Esotropia associated with high myopia.

PURPOSE OF REVIEW: The aim of the present article is to describe the pathophysiology of esotropia associated with high myopia, commonly known as heavy eye syndrome, and discuss the preoperative evaluation and surgical options in these complex patients. RECENT FINDINGS: Numerous studies have looked to determine the cause of esotropia in patients with high myopia. Orbital imaging has shown a nasal displacement of the superior rectus muscle and an inferior displacement of the lateral rectus muscle. As such, traditional resection-recession surgery can be ineffective in these patients. Instead, correcting the deviant muscles paths is necessary. Recent studies have shown that loop myopexy with or without medial rectus recession can be performed without sclera fixation sutures to correct the underlying pathophysiology. SUMMARY: Heavy eye syndrome or strabismus fixus is a rare restrictive strabismus. Careful preoperative evaluation must be performed in order to correctly diagnose these patients. If posterior globe prolapse with superior and lateral rectus muscle displacement is seen, loop myopexy can be a well tolerated and effective procedure in treating heavy eye syndrome.

Achromatopsia: a review.

PURPOSE OF REVIEW: The purposes of this article are to examine the literature published on achromatopsia and provide a comprehensive review of the clinical disease, genetic characteristics, and potential for therapy. Specifically, this article will describe recent advances in gene therapy in animal models, clinical features in human, and barriers to human translation. RECENT FINDINGS: Building on prior success with adeno-associated virus (AAV) therapy in mice models for achromatopsia with mutations in the CNGB3, CNGA3, or GNAT2 genes, multiple cone-specific promoters have recently been developed and shown success in mice and nonhuman primates. A sheep CNGA3 model has also been characterized. Two clinical trials are under way: one to better characterize humans with achromatopsia and another to study a ciliary neurotrophic factor (CNTF) implant as a treatment for patients with the CNGB3 mutation. SUMMARY: Genetic understanding and disease characterization of achromatopsia continues to evolve, as do gene therapy tools and animal models. The potential for the treatment of achromatopsia in humans with gene therapy shows great promise.

Strabismus surgery for children with developmental delay.

PURPOSE OF REVIEW: To describe recent evidence regarding the surgical approach of strabismus in children with various forms of developmental delay. RECENT FINDINGS: There remains variability in surgical outcomes with or without dose adjustment in strabismus surgery for children with developmental delay. However, this should not deter one from performing surgery - even early surgery, as fusional potential remains possible, which can especially impact the quality of vision and quality of life in developmentally delayed children.Future prospective, comparative, long-term studies with larger sample sizes for strabismus surgery in children with developmental delay are still needed. SUMMARY: Strabismus is one of the most common ophthalmologic findings in children with developmental delay. Surgical correction of strabismus in children with developmental delay is well tolerated and effective, although it remains slightly less predictable, which can depend on the specific type of delay or underlying neurological deficit. Careful consideration of types and severity of developmental delay and attempts to measure binocular potential can help guide the timing, dosage, and type of treatment.Reoperations tend to be more frequently encountered in this population, and this higher degree of variability should be addressed in the consent process.Considering adjusting the surgical dosage in this population, taking careful preoperative measurements, and checking for fusional potential should be taken into account when managing children with developmental delay.

Progressive myelinated retinal nerve fibers in a 10-year-old boy with Crouzon syndrome after craniofacial surgery.

Purpose: We present a case of a 10-year-old boy with Crouzon syndrome that demonstrates progressive myelinated retinal nerve fibers (MRNF). Observations: A 10-year-old boy was referred for ophthalmic examination due to clusters of opaque white fibers around his optic nerve. Past surgical history includes craniofacial surgery at 3 years of age secondary to the deteriorating vision from increased intracranial pressure and papilledema. Upon examination (now 6.5 years post-craniofacial surgery), the patient denied any ocular complaints. The fundus examination showed progressively enlarged myelination of the retinal nerve fiber layer (right eye > left eye). Although previous cases of MRNF with Crouzon syndrome have been reported, our case is unique given its post-operative status with early onset of MRNF. Conclusion and importance: This case report documents the photographic progression of bilateral myelinated retinal nerve fibers (MRNF) in a pediatric case of Crouzon syndrome post-craniofacial surgery secondary to increased intracranial pressure and papilledema. Based on our patient, craniofacial decompression surgery may not prevent the development of MRNF. The exact mechanisms of MRNF are still being studied. Further investigations correlating craniofacial surgeries, increased intracranial pressure, and progression of myelinated retinal nerve fibers are needed to understand this process.

Engineering cartilage in a photochemically crosslinked collagen gel.

This study's purpose was to investigate whether photochemically crosslinking collagen gel to encapsulate chondrocytes (articular, auricular, costal) would permit new cartilage formation in vivo, and to determine whether this neocartilage had the ability to integrate with existing native cartilage. Chondrocytes from swine were embedded in collagen gel that was photochemically crosslinked using riboflavin and visible light. Controls were collagen gels containing cells that were not crosslinked. Cylindrical implants (0.1 cc) were placed in athymic mice for 4 and 8 weeks. To study integration, the constructs were crosslinked within articular cartilage rings and implanted in the mice. Samples were analyzed in terms of macroscopic, microscopic, and biochemical aspects. Photocrosslinking did not affect the amount of glycosaminoglycan and type II collagen produced by the cells. We found that photochemical crosslinking collagen gel enhances the physical parameters of the gel and permits new cartilage formation that can integrate with existing native cartilage.

The Role of Superior Oblique Posterior Tenectomy Along With Inferior Rectus Recessions for the Treatment of Chin-up Head Positioning in Patients With Nystagmus.

PURPOSE: To evaluate the clinical outcomes of bilateral superior oblique posterior 7/8th tenectomy with inferior rectus recession on improving chin-up head positioning in patients with horizontal nystagmus. METHODS: Medical records were reviewed from 2007 to 2017 for patients with nystagmus and chin-up positioning of 15° or more who underwent combined bilateral superior oblique posterior 7/8th tenectomy with an inferior rectus recession of at least 5 mm. RESULTS: Thirteen patients (9 males and 4 females) were included, with an average age of 7.3 years (range: 1.8 to 15 years). Chin-up positioning ranged from 15° to 45° degrees (average: 30°). Three patients had prior horizontal muscle surgeries, 1 for esotropia and 2 for horizontal null zones causing anomalous face turns. Ten patients underwent other concomitant eye muscle surgery: 3 had esotropia, 1 had exotropia, and 2 had biplanar nystagmus null point requiring a horizontal Anderson procedure. Four patients underwent simultaneous bilateral medial rectus tenotomy and reattachment. All patients had improved chin-up positioning. Eight patients had complete resolution, whereas 5 had minimal residual chin-up positioning. Three patients developed an eccentric horizontal gaze null point with compensatory anomalous face turn with onset 2 weeks, 2 years, and 3 years postoperatively. Average follow-up was 42.7 months. No postoperative pattern deviations, cyclodeviations, or inferior oblique overaction were seen. No surgical complications were noted. CONCLUSIONS: Bilateral superior oblique posterior 7/8th tenectomy in conjunction with bilateral inferior rectus recession is a safe and effective procedure for improving chin-up head positioning in patients with horizontal nystagmus with a down gaze null point. [J Pediatr Ophthalmol Strabismus. 2018;55(4):234-239.].

Bilateral posterior tenectomy of the superior oblique muscle for the treatment of A-pattern strabismus.

PURPOSE: To evaluate the efficacy of bilateral posterior superior oblique tenectomy for the treatment of A-pattern strabismus due to superior oblique overaction regardless of the magnitude of the pattern. METHODS: The medical records of patients with A-pattern esotropia or exotropia in the presence of superior oblique overaction who underwent combined horizontal muscle surgery along with bilateral superior oblique posterior 7/8 tenectomy from 2003 to 2013 were retrospectively reviewed. Patients with at least 3 months' follow-up were included. RESULTS: A total of 73 patients were included. Of these, 46 had esotropia; 27, exotropia. The preoperative A-pattern deviation for the study population was 19.6(Δ) ± 11.4(Δ) (range, 10-60), with a final postoperative patten collapse of 18.2 ± 3.6. Superior oblique overaction was 2.3 ± 0.7 preoperatively and 0.3 ± 0.7 postoperatively. Overall, 87.7% of patients had a successful collapse of their pattern to <10(Δ) following the initial bilateral superior oblique posterior tenectomy, with an additional 4.1% following a second procedure. Of patients with a pattern deviation of <25(Δ), 87.9% had successful collapse of the pattern following 1 surgery, and 86.7% of patients who had a pattern of ≥25(Δ) had successful collapse. Postoperatively, 7 patients demonstrated mild inferior oblique overaction. No surgical complications were noted. CONCLUSIONS: A uniform dose of bilateral posterior 7/8 tenectomy surgery successfully collapses A-pattern deviations of all magnitudes.

Iritis and iris atrophy after eyebrow epilation with alexandrite laser.

PURPOSE: To report a case of bilateral iritis and transillumination defects after laser hair removal of the eyebrows with an alexandrite laser. METHODS: A 41-year-old male presented with bilateral eye pain and mild photophobia 2 days after receiving alexandrite (755 nm) laser epilation of both eyebrows. Examination showed visual acuity of 20/20 in both eyes, 2+ conjunctival injection in both eyes, 1+ cells in the anterior chamber of right eye and trace cells in left eye, poor right pupil dilation, and left pupil without movement. Intraocular pressure and fundus examination were normal. He was diagnosed with iritis and iris atrophy, associated with laser epilation. Topical steroids and cycloplegic drops were prescribed for 1 month. RESULTS: After 1 month of treatment, transillumination defects remained in both eyes, but greater in right. In dim light, the right pupil was 4 mm and oval and the left pupil was 6 mm and round. Visual acuity remained 20/20 in both eyes. CONCLUSION: Laser hair removal of the eyebrows can lead to permanent ocular damage even with eye protection, and should be avoided.

Embryonic stem cell-derived motor neurons preserve muscle after peripheral nerve injury.

BACKGROUND: The potential of motor neuron progenitor cell transplants to preserve muscle tissue after denervation was studied in in vivo and in vitro adult mammalian model of peripheral nerve injury. METHODS: Embryonic stem cells were differentiated to induce cholinergic motor neuron progenitors. Flourescent-labeled progenitor cells were injected into the gastrocnemius muscle of Sprague-Dawley rats (n = 10) after denervation by ipilateral sciatic nerve transection. Control rats received injections of either a phosphate-buffered saline solution only (n = 12), murine embryonic fibroblast (STO) cells (n= 6), or undifferentiated embryonic stem cells (n= 6). Muscles were weighed and analyzed at 7 and 21 days using histology, histomorphometry, and immunostaining. RESULTS: Seven days after progenitor cell transplant, both muscle mass and myocyte cross-sectional area were preserved, compared with control muscles, which demonstrated muscle mass reduction to 70 percent and reduction of cross-sectional area to 72 percent of normal. Fluorescent microscopy of transplanted muscles confirmed the presence of motor neuron progenitors. Presynaptic neuronal staining of the transplants overlapped with alpha-bungarotoxin-labeled muscle fibers, revealing the presence of new neuromuscular junctions. By 21 days, muscle atrophy in the experimental muscles was equal to that of controls and no transplanted cells were observed. Co-culture of the motor neuron progenitor cells and myocytes also demonstrated new neuromuscular junctions by immunofluorescence. CONCLUSIONS: Transplanted motor neuron progenitors prevent muscle atrophy after denervation for a brief time. These progenitor cell transplants appear to form new neuromuscular junctions with denervated muscle fibers in vivo and with myocytes in vitro.