Congenital cataract is a challenging ophthalmological disorder which can cause severe visual loss. It can be diagnosed at birth or during the first year of life. Early diagnosis and treatment are crucial for the visual prognosis. It can be associated with various ocular and systemic abnormalities. Determining whether congenital cataract is isolated or associated with other pathology is an indispensable step for the prediction of potential vision as well as early diagnosis and treatment of conditions that can cause morbidity or mortality. Many genes have been identified in the molecular etiology of congenital cataract. Most mutations have been reported in the crystallin genes. Determination of the genetic cause may not only enable individualized genetic counseling but also help to identify concomitant ocular and/or systemic disorders depending on the characteristics of the genetic test used. Recently, next-generation sequencing in particular has become an evolving technology for determining the molecular etiology of congenital cataract and furthering our knowledge of the disease.

Objective. To evaluate and quantify the effect of inferior oblique muscle weakening on horizontal deviations. Methods. The medical files of patients who had undergone an inferior oblique weakening as a single procedure were all reviewed. The main measures were the type of inferior oblique overaction (IOOA), pre- and postoperative amount of IOOA, and horizontal deviations in primary position. Results. The study was conducted with 66 patients (30 males, 36 females). The median age was 11 years (149). Of the 66 patients, 30 (45.5%) had primary and 36 (54.5%) had secondary IOOA. The most common procedure was inferior oblique anteriorization in 32 patients (48.5%). The mean postoperative horizontal and vertical deviations and the amount of IOOA were decreased postoperatively ( for all). The median amount of correction of horizontal near and distance deviations was (020). The preoperative amount of IOOA, the presence of fourth nerve palsy, and the type of the weakening procedure had no significant effect on the amount of correction of horizontal deviations. Conclusion. The inferior oblique weakening procedures have secondary effects and warrant reduction of horizontal deviations in varying degrees. This should be borne in mind in planning a simultaneous horizontal muscle surgery and setting the surgical amount.

To investigate the ultrastructural changes of the rabbit retina induced by intravitreal methotrexate injection. Ten New Zealand white rabbits were enucleated bilaterally at different time periods after intravitreal methotrexate injection. One rabbit was used as control group and one rabbit was used as intact group. Histopathological examinations were performed under light and electron microscopy. Early (within first three days after injection) and long-term (one month after serial injections) effects of intravitreal methotrexate on the retina were investigated. Retinal edema, vacuolization, and disintegration of mitochondria of the retinal cells were observed as early changes. The main long-term effects after serial injections were edema in the photoreceptor, inner nuclear, and ganglionic cell layers. Cellular disorganisation was seen on light microscopy. Electron microscopic examination revealed mitochondrial degeneration and vacuole formation in retinal cells, nuclear degeneration in outer nuclear layer, and membranous whorl formation in photoreceptor and nerve fiber layers. High dose intravitreal methotrexate injection may cause significant ultrastructural changes in the rabbit retina in varying severity. This finding may highlight the potential side effects of methotrexate on human retina in higher doses.

Purpose To report and to analyze the efficacy of horizontal rectus muscle transposition and inferior oblique muscle weakening in terms of pattern correction for patients with V pattern. Methods The review of the medical files identified 55 patients who had esotropia (ET) or exotropia (XT) with V pattern. The primary outcome measure was the amount of V pattern collapse (Δ). Results Of the 55 patients (mean age 22.1±9.5 years), 27 (49.1%) were males and 28 (50.9%) were females. The type of deviations was XT in 30 patients (54.5%) and ET in 25 patients (45.5%). Inferior oblique muscle weakening was performed in 43 (78.2%) patients, whereas horizontal muscle transposition was carried out in 12 (21.8%) patients in addition to recession-resection procedures. The amount of pattern was significantly reduced in both groups (P=0.01 for the horizontal offset group and P<0.01 for the oblique muscle weakening group). Conclusion Oblique muscle weakening surgery and horizontal muscle offset are effective in the correction of V pattern when the amount of pattern is under 30Δ.