus diagnosis and surgery, adjusting for patient age, sex, and geographic region. RESULTS: Blepharoplasty was performed in 368,623 patients (median [interquartile range] age, 69 [63-75] years, and 69% female). Compared with those undergoing upper eyelid blepharoplasty, patients treated with lower eyelid blepharoplasty were slightly younger (median age, 66 vs. 69 years; p < 0.001) and more likely to be female (71% vs. 69%; p < 0.001). There was a greater 3-year incidence of strabismus diagnosis (2.0% vs. 1.5%; p < 0.001) and a greater 3-year incidence of strabismus surgery (0.15% vs. 0.06%; p = 0.003) for individuals undergoing lower vs. upper blepharoplasty. After adjusting for age, sex, and geographic region, lower blepharoplasty was associated with a higher 3-year risk of strabismus diagnosis (HR, 1.49; 95% CI, 1.23-1.81; p < 0.001) and surgery (HR, 2.53; 95% CI, 1.27-5.03; p = 0.008). CONCLUSIONS: This registry-based analysis found that individuals undergoing lower eyelid blepharoplasty were at higher risk of strabismus compared with those undergoing upper eyelid blepharoplasty. Using large databases to understand the incidence of complications of frequently performed procedures may improve ophthalmologists' ability to provide data-driven counseling on surgical risks prior to intervention.

Comparison of baseline biometry measures in eyes with pediatric cataract to age-matched controls.

PURPOSE: To compare baseline biometry measurements in eyes with pediatric cataract versus age-matched controls METHODS: This is a cross-sectional study conducted at a tertiary care hospital that included two arms-prospective arm to collect data from normal eyes and retrospective arm for eyes with pediatric cataract. In the prospective arm, biometry measurements were obtained in healthy children aged 0 to 10 years. Children under the age of four had measurements under anesthesia for an unrelated procedure, while older children had in-office measurements using optical biometry. For comparison, biometric data was collected in children with pediatric cataract through record review. One eye of each patient was randomly selected. Axial length (AL) and keratometry (K) were compared by age and laterality. The medians were compared using Wilcoxon rank-sum tests and variances using Levene's test. RESULTS: There were 100 eyes in each arm, 10 eyes in each age bin of 1-year interval. There was more variability in baseline biometry in eyes with pediatric cataract and a trend for longer AL and steeper K in cataract eyes than aged-matched controls. The difference in AL means was significant in age group 2-4 years, and variances were significant across all age groups (p=0.018). Unilateral cataracts (n=49) showed a trend toward greater variability in biometry than bilateral cataracts, but this did not reach statistical significance. CONCLUSION: Baseline biometry measures are more variable in eyes with pediatric cataract compared to age-matched controls with a trend toward longer AL and steeper K.

Adjustable Suture Technique Is Associated with Fewer Strabismus Reoperations in the Intelligent Research in Sight Registry.

PURPOSE: To compare the reoperation rates after strabismus surgery with and without the adjustable suture technique. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients 18 years of age or older in the Intelligent Research in Sight (IRIS®) Registry who underwent strabismus surgery between January 1, 2013, and December 31, 2018. METHODS: Data were collected from the electronic health records of practices participating in the IRIS Registry. The primary exposure of interest was use of the adjustable suture technique, identified by Current Procedural Terminology coding. MAIN OUTCOME MEASURES: The primary outcome was repeat strabismus surgery within 1 year of initial strabismus surgery. Odds ratios (ORs) were derived from a multivariable logistic regression model evaluating the association between the use of adjustable sutures and reoperation rate, adjusting for patient demographics and surgical factors. RESULTS: A total of 34 872 patients who underwent strabismus surgery during the study interval were identified: 72% underwent horizontal muscle surgery, 17% underwent vertical muscle surgery, and 11% underwent combined horizontal and vertical muscle surgery. Adjustable sutures were used in 18% of patients. The overall reoperation rate within 1 year of strabismus surgery was 7.7%. The 1-year reoperation rate was 6.0% for patients treated with adjustable sutures and 8.1% for patients treated without adjustable sutures (P < 0.001). The multivariable regression model revealed a statistically significant 30% decrease in the odds of reoperation within 1 year of surgery when adjustable sutures were used (OR, 0.70; 95% confidence interval [CI], 0.62-0.78), a 40% increase in those with a history of prior strabismus surgery (OR, 1.40; 95% CI, 1.28-1.53), and a 9% increase per decade of age at surgery (OR, 1.09; 95% CI, 1.06-1.11). CONCLUSIONS: In adults cared for in practices participating in the IRIS Registry, the adjustable suture technique was associated with a significantly lower reoperation rate within 1 year of undergoing horizontal or combined horizontal and vertical strabismus surgery. Adjustable suture use in vertical strabismus surgery alone did not reduce the 1-year reoperation rate significantly. A history of prior strabismus surgery was associated with increased odds of reoperation.

A Posttraumatic Dilated, Proptotic Eye Does Not Always Need a Lateral Canthotomy! A Review of Superior Orbital Fissure Syndrome for Emergency Physicians.

BACKGROUND: Superior orbital fissure syndrome (SOFS) is a rare constellation of findings consisting of ophthalmoplegia, ptosis, a fixed dilated pupil, forehead anesthesia, and loss of the corneal reflex. This syndrome, though rare, is most often encountered in trauma with individuals sustaining a facial fracture. CASE REPORT: We present a case of a young woman who was diagnosed with SOFS after a fall in her house, hitting her face on a nightstand. Treatment consisted of high-dose i.v. steroids followed by a taper with close follow-up in the Ophthalmology clinic. We provide a brief review of SOFS, including treatment considerations and follow-up. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: SOFS can be easily overlooked in an individual presenting to the emergency department after facial trauma with proptosis. However, a thorough examination of the eye, visual acuity, and intraocular pressure will focus the physician on SOFS rather than the need for immediate decompression via lateral canthotomy. This report describes a traumatic cause of SOFS, the pathophysiology and treatment, and summarizes existing literature.

Unraveling inter-species differences in hagfish slime skein deployment.

Hagfishes defend themselves from fish predators by producing defensive slime consisting of mucous and thread components that interact synergistically with seawater to pose a suffocation risk to their attackers. Deployment of the slime occurs in a fraction of a second and involves hydration of mucous vesicles as well as unraveling of the coiled threads to their full length of ∼150 mm. Previous work showed that unraveling of coiled threads (or 'skeins') in Atlantic hagfish requires vigorous mixing with seawater as well as the presence of mucus, whereas skeins from Pacific hagfish tend to unravel spontaneously in seawater. Here, we explored the mechanisms that underlie these different unraveling modes, and focused on the molecules that make up the skein glue, a material that must be disrupted for unraveling to proceed. We found that Atlantic hagfish skeins are also held together with a protein glue, but compared with Pacific hagfish glue, it is less soluble in seawater. Using SDS-PAGE, we identified several soluble proteins and glycoproteins that are liberated from skeins under conditions that drive unraveling in vitro Peptides generated by mass spectrometry of five of these proteins and glycoproteins mapped strongly to 14 sequences assembled from Pacific hagfish slime gland transcriptomes, with all but one of these sequences possessing homologs in the Atlantic hagfish. Two of these sequences encode unusual acidic proteins that we propose are the structural glycoproteins that make up the skein glue. These sequences have no known homologs in other species and are likely to be unique to hagfishes. Although the ecological significance of the two modes of skein unraveling described here are unknown, they may reflect differences in predation pressure, with selection for faster skein unraveling in the Eptatretus lineage leading to the evolution of a glue that is more soluble.

Spontaneous unraveling of hagfish slime thread skeins is mediated by a seawater-soluble protein adhesive.

Hagfishes are known for their ability to rapidly produce vast quantities of slime when provoked. The slime is formed via the interaction between seawater and two components released by the slime glands: mucin vesicles from gland mucous cells, which swell and rupture in seawater to form a network of mucus strands, and intermediate filament-rich threads, which are produced within gland thread cells as tightly coiled bundles called skeins. A previous study showed that the unraveling of skeins from Atlantic hagfish (Myxine glutinosa) requires both the presence of mucins and hydrodynamic mixing. In contrast, skeins from Pacific hagfish (Eptatretus stoutii) unravel in the absence of both mucins and mixing. We tested the hypothesis that spontaneous unraveling of E. stoutii skeins is triggered by the dissolution of a seawater-soluble protein adhesive and the release of stored strain energy within the coiled thread. Here we show that, as predicted by this hypothesis, unraveling can be initiated by a protease under conditions in which unraveling does not normally occur. We also demonstrate, using high resolution scanning electron microscopy, that the treatment of skeins with solutions that cause unraveling also leads to the disappearance of surface and inter-thread features that remain when skeins are washed with stabilizing solutions. Our study provides a mechanism for the deployment of thread skeins in Pacific hagfish slime, and raises the possibility of producing novel biomimetic protein adhesives that are salt, temperature and kosmotrope sensitive.

Leukocoria in a 4-year-old boy.

A healthy 4-year-old boy referred for evaluation of an abnormal red reflex in the left eye was noted, on fundus examination, to have extensive white, striated lesions surrounding the optic nerve that involved the superior and inferior macular arcades. On further examination, he was found to have ipsilateral high myopia and amblyopia. The triad of unilateral myelinated retinal nerve fibers, myopia, and amblyopia led to a diagnosis of Straatsma syndrome, which requires early treatment to prevent permanent vision loss. Treatment comprised a contact lens for refractive correction of the left eye, patching of the right eye, and full-time polycarbonate protective lenses. With 2 years' follow-up, the left eye failed to improve appreciably.

Factors Associated With Incidental Retinal Emboli in the U.S. Adult Population.

PURPOSE: We sought to estimate the prevalence of incidental retinal emboli and identify associated factors using a nationally representative sample of the U.S. DESIGN: Cross-sectional study. METHODS: We included adult (age ≥40 years) participants of the 2005-2008 National Health and Nutrition Examination Survey (NHANES). Incidental retinal emboli were identified through retinal fundus photography. Multivariable logistic regression was used to determine the association between the presence of retinal emboli and sociodemographic, lifestyle, and clinical factors (age, sex, race/ethnicity, education, income, smoking, alcohol use, body mass index [BMI], hypertension, diabetes, hypercholesterolemia, and history of cardiovascular disease). RESULTS: This study included 5,764 adults (53% female). Incidental retinal emboli were identified in 0.7% (39/5764) of individuals. The survey-weighted prevalence of retinal emboli increased with age, from 0.1% in participants 40-49 years of age to 1.4% in participants≥70 years of age. The prevalence did not differ by sex or race/ethnicity. Factors associated with retinal emboli after adjusting for age and sex included underweight BMI (odds ratio [OR] 7.24 [95% confidence interval {CI} 1.06-49.3]), current smoking (OR 6.16 [95% CI 1.49-25.5]), low household income (OR 4.41 [95% CI 1.3-15.0]), and hypertension (OR 2.67 [95% CI 1.31-5.44]). CONCLUSIONS: In a cohort representative of the U.S. adult population, the prevalence of incidental retinal emboli increased with age but did not differ by sex, race, or ethnicity. Further investigation into the potential association of socioeconomic and nutritional status with retinal emboli may enable opportunities to identify individuals with underlying cardiovascular risk.

Mental Health Conditions Associated With Strabismus in a Diverse Cohort of US Adults.

Importance: Greater understanding of the association between strabismus and mental health conditions across sociodemographic backgrounds may inform strategies to improve mental well-being in this population. Objective: To describe the association of strabismus with mental health conditions in a diverse cohort of US adults. Design, Setting, and Participants: This cross-sectional study used data from the National Institutes of Health's All of Us Research Program, an ongoing program launched in 2015. The study included 3646 adults (aged ≥18 years) with strabismus and 3646 propensity score-matched controls. Statistical analysis was conducted from September 12, 2023, to January 29, 2024. Main Outcomes and Measures: Adults with strabismus were propensity score matched on age, gender, race and ethnicity, income, educational level, and insurance status in a 1:1 ratio with adults without strabismus. The prevalences of anxiety, depression, substance use and addiction, bipolar disorder, and schizophrenia spectrum disorder among adults with strabismus were compared with controls. Logistic regression was used to evaluate the association of mental health conditions with sociodemographic factors in each group. Results: This study included 3646 adults with strabismus (median age, 67 years [IQR, 53-76 years]; 2017 women [55%]) and 3646 propensity score-matched controls (median age, 67 years [IQR, 53-76 years]; 2017 women [55%]). Individuals with strabismus had higher prevalences of anxiety (1153 [32%] vs 519 [14%]; difference, 17%; 95% CI, 15%-19%; P < .001), depression (1189 [33%] vs 514 [14%]; difference, 19%; 95% CI, 17%-20%; P < .001), substance use and addiction (116 [3%] vs 51 [1%]; difference, 2%; 95% CI, 1%-3%; P < .001), bipolar disorder (253 [7%] vs 101 [3%]; difference, 4%; 95% CI, 3%-5%; P < .001), and schizophrenia spectrum disorder (103 [3%] vs 36 [1%]; difference, 2%; 95% CI, 1%-3%; P < .001) compared with individuals without strabismus. Among adults with strabismus, higher odds of mental health conditions were associated with younger age (odds ratio [OR], 1.11 per 10-year decrease; 95% CI, 1.06-1.16 per 10-year decrease), female gender (OR, 1.62; 95% CI, 1.41-1.85), Black or African American race and ethnicity (OR, 1.22; 95% CI, 1.01-1.48), low income (OR, 3.06; 95% CI, 2.56-3.67), and high school education or less (OR, 1.58; 95% CI, 1.34-1.85). Conclusions and Relevance: In a diverse and nationwide cohort, adults with strabismus were more likely to have mental health conditions compared with adults without strabismus. Further investigation into the risk factors for poor mental health among adults with strabismus across sociodemographic backgrounds may offer novel opportunities for interventions to improve mental well-being in this population.

Risk Factors for Glaucoma Diagnosis and Surgical Intervention following Pediatric Cataract Surgery in the IRIS® Registry.

PURPOSE: To compare demographic and clinical factors associated with glaucoma following cataract surgery (GFCS) and glaucoma surgery rates between infants, toddlers, and older children using a large, ophthalmic registry. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients in the IRIS® Registry (Intelligent Research in Sight) who underwent cataract surgery at ≤ 17 years old and between January 1, 2013 and December 31, 2020. METHODS: Glaucoma diagnosis and procedural codes were extracted from the electronic health records of practices participating in the IRIS Registry. Children with glaucoma diagnosis or surgery before cataract removal were excluded. The Kaplan-Meier estimator was used to determine the cumulative probability of GFCS diagnosis and glaucoma surgery after cataract surgery. Multivariable Cox regression was used to identify factors associated with GFCS and glaucoma surgery. MAIN OUTCOME MEASURES: Cumulative probability of glaucoma diagnosis and surgical intervention within 5 years after cataract surgery. RESULTS: The study included 6658 children (median age, 10.0 years; 46.2% female). The 5-year cumulative probability of GFCS was 7.1% (95% confidence interval [CI], 6.1%-8.1%) and glaucoma surgery was 2.6% (95% CI, 1.9%-3.2%). The 5-year cumulative probability of GFCS for children aged < 1 year was 22.3% (95% CI, 15.7%-28.4%). Risk factors for GFCS included aphakia (hazard ratio [HR], 2.63; 95% CI, 1.96-3.57), unilateral cataract (HR, 1.48; 95% CI, 1.12-1.96), and Black race (HR, 1.61; 95% CI, 1.12-2.32). The most common surgery was glaucoma drainage device insertion (32.6%), followed by angle surgery (23.3%), cyclophotocoagulation (15.1%), and trabeculectomy (5.8%). CONCLUSIONS: Glaucoma following cataract surgery diagnosis in children in the IRIS Registry was associated with young age, aphakia, unilateral cataract, and Black race. Glaucoma drainage device surgery was the preferred surgical treatment, consistent with the World Glaucoma Association 2013 consensus recommendations for GFCS management. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Surgical Approach and Reoperation Risk in Intermittent Exotropia in the IRIS Registry.

Importance: There is no consensus on the optimal surgical treatment for children with intermittent exotropia (IXT). Objective: To compare the 5-year reoperation rates for children with IXT treated with horizontal muscle strabismus surgery using bilateral lateral rectus recession (BLR) vs unilateral lateral rectus recession with medial rectus resection (RR). Design, Setting, and Participants: This cohort study examined data obtained from the Intelligent Research in Sight (IRIS) Registry on 7482 children (age, <18 years) with IXT who underwent horizontal eye muscle strabismus surgery between January 1, 2013, and December 31, 2017. Children undergoing initial surgeries involving 3 or more horizontal muscles, vertical muscles, or reoperations were excluded. Main Outcomes and Measures: The primary outcome was the adjusted cumulative incidence of repeat horizontal muscle surgery within 5 years after the initial surgery. Reoperation risk was analyzed using adjusted hazard ratios (AHRs) derived from multivariable Cox regression models, adjusting for individual demographic and surgical factors (age, sex, race and ethnicity, US Census region, and surgeon subspecialty). Data were analyzed between January 16 and September 20, 2023. Results: The study included 7482 children (median [IQR] age at initial surgery, 6 [4-9] years; 3945 females [53%]) with IXT treated with horizontal muscle strabismus surgery. Bilateral lateral rectus recession was performed more frequently than RR (85.3% vs 14.7%, P < .001), especially in younger children (rates of BLR vs RR by age: age 0 to ≤4 years, 88.4% vs 11.6%; age 5 to ≤11 years, 84.7% vs 15.3%; age 12 to ≤17 years, 78.1% vs 21.9%; P < 0.001). After data adjustment, the 5-year cumulative incidence of reoperation was 21.3% (95% CI, 20.1%-22.5%). The adjusted 5-year cumulative incidence of reoperation was higher for BLR than for RR (22.2% vs 17.2%; difference, 4.9%; 95% CI, 1.9%-8.0%). Unilateral lateral rectus recession with medial rectus resection was associated with a lower 5-year reoperation risk compared with BLR (AHR, 0.77; 95% CI, 0.64-0.93). Younger age at time of initial surgery was associated with a higher reoperation risk (AHR per 1-year decrease, 1.09; 95% CI, 1.07-1.11) after adjusting for all other covariates. Conclusions and Relevance: In this nationwide registry, approximately 1 in 5 children with IXT underwent reoperation within 5 years after the initial surgery. Children treated with RR were less likely to require a reoperation within 5 years compared with those treated with BLR. Further efforts to identify modifiable risk factors for reoperation are needed to reduce the surgical burden and improve outcomes for children with IXT.

Factors associated with the use of botulinum toxin injections for adult strabismus in the IRIS Registry.

This cross-sectional study used data from a large nationwide registry to describe the factors associated with use of botulinum toxin injections for adults with strabismus in the United States. Botulinum toxin injections were performed on 3.1% of adults undergoing an intervention for strabismus between 2013 and 2020. Adults treated with botulinum toxin injections were more likely to be older and female. Compared to non-Hispanic White patients, non-Hispanic Black patients were three times less likely to receive treatment with botulinum toxin after adjusting for age, sex, geographic region, and type of insurance. Efforts to understand the factors contributing to disparities in the use of botulinum toxin for strabismus may lead to opportunities for more equitable access to this intervention.

Association of Neighborhood Opportunity With Severity of Retinoblastoma at Presentation.

PURPOSE: To examine the relationship between the Child Opportunity Index (COI) and severity of retinoblastoma at presentation. DESIGN: Cross-sectional study. METHODS: Children (age <18 years) treated for retinoblastoma at a tertiary care center between January 2000 and May 2023 were included. Residential census tract was used to determine the overall and domain-specific COI score for each child. Collected variables included age, sex, race/ethnicity, insurance type, and the International Classification of Retinoblastoma (ICRB) Group at initial examination. The primary outcome was Group D or E retinoblastoma at presentation. Mixed effects regression models were used to estimate the association of COI scores with disease severity at presentation. RESULTS: This study included 125 children (51.2% male). Median age at diagnosis was 13 months (IQR, 5-24 months). One hundred nine (87.2%) children presented with Group D or E retinoblastoma and 33 (26.4%) resided in low or very low opportunity neighborhoods. Children residing in neighborhoods with low overall COI scores (OR, 1.62; 95% CI, 1.01-2.58; P = .044) and low education COI scores (OR, 1.77; 95% CI, 1.13-2.79; P = .013) were at increased odds of presenting with ICRB Group D or E retinoblastoma after adjusting for individual-level socioeconomic factors. CONCLUSION: Children residing in low opportunity neighborhoods-particularly low education opportunity-more often presented with advanced stage retinoblastoma than children residing in neighborhoods with higher opportunity scores. Efforts to improve preventative vision care and access to eye specialty care for children residing in low-resource areas are needed to reduce existing disparities in retinoblastoma.

Factors Associated with Missing Sociodemographic Data in the IRIS® (Intelligent Research in Sight) Registry.

Purpose: To describe the prevalence of missing sociodemographic data in the IRIS® (Intelligent Research in Sight) Registry and to identify practice-level characteristics associated with missing sociodemographic data. Design: Cross-sectional study. Participants: All patients with clinical encounters at practices participating in the IRIS Registry prior to December 31, 2020. Methods: We describe geographic and temporal trends in the prevalence of missing data for each sociodemographic variable (age, sex, race, ethnicity, geographic location, insurance type, and smoking status). Each practice contributing data to the registry was categorized based on the number of patients, number of physicians, geographic location, patient visit frequency, and patient population demographics. Main Outcome Measures: Multivariable linear regression was used to describe the association of practice-level characteristics with missing patient-level sociodemographic data. Results: This study included the electronic health records of 66 477 365 patients receiving care at 3306 practices participating in the IRIS Registry. The median number of patients per practice was 11 415 (interquartile range: 5849-24 148) and the median number of physicians per practice was 3 (interquartile range: 1-7). The prevalence of missing patient sociodemographic data were 0.1% for birth year, 0.4% for sex, 24.8% for race, 30.2% for ethnicity, 2.3% for 3-digit zip code, 14.8% for state, 5.5% for smoking status, and 17.0% for insurance type. The prevalence of missing data increased over time and varied at the state-level. Missing race data were associated with practices that had fewer visits per patient (P < 0.001), cared for a larger nonprivately insured patient population (P = 0.001), and were located in urban areas (P < 0.001). Frequent patient visits were associated with a lower prevalence of missing race (P < 0.001), ethnicity (P < 0.001), and insurance (P < 0.001), but a higher prevalence of missing smoking status (P < 0.001). Conclusions: There are geographic and temporal trends in missing race, ethnicity, and insurance type data in the IRIS Registry. Several practice-level characteristics, including practice size, geographic location, and patient population, are associated with missing sociodemographic data. While the prevalence and patterns of missing data may change in future versions of the IRIS registry, there will remain a need to develop standardized approaches for minimizing potential sources of bias and ensure reproducibility across research studies. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Complications After Pediatric Penetrating Keratoplasty: An IRIS Registry Study.

PURPOSE: To describe the frequency of postoperative complications in children undergoing penetrating keratoplasty (PK). METHODS: This retrospective cohort study included pediatric patients (aged 0-18 years) in the Intelligent Research in Sight (IRIS) Registry who underwent primary PK between January 2013 and December 2020. Patients were identified using Current Procedure Terminology codes. Postoperative complications were identified using International Classification of Diseases Revision 9 and 10 codes and categorized as complications affecting the anterior segment (epithelial defect, infectious keratitis, neurotrophic keratitis, and glaucoma) or posterior segment (vitreous hemorrhage, retinal detachment, choroid detachment, choroidal hemorrhage, endophthalmitis, epiretinal membrane, and proliferative vitreoretinopathy). RESULTS: Of the 544 pediatric patients undergoing PK, 259 (47.6%) experienced postoperative complications. Anterior segment complications (n = 222, 40.8%) were more common than posterior segment complications (n = 96, 17.6%). The most common anterior complication was infectious keratitis (n = 163, 30.0%) with a median onset time of 275 days (IQR 50-560 days) after surgery. Vitreous hemorrhage (n = 52, 9.6%) and retinal detachment (n = 48, 8.8%) were the most common posterior segment complications. CONCLUSIONS: Infectious keratitis was the most common postoperative complication in children undergoing PK. More complications occurred in the anterior segment (70%) of the eye as compared with the posterior segment (30%). These findings demonstrate the challenges associated with pediatric PK and may help guide postoperative monitoring and management.