Modified horizontal muscle transposition without tenotomy and splitting for a case of inferior rectus and inferior oblique muscles aplasia with hemifacial microsomia.

Aplasia of the inferior rectus and inferior oblique muscles is extremely rare. Failure of the normal embryologic development of the inferior mesodermal complex can lead to agenesis of inferior rectus, inferior oblique, and lower sections of the lateral rectus muscles. This rare condition is usually seen in association with craniofacial syndromes or in conjunction with microcornea, microphthalmos, Axenfeld-Rieger syndrome, and coloboma. The usual treatment for this condition is a reverse Knapp procedure to improve the vertical alignment; however, this procedure can lead to complications, such as anterior segment ischemia, undercorrection, and torsional problems. To our knowledge, unilateral inferior rectus and inferior oblique muscle aplasia has not been described previously in a patient with congenital facial nerve palsy and optic nerve hypoplasia. In the present case, the patient was successfully treated with a modified minimally invasive horizontal rectus muscle transposition procedure.

Predicted vs measured posterior corneal astigmatism for toric intraocular lens calculations.

PURPOSE: To evaluate the astigmatic correction obtained with a toric intraocular lens using the keratometric readings (Ks) from a swept-source optical coherence tomography (SS-OCT) biometer and the Barrett toric formula with its predicted posterior corneal astigmatism (PCA) value and to compare the results with those expected by using the OCT Ks and a measured PCA from a scheimpflug topographer and by using the SimKs and the measured PCA from the Scheimpflug topographer. SETTING: Private practice, Lynwood, California. DESIGN: Retrospective observational study. METHODS: All measurements were performed by the SS-OCT biometer and the Scheimpflug topographer and using the Barrett toric formula. RESULTS: We evaluated 122 eyes of 122 patients. The mean absolute errors in predicted residual astigmatism for the entire series were 0.41 ± 0.19 diopters (D) (0.00 to 0.85 D) using the OCT Ks and predicted PCA, 0.45 ± 0.25 D (0.00 to 1.01 D) using the OCT Ks and measured PCA, and 0.49 ± 0.25 D (0.00 to 1.30 D) using the SimKs and measured PCA. The statistically significant differences between the errors had a P value of .062 for the entire series (n = 122), .26 for the subgroup with against-the-rule astigmatism (n = 68), .47 for the subgroup with oblique astigmatism (n = 11), and .05 for the subgroup with with-the-rule astigmatism (n = 43). The percentage of eyes within ±0.50 D were 74% (n = 90), 71% (n = 87) and 64% (n = 78) (P = .13) and within ±0.75 D were 99% (n = 121), 95% (n = 116) and 84% (n = 102) (P < .001), respectively. CONCLUSIONS: The Barrett toric formula and its predicted PCA performed better with the OCT K readings than with the topographer SimKs and a measured PCA.