Milan P. Ranka

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.

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.

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.

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.].