Probing versus primary nasal endoscopy for the treatment of congenital dacryocystoceles.

PURPOSE: To compare outcomes and complications of three surgical techniques for the treatment of congenital dacryocystoceles: nasolacrimal probing and irrigation (P+I), P+I plus nasal endoscopy (NE) with intranasal cyst marsupialization, and primary NE with intranasal cyst marsupialization. METHODS: The medical records of children ≤2 years of age at a single academic center with a diagnosis of dacryocystocele from 2012 to 2022 were retrospectively identified and reviewed. The primary outcome was resolution of the dacryocystocele (ie, elimination of the medial canthal mass and resolution of tearing or discharge) after a single procedure ("primary success"). Surgical techniques were compared using exact logistic regression. RESULTS: Of 54 patients, 21 (39%) underwent P+I, 23 (43%) underwent P+I plus nasal endoscopy, and 10 (18%) underwent primary NE. Primary success was 76% for P+I and 100% for the other two cohorts. Most patients (89%) who underwent P+I received general anesthesia compared with none who underwent primary nasal endoscopy. Most complications were related to the use of general anesthesia, with a complication rate of 10% for P+I, 48% for P+I plus NE, and 0% for primary NE. Most P+I procedures required hospital admission compared to half of primary NE procedures. CONCLUSIONS: In our study cohort, primary NE provided good outcomes and was associated with a lower complication rate than P+I with or without NE.

Designing custom three-dimensional printed eyeglasses for children with frontonasal abnormalities: addressing challenges in access and fit.

Improving access to comfortable and well-fitting glasses for children with craniofacial differences may improve their visual outcomes. The purpose of this study was to describe challenges in spectacle fitting facing patients with frontonasal dysplasia and to report successful methods for creating custom 3D designed glasses. Additionally, the process of systematically collecting and analyzing spectacle-fitting challenges can inform future processes of automated design of 3D printed glasses and can be applied to other specific craniofacial syndromes.

Pediatric Cataract: Disparately Blinding Globally and in the United States.

Childhood cataract is a complex condition requiring longitudinal care, including early diagnosis, timely referral to a specialist, early surgical intervention, and dedicated postoperative care. Adherence to refractive correction and amblyopia therapy are critical for visual rehabilitation, even months to years after the cataract is removed. We review the impact of the social determinants of health on each step in the visual rehabilitation pathway for children with congenital and infantile cataracts. Children from socioeconomically marginalized backgrounds are more likely to experience delays in access to care and utilization of surgical services. They are also less likely to adhere to amblyopia therapy, with corresponding decrements in visual outcomes. Additional sociocultural factors, including parental stress, self-efficacy, and health literacy, pose barriers for these children. Standardizing clinical roles, improving health communication, managing parental stress, and implementing systemic policy changes may alleviate socioeconomic disparities in outcomes for children with cataracts.

Abnormal Eye Movements in a Young Girl.

A 5-year-old girl was referred for nystagmus with a history of esophageal atresia, small bowel obstruction, mild cognitive impairment, low tone, and increased reflexes. Alternating vertical and torsional nystagmus was noted. What would you do next?

Retinopathy and optic atrophy in a case of COQ2-related primary coenzyme Q10 deficiency.

PURPOSE: To describe a case of primary coenzyme Q10 deficiency in a child manifesting as early-onset renal failure, retinal dystrophy, and optic atrophy leading to progressive vision loss. METHODS: Clinical presentation and workup including visual fields, electroretinogram, and optical coherence tomography are presented. Genetic testing was performed. RESULTS: An eight-year-old female with nephropathy requiring renal transplantation subsequently developed progressive cone-rod dystrophy and optic atrophy. The patient had negative results on a targeted next-generation sequencing retinal dystrophy panel but whole-exome sequencing revealed two variants in COQ2 (likely biallelic), consistent with a diagnosis of primary coenzyme Q10 deficiency. CONCLUSIONS: Primary coenzyme Q10 deficiency is a rare disorder with variable systemic and ocular findings; there is also genetic heterogeneity. Genetic testing aids in the diagnosis of this condition, and variants in the COQ2 and PDSS1 genes appear to have the strongest association with ocular manifestations. Oral supplementation of coenzyme Q10 may slow progression of disease. This case highlights the utility of whole-exome sequencing in the diagnosis of a rare syndromic form of ocular disease and reports a novel phenotypic association for this condition.

Congenital ciliary body cysts causing lens abnormalities and secondary angle closure glaucoma in a child.

Purpose: To report a case of congenital ciliary body cysts causing microspherophakia, ectopia lentis, and secondary angle closure glaucoma in an infant. Observations: A 16-month-old male was found to have bilateral ciliary body cysts associated with zonular laxity or absence causing microspherophakia and ectopia lentis as demonstrated on multimodal imaging. Additionally, the patient had secondary angle closure glaucoma which was likely multi-factorial related to both lens abnormalities and anterior displacement of the iris from the cysts themselves. The patient underwent lensectomy and cyst removal which resulted in intraocular pressure stabilization and visual rehabilitation. Conclusions and Importance: Congenital ciliary body cysts are a rare cause of lens abnormalities and secondary angle closure glaucoma in children. Information regarding genetic underpinnings or systemic associations is limited.

Using a Smartphone 3-Dimensional Surface Imaging Technique to Manufacture Custom 3-Dimensional-Printed Eyeglasses.

Importance: Finding a suitable fit in glasses for pediatric patients with congenital and acquired craniofacial abnormalities is difficult; consequently, these children are at high risk of vision loss secondary to refractive amblyopia as they often have poor adherence to daily glasses wearing. Custom 3-dimensional (3D)-printed glasses may have an improved design and fit, but access is limited by the availability of computed tomography and magnetic resonance imaging (MRI). Objective: To describe a method for using a commercially available smartphone 3D surface imaging (3DSI) technique to capture facial anatomy as a basis for custom glasses design. Design, Setting, and Participants: This quality improvement study analyzes data from a case series in a primary academic center with multiple referral centers throughout the United States. The evaluation included reported fit descriptions from patients with poor glasses adherence due to craniofacial abnormalities. Main Outcomes and Measures: Key anatomic parameters for glasses fit (face width, distance from ear bridge to nasal bridge, distance from center of pupil to center of nasal bridge, distance from lateral to medial canthus, ear vertical offset, and nasal bridge width) were compared between scans. A 3DSI scan was considered successful if these key parameters could be determined and the difference in measurements was less than 5% between MRI and 3DSI. A second outcome measure included the fit of glasses designed by the 3DSI method as reported by the patient, parent, or guardian. Results: Measurements of key parameters for glasses fit were similar across MRI and 3DSI scans with a mean (SD) difference of 1.47 (0.79) mm between parameters (range, 0.3-4.60 mm). Among 20 patients aged 1 to 17 years with craniofacial abnormalities, all achieved a successful fit (reporting daily glasses adherence without irritation) as judged by the patient, parent, or guardian. A mean of 1.7 revisions were made from initial prototype to final frame production using 3DSI technology. Conclusions and Relevance: This study demonstrated that smartphone-enabled 3DSI coupled with widely available 3D printing technology can produce custom frames with a successful fit for patients with craniofacial anomalies. This accessible and well-tolerated imaging process may have implications for adherence with glasses wearing among patients at risk of vision loss due to amblyopia.

Ocular examinations, findings, and toxicity in children taking vigabatrin.

BACKGROUND: The antiepileptic medication vigabatrin has been associated with ocular toxicity, and close ophthalmic monitoring has been recommended; however, there is no clear consensus regarding the value and feasibility of such monitoring in children. We describe ophthalmic assessments in children in a real-world clinical setting, the incidence of vigabatrin-related ocular toxicity, and the utility of regular screening or ancillary testing in children taking vigabatrin. METHODS: The medical records of children taking vigabatrin with one or more ophthalmic assessments at Children's Hospital of Philadelphia or University of California, San Francisco, between May 2010 and May 2021, were reviewed retrospectively. Abnormalities on ophthalmic examination, visual field (VF), electroretinogram (ERG), and optical coherence tomography (OCT) were reviewed and categorized as attributable to vigabatrin, possibly attributable to vigabatrin, or not attributable to vigabatrin. RESULTS: A total of 1,281 assessments of 284 children (mean age, 2.09 years) were included. Of these, 283 (99.6%) had funduscopic examination(s), 37 (13.0%) had ERG, 19 (6.7%) had OCT, and 6 (2.1%) had formal VF. Rate of examinations and ERGs per child decreased over the 10-year study period. Two children (0.7%) had definite vigabatrin-related ocular toxicity, both identified on ERG. An additional 4 children (1.4%) had optic atrophy of unclear relation to vigabatrin, categorized as possible toxicity. The remaining 278 children did not have abnormal examination or testing findings attributable to vigabatrin. CONCLUSIONS: The incidence of vigabatrin-related ocular toxicity in children was low in our cohort. Ocular and neurologic comorbidities and limited examinations in children make identification of such toxicity challenging and the value of screening is unclear.

Parental perspectives on factors influencing eyeglass wear compliance in preschoolers from low-income families in San Francisco.

PURPOSE: To investigate factors associated with spectacle wear among low-income preschoolers who receive glasses through the See Well to Learn (SWTL) program. METHODS: Qualitative study of parental perceptions of factors contributing to compliance during a longitudinal study of eyeglass wear utilizing thematic analysis of a series of three scripted phone calls during the 2017-2018 school year. Participants were parents of 164 children ages 3-5, from 51 Head Start preschools in the greater San Francisco region. RESULTS: A total of 470 scripted parental telephone calls were successfully completed during the study period. Six major themes affecting glasses compliance in this group were identified including: (1) awareness of need and noted visual improvement; (2) continuous efforts to improve compliance by working with parent; (3) collaborative efforts between home and school such as parent-teacher encouragement; (4) child comfort and eyewear preferences; (5) the importance of two functional pairs of eyewear to achieve full-time wear; and (6) coordination of care offered by the SWTL program. CONCLUSIONS: This study offers insight into factors contributing to child eyewear compliance during critical years of vision development. These findings offer lessons to improve compliance and identify a need to adjust California's current policies on vision coverage for children.

Chorioretinal Findings as the Initial Presentation of Chronic Granulomatous Disease.

To describe a case of chronic granulomatous disease (CGD) with ocular lesions as the presenting findings. An ocular examination of a 4-month-old male infant with poor vision revealed punched-out macular and perivascular chorioretinal fibrosis and atrophy with peripheral retinal nonperfusion. Subsequently, he was hospitalized for recurrent infections and was diagnosed with CGD. Repeated examination demonstrated enlargement of the chorioretinal lesions without evidence of active inflammation or neovascularization. CGD causes recurrent, severe, life-threatening infections in children and should be considered in the differential diagnosis of chorioretinal lesions with peripheral retinal nonperfusion. [Ophthalmic Surg Lasers Imaging Retina. 2022;53(4):234-238.].

S1P defects cause a new entity of cataract, alopecia, oral mucosal disorder, and psoriasis-like syndrome.

In this report, we discovered a new entity named cataract, alopecia, oral mucosal disorder, and psoriasis-like (CAOP) syndrome in two unrelated and ethnically diverse patients. Furthermore, patient 1 failed to respond to regular treatment. We found that CAOP syndrome was caused by an autosomal recessive defect in the mitochondrial membrane-bound transcription factor peptidase/site-1 protease (MBTPS1, S1P). Mitochondrial abnormalities were observed in patient 1 with CAOP syndrome. Furthermore, we found that S1P is a novel mitochondrial protein that forms a trimeric complex with ETFA/ETFB. S1P enhances ETFA/ETFB flavination and maintains its stability. Patient S1P variants destabilize ETFA/ETFB, impair mitochondrial respiration, decrease fatty acid ß-oxidation activity, and shift mitochondrial oxidative phosphorylation (OXPHOS) to glycolysis. Mitochondrial dysfunction and inflammatory lesions in patient 1 were significantly ameliorated by riboflavin supplementation, which restored the stability of ETFA/ETFB. Our study discovered that mutations in MBTPS1 resulted in a new entity of CAOP syndrome and elucidated the mechanism of the mutations in the new disease.

Visual Acuity and Ophthalmic Outcomes 5 Years After Cataract Surgery Among Children Younger Than 13 Years.

IMPORTANCE: Cataract is an important cause of visual impairment in children. Data from a large pediatric cataract surgery registry can provide real-world estimates of visual outcomes and the 5-year cumulative incidence of adverse events. OBJECTIVE: To assess visual acuity (VA), incidence of complications and additional eye operations, and refractive error outcomes 5 years after pediatric lensectomy among children younger than 13 years. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study used data from the Pediatric Eye Disease Investigator Group clinical research registry. From June 2012 to July 2015, 61 eye care practices in the US, Canada, and the UK enrolled children from birth to less than 13 years of age who had undergone lensectomy for any reason during the preceding 45 days. Data were collected from medical record reviews annually thereafter for 5 years until September 28, 2020. EXPOSURES: Lensectomy with or without implantation of an intraocular lens (IOL). MAIN OUTCOMES AND MEASURES: Best-corrected VA and refractive error were measured from 4 to 6 years after the initial lensectomy. Cox proportional hazards regression was used to assess the 5-year incidence of glaucoma or glaucoma suspect and additional eye operations. Factors were evaluated separately for unilateral and bilateral aphakia and pseudophakia. RESULTS: A total of 994 children (1268 eyes) undergoing bilateral or unilateral lensectomy were included (504 [51%] male; median age, 3.6 years; range, 2 weeks to 12.9 years). Five years after the initial lensectomy, the median VA among 701 eyes with available VA data (55%) was 20/63 (range, 20/40 to 20/100) in 182 of 316 bilateral aphakic eyes (58%), 20/32 (range, 20/25 to 20/50) in 209 of 386 bilateral pseudophakic eyes (54%), 20/200 (range, 20/50 to 20/618) in 124 of 202 unilateral aphakic eyes (61%), and 20/65 (range, 20/32 to 20/230) in 186 of 364 unilateral pseudophakic eyes (51%). The 5-year cumulative incidence of glaucoma or glaucoma suspect was 46% (95% CI, 28%-59%) in participants with bilateral aphakia, 7% (95% CI, 1%-12%) in those with bilateral pseudophakia, 25% (95% CI, 15%-34%) in those with unilateral aphakia, and 17% (95% CI, 5%-28%) in those with unilateral pseudophakia. The most common additional eye surgery was clearing the visual axis, with a 5-year cumulative incidence of 13% (95% CI, 8%-17%) in participants with bilateral aphakia, 33% (95% CI, 26%-39%) in those with bilateral pseudophakia, 11% (95% CI, 6%-15%) in those with unilateral aphakia, and 34% (95% CI, 28%-39%) in those with unilateral pseudophakia. The median 5-year change in spherical equivalent refractive error was -8.38 D (IQR, -11.38 D to -2.75 D) among 89 bilateral aphakic eyes, -1.63 D (IQR, -3.13 D to -0.25 D) among 130 bilateral pseudophakic eyes, -10.75 D (IQR, -20.50 D to -4.50 D) among 43 unilateral aphakic eyes, and -1.94 D (IQR, -3.25 D to -0.69 D) among 112 unilateral pseudophakic eyes. CONCLUSIONS AND RELEVANCE: In this cohort study, development of glaucoma or glaucoma suspect was common in children 5 years after lensectomy. Myopic shift was modest during the 5 years after placement of an intraocular lens, which should be factored into implant power selection. These results support frequent monitoring after pediatric cataract surgery to detect glaucoma, visual axis obscuration causing reduced vision, and refractive error.

AAPOS uniform guidelines for instrument-based pediatric vision screen validation 2021.

BACKGROUND: As instrument-based pediatric vision screening technology has evolved, the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) has developed uniform guidelines (2003, updated 2013) to inform the development of devices that can detect specified target levels of amblyopia risk factors (ARFs) and visually significant refractive error. Clinical experience with the established guidelines has revealed an apparent high level of over-referral for non-amblyopic, symmetric astigmatism, prompting the current revision. METHODS: The revised guidelines reflect the expert consensus of the AAPOS Vision Screening and Research Committees. RESULTS: For studies of automated screening devices, AAPOS in 2021 recommends that the gold-standard confirmatory comprehensive examination failure levels include anisometropia >1.25 D and hyperopia >4.0 D. Astigmatism >3.0 D in any meridian and myopia < -3 D should be detected in children <48 months, whereas astigmatism >1.75 D and myopia < -2 D should be detected after 48 months. Any media opacity >1 mm and manifest strabismus of >8Δ should also be identified. Along with performance in detecting ARFs and refractive error, validation studies should also report screening instrument performance with regard to presence or absence of amblyopia. Instrument receiver operating characteristic curves and Bland-Altman analysis are suggested to improve comparability of validation studies. CONCLUSIONS: Examination failure criteria have been simplified and the threshold for symmetric astigmatism raised compared to the 2013 guidelines, whereas the threshold for amblyogenic anisometropia has been decreased. After age 4 years, lower magnitudes of symmetric astigmatism and myopia are also targeted despite a low risk of amblyopia, because they can influence school performance and may warrant consideration of myopia prevention therapy.

Perceived Barriers to Increasing Diversity within Oculofacial Plastic Surgery.

Purpose Physician diversity is limited in ophthalmology and oculofacial plastic surgery. Determination of barriers within the application process for oculofacial plastic surgery may help target efforts to improve the recruitment of underrepresented groups. This study aimed to illuminate perceived barriers to increasing diversity in oculofacial plastic surgery trainees, according to the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) fellows and fellowship program directors (FPDs). Methods During the month of February 2021, we sent surveys out to 54 current oculofacial plastic surgery fellows and 56 FPDs at 56 oculofacial plastic surgery programs recognized by the ASOPRS nationwide using a 15-question Qualtrics survey. Results Sixty-three individuals (57%) responded to the survey: 34 fellows (63%) and 29 FPDs (52%). Eighty-eight percent of fellows and 68% of FPDs identified as non-underrepresented in medicine (UiM). Forty-four percent of fellows and 25% of FPDs identified as men. FPDs most commonly noted, "Not enough minorities applying to our program" and "The objective data (Ophthalmic Knowledge Assessment Program score, United States Medical Licensing Examination Step scores, clinical honors, Alpha Omega Alpha status, letter of recommendation) for minority applicants often do not meet the threshold required to offer an interview or to be ranked to match" as barriers. Among fellows, the lowest-rated considerations when applying to oculofacial plastic surgery were "Racially/ethnically diverse faculty" and "Perceptions of minority candidates by fellowship programs," whereas "Likelihood of matching in program of choice" was ranked highest in considerations. Fellows identifying as men indicated greater concern for "Financial factors related to fellowship (e.g., loans, salary, cost of living, or cost of interviewing)" compared to fellows identifying as women who noted greater concern for "Program or preceptor acceptance of starting or having a family during fellowship." Conclusion Responses from FPDs suggest that efforts focused on recruiting and supporting diverse students to medicine and ophthalmology, mentoring applicants interested in oculofacial plastic surgery, and restructuring the application process to decrease bias, may improve diversity within the subspecialty. The lack of UiM representation in this study, 6% fellows and 7.4% FPDs identified as UiM, shows both the stark underrepresentation and the need for further research into this topic.

As the worm turns: An infant with exotropia.

A two-year-old full-term boy with a history of an intermittent exotropia presented to the pediatric ophthalmology clinic for routine follow-up. He was found to have a stable sensorimotor examination however dilated funduscopic examination of the right eye was significant for a dim foveal reflex with a new discrete, white, elevated retinal lesion superotemporal to the fovea with surrounding subretinal exudates. An examination under anesthesia (EUA) was performed two days later that revealed a subretinal posterior pole granuloma with hyperfluorescence and late leakage from the lesion without telangiectatic vessels on fluorescein angiography. A repeat EUA one month later demonstrated an increase in surrounding subretinal and overlying intraretinal fluid. The patient was started on topical 1% prednisolone with a presumed diagnosis of Toxocara granuloma. At EUA, three months later, the subretinal and intraretinal fluid had resolved. The topical steroids were tapered, and the patient continues to be followed closely.

The flipped-classroom approach to teaching horizontal strabismus in ophthalmology residency: a multicentered randomized controlled study.

BACKGROUND: The flipped-classroom involves watching prerecorded lectures at home followed by group learning exercises within the classroom. This study compares the flipped classroom approach with the traditional classroom for teaching horizontal strabismus didactics in ophthalmology residency. METHODS: In this multicenter, randomized controlled survey study from October 2017 to July 2018, 110 ophthalmology residents were taught esotropia and exotropia sequentially, randomized by order and classroom style. Flipped classroom participants were assigned a preclass video lecture prior to the in-class case-based activity. The traditional classroom included a preparatory reading assignment and an in-person lecture. Residents completed three identical 5-question assessments (pretest, post-test, and 3-month retention) and surveys for each classroom. The primary outcome measured residents' preferences for classroom styles; the secondary outcome compared knowledge acquisition. RESULTS: In our study cohort, the flipped classroom resulted in greater at-home preparation than the traditional classroom (P = 0.001) and was preferred by 33 of 53 residents (62%); 45 of 53 (85%) wished to see the flipped classroom used at least 25% of the time. The exotropia flipped classroom scored higher than traditional classroom on the pretest (3.71/5 [74%] vs 2.87/5 [57%]; P < 0.001) and post-test (4.53/5 [91%] vs 4.13/5 [83%]; P = 0.01) but not the 3-month retention test (3.53/5 [71%] vs 3.37/5 [67%]; P = 0.48). The esotropia classroom styles did not differ on pre- or post-test but demonstrated higher scores for the traditional classroom at 3-month retention (3.43/5 [69%] vs 2.92/5 [58%]; P = 0.03). Advantages cited for flipped classroom include being interactive and engaging while incentivizing better classroom preparation. CONCLUSIONS: The flipped classroom method was received favorably by trainees and may complement traditional methods of teaching.

Prevalence and Factors Associated With Eyeglass Wear Compliance Among Preschoolers From Low-Income Families in San Francisco, California.

IMPORTANCE: Despite growing support for early school-based vision screening and eyeglass provision, few studies have rigorously monitored the compliance of eyeglass wear among preschool-aged children who receive eyeglasses through such programs. OBJECTIVE: To assess the prevalence and factors associated with eyeglass wear compliance among preschoolers from low-income families who receive eyeglasses through the See Well to Learn program. DESIGN, SETTING, AND PARTICIPANTS: Longitudinal cross-sectional study of eyeglass wear compliance patterns among 188 children 3 to 5 years of age from 51 Bay Area Head Start preschools in San Francisco, California. The study conducted during the 2017 to 2018 school year included students with a failed vision screening who met predetermined refractive criteria following cycloplegic refraction and received eyeglasses through the See Well to Learn program. EXPOSURES: Eyeglass distribution. MAIN OUTCOMES AND MEASURES: Eyeglass wear compliance, measured by a school-year's worth of weekly teacher reports, was a longitudinal measure of consistent eyeglass wear, defined by eyeglass wear for more than 50% of every school day (compliance score of 4). RESULTS: Of 188 students (91 boys [49%]; 94 girls [51%]; mean [SD] age, 3.89 [0.5] years), 133 (71%; 95% CI, 64%-77%) maintained a mean compliance score throughout the school year of 4 or higher. Compliance prevalence was relatively stable throughout the school year, ranging from 139 students (74%) to 164 students (87%). Baseline uncorrected visual acuity in both the better-seeing and worse-seeing eyes was the only assessed factor that was associated with compliance. In the better-seeing eye, the mean uncorrected visual acuity of students with eyeglass wear compliance was 0.473 logMAR (95% CI, 0.433-0.514) (Snellen equivalent, 20/60) compared with 0.394 logMAR (95% CI, 0.334-0.454) (Snellen equivalent, 20/50) for students with noncompliance (P = .03). In the worse-seeing eye, the mean uncorrected visual acuity of students with compliance was 0.576 logMAR (95% CI, 0.530-0.623) (Snellen equivalent, 20/75) compared with 0.492 logMAR (95% CI, 0.433-0.551) (Snellen equivalent, 20/62) for students with noncompliance (P = .03). In the better-seeing eye, the difference between students with compliance vs noncompliance was 0.079 logMAR (95% CI, 0.009-0.150) (5 Snellen letter difference) compared with 0.084 logMAR (95% CI, 0.007-0.160) (5 Snellen letter difference) in the worse-seeing eye. CONCLUSIONS AND RELEVANCE: This study found that nearly 3 of 4 preschool students consistently wore their glasses at school during their first year of use, supporting the continued implementation of preschool-based vision screening programs. These findings suggest that programs involving school-based screening and eyeglass delivery may lessen disparities in accessing pediatric vision care. Consistent with previous studies, students with poorer uncorrected baseline visual acuity were found to be more likely to wear eyeglasses compliantly.