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Objective: To assess the efficacy of repositioning Baerveldt aqueous implant tubes from the anterior chamber into the vitreous cavity in the management of anterior chamber tube-related complications., Design: Noncomparative case series., Participants: Nine eyes of eight consecutive subjects with anterior segment problems (corneal decompensation with a shallow anterior chamber or recurrent tube erosion unresponsive to conventional revision)., Intervention: Baerveldt implant tubes were repositioned from the anterior chamber into the vitreous cavity after pars plana vitrectomy., Main Outcome Measures: Preservation of visual acuity, maintenance of intraocular pressure (IOP) control, and resolution of the anterior segment problem., Results: Nine eyes of eight subjects were collaboratively managed by the operating glaucoma and vitreoretinal surgeons and followed postoperatively for an average time of 17 months (range, 2-42 months). Visual acuity remained stable or improved in seven of the nine eyes. IOP remained controlled in all eyes, with an average IOP of 14.3 +/- 3.0 standard deviation mmHg (range, 10-18 mmHg). Progression of the anterior segment problem, which dictated the revision, was halted in three of five eyes with corneal decompensation and shallow anterior chambers and in all eyes with recurrent tube erosion. Postoperative complications included one successfully repaired retinal detachment occurring 9 months postoperatively., Conclusions: Repositioning of an anterior chamber Baerveldt shunt tube into the vitreous cavity is a viable option for resolving recalcitrant tube-related anterior segment complications.

Purpose: Goniotomy is a surgical treatment of choice to treat primary infantile glaucoma. Goniotomy has been studied in vitro in animal and human cadaver eyes with several lasers. The objective of this study was to investigate the functional and morphologic effectiveness of goniotomy with the free electron laser in comparison with conventional needle goniotomy in early congenital glaucoma rabbits., Materials and Methods: Ten rabbits with early congenital glaucoma underwent goniotomy over 100 to 120 degrees with a needle or the free electron laser. The wavelength was 6.45 microm, and the energy level ranged from 2.2 to 3.5 mJ at 30 Hz. Because most corneas were edematous in these rabbits, an Olympus 0.8-mm diameter endoscope was coupled to the laser waveguide or the needle and inserted into the anterior chamber filled with a viscoelastic material to perform the goniotomy. Intraocular pressures were followed up to 3 weeks before an acute goniotomy was performed in the contralateral eye. All eye specimens were processed for light microscopic evaluation., Results: Incision of the pectinate ligaments and underlying trabecular meshwork was visualized through the endoscope on a video monitor during the surgeries. The mean intraocular pressure decreased after free electron laser goniotomy and after needle goniotomy, and the edematous corneas became clear in some cases. Histologic study showed successful lysing of the pectinate ligaments by the free electron laser with no obvious collateral thermal damage. However, some areas of peripheral anterior synechiae occurred. Similar results were observed in needle goniotomy cases., Conclusions: The free electron laser is capable of performing goniotomy in rabbit eyes with lower intraocular pressures in treated eyes 3 weeks after surgery. The histologic results of free electron laser goniotomy are comparable to those of conventional goniotomy. The endoscope provides beneficial visualization to perform the goniotomy in eyes with edematous corneas. The rabbit with early congenital glaucoma is also a useful infantile glaucoma surgical model.

Purpose: The authors develop a simple and economical method of applying reproducible intraoperative doses of mitomycin C for glaucoma filtering surgery., Methods: A three-part protocol was developed to study several properties of half corneal light shields (HCLSs). Part A tested the amount of mitomycin C (0.4 mg/ml) absorbed, the expansion dimensions attained, and the amount released to filter paper. In part B, the in vitro release of mitomycin C to an enucleated pig eye was examined. In part C, the in vivo release during intraoperative filtering surgery was tested., Results: The amount of mitomycin C solution absorbed by the HCLSs ranged from 1.07 x 10(-2) mg to 1.19 x 10(-2) mg; expansion width ranged from 6.8 mm to 7.0 mm; expansion height ranged from 3.6 mm to 3.8 mm; expansion thickness was constant at 0.6 mm. The amount of solution released to filter paper ranged from 6.8 x 10(-3) mg to 8.6 x 10(-3) mg. The amount of solution transferred to the pig eye ranged from 1.0 x 10(-3) mg to 2.7 x 10(-3) mg. The amount of solution released in filtering surgery ranged from 2.0 x 10(-3) mg to 4.8 x 10(-3) mg., Conclusions: The contact surface area, the amount absorbed, and the amount released by each HCLS was reproducible. The uniform thickness theoretically provides a uniform distribution of mitomycin C. This method may allow standardization of intraoperative mitomycin C application, and may reduce the incidence of complications.

Purpose: When patients with glaucoma require cataract surgery, combined procedures offer important advantages over cataract surgery alone. Because mitomycin C has improved the success rate of a trabeculectomy in patients at high risk for filtration failure, the authors investigated whether it also would increase the survival rate of functioning filters in combined procedures., Methods: Patients with both cataract and glaucoma underwent combined mitomycin C trabeculectomy, extracapsular cataract extraction, and intraocular lens implantation. Mitomycin C (0.5 mg/ml) was applied topically to the trabeculectomy site for 5 minutes before the cataract extraction. Intraocular pressure (IOP), visual acuity, and astigmatism were measured preoperatively and postoperatively. One-year results are available for 74 patients., Results: At 1 year, 54 (73%) of 74 patients had IOPs of 15 mmHg or less without glaucoma medications. Visual acuity was 20/40 or better in 44 (60%) of 74 patients. Ten (15%) patients had a shift of more than 2 diopters of astigmatism against the rule compared with preoperative values. No notable corneal epithelial toxicity was present. Postoperative symptomatic hypotony with the wound construction occurred in 3 (4%) of 74 patients, with 1 patient requiring surgical revision. Other potential complications of mitomycin C include endothelial toxicity (1 patient had decreased vision due to endothelial folds) and wound stability (1 patient had wound rupture after direct ocular trauma)., Conclusion: The 1-year survival rate of a functioning trabeculectomy using mitomycin C in combined glaucoma and cataract surgery is encouraging. The longer-term benefits and possible adverse effects of mitomycin C in combined procedures are unknown and continue to be investigated.

Purpose: The purpose of this study is to determine if an endoscope would improve visualization of the anterior chamber angle and facilitate goniotomy in a surgical cloudy corneal model of primary infantile glaucoma., Methods: A 23-gauge needle coupled to a 0.8-mm diameter flexible endoscope entered the anterior chamber of porcine cadaver eyes through a corneal incision near the limbus. Internal structures were observed on a videoscreen and recorded as the needle approached and incised pectinate ligaments near Schwalbe's line. The eyes were then prepared for light microscopy and scanning electron microscopy., Results: Internal structures were clearly visualized on the videoscreen during the goniotomy. The incision of pectinate ligaments was accompanied by the iris falling back and opening of the trabecular meshwork compared with the untreated portion of the angle. This was confirmed histopathologically., Conclusions: An endoscope coaxially coupled to a goniotomy needle tip allows visualization of the anterior chamber angle during goniotomy in the pig despite the presence of a cloudy cornea. The porcine anterior chamber angle is a useful animal model for studying the surgical treatment of primary infantile glaucoma.