Superior oblique tendon resection or inferior oblique muscle recession in vertical deviations.

This study reports the results on patients undergoing superior oblique (SO) tendon resections with or without inferior oblique (IO) muscle recession to correct vertical deviations. The design of this study was nonrandomized, baseline-controlled, and postsurgical versus presurgical and was performed in a solo practice affiliated with a university ophthalmology department. One hundred ninety-five patients underwent surgery. Patients were evaluated presurgically and postoperatively in the major fields of muscle action. Resections were based on measurements at 14 inches in the field of major function of the SO. The surgical approach was a radial, rather than circumferential, incision extending from the limbus to the tarsus parallel to the lateral border of the superior rectus, followed by resection of the SO tendon. Surgery resulted in improved fusion in 78% of the cases. Average deviation in the left superior oblique field in SO tendon resection only (n = 14) was reduced from 11.0 to 1.7 prism diopters, and fusion improved 85% after treatment. In 181 cases of SO tendon resection or IO recession, the left superior oblique field was reduced from 15.8 to 3.6 diopters. SO tendon resection was successfully utilized to treat underacting SO muscle and vertical deviations. A radial incision facilitated the surgical procedure, and its use is recommended to those performing the surgery.

Rapid estimates of relative water content.

Relative water content may be accurately estimated using the ratio of tissue fresh weight to tissue turgid weight, termed here relative tissue weight. That relative water content and relative tissue weight are linearly related is demonstrated algebraically. The mean value of r(2) for grapevine (Vitis vinifera L. cv. Shiraz) leaf tissue over eight separate sampling occasions was 0.993. Similarly high values were obtained for maize (Zea mays cv. Cornell M-3) (0.998) and apple (Malus sylvestris cv. Northern Spy) (0.997) using a range of leaf ages. The proposal by Downey and Miller (1971. Rapid measurements of relative turgidity in maize (Zea mays L.). New Phytol. 70: 555-560) that relative water content in maize may be estimated from water uptake was also investigated for grapevine leaves; this was found to be a less reliable estimate than that obtained with relative tissue weight. With either method, there is a need for calibration, although this could be achieved for relative tissue weight at least with only a few subsamples.