Autogenous Fascia Lata Graft Fixation to Treat Exotropia Resulting From Iatrogenic Medial Rectus Transection.

PURPOSE: To describe autogenous fascia lata graft fixation as a novel method to treat exotropia related to medial rectus (MR) muscle injury following functional endoscopic sinus surgery. METHODS: Three consecutive patients with MR transection and exotropia after functional endoscopic sinus surgery were selected. Preoperative examination was performed; no MR function was noted for over 3 months after injury. CT and dynamic functional MRI were performed, where MR transection and medial wall breach were noted. An autogenous fascia lata graft was harvested and fixated from the remaining periosteum of the posterior-most extent of the medial orbital wall and attached to the globe at the MR insertion. In addition, an ipsilateral lateral rectus muscle recession was performed. RESULTS: Alignment of the eyes in primary gaze and downgaze was achieved and remained so at the 3-month postoperative examinations, with minimal head turn or prism correction (<5 prism diopters) necessary to control diplopia. Two patients required recession of the fascial graft for a minor overcorrection and have remained stable for over 6 months. CONCLUSIONS: Severe exotropia secondary to MR damage following functional endoscopic sinus surgery is a known complication historically difficult to treat. Traditional surgical methods, including vertical muscle transposition, commonly result in complete recurrence of exotropia and increase risk of anterior ocular ischemia. Unlike simple nonabsorbable suture fixation, fascial grafts are completely biointegratable, do not result in significant inflammation, and are unlikely to rupture. Fascia lata graft fixation of the MR to the posterior orbital medial wall is a new and successful method to eliminate exotropia after MR injury.

Radiation-induced ocular motor cranial nerve palsies in patients with pituitary tumor.

BACKGROUND: Radiation therapy is often used in the treatment of pituitary tumor. Diplopia due to radiation damage to the ocular motor cranial nerves has been infrequently reported as a complication in this clinical setting. METHODS: Retrospective case series of 6 patients (3 men and 3 women) with pituitary adenoma, all of whom developed diplopia following transsphenoidal resection of pituitary adenoma with subsequent radiation therapy. None had evidence of tumor involvement of the cavernous sinus. RESULTS: Five patients developed sixth nerve palsies, 3 unilateral and 2 bilateral, and in 1 patient, a sixth nerve palsy was preceded by a fourth cranial nerve palsy. One patient developed third nerve palsy. Five of the 6 patients had a growth hormone-secreting pituitary tumor with acromegaly. Following transsphenoidal surgery in all 6 patients (2 had 2 surgeries), 4 had 2 radiation treatments consisting of either radiosurgery (2 patients) or external beam radiation followed by radiosurgery (2 patients). CONCLUSIONS: Patients with pituitary tumors treated multiple times with various forms of radiation therapy are at risk to sustain ocular motor cranial nerve injury. The prevalence of acromegalic patients in this study reflects an aggressive attempt to salvage patients with recalcitrant growth hormone elevation and may place the patient at a greater risk for ocular motor cranial nerve damage.

Effect of pulsed electromagnetic fields (PEMF) on late-phase osteotomy gap healing in a canine tibial model.

The effects of a pulsed electromagnetic field (PEMF) on late bone healing phases using an osteotomy gap model in the canine mid-tibia were investigated. A transverse mid-diaphyseal tibial osteotomy with a 2-mm gap was performed unilaterally in 12 adult mixed-breed dogs and stabilized with external fixation. Animals in the variable group (n = 6) were treated with PEMF for 1 h daily starting 4 weeks after surgery for a total of 8 weeks, whereas no stimulation signal was generated in the control group (n = 6). Functional load-bearing and radiographic assessments were conducted time-sequentially until euthanasia 12 weeks after surgery. Torsional tests and an analysis of undecalcified histology were performed on the retrieved mid-tibial diaphysis containing the osteotomy site. In the PEMF group, load-bearing of the operated limb recovered earlier when compared to the control group (p < 0.05). Load-bearing in the PEMF group at 8 weeks was greater than in the control group (p < 0.02). The periosteal callus area increased following surgery at 6 weeks (p < 0.05) and thereafter (p < 0.01) in the PEMF group, while a significant increase was observed at 8 and 10 weeks after surgery (p < 0.05) in the control group. Both the normalized maximum torque and torsional stiffness of the PEMF group were significantly greater than those of the control group (p < 0.04 and p < 0.007, respectively). Histomorphometric analyses revealed greater new-bone formation (p < 0.05) in the osteotomy gap tissue and increased mineral apposition rate (p < 0.04) and decreased porosity in the cortex adjacent to the osteotomy line (p < 0.02) in the PEMF group. PEMF stimulation of 1 h per day for 8 weeks provided faster recovery of load-bearing, a significant increase in new bone formation, and a higher mechanical strength of the healing mid-tibial osteotomy. This study revealed enhancing effects of PEMF on callus formation and maturation in the late-phase of bone healing.

The effect of recombinant human osteogenic protein-1 (bone morphogenetic protein-7) impregnation on allografts in a canine intercalary bone defect.

The utility of cortical allografts in repairing large bone defects is limited by their slow and incomplete incorporation into host bone. In order to determine the effects of recombinant human osteogenic protein-1 (rhOP-1) impregnation on allograft incorporation, we used a canine intercalary bone defect model. Bilateral resection of a 4 cm segment of the femoral diaphysis and reconstruction with structural bone allografts were performed. In one limb, the allograft was soaked in solution with rhOP-1 for 1 h before implantation. In the other limb, the allograft was soaked in the same solution without rhOP-1. Dynamic load-bearing, radiographic analysis, biomechanical testing, and histomorphometric analysis were conducted. Radiographic analysis showed significantly larger periosteal callus area in the rhOP-1 treated group at week 2. The rhOP-1 significantly increased allograft bone porosity and significantly increased the number of active osteons in the allografts. There were no significant differences between the rhOP-1 treated and non-treated allografts in load bearing and biomechanical analyses. These findings indicate that rhOP- I increases intercalary allograft remodeling without deleterious effects in mechanical and functional strength.

Bilateral canalicular and nasolacrimal duct obstruction in congenital erosive and vesicular dermatosis: a case report and review of the literature.

We report the ocular findings in a 2.5-year-old girl with a history of congenital erosive and vesicular dermatosis at birth. We highlight the complexity of the associated nasolacrimal duct obstruction with canalicular scarring and review the ocular manifestations of this rare disease.

Postoperative outcomes of patients initially overcorrected for intermittent exotropia.

BACKGROUND: Esotropic overcorrection on postoperative day 1 after surgery for intermittent exotropia is generally thought to increase the likelihood of long-term satisfactory alignment; however, it is unclear why some patients who are initially overcorrected demonstrate recurrent intermittent exotropia whereas others maintain esotropic to orthotropic alignment. METHODS: The records of all patients who underwent primary surgical correction of intermittent exotropia were reviewed; those with any degree of esotropia on postoperative day 1 were included. The status at the last visit was categorized as orthotropic to <8(Δ) exotropia or having recurrent exotropia >8(Δ), monofixational esotropia <10(Δ), or esotropia >10(Δ). RESULTS: A total of 63 patients met the inclusion criteria. The mean postoperative day 1 alignment was 6(Δ) ± 3(Δ) esotropia at distance and 5(Δ) ± 3(Δ) esotropia at near. At the last visit, 31 (49%) were orthotropic to <8(Δ) exotropia, 26 (41%) had recurrence of exotropia >8(Δ), and 6 (10%) had monofixational esotropia <10(Δ). There was no significant difference between outcome groups in onset age, age at surgery, stereopsis, deviation (preoperatively or on postoperative day 1), or follow-up length. Risk factor analysis revealed no association between exotropia type, surgical approach, or postoperative day 1 alignment and risk of recurrent intermittent exotropia or monofixational esotropia, although there was a trend toward recurrent intermittent exotropia in those least overcorrected. CONCLUSIONS: Recommended overcorrection on postoperative day 1 for intermittent exotropia can result in esotropia, intermittent exotropia, or orthotropia. The results of overcorrection for exotropia are variable and unpredictable. We were unable to determine associations with the recurrence of exotropia or secondary esotropia.

New corticosteroid-eluting porous polyethylene implant for the management of lower eyelid retraction: a pilot study.

PURPOSE: Lower eyelid retraction after trauma presents a challenging management problem. We postulated that a porous polyethylene (pPE) eyelid spacer coated with a polyvinyl alcohol (PVA) and triamcinolone acetonide (TA) matrix could deliver corticosteroid locally over extended periods and modulate inflammation and scar formation. We designed a pPE corticosteroid-eluting implant and evaluated its characteristics in vitro and in vivo. METHODS: The release characteristics of pPE implants coated with a PVA/TA matrix of low, intermediate, and high doses of TA were studied in vitro. The implants were then placed in the posterior lamella of lower eyelids of Dutch Belted rabbits for 12 weeks. Clinical events were recorded and eyelids were examined for gross and histologic features, including capsular thickness and degree of vascularity, fibrovascular ingrowth, and inflammatory response. RESULTS: In vitro, implants coated with the intermediate and high doses of TA released the drug at a steady rate for at least 78 days. In rabbits, the PVA and PVA/TA coating prevented fibrovascular ingrowth, except where breaks in the PVA/TA coat were present. Implants with PVA/TA coating demonstrated less inflammation and capsule vascularity. An inverse correlation between TA dose and capsule thickness was noted. CONCLUSIONS: We describe a novel drug-release pPE eyelid implant. The corticosteroid-eluting implant demonstrated antiangiogenic and anti-inflammatory properties, which could prove beneficial in the treatment of lower eyelid retraction.