Evaluation of Barrett universal II formula for intraocular lens power calculation in Asian Indian population

Purpose: Barrett Universal II (BU-II) is considered as one of the most accurate intraocular lens (IOL) power calculation formulas; however, there is no literature studying the same in Indian population. The aim of this study was to evaluate the accuracy of BU-II formula in prediction of IOL power for cataract surgery in Asian Indian population. This was an institutional, prospective, observational study. Methods: Patients with senile cataract who underwent phacoemulsification with posterior chamber IOL implantation were enrolled in the study. Biometry data from Lenstar-LS900 was used and IOL power was calculated using four IOL formulas: modified SRK-II, SRK/T, Olsen, and BU-II. Primary outcome was measured as the prediction error in postoperative refraction for each formula and secondary outcome was measured as the difference in mean absolute errors between the four formulas. SPSS Version-21 with P < 0.05 considered significant. Results: A total of 244 eyes were included in the study and were divided into three groups in accordance to axial length (AL): Group 1 (AL: 22�.5 mm; N = 135), Group 2 (AL <22 mm; N = 53), and Group 3 (AL >24.5 mm; N = 56). BU-II formula gave the lowest mean absolute error (0.37 � 0.27D) and median absolute error (0.34) in predicted postoperative refraction in the entire study population. When compared with the other formulas, mean absolute error was significantly lower in all three groups (P < 0.0005) as well, except for Olsen formula in the normal AL group, where the results were comparable (P = 0.742). Conclusion: BU-II performed as the most accurate formula in the prediction of postoperative refraction over a wide range of ALs.

Bilateral hemorrhagic proptosis due to an uncommon cause in ocular emergency

A 19-year-old male patient presented to the ocular emergency services with sudden onset of proptosis, pain, and bloody discharge. Further evaluation revealed bilateral visual acuity of finger counting close to face vision with an accurate projection of rays. Computed tomography scan of the head and orbit revealed diffuse orbital hemorrhage (mainly along the ocular coats) in the absence of any subperiosteal or intracranial hemorrhage. A complete hematological workup was done and it revealed decreased factor IX levels (9% of normal) consistent with hemophilia B (Christmas disease). The patient was managed medically with factor IX supplementation. At the end of 6 weeks, patient's visual acuity improved to 20/20 in both the eyes.

Ultrasound biomicroscopy image patterns in normal upper eyelid and congenital ptosis in the Indian population

Purpose: To study the features of upper eyelid in healthy individual and different types of congenital ptosis in the Indian population using ultrasound biomicroscopy (UBM). Methods: This was a prospective observational study at a tertiary care center. Eyelid structure of healthy individuals with no eyelid abnormalities (n = 19); simple congenital ptosis (n = 33) cases; Marcus Gunn jaw-winking ptosis (MGJWP, n = 7) cases, and blepharophimosis-ptosis-epicanthus inversus syndrome (BPES, n = 20) cases were studied on a vertical UBM scan using 50-MHz probe. Lid-thickness, tarsal-thickness, orbicularis oculi and levator-Muller-orbital septum-conjunctival (LMSC) complex were measured in primary gaze. Comparison was made between four groups and results were statistically analyzed using ANOVA test. In normal individuals, LMSC measurements were repeated in down-gaze imaging. Results: Skin with subcutaneous tissue, LMSC complex and pre-aponeurotic fat-pad appeared echodense while orbicularis oculi and tarsus appeared echolucent. In primary gaze, mean thickness (± standard deviation) of the eyelid, tarsus, orbicularis oculi and LMSC, respectively, were: 1.612 ± 0.205, 0.907 ± 0.098, 0.336 ± 0.083, and 0.785 ± 0.135 mm in normal individual. LMSC showed 46.64% increase in thickness on down-gaze. The mean eyelid thickness and LMSC were thicker in MGJWP and BPES as compared to normal. In different types of congenital ptosis cases, various patterns of UBM imaging were observed. Conclusion: UBM allows noninvasive imaging of eyelid structures with good anatomical correspondence in normal eyelids and study the structural alterations of eyelids in different types of congenital ptosis. UBM can be used to highlight the anatomical difference in normal eyelids that may help modify the surgery for better cosmetic outcomes. Furthermore, it has the potential to be used in preoperative evaluation and operative planning in certain types of acquired ptosis, which needs to be evaluated.