Magnetic Resonance Imaging Characteristics of a Baerveldt Glaucoma Implant.

PURPOSE: Evaluate for normative postoperative magnetic resonance imaging (MRI) characteristics of a Baerveldt Glaucoma Implant (BGI). DESIGN: Prospective case series. PARTICIPANTS: Seven subjects with uncontrolled glaucoma requiring a primary superotemporal BGI. METHODS: Subjects prospectively underwent sequential MRI orbital scans without contrast at 0 to 2 weeks, 6 to 8 weeks, and 4 to 6 months after implantation of a BGI model 103-250. Masked to the postoperative time course, a radiologist measured bleb and implant characteristics. MAIN OUTCOME MEASURES: Linear measurements of the maximum bleb height at the anterior, middle, and posterior sections of the endplate were measured. Intraocular pressure (IOP) was correlated to bleb height. RESULTS: On axial T2-weighted images, the height of fluid below and above the BGI endplate increased from the initial to the final MRI images: 0.49 mm to 1.83 mm and 0.57 mm to 1.08 mm (middle 1/3), respectively. On coronal T2-weighted images, fluid below and above the BGI endplate increased from 0.47 mm to 1.53 mm and 0.49 mm to 1.38 mm, respectively. Maximum inverse correlation between bleb height and IOP was observed at the 6 to 8 week coronal T2 images (r=-0.963, P=0.002). CONCLUSIONS: Fluid collections and endplate characteristics are easily visualized with MRI. Dynamic changes occur over the early postoperative time course. Bleb height is inversely correlated to IOP at 6 to 8 weeks, but disappears at 4 to 6 months.

Postoperative imaging of the orbital contents.

Ophthalmologists perform a wide array of interventions on the orbital contents. The surgical treatment of glaucoma, cataracts, retinal detachment, and ocular trauma or malignancy results in alteration of the standard anatomy, which is often readily evident at radiologic examinations. The ability to accurately recognize the various imaging manifestations after orbital surgery is critical for radiologists to avoid misdiagnosis. Of particular importance is familiarity with the numerous types of implanted devices, such as glaucoma drainage devices, orbital implants, and eyelid weights. Although knowledge of patients' surgical history is helpful, this information is often not available at the time of interpretation. Fortunately, there are characteristic posttreatment findings that enable diagnosis. The imaging features of the most commonly performed ophthalmologic procedures are highlighted, with emphasis on computed tomography and magnetic resonance (MR) imaging, because they are currently the primary modalities involved in evaluating the orbits. Glaucoma drainage devices and orbital implants after enucleation are two of the more pertinent implanted devices because their composition has substantially evolved over the past 2 decades, which affects their imaging appearance. Some devices, such as the Baerveldt Glaucoma Implant and platinum-weighted eyelid implants, may distort radiologic images. The MR imaging safety profiles of numerous implanted devices are also reported.

Outcomes of fornix-based versus limbus-based conjunctival incisions for glaucoma drainage device implant.

PURPOSE: To determine the effect of conjunctival incision location on the long-term efficacy of nonvalved glaucoma drainage devices. MATERIALS AND METHODS: We conducted a retrospective review of patients ≥18 years of age with uncontrolled glaucoma [intraocular pressure (IOP) ≥18 mm Hg] who underwent glaucoma drainage device implantation. A comparison was made of a limbal-based (LB-BGI) versus fornix-based (FB-BGI) conjunctival flap during placement of a 350-mm Baerveldt glaucoma implant (AMO, Santa Ana, CA) in subjects with at least 1 year of follow-up data. The primary outcome measure was IOP; secondary outcome measures were medication burden, visual acuity, and surgical complications. RESULTS: One hundred sixty eyes of 147 glaucoma patients were included. Two years after surgery, the IOP in the LB-BGI group was 14.3±5.3 mm Hg and in the FB-BGI group 13.1±4.7 mm Hg (P=0.47). Overall success of IOP control was achieved at the final visit (range 1 to 5 y) in 90% of the LB-BGI group and 87% of the FB-BGI group (P=0.63). The medication burden of the 2 groups at 1 and 2 years after surgery was not statistically significantly different. Worsening of visual acuity by more than 2 lines was not statistically different between the groups 2 years after the surgery and at the final visit (P=0.47, P=0.60, respectively). A greater number of eyes developed endophthalmitis and were more likely to undergo subsequent tube revision in the FB-BGI group, but the differences were not significant. CONCLUSIONS: Both incision techniques were equally effective in controlling IOP. Each surgical approach has its advantages and this study suggests that either technique may be used safely and effectively.

Long-term success in the correction of exposed glaucoma drainage tubes with a tube extender.

PURPOSE: To report long-term success of surgical correction of exposed glaucoma drainage device (GDD) tubes with a commercially available tube extender. DESIGN: Observational case series. METHODS: Chart review of surgical correction for GDD tube exposure by rerouting the tube using the New World Medical Tube Extender (NWMTE; New World Medical, Rancho Cucamonga, California, USA). RESULTS: Surgical revision of GDD tube exposure with the NWMTE controlled intraocular pressure without repeat exposure up to three years after surgery. CONCLUSIONS: A tube extender can provide long-term correction of an exposed GDD tube by bypassing weakened tissue, thus avoiding or delaying a second implant surgery.

Effect of adult strabismus on ratings of official U.S. Army photographs.

PURPOSE: To determine if strabismus affects the ratings of official U.S. Army photographs. METHODS: Photographs of seven women and seven men officers (subjects) were digitally altered to give the impression of strabismus. Four photographs of each subject were obtained: two in an orthotropic state; one in a left exotropic state; and one in a left esotropic state. The photographs were presented randomly to a panel of 38 raters. Masked to the study design, the raters rated every photograph on a 1 to 10 Likert scale. The results were grouped according to eye alignment: two orthotropic groups, one exotropic group, and one esotropic group. Comparisons of the mean ratings were made between each eye alignment group and based on the subject's gender. RESULTS: The mean rating for each orthotropic group was 5.4 and 5.5 Likert scale units with a SD of 0.8 and 0.9, respectively (group 1 and group 2). The mean rating for the exotropic group was 5.4 Likert scale units with a SD of 0.7. The mean rating for the esotropic group was 5.1 Likert scale units with a SD of 0.8. Significantly lower ratings were obtained for the esotropic group compared with the orthotropic group (p=0.028). Women received significantly lower ratings regardless of eye alignment (p=0.044). CONCLUSIONS: This study indicates that the presence of esotropia negatively affects the rating of an official U.S. Army photograph; furthermore, female gender negatively affects ratings.