The relative timing of trunk muscle activation is retained in response to unanticipated postural-perturbations during acute low back pain.

The purpose of this study was to assess the activation of the erector spinae (ES) and external oblique (EO) in response to unanticipated, bi-directional postural perturbations before and after the induction of acute low back pain (LBP) in healthy individuals. An experimental session consisted of a baseline, control, and an acute LBP condition. For the control and acute LBP condition, isotonic or hypertonic saline (HS), respectively, was injected into the right ES muscle. In each condition, participants stood on a moveable platform during which 32 randomized postural perturbations (8 repetitions of 4 perturbation types: 8 cm anterior slides, 8 cm posterior slides, 10° anterior tilts, and 10° posterior tilts) with varying inter-perturbation time intervals were performed over a period of 4-5 min. Bilateral surface electromyography (EMG) was recorded from the ES and EO in addition to subjective pain records. During the acute LBP condition: (1) the onset time of the ES and EO was delayed for the forward and backward sliding perturbations (P < 0.05); (2) EMG amplitude was reduced bilaterally for all perturbations (P < 0.05); (3) the order of activation and interval between the onset times of the ES and EO were unaltered and (4) ES, but not EO, activity was adjusted to account for the directional differences between the perturbations. This study revealed that re-establishment of posture and balance was a result of the individuals' ability to rapidly modulate ES with respect to EO activity and that the bi-directional postural responses, although shifted in time and amplitude, retained temporal features in the presence of acute LBP.

Microscopically controlled excision of conjunctival squamous cell carcinoma.

Although surgical excision, with or without adjunctive cryotherapy, is an accepted method of managing conjunctival squamous cell carcinoma, histologically verified tumor-free surgical margins cannot be assured by excision alone. We used a tissue conservation method, an adaptation of the Mohs' micrographic technique for cutaneous tumors, to monitor the conjunctival tissue margins by histologic review at initial tumor excision. We treated 19 patients with squamous cell carcinoma of the conjunctiva by this technique. Lamellar sclerectomy was used if the deep tissue margin was positive for residual tumor cell after the first stage review. Adjunctive cryotherapy was utilized in one patient because the deep scleral margin remained positive after lamellar sclerectomy, and further excision was not possible. In all patients, the tumor-free conjunctival defect was allowed to heal by secondary intention. During six months to 60 months of follow-up, no recurrences were documented. The only complication encountered was conjunctival scarring with secondary restricted motility in one patient. We believe this method of tissue margin surveillance offers a high cure rate for the treatment of conjunctival squamous cell carcinoma.

Surgical correction of lower-eyelid tarsal ectropion by reinsertion of the retractors.

Lower-eyelid tarsal ectropion is an unusual form of eyelid malposition in which the entire lid is everted. The cause is most likely the disinsertion of the lower-eyelid retractors. In 12 eyelids of six patients, a transconjunctival approach was used to reunite the retractors with the inferior tarsal border. In eight eyelids, a horizontal tightening procedure was also needed. The looping passage of fornix sutures through the full thickness of the eyelid created a vector force that helped rotate the lid margin inward. The subsequent formation of an inflammatory cicatrix induced by the absorbable sutures also contributed to maintain the lid in an upright posture. During follow-up periods ranging from 8 to 36 months, there were no instances of overinversion, recurrent ectropion, or suture abscess.

Ophthalmic complications of sinus surgery.

Seven patients with orbital complications of sinus surgery seen over a 10-year period are reported. Severe intraoperative orbital hemorrhage occurred in three patients while undergoing external or intranasal ethmoidectomy. In one patient, an avulsed anterior ethmoidal artery was identified as the source of bleeding, whereas in two others bleeding was due to snaring of orbital tissues. In two of these three cases, intraoperative recognition and prompt treatment of the expanding hematoma resulted in preservation of vision. Motility disturbances due to extraocular muscle injury occurred in two patients after intranasal ethmoidectomy and in one patient after a Caldwell-Luc procedure. Bilateral blindness resulted from transection of both optic nerves in one patient during bilateral intranasal endoscopic ethmoidectomies. Recommendations for prevention, intraoperative recognition, and management of such ophthalmic complications of sinus surgery are given.

Management of subluxated and posteriorly dislocated intraocular lenses using pars plana vitrectomy instrumentation.

Thirty-four patients with subluxated and posteriorly dislocated intraocular lenses (IOLs) had repositioning, replacement, or removal of the IOL using pars plana instrumentation. Of the 25 cases posteriorly dislocated into the formed vitreous, ten posterior chamber IOLs were repositioned into the ciliary sulcus, one anterior chamber IOL was repositioned into the anterior chamber angle, and eight posterior chamber IOLs were exchanged for anterior chamber IOLs through a limbal incision. In the remaining six cases, the IOL was removed but was not replaced because of concurrent ocular pathology. In nine cases with subluxation of an anterior chamber IOL into a large basal iridectomy, a pars plana approach after vitrectomy was used for repositioning the IOL into the anterior chamber angle. Complications included each of the following: intraoperative retinal dialysis, postoperative extension of a pre-existing subclinical retinal detachment, recurrent subluxation of an anterior chamber IOL, breakdown of chronic cystoid macular edema to form a macular hole, and pseudophakic pupillary block requiring laser iridotomy.

Peripapillary crescents and halos in normal-tension glaucoma and ocular hypertension.

In normal-tension glaucoma ("low-tension" glaucoma), 21 of 33 eyes (64%) had a peripapillary chorioscleral crescent or halo, compared with 13 of 38 eyes (34%) with ocular hypertension. The average area of bared choroid and sclera was greater in normal-tension glaucoma (5.8 arbitrary units of area) than in ocular hypertension (1.4 units). Myopic eyes were prevalent among the normal-tension glaucoma group. When eyes with more than 4 diopters (D) of myopia were excluded from the analysis, the difference in prevalence and size of chorioscleral crescents and halos remained. Thus, the presence of a crescent correlates with disc damage, but further work is needed to determine if the correlation represents peripapillary atrophy that accompanies glaucomatous nerve atrophy or represents a greater susceptibility of discs with preexisting peripapillary abnormality.

Lymphogranuloma venereum conjunctivitis with a marginal corneal perforation.

The authors have recently treated a case of Parinaud's oculoglandular syndrome due to Chlamydia trachomatis serotype L2, a causative agent of lymphogranuloma venereum (LGV). The ocular manifestations included a mixed papillary-follicular conjunctivitis with fleshy superior limbal lesions in both eyes. A superior marginal corneal perforation requiring a therapeutic corneal graft was present in the right eye. The patient had vaginitis, inguinal lymphadenopathy, a history of Sjögren's syndrome, and seropositivity to human immunodeficiency virus (HIV). The ocular disease resolved completely after 6 weeks of oral tetracycline therapy.