Effect of vertical central plication on vertical deviations.

PURPOSE: To evaluate the surgical effect of the Wright central plication on vertical rectus muscles to correct vertical strabismus. METHODS: In this multicenter, retrospective, observational outcomes study, data were collected from two surgeons in different practice settings (2017-22). All patients who underwent vertical rectus central plication were included; those undergoing any concurrent strabismus surgery for vertical strabismus were excluded. Primary outcome was amount of strabismus correction in prism diopters per vertical rectus central plication. Secondary outcome was to determine factors associated with better or worse surgical outcomes and patient and patient responses. Data were analyzed using descriptive and bivariate statistics. RESULTS: A total of 36 patients were included. Mean age was 60 years. Mean follow-up was 8.4 months. Of the 36 patients, 11 (31%) had idiopathic strabismus, and 7 (19%) had congenital superior oblique palsy. The remainder had a history that included prior ocular surgery, trauma, and Brown syndrome; 16 (44 %) had prior strabismus surgery. Of 31 patients with preoperative diplopia, 23 (74%) had postoperative resolution of diplopia, and 10 of 16 patients with preoperative prisms (63%) no longer required prisms postoperatively. Mean vertical deviation change was 4.7Δ. Subgroup analysis removing patients with congenital superior oblique palsy showed a larger response of 5.5Δ. 78% of patients had a final deviation <5Δ. No complications or induced postoperative diplopia was reported. CONCLUSIONS: In our study cohort, vertical rectus central plication corrected approximately 5Δ (range, 4.5Δ-5.5Δ) of vertical strabismus due to a variety of causes.

Management of vernal keratoconjunctivitis: Navigating a changing treatment landscape.

Vernal keratoconjunctivitis (VKC) is a chronic, progressive, and potentially sight-threatening form of ocular inflammatory disease that primarily affects children and young adults. Prevalence varies by region, ranging from <2 per 10,000 in the United States to as high as 1,100 per 10,000 in parts of Africa. The rarity of VKC in developed countries can make differential diagnosis challenging, and treatment is often delayed until the disease is advanced, and symptoms are significantly impacting patients' quality of life. Although once viewed primarily as an immunoglobulin E-mediated condition, approximately 50% of patients with VKC do not exhibit allergic sensitization. It is now recognized that the immunopathology of VKC involves multiple inflammatory pathways that lead to the signs, symptoms, and conjunctival eosinophilic and fibroproliferative lesions that are a hallmark of the disease. We examine the evolution of our understanding of the immunopathology of VKC, the expanding VKC treatment armamentarium, the clinical implications of emerging treatment approaches, and future directions for VKC research and practice.

Missed appointments in a tertiary academic pediatric ophthalmology and adult strabismus service: cross-sectional study and literature review.

PURPOSE: To investigate the rate of missed appointments in a Canadian academic hospital-based pediatric ophthalmology and adult strabismus practice and the demographic and clinical factors associated with missed appointments. METHODS: This cross-sectional study included all consecutive patients seen from June 1, 2018, to May 31, 2019. Multivariable logistic regression model assessed associations between clinical and demographic variables with no-show status. A literature review on evidence-based interventions to reduce no-show appointments in ophthalmology was performed. RESULTS: Of 3,922 visits, 718 (18.3%) were no-shows. Characteristics associated with no-shows included new patient (OR = 1.4; 95% CI, 1.1-1.7 [P = 0.001]), age 4-12 years (OR = 1.6; 95% CI, 1.1-2.3 [P = 0.011]) or age 13-18 years (OR = 1.8; 95% CI, 1.2-2.7 [P = 0.007]) compared with age 19+ years, history of previous no-shows (OR = 2.2; 95% CI, 1.8-2.7 [P = 0.001]), referrals from nurse practitioners (OR = 1.8; 95% CI, 1.0-3.2 [P = 0.037]), nonsurgical diagnoses such as retinopathy of prematurity (OR = 3.2; 95% CI, 1.8-5.6 [P < 0.001]), and winter season (OR = 1.4; 95% CI, 1.2-1.7 [P < 0.001]). CONCLUSIONS: Missed appointments in our pediatric ophthalmology and strabismus academic center are more likely new patient referrals, prior no-shows, referrals from nurse practitioners, and nonsurgical diagnoses. These findings may facilitate targeted strategies to help improve utilization of healthcare resources.

Pathophysiology of retinopathy of prematurity.

Retinopathy of prematurity (ROP) is a vasoproliferative disease occurring in premature infants that affects the blood vessels of the developing retina. ROP results in the development of vascular shunts, neovascularization, and in its most severe form tractional retinal detachment. The development of retinal vascular shunts and neovascularization in ROP is related to local ischemia in the immature and incompletely vascularized retina. Understanding the pathophysiology of ROP helps physicians both in the prevention and treatment of ROP and will be discussed in this review article. The role of oxygen in the pathophysiology of ROP will be reviewed with recent studies discussed.

Wright hang-back recession with fibrin glue compared with standard fixed suture recession for the treatment of horizontal strabismus.

OBJECTIVE: To evaluate the clinical safety and efficacy of the novel Wright hang-back recession with fibrin glue for the treatment of horizontal strabismus. STUDY DESIGN: Retrospective, case-controlled clinical study comparing surgical outcomes of the Wright hang-back rectus recession with fibrin glue (WHBG) versus standard fixed suture rectus recession (SFR). METHODS: Medical records of all patients who underwent strabismus surgery by one strabismus surgeon between 2016 and 2018 for horizontal deviations only, including cases of WHBG (group 1) or SFR (group 2), were reviewed. Good surgical outcome was defined as a postoperative deviation ≤10 prism diopters (PD) at a minimum 2 months of follow-up. RESULTS: 32 eyes of 17 patients underwent WHBG and 32 eyes of 17 patients underwent SFR; in each group, 35% had esotropia and 65% had exotropia. Mean preoperative deviations between groups were similar: esotropia 25.5 PD and exotropia 26.6 PD in WHBG; esotropia 28.3 PD and exotropia 23.8 PD in SFR. The mean postoperative deviation was <7 PD for both groups. Good surgical outcomes were similar between groups, 16/17 (94%) in WHBG and 15/17 (88%) in SFR, with no complications. CONCLUSIONS: WHBG was safe and effective with postoperative results similar to SFR. WHBG has an important advantage, eliminating the complication of retinal perforation that can occur with SFR while avoiding under- or overcorrection that can occur with traditional hang-back recession. This technique increases patient safety without sacrificing surgical outcomes and is especially useful in patients with thin sclera such as patients with high myopia or with difficult posterior exposure.

Bilateral severe microphthalmia in a neonate with trisomy 8 mosaicism: A new finding.

Mosaic Trisomy 8 is a rare chromosomal abnormality estimated to occur one in 30,000 newborns. The phenotype is highly variable and the severity does not appear to be correlated with the proportion of cells that contain the additional chromosome. Ocular involvement in Trisomy 8 mosaicism has previously been described to include corneal opacities, retinal dystrophy, coloboma, and unilateral microphthalmia. We report a case of severe bilateral microphthalmia in a neonate with Trisomy 8 mosaicism, a previously unrecognized ophthalmic manifestation.

Use of neuromuscular blocking drugs in strabismus surgery: systematic review and ophthalmology survey study.

OBJECTIVE: Nondepolarizing neuromuscular blocking drugs have been advocated for accurate forced duction testing (FDT) during strabismus surgery. The purpose of this study was to evaluate the literature on use of muscle relaxants (MRs) in strabismus surgery and to evaluate the current practice of pediatric ophthalmologists. DESIGN: Systematic review and survey study. PARTICIPANTS: Seventy-seven pediatric ophthalmologists. METHODS: MEDLINE, EMBASE, CENTRAL, Web of Science, and OpenGrey were searched to August 2019. Reporting followed the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Primary studies on depolarizing or nondepolarizing MRs in patients undergoing strabismus surgery were included. Primary outcomes included indications and prevalence of use. A 23-question survey was emailed to pediatric ophthalmologists worldwide to collect practice pattern information involving MRs in strabismus surgery. RESULTS: Three studies were included in the systematic review. MRs were used in 34%-45% of patients undergoing strabismus surgery in one 1999 study for FDT. No evidence exists to support the use of MRs for facilitating FDT. Seven of 77 (9.1%) pediatric ophthalmologists requested MRs for FDT. Those who use MRs were more likely to be practicing outside the United States (p < 0.05) and in academic hospitals or private centres rather than in community settings. Drawbacks appeared to outweigh benefits, with the biggest drawback identified as increased turnover time between surgical cases (44%). CONCLUSIONS: Inadequate evidence exists in the literature to support the use of nondepolarizing MRs to maintain paralysis of extraocular muscles during strabismus surgery, and this is an uncommon practice among pediatric ophthalmologists.

Validation of a novel strabismus surgery 3D-printed silicone eye model for simulation training.

PURPOSE: To demonstrate the validity of a new 3D-printed silicone model for practicing strabismus surgery, compared with the rabbit head, in terms of simulator fidelity. METHODS: In this multicenter study, a validated questionnaire was developed to assess fidelity of the model and rabbit head. Participants were asked to rate overall globe, conjunctiva, muscle, and scleral fidelity using a 5-point scale. The survey instrument was disseminated at three strabismus instruction courses: at two meetings, participants practiced on the model and rabbit head prior to completing the questionnaire; at the third, instructors demonstrated advanced surgical skills using only the model and then completed the questionnaire. Repeated measures analysis of variance compared ratings. Pearson's or Spearman's correlation evaluated correlation between years of experience to participants' responses. Qualitative data were coded into themes. RESULTS: A total of 47 participants completed the questionnaire. The model rated 18% higher than rabbit head for anatomical accuracy (mean difference, 0.667; P = 0.001) and 25% higher for position of eyes within the head (mean difference, 0.867; P = 0.006). More experienced participants were more likely to strongly agree that the silicone conjunctiva effectively mimics real conjunctiva (ρ = 0.337; P = 0.036) and that scleral tissue effectively mimics real sclera (ρ = 0.298, P = 0.042). Qualitative data supported the model. CONCLUSIONS: This study demonstrated the validity of the surgical model in terms of fidelity compared to the rabbit head.

Intraocular calcidiol: Uncovering a role for vitamin D in the eye.

Vitamin D has emerged as a potentially important molecule in ophthalmology. To date, all ophthalmic data pertaining to vitamin D has been restricted primarily to tear and serum analysis in human patients. Considering the isolated nature of the eye, we sought to determine the presence of intraocular vitamin D in ocular disease. METHODS: 25-Hydroxyvitamin D3 (25(OH)D3) concentrations were measured in the eye and blood of 120 participants undergoing ophthalmic procedures. Ocular localization of the 1,25-dihydroxyvitamin D3-generating (CYP27B1) and deactivating (CYP24A1) hydroxylases was performed by immunohistochemistry. Gene expression of CYP27B1, CYP24A1 and VEGF-A was measured in eyes from patients with and without disease. RESULTS: 25(OH)D3 was quantified in 112 ocular samples. In 40 cataract patient samples, the average 25(OH)D3 concentration was 0.057 ng/mL, compared to 72 retinal disease patient samples, average of 0.502 ng/mL (p < 0.001). Intraocular 25(OH)D3 did not correlate with serum levels of 25(OH)D3. There was no difference between the level of 25(OH)D3 measured in the aqueous and vitreous humour. The vitamin D-specific CYPs 27B1 and 24A1, strongly localized to complementary regions of the ciliary body, retinal pigment epithelium and neural retina. Gene expression analysis confirmed retinal CYP27B1 correlated strongly with VEGF-A in eyes from diabetic patients (r = 0.92, p < 0.001). CONCLUSIONS: Our data confirms that vitamin D is present in the humours of the human eye and that local synthesis/degradation is possible via the ocular CYP27B1 and CYP24A1. This argues for a functional role for local vitamin D production and signaling in the eye and suggests that vitamin D may be an important intraocular mediator in disease pathogenesis.

Foreign body extrusion associated with N-butyl-2-cyanoacrylate glue used with rectus muscle hang-back recession.

OBJECTIVE: Standard rectus muscle recessions require suturing muscle to sclera posterior to the insertion, which is dangerous as the sclera is thin. Extraocular muscle hang-back recession can avoid the posterior scleral needle pass but has been reported to be unstable. The purpose of this study is to assess the use of N-butyl-2-cyanoacrylate to aid reattachment of rectus muscle to sclera during hang-back recession. DESIGN: 2 Phase Study: Phase 1 was a wet lab animal study; Phase 2 was a small case series. PARTICIPANTS: Phase 1, 14 frozen bank rabbit heads; Phase 2, 4 human adult patients with myopia and large exotropia. METHODS: Phase 1: Frozen bank rabbit heads were used to simulate human hang-back rectus muscle recession. Fourteen rectus muscles were recessed by hang-back and glued to sclera with either cyanoacrylate glue alone (group 1) or glue over prolene mesh for greater stability (group 2). Primary outcome was muscle detachment force measured at 20, 30, and 40 seconds. Phase 2: Four patients with myopia and large exotropia who underwent bilateral hang-back lateral rectus recessions with cyanoacrylate glue were retrospectively studied. RESULTS: Phase 1: Group 1 mean detachment force measured at 30 seconds was 172.07 g versus 376.5 g in group 2 (p < 0.01). Phase 2: All patients had excellent postoperative alignment within 5 PD of orthophoria and no overcorrections. Two patients had unilateral glue extrusion at 1 month requiring in-office removal under topical anaesthesia. CONCLUSIONS: Cyanoacrylate glue with or without mesh resulted in adequate muscle-to-sclera adhesion with a detachment force at least 2 times the force of a normal rectus muscle contraction. Patients undergoing hang-back lateral rectus recession with cyanoacrylate glue had excellent stable postoperative alignment; however, half had the complication of late extrusion of glue foreign body.

Silicone oil migration into periorbital space surrounding an extraocular muscle after sutureless 23-gauge vitrectomy in a child.

We report the case of an 11-year-old girl with a rare finding of silicone oil migration into the periorbital space surrounding an extraocular muscle, discovered during strabismus surgery for a sensory exotropia that had developed after retinal detachment repair by pars plana vitrectomy with intraocular silicone oil.