Corneal topographic changes after extraocular muscle surgery.

PURPOSE: Changes in refractive error have been reported after strabismus surgery. The influence of extraocular muscle tension on corneal topography is thought to be an important mechanism contributing to this alteration. This study investigates topographic changes after strabismus surgery in human beings. METHODS: The corneal topography of 63 eyes of 43 patients who underwent either strabismus or optic nerve sheath fenestration (ONSF) surgery was measured before and after operation. The ONSF surgery involved removing and reattaching the medial rectus muscle, thus acting as a control for the strabismus procedures. Corneal power was measured centrally and at 1.5 and 3.0 mm in 8 meridians. Analysis of variance was performed to compare the difference in preoperative and post-operative corneal power for all procedures and comparing recessions, resections, combined recession and resection, and ONSF as grouped procedures. RESULTS: All groups showed a significant change in preoperative to postoperative corneal power (P< .01). A significant change was seen between all grouped procedures except when the resection was compared with ONSF and compared with recession. CONCLUSIONS: Change in the tension of 1 muscle does not produce a change in the adjacent quadrant as much as it produces a significant change in the entire corneal surface, which illustrates the interaction and interdependence all corneal positions have with respect to each other.

Clinical assessment of the piggyback bifocal contact lens system.

PURPOSE: We performed a qualitative and quantitative assessment of contact lens performance at 1 and 6 months among 24 patients enrolled in the Piggyback Bifocal Contact Lens Study. METHODS: We fit 24 presbyopic patients with the Piggyback Bifocal Contact Lens System (i.e., a plano soft lens with a 9.4 mm cutout portion on which a bifocal RGP lens rides or "piggybacks"). Patients were evaluated prior to inclusion in the study and then at one month and six months after obtaining their lenses. Evaluations included slit lamp examination, evaluation of visual acuity at near and distance, and subjective rating of the patients' comfort. RESULTS: At one month, 61% of patients had Snellen acuities of 20/30 or better, 79% had near acuities of J2 or better, and 60% rated their comfort as good or very good. At six months, 100% of patients had Snellen acuities of 20/30 or better, 90% had near acuities of J2 or better, and 86% of patients rated their comfort as good or better. Twelve patients did not complete the study due to their decision to drop the study. CONCLUSIONS: The Piggyback Bifocal Contact Lens System is a well-tolerated, satisfactory means of optical correction for the motivated presbyope.

A quantitative and qualitative assessment of the NOVAWET-Perception bifocal contact lens.

PURPOSE: We prospectively evaluated the NOVAWET-Perception multifocal contact lens for comfort and performance. METHODS: We fit 28 presbyopic patients with this multifocal contact lens. This multifocal rigid gas permeable lens has a multiaspheric back surface and multiple eccentricity values, allowing for a natural field of vision at all angles. Patients were evaluated prior to inclusion in the study and then at 1,3, and 9 months. Evaluations included slit lamp examination, visual acuity, contrast sensitivity, and completion of a questionnaire regarding comfort and overall satisfaction. RESULTS: At the end of the study, 14 of 28 patients (50%) were successfully wearing the NOVAWET-Perception lenses. Of these, 12 (86%) achieved J2 or better near vision and 13 (93%) achieved 20/25 or better distance vision. Fourteen patients failed to complete the study. CONCLUSIONS: We believe the NOVALENS multifocal contact lens is a viable option for the correction of many presbyopic patients.

Intravitreal delivery of ciprofloxacin.

The objective of this work was to evaluate various methods of sustained delivery to achieve therapeutic intravitreal levels of ciprofloxacin as a potential therapy for endophthalmitis. Two types of intravitreal bioerodible sustained release devices of ciprofloxacin were evaluated in vitro. The most promising device was evaluated in rabbits and results compared with subconjunctival injections of a ciprofloxacin suspension. Subconjunctival injections failed to deliver therapeutic concentrations of ciprofloxacin into either the aqueous or vitreous. In vivo evaluation of the intravitreal device consistently delivered ciprofloxacin at levels above 1 ug/ml for up to four weeks. No retinal activity was noted by clinical examination or by electroretinogram. Intravitreal implantation of bioerodible ciprofloxacin devices can maintain vitreous concentrations above 1 ug/ml, more than the MIC90 of most organisms associated with endophthalmitis. Implantation of these devices appears to be well tolerated and may represent a viable treatment for this disease. Further studies in endophthalmitis models are needed to evaluate device efficacy.

Clinical experience with the SimulVue soft bifocal contact lens.

We fit the SimulVue bifocal contact lens, a soft lens with a simultaneous vision design, in 30 presbyopic patients. The lens has a central near correction surrounded by a concentric peripheral distance correction. Patients were evaluated prior to inclusion in the study and followed for a period of 1 year. The evaluation included visual acuity and contrast sensitivity at both distance and near with and without lenses. In addition, patients completed a questionnaire at the end of the study. At the end of 1 year, 16 of 30 (53%) patients were successfully wearing the contact lenses. Of these, 13 of 16 patients (81%) achieved J2 or better near vision, and 10 of 16 (63%) achieved 20/25 or better distance vision in both eyes. Greater reduction of contrast sensitivity occurred at near, with only 38% of patients (6/16) retaining their normal contrast sensitivity; whereas at distance, 81% of patients (13/16) retained normal contrast sensitivity. Fourteen patients failed to complete the study. The most common reasons cited were poor vision at distance (6/14, 43%), poor vision at near (6/14, 43%), and ghosting of images (4/14, 29%). We believe that the SimulVue contact lens is a viable option for the correction of many presbyopic patients.

A quantitative and qualitative assessment of the Solitaire Bifocal Contact Lens.

We performed qualitative and quantitative assessments of contact lens performance at 1 and 6 months among 23 patients enrolled in the Solitaire Bifocal Contact Lens Study. Overall satisfaction and comfort at 6 months was rated good to excellent in 83% and 84% of patients, respectively. Daytime acuity at distance and near were rated very good to excellent in 75% and 83% of subjects. Quantitative measurements of distance and near acuities at 1 month revealed 83% and 88% of subjects, respectively, seeing better than or equal to 20/25 or J1. At 6 months there was a moderate decrease in the measured distance acuity. A disparity in glare disability was noted, with 53% of subjects indicating significant glare problems but only 21% of glare tested patients having acuities worse than 20/40. Attrition from the study was highest in the first month and was more common among first-time contact lens users. Overall, this segmented bifocal contact lens is well-tolerated and provides good distance and near vision for presbyopic patients.

Dermochondral corneal dystrophy (of François).

Dermochondral corneal dystrophy (of François) has been reported rarely in the literature. It consists of a triad of findings characterised by the development of skin nodules, acquired deformities of the extremities, and a corneal dystrophy. The corneal dystrophy is central and superficial with whitish subepithelial opacities. We present two brothers who display previously unreported ocular findings. Specifically, they developed confluent opacification of their central corneas with anterior stromal involvement, and peculiar anterior cortical cataracts. These findings should be added to the spectrum of findings seen in this rare disorder.

Management of uveitis.

The management of uveitis continues to rely on the relatively nonspecific use of topical, periocular, and systemic steroids. A notable exception is infectious causes of uveitis, which often require specific antimicrobial agents. This is particularly true in immunosuppressed patients in whom infectious diseases such as toxoplasmosis and herpes zoster may have atypical and fulminant clinical courses necessitating early therapeutic intervention. Analysis of local antibody production in the aqueous or vitreous humor may aid in the diagnosis. Severe forms of endogenous uveitis such as Behçet's disease have often required the use of nonspecific cytotoxic agents such as chlorambucil or cyclophosphamide. Agents such as cyclosporine and FK-506 are newer immunosuppressives that may have less severe long-term systemic side effects. Chorioretinal biopsy offers an additional tool for the specific etiologic diagnosis of uveitis. The role of posterior chamber lens implantation in patients with a history of uveitis continues to evolve.

Fuchs' superficial marginal keratitis.

We studied three cases of Fuchs' superficial marginal keratitis, an uncommon condition that is characterized by intermittent, recurrent episodes of ocular irritation accompanied by marginal infiltrates and that is followed by progressive marginal superficial stromal thinning. Usually, it has an indolent course with spontaneous remission, and good visual acuity is preserved. In advanced cases, a pseudopterygium develops in the area of marginal thinning. The pseudopterygium encroaches onto the cornea over a period of years, but spares the central cornea. In two of our three cases, the degree of thinning beneath the pseudopterygium became marked. This led to corneal perforation during pseudopterygium excision in one case, and after blunt trauma in the other. These complications indicate the need for special precautions when caring for these patients.

Use of anabolic steroids by athletes. Do the risks outweigh the benefits?

The use of anabolic steroids by both competitive and noncompetitive athletes has reached alarming proportions. Although use is most common in bodybuilders and weight lifters, athletes participating in track and field events and football also take the steroids. The recent resurgence in physical fitness awareness has only exacerbated the problem, and the physician needs to acknowledge the potential for abuse in any athlete. Despite the difficulties and ethical problems in designing good controlled studies with high-dose steroids, evidence suggests that steroids do increase muscular strength in certain subgroups of athletes. Unfortunately, numerous side effects and permanent damage may occur, and the athlete may be at risk for the development of fatal liver tumors or cardiovascular disease.

Magnetic resonance imaging in the evaluation of optic nerve gliomas.

Five patients with optic nerve gliomas were evaluated by magnetic resonance imaging (MRI). Images obtained with MRI were equal to computed tomography (CT) in evaluation of the orbital components of these tumors and superior to CT in evaluating the intracanalicular, chiasmal, and post-chiasmal extension of tumor. MRI is unimpeded by artifacts produced by surrounding bone, as encountered in CT, and also proves to be more sensitive in delineating subtle differences in fat content and hydration of neural tissues. Thus, MRI is extremely valuable in furthering our understanding of the natural and therapeutic response of optic nerve gliomas.