Controlled trial of hyperbaric oxygen treatment for alkali corneal burn in the rabbit

Purpose: To evaluate the efficacy of hyperbaric oxygen therapy in the treatment of alkali-induced corneal burns in an animal model. Methods: Twenty-four rabbits were randomized into a control group (n = 12) and hyperbaric oxygen treatment group (n = 12). After induction of anaesthesia, the alkali burn model was established by application of 1 N sodium hydroxide to one eye of each rabbit. The hyperbaric oxygen treatment group was treated each day for 21 days with hyperbaric oxygen at 2.4 Atmospheres Absolute (ATA) for 1 h. The eyes of the animals were examined daily for 2 weeks and then weekly until the end of the trial. The principal endpoint was that of perforation of the cornea at which time the animals were killed with a lethal dose of either intravenous or intraperitoneal barbiturate and the eyes immediately enucleated and fixed in 10% neutral buffered formalin. All animals in which complete healing took placed were also killed, the eyes removed, fixed and examined histologically. Photographs were taken of the rabbit's eyes at weekly intervals and the area of vascularization and epithelial defects in the hyperbaric and control groups were compared. Results: Equal numbers (seven) of the control and hyperbaric oxygen treated groups had perforated corneas and there was no statistical difference in the mean time to perforation (control 30.1 days; treated 30 days). There was also no statistical difference between the two groups with respect to epithelial defect size. Conclusion: Treatment with hyperbaric oxygen for 1 h daily for 21 days had no beneficial effect on alkali-induced corneal burns.

Partial Jensen's procedure for the treatment of myopic strabismus fixus

Myopic strabismus fixus (MSF) is a rare strabismus entity of uncertain etiology. The most recent explanation of etiology was provided by Yokoyama et al,(1) who noted that the enlarged globe in high myopia herniates superotemporally and retroequatorially through the muscle cone. In a typical case, the eye is fixed in depression and adduction. We report the use of a partial Jensen's procedure (superior arm only) for the treatment of MSF.

Primary trabeculodysgenesis in association with neonatal Marfan syndrome

We present the clinical and ophthalmological findings in two infants with neonatal Marfan syndrome (nMFS) and primary trabeculodysgenesis (PT). Fibrillin 1 (FBN1) mutations were confirmed in both cases. Numerous eye anomalies have been recognized in infants with nMFS, but PT has not been reported previously. Our report expands the phenotype of nMFS, and highlights the importance of early and careful ophthalmological assessment of these infants. (C) 2004 Wiley-Liss, Inc.

Panoptic versus conventional ophthalmoscope

Background: The 'ease of use' andaccuracy in measurement of the vertical optic cup/discratio (VCDR) was compared between the conventional direct ophthalmoscope(CO) and Panoptic direct ophthalmoscope (PO) in a group of 'naive' firstyear medical students to determine which would be more suitablefor non-ophthalmologists. Methods: In this quasi-randomized method comparison study,eight students received an introductory session on ophthalmoscopythen examined 18 eyes (9 left, 9 right) with each ophthalmoscopein a private practice. The subjects were the eight students themselvesplus two other subjects. Each subject (n = 10)had one eye dilated. Students determined a VCDR and a subjectivescore of 'ease of use' on a scale of 1 (difficult)to 10 (easy). A consultant ophthalmologist (GAG) determined thebenchmark VCDR for each eye with each ophthalmoscope. Results: Of 288 eye examinations, there were 111 measure-ments of VCDR using the CO (47 undilated, 64dilated), and 140 measurements using the PO (75 undilated, 65 dilated).Differences in the students' estimated VCDR and the benchmarkwere similar for the CO and PO (P = 0.67). 'Easeof use' was scored in 288 eyes and the median score washigher in the PO overall (CO: median 8, IQR 6-9; PO median9, IQR 8-10; P < 0.0001), andwithin each session (P < 0.0001 foreach session). Conclusions: Medical students found the PO mucheasier to use, with accuracy of rating the VCDR similar to the CO. Thiscomparison would support the wider use of the PO amongst medicalstudents, general practitioners and other primary care providers.

Psilocybin impairs high-level but not low-level motion perception

The hallucinogenic serotonin(IA&2A) agonist psilocybin is known for its ability to induce illusions of motion in otherwise stationary objects or textured surfaces. This study investigated the effect of psilocybin on local and global motion processing in nine human volunteers. Using a forced choice direction of motion discrimination task we show that psilocybin selectively impairs coherence sensitivity for random dot patterns, likely mediated by high-level global motion detectors, but not contrast sensitivity for drifting gratings, believed to be mediated by low-level detectors. These results are in line with those observed within schizophrenic populations and are discussed in respect to the proposition that psilocybin may provide a model to investigate clinical psychosis and the pharmacological underpinnings of visual perception in normal populations.

The surgical management of consecutive exotropia

Purpose: To review the results and techniques of surgical treatment of consecutive exotropia. Methods: We performed a retrospective chart review of all patients who underwent surgery for consecutive exotropia in a pediatric ophthalmology practice between 1992 and 2001. Patients were excluded if follow-up lasted < 6 weeks or if exotropia was caused by other ocular disorders such as previous trauma or congenital cataracts. Results: Fifty-nine patients were identified. The procedure performed in the majority of cases was unilateral lateral rectus recession and medial rectus advancement to the original insertion. Seven patients underwent bilateral lateral rectus recession, and 6 underwent lateral rectus recession combined with medial rectus resection. The mean interval between original surgery and surgery for consecutive exotropia was 14.1 years (range 4 months to 47.5 years). The mean preoperative distance exodeviation was 31.7 prism diopters (PD). Satisfactory alignment lie, within 10 PD of orthophoria) was achieved in 36 patients (61%) at week 1 and 42 patients (71%) at final follow-up. Mean follow up was 16.0 months. Thirty-nine patients (66%) demonstrated an exodrift after surgery (mean 7.6 PD). Conclusion: Consecutive exotropia may occur many years, even decades, after esotropia surgery. Lateral rectus recession with advancement of the previously recessed medial rectus is an effective treatment. An exotropic drift occurs after consecutive exotropia surgery, usually within the first 6 weeks. A suitable ocular alignment immediately after surgery for consecutive exotropia is a small-angle esotropia of 5 to 10 PD.

Medial upper eyelid shortening to correct medial eyelid laxity in floppy eyelid syndrome: A new surgical approach

Purpose: To describe and present the results of a new surgical technique for patients with floppy eyelid syndrome, based on the medial upper eyelid stretching encountered in this condition. Methods: A case series of 24 patients with floppy eyelid syndrome who where found to have symptomatic predominately medial upper eyelid laxity was analyzed. The history, clinical features, histopathology, and outcome were reviewed after patients underwent medial upper eyelid shortening with or without upper eyelid skin reduction as the first surgical procedure. Results: Of the 24 patients, 18 were men (75%) with a mean age at referral of 56 years, having ocular discomfort and conjunctival irritation/papillary conjunctivitis as the main complaints at presentation. Obesity was present in 96% of cases, with lower eyelid laxityl/ectropion (50%) and upper eyelid eyelash ptosis (29%) in conjunction with the upper eyelid laxity. The affected side was related to sleeping habits or recurrent mechanical eyelid trauma. Histologic studies showed a nonspecific inflammatory cell infiltrate and loss of elastin with loose dermal connective tissue. After surgery, complete relief of ocular symptoms and good functional and cosmetic results were present in all cases after 18 months of follow-up. Conclusions: This new surgical approach is based on the presence of predominately medial upper laxity in patients with floppy eyelid syndrome. The excision of this stretched area stabilized the upper eyelid in an anatomic fashion, providing a good and stable long-term result. The possible mechanisms involved in the medial upper eyelid stretching are discussed.

Amblyopia due to inflamed chalazion in a 13-month-old infant

Meibomian gland cysts (chalazia) are very common lesions in childhood and are not thought of as visually threatening lesions. A case is reported of dense amblyopia and secondary exotropia resulting from an upper eyelid chalazion.

Pig eye trabeculectomy - a wet-lab teaching model

Purpose A teaching model for trabeculectomy is described using pig eyes prepared in formalin. Method The model enables trainee surgeons to practice various aspects of tissue handling required for successful trabeculectomy including the construction of a fornix-based conjunctival flap, scleral flap with buried releasable sutures, and water-tight conjunctival closure. Results Exposure to the necessary skills required to perform trabeculectomy surgery can be improved by the use of wet laboratory practice. Conclusions Trabeculectomy surgery experience is becoming more limited as fewer procedures are being performed due to the efficacy of recent medications. Wet laboratories will become an increasingly important aspect of a comprehensive ophthalmology training programme.

Prognostic indicators for open globe injury

Background: The purpose of the study is to identify factors predictive of outcome after open globe injury in 273 patients admitted to the Royal Brisbane Hospital, Queensland, Australia between 1992 and 2003. Methods: Data were collected retrospectively regarding demographic and geographical factors, injury circumstances, initial visual acuity (VA), injury parameters, details of initial and subsequent surgery, final best corrected VA and complications. Multivariate analysis using binary logistic regression was utilized to identify which factors were related to outcome. Results: 83% of patients were male, with a mean age of 38.3 years. The mean duration of follow up was 16.6 months and 58% of patients (135 of 231) achieved an overall improvement in their vision. Forty-one cases (15%) were enucleated, with half of these cases performed primarily. The prognostic factors indicating the likelihood of a VA of counting fingers or worse were poor initial VA, a large laceration > 10 mm and the presence of a relative afferent pupil defect. Rural patients had a significantly worse final VA than city dwellers and had higher rates of endophthalmitis and enucleation. Conclusions: Assessment of prognostic factors at the time of presentation of an open globe injury enables realistic expectations of final visual outcome by the doctor and the patient. In order to improve outcomes in patients from rural areas, access to specialized eye services need to be upgraded.

Topical interferon alfa-2b for the treatment of recalcitrant ocular surface squamous neoplasia

center dot PURPOSE: To evaluate topical interferon alfa-2b (IFN-alpha 2b) for the treatment of recalcitrant ocular surface squamous neoplasia (OSSN). center dot DESIGN: Prospective, noncomparative, interventional consecutive case series. center dot METHODS: Ten patients with recalcitrant OSSN were treated with topical IFN-alpha 2b (1 million IU/ml) four times a day until clinical resolution of the lesion or until the lesion appeared nonresponsive-that is, treatment failure. Progress was assessed by clinical examination and photographic records, with a minimum follow,up of six months. center dot RESULTS: Eight of 10 patients achieved clinical resolution from topical IFN-alpha 2b treatment. One patient developed invasive squamous cell carcinoma and underwent exenteration. The other patient required further mitomycin C therapy to achieve clinical resolution. The mean duration to clinical resolution for the eight patients treated with IFN-alpha 2b was 21.9 weeks (range six to 59 weeks). There have been no recurrences for any of the nine patients during follow-up (mean 55.0 weeks; range 26 to 84 weeks). center dot CONCLUSIONS: Topical IFN-alpha 2b is an important treatment modality for recalcitrant OSSN; it avoids the risks of further limbal stem cell destruction from other agents and surgical excision. If invasive disease is diagnosed at any stage, topical therapy is contraindicated, necessitating surgical excision. (Am J Ophthalmol 2006; 142:568-571. (c) 2006 by Elsevier Inc. All rights reserved.)