Identification of KIF21A mutations as a rare cause of congenital fibrosis of the extraocular muscles type 3 (CFEOM3).

PURPOSE. Three congenital fibrosis of the extraocular muscles phenotypes (CFEOM1-3) have been identified. Each represents a specific form of paralytic strabismus characterized by congenital restrictive ophthalmoplegia, often with accompanying ptosis. It has been demonstrated that CFEOM1 results from mutations in KIF21A and CFEOM2 from mutations in PHOX2A. This study was conducted to determine the incidence of KIF21A and PHOX2A mutations among individuals with the third CFEOM phenotype, CFEOM3. METHODS. All pedigrees and sporadic individuals with CFEOM3 in the authors' database were identified, whether the pedigrees were linked or consistent with linkage to the FEOM1, FEOM2, and/or FEOM3 loci was determined, and the appropriate pedigrees and the sporadic individuals were screened for mutations in KIF21A and PHOX2A. RESULTS. Twelve CFEOM3 pedigrees and 10 CFEOM3 sporadic individuals were identified in the database. The structures of eight of the pedigrees permitted the generation of meaningful linkage data. KIF21A was screened in 17 probands, and mutations were identified in two CFEOM3 pedigrees. One pedigree harbored a novel mutation (2841G-->A, M947I) and one harbored the most common and recurrent of the CFEOM1 mutations identified previously (2860C-->T, R954W). None of CFEOM3 pedigrees or sporadic individuals harbored mutations in PHOX2A. CONCLUSIONS. The results demonstrate that KIF21A mutations are a rare cause of CFEOM3 and that KIF21A mutations can be nonpenetrant. Although KIF21A is the first gene to be associated with CFEOM3, the results imply that mutations in the unidentified FEOM3 gene are the more common cause of this phenotype

Superior Oblique Surgery: When And How?

Background The purpose of this paper is to review different types of superior oblique muscle surgeries, to describe the main areas in clinical practice where superior oblique surgery is required or preferred, and to discuss the preferred types of superior oblique surgery with respect to their clinical outcomes. Methods A consecutive nonrandomized retrospective series of patients who had undergone superior oblique muscle surgery as a single procedure were enrolled in the study. The diagnosis, clinical features, preoperative and postoperative vertical deviations in primary position, type of surgery, complications, and clinical outcomes were reviewed. The primary outcome measures were the type of strabismus and the type of superior oblique muscle surgery. The secondary outcome measure was the results of the surgeries. Results The review identified 40 (20 male, 20 female) patients with a median age of 6 (2–45) years. Nineteen patients (47.5%) had Brown syndrome, eleven (27.5%) had fourth nerve palsy, and ten (25.0%) had horizontal deviations with A pattern. The most commonly performed surgery was superior oblique tenotomy in 29 (72.5%) patients followed by superior oblique tuck in eleven (27.5%) patients. The amount of vertical deviation in the fourth nerve palsy and Brown syndrome groups (P = 0.01 for both) and the amount of A pattern in the A pattern group were significantly reduced postoperatively (P = 0.02). Conclusion Surgery for the superior oblique muscle requires experience and appropriate preoperative evaluation in view of its challenging nature. The main indications are Brown syndrome, fourth nerve palsy, and A pattern deviations. Superior oblique surgery may be effective in terms of pattern collapse and correction of vertical deviations in primary position.PubMe

Inferior Oblique Muscle Weakening: Is It Possible To Quantify Its Effects On Horizontal Deviations?

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 (1–49). 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 (p = 0.001 for all). The median amount of correction of horizontal near and distance deviations was 4Δ (0–20). 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.PubMedWoSScopu

Clinical Risk Factors For The Development Of Consecutive Exotropia: A Comparative Clinical Study

AIM: To compare a group of patients with consecutive exotropia with patients who had <= 10 prism diopters (PD) esotropia or no deviation postoperatively in terms of probable clinical risk factors for the development of consecutive exotropia. METHODS: The study recruited fourteen patients who developed consecutive exodeviation during follow-up period after the correction of esotropia who were categorized as group 1 and thirty-one patients who had still PD esotropia or no deviation at the final visit that were considered as group 2. Clinical risk factors leading the development of consecutive deviation were analyzed as the main outcome measures. RESULTS: The mean age of patients was 4.57 +/- 3.11y in group 1 and 5.10 3 +/- 52y in group 2 (P=0.634). There was no significant difference of preoperative near and distant deviations among two groups (P=0.835, 0.928 respectively). The mean amount of medial rectus recession and lateral rectus resection was similar in both groups (P =0.412, 0.648 respectively). Convergence insufficiency and neurological diseases were more frequent in group 1 (P=0.007, 0.045). Accompanying neurological disease was found to be as a significant factor increasing the risk of the development of consecutive exotropia significantly [odds ratios (OR): 5.75 (1.04-31.93)]. CONCLUSION: Accompanying neurological disease appears to be a significant clinical risk factor for the development of consecutive exodeviation during postoperative follow-up after the correction of esotropia. However, larger studies are needed in order to interpret the results to the clinical practice and to ascertain other concurrent risk factors.WoSScopu

Factors Influencing Success And Dose-Effect Relation Of Botulinum A Treatment

Botulinum toxin type A (BTA) treatment is an alternative to strabismus surgery. In this retrospective study the data on 45 esotropic and 49 exotropic patients with concomitant strabismus who were treated with BTA were analysed for dose-effect relationship, the effect of repeat doses and amblyopia on success of botulinum treatment, The esotropic patients were treated with a total of 80 and exotropic patients with 91 injections, The deviations were corrected within 5 degrees of straight in 33% of esotropic and 18% of exotropic patients. In esotropic patients the effect was dose dependent, This relation was not shown in exotropic patients, The repeat doses of BTA corrected the deviation to the same extent as the primary ones for both esotropic and exotropic patients.WoSScopu