Clinical experience of trabeculotomy for the surgical treatment of aniridic glaucoma.

OBJECTIVE: The purpose of this study is to determine the efficacy of initial trabeculotomy in the patient with aniridic glaucoma. DESIGN: Clinical charts were reviewed. PARTICIPANTS: Twenty-nine eyes of 16 patients with aniridia were studied. INTERVENTION: Glaucoma surgery was performed. As an initial procedure, trabeculotomy was performed in 12 eyes, other surgery was performed in 17 eyes (trabeculectomy, 5; goniotomy, 5; other, 7). MAIN OUTCOME MEASURES: Success was defined as an intraocular pressure (IOP) of 21 mmHg or lower, and no further surgery was performed. RESULTS: Ten (83%) of 12 eyes obtained IOP control after first (6 eyes) or second (4 eyes) trabeculotomy with a mean follow-up period of 9.5 years. Five eyes maintained visual acuity of 20/40 to 20/200. No serious complications were found after trabeculotomy. Three (18%) of 17 eyes were controlled with the first glaucoma surgery other than trabeculotomy (goniotomy, trabeculectomy, trabeculectomy combined with trabeculotomy, and Molteno implant). Good IOP control was obtained in 8 (47%) of 17 eyes after several surgeries with a mean follow-up period of 10.4 years. Four of 17 eyes became phthisical. CONCLUSION: This study suggests that trabeculotomy is the preferred initial operation for uncontrolled glaucoma with aniridia.

Endoscopic diode laser cyclophotocoagulation with a limbal approach.

BACKGROUND AND OBJECTIVE: Endoscopic diode laser cyclophotocoagulation with a limbal approach was reviewed retrospectively. The delivery system and procedure used as well as the role of this procedure in the management of glaucoma are discussed. PATIENTS AND METHODS: An 810-nm pulsed continuous-wave diode laser capable of 1.2-W output was used. The maximum treatment area is 7 to 8 clock hours with a single limbal incision. Generally, 800 mW were used for less than 1 second, for a total of 0.8 J per treatment. RESULTS: Eight eyes of 6 patients were treated. The mean follow-up time for each procedure was 3.2 months (range 1 to 8 months) and for each eye was 5.1 months (range 2 to 8 months). Pre- and postoperative intraocular pressures were determined. Postoperative inflammation was the most common complication. CONCLUSION: One reason for the failure of transscleral cyclophotocoagulation, particularly in congenital glaucoma, may be displacement of the ciliary processes. This displacement does not permit the indirect treatment to reach the appropriate area. Because endoscopic laser cyclophotocoagulation allows direct visualization, treatment can be accurately applied to individual ciliary processes.

Update on the subconjunctival THC:YAG (holmium) laser sclerostomy Ab externo clinical trial: a 4-year report.

BACKGROUND AND OBJECTIVE: This is a follow-up report on 103 THC:YAG (holmium) sclerostomies ab externo performed on 87 eyes of 81 patients. PATIENTS AND METHODS: The patients received pulse energies of 0.06 to 0.13 J (mean total energy 4.4 +/- 3.3 J, range 0.6 to 17.1 J). RESULTS: The estimated success rates with or without medication, and allowing a second procedure, were 44% at 2 years and 36% at 4 years. The mean preoperative intraocular pressure (IOP) was 29.7 +/- 11.4 mm Hg, and the mean postoperative IOP in the successful patients was 13.6 +/- 4.6 mm Hg (P < .01). Hypotony and iris incarceration were the most frequent early complications. CONCLUSIONS: Although holmium laser sclerostomy is a relatively straightforward procedure and offers some advantages over standard trabeculectomy in select cases, it currently has a number of drawbacks that limit its use.

A high prevalence of occludable angles in a Vietnamese population.

PURPOSE: To assess the prevalence of occludable angles in a Vietnamese population. METHODS: The authors retrospectively reviewed the angle status in 482 Vietnamese patients who presented to a general ophthalmology practice. All angles were graded by a glaucoma specialist according to the Shaffer method. Patients were excluded if they had known glaucoma or narrow angles, or a history of trauma or intraocular surgery. RESULTS: A total of 29.5% of all patients surveyed and 47.8% of those 55 years of age or older had grade 0 to 2 angles. In the Framingham study, 3.8% of white patients 55 years of age or older had grade 0 to 2 angles. Of the patients in our study population, 8.5% had grade 0 to 1 angles and were considered at high risk for occlusion. CONCLUSIONS: Vietnamese patients have a much higher prevalence of narrow angles and a greater risk of angle-closure glaucoma than white patients.

Trabeculectomy with intraoperative sponge 5-fluorouracil.

PURPOSE: To retrospectively assess the outcome of trabeculectomy surgery performed using intraoperative sponge 5-fluorouracil (5-FU) (50 mg/ml). METHODS: Trabeculectomy with intraoperative sponge 5-FU was performed on 140 eyes of 119 patients. The reduction in intraocular pressure (IOP), the number of supplementary postoperative injections, and any treatment complications were noted. RESULTS: The mean preoperative IOP was 25.7 +/- 8.6 mmHg. The mean postoperative IOP was 12.5 +/- 5.7 mmHg with a mean IOP reduction of 52 percent (P < 0.0001). One hundred twenty-one (86.4 percent) eyes required no postoperative glaucoma medications, with the mean number of glaucoma medications dropping from 2.5 +/- 1.1 before operation to 0.3 +/- 0.8 after operation (P < 0.001). One hundred five eyes received a mean of 5.3 +/- 2.7 postoperative 5-FU injections. There was no significant difference in final IOP or success rate between low- and high-risk eyes, but high-risk eyes seemed to require supplementary postoperative 5-FU. Corneal epithelial damage arose in 52 (37 percent) eyes and correlated strongly with postoperative 5-FU supplementation. CONCLUSION: Intraoperative sponge 5-FU is a reasonably safe and effective adjunct to trabeculectomy surgery.

Long-term results of noncontact transscleral neodymium:YAG cyclophotocoagulation.

PURPOSE: To determine the long-term efficacy of noncontact transscleral neodymium:YAG (Nd: YAG) cyclophotocoagulation. METHODS: A retrospective analysis was made of 167 patients (173 eyes) with intractable glaucoma treated with noncontact Nd:YAG cyclophotocoagulation between December 1987 and November 1993, reviewing the treatment parameters, complications, and pre- and posttreatment intraocular pressure (IOP). The IOP was compared using a Student's t test, and the results were subjected to a Kaplan-Meier life-table analysis. Success was defined as an IOP of 22 mmHg or lower in the absence of phthisis and without having undergone any additional surgical procedures. RESULTS: Mean follow-up was 30.5 +/- 22.8 months. Mean preoperative IOP was 40.0 +/- 12.9 mmHg. Mean postoperative IOP was 19.8 +/- 11.4 mmHg (P < 0.05). The mean number of treatment sessions was 1.8 +/- 1.3 (range, 1-8) with 95 eyes (55%) having only one treatment. Kaplan-Meier survival analysis showed a probability of continued success at 3 years of approximately 73% and at 5 years of 45%. Complications included loss of two or more lines of Snellen visual acuity or one or more categories in the low-vision range (40%), phthisis (6.9%), epithelial defects (1.9%), and hyphema (0.6%). CONCLUSION: This study suggests that Nd:YAG transscleral cyclophotocoagulation provides a useful long-term reduction of IOP in eyes with advanced or complicated glaucoma, but there is a significant risk of visual loss associated with the procedure.

Update of the subconjunctival THC:YAG (holmium) laser sclerostomy ab externo clinical trial: 30-month report.

A THC:YAG laser (thulium, holmium, chromium-doped YAG crystal) was used to create 93 thermal sclerostomies ab externo in 81 glaucomatous eyes of 76 patients. Pulse energies of 80 to 120 mJ were used, with a repetition rate of 5 pulses per second. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Estimated probability of success was 0.66 at 12 months and 0.57 up to 30 months. The mean intraocular pressure in the successful cases was 12.8 +/- 4.0 mm Hg.

Laser sclerostomy for the management of glaucoma.

Laser sclerostomy can be performed in a less invasive manner than standard filtering surgery. Recent studies have explored the use of laser energy of varying wavelengths, properties, and tissue interaction to create thermal sclerostomies. Several methods deliver laser energy by mirrored contact lenses to the internal face of the filtration angle or by fiberoptic cables for ab interno or ab externo sclerostomy formation. Certain laser techniques can be performed outside the standard operating room, in a clinic or minor surgery room. This article reviews the various laser sclerostomy techniques currently being investigated.

Subconjunctival THC:YAG ("holmium") laser thermal sclerostomy ab externo. A one-year report.

BACKGROUND: Laser sclerostomy can be performed in a less-invasive manner than standard filtering surgery. Longer wavelengths in the infrared range have water-absorptive characteristics that facilitate perforation of the sclera. The goal was to perform laser sclerostomy ab externo to avoid intraocular instrumentation and minimize conjunctival trauma. METHODS: A thulium, holmium, chromium-doped:YAG (THC:YAG) crystal laser was used to create thermal sclerostomies in 49 glaucomatous eyes of 46 patients. The laser is a long-pulsed (300-microsecond), compact, self-contained, solid-state laser operating in the near infrared (2.1 microns). Energy was delivered via a specially designed 22-gauge (712-microns) optic probe that emits energy at a right angle to the long axis of the fiber. Pulse energies of 80 to 120 mJ were used. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Subconjunctival 5-fluorouracil (5-FU) injections were administered in 46 eyes. Success was defined as an intraocular pressure (IOP) of less than or equal to 22 mmHg with or without medications. For eyes in which preoperative IOP was less than or equal to 22 mmHg, success was defined as a decrease in IOP of greater than or equal to 30%. RESULTS: Estimated probability of success allowing for one retreatment was 0.75 at 6 months and 0.68 at 12 months. Mean IOP of successful cases was 13.3 mmHg at both 6 and 12 months. Twelve cases failed within the initial 6 months, and two additional cases failed by 12 months. CONCLUSION: THC:YAG ("holmium") laser thermal sclerostomy is an alternative to other full-thickness filtration procedures. Further evaluation and understanding will define its ultimate role in glaucoma management.

Transcanalicular THC:YAG dacryocystorhinostomy.

Chromium-sensitized and thulium- and holmium-doped YAG lasers (THC:YAG laser) were used to create a nasal bony ostium in the area of the lacrimal sac fossa in four fresh frozen bisected human cadaver heads. The lasers-long pulsed (300 milliseconds), compact, self-contained, and solid state--operate in the near infrared (2.1 microns). The opening was created by passing the 320-micrometer laser fiber across the canalicular system. Pulse energies of 250 to 900 mJ were used with a repetition rate of 5 to 15 pulses per second. Energy levels ranging from 1.25 to 9 W produced a full-thickness bony ostium approximately 3 to 4 mm in diameter. Silicone tubing was then threaded through the superior and inferior canaliculus system in the standard fashion. This technique may simplify conventional dacryocystorhinostomy as well as endonasal laser dacryocystorhinostomy procedures.

Holmium laser sclerostomy in glaucoma management: a new tool for an old procedure.

A THC: YAG laser (thulium, holmium, chromium doped YAG crystal) was used to create thermal sclerostomies in 49 glaucomatous eyes of 46 patients. The laser is a long-pulsed (300 microseconds), compact, self contained, solid state laser operating in the near infrared (2.1 mu). A 1 mm conjunctival stab incision was made 12 mm away from the sclerostomy site to allow entry of a specially designed 22-gauge (712 mu) optic probe that delivers energy at a right angle to the long axis of the fiber. Probe insertion produced minimal disturbance of the conjunctiva. Pulse energies of 80 mJ tot 120 mJ were used with a repetition rate of 5 pulses/sec. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Subconjunctival 5-fluorouracil injections were administered in 46 eyes. Estimated probability of success was 74% at 6 months and 67% at 12 months. Mean intraocular pressure of successful cases was 13.3 mmHg at both both 6 months & 12 months. Twelve cases failed within the initial 6 months, and two additional cases failed by 12 months.

Subconjunctival THC:YAG laser thermal sclerostomy.

A THC:YAG laser (thulium, holmium, chromium-doped YAG crystal) was used to create thermal sclerostomies in 21 glaucomatous eyes of 19 patients. The laser is a long-pulsed (300 microsec), compact, self-contained, solid state laser operating in the near infrared (2.1 mu). A 1-mm conjunctival stab incision was made 12 mm away from the sclerostomy site to allow entry of a specially designed 22-gauge (712 mu) optic probe that delivers energy at a right angle to the long axis of the fiber. Probe insertion produced minimal disturbance of the conjunctiva. Pulse energies of 80 mJ to 120 mJ were used with a repetition rate of 5 pulses/second. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 4.8 J. Subconjunctival 5-fluorouracil injections were administered in 15 eyes. At 3 months the mean intraocular pressure of successful cases (16) was 14 mmHg (range, 9 to 22 mmHg). Of successful cases, the mean intraocular pressure at 6 months was 13 mmHg (range, 2 to 22 mmHg). Five cases failed within the initial 3 months, and 3 additional cases failed by 6 months. The authors conclude that this full-thickness sclerostomy technique may simplify filtering surgery without anterior chamber instrumentation and with minimal conjunctival trauma.

A new contact neodymium:YAG laser for cyclophotocoagulation.

A newly developed compact (40 kg), self-contained contact Neodymium:YAG laser produces high-peak, high-energy (800 mJ/pulse), short (1.0 millisecond) pulses with 1 to 3 pulses/exposure. Energy is delivered via a 320-microns cleaved quartz fiber optic probe. Cyclophotocoagulation was performed in five eyes of three medium-sized Dutch-pigmented rabbits. The eyes received exposures of 1 to 3 pulses/exposure. Energy delivered ranged from 100 to 800 mJ/pulse. Histopathology revealed ciliary body disruption and hemorrhage with no damage to overlying sclera. When used for transscleral cyclodiathermy in the rabbit, the laser created significant ciliary body disruption with minimal scleral injury.

Subconjunctival THC: YAG laser limbal sclerostomy Ab externo in the rabbit.

A chromium-sensitized, and thulium and holmium-doped YAG laser (THC:YAG laser) was used to create bilateral limbal sclerostomies in six Dutch pigmented rabbits. The laser is a long-pulsed (300 microseconds) [corrected], compact, self-contained, solid-state laser operating in the near infrared (2.1 microns). A 1-mm conjunctival stab incision was made 12 mm away from the sclerostomy site to allow entry of a specially designed 26-gauge (480 microns) optic probe that delivers energy at right angles to the long axis of the fiber. Probe insertion minimally disturbed the conjunctiva. Pulse energies of 60 to 150 mJ were used with a repetition rate of 5 pulses/s. Energy levels ranging from 1.35 to 6.6 J produced full-thickness sclerostomies. Histopathology showed a sharply defined perforating limbal wound at all energy levels. The overlying conjunctiva was intact, with swelling of the adjacent cornea. A peripheral iridectomy was intentionally created with the laser through the peripheral limbus, resulting in a sharply defined perforating tract through the iris/ciliary body. This technique may simplify filtering sclerostomy surgery, without anterior chamber instrumentation and with minimal conjunctival trauma.

Analysis of surgical and medical management of glaucoma in Sturge-Weber syndrome.

Management of glaucoma associated with Sturge-Weber syndrome (SWS) is difficult. The authors reviewed 36 eyes of 30 SWS patients with either early or late-onset glaucoma with a mean follow-up of 122 months (range, 24-253 months). Intervals between required surgical or medical interventions were analyzed. Intervention was attributed to elevated intraocular pressure (IOP) in 55% of cases and disc change in 45%. Median stable postoperative interval with goniotomy was 12 months; with trabeculotomy, 21 months; with trabeculectomy, 34 months; with argon laser trabeculoplasty, 25 months; and with medications, 57 months. Survival analysis shows statistically significant differences between goniotomy and medications. Intraoperative choroidal expansions developed in 24% of cases receiving a trabeculectomy, and none developed with either goniotomy or trabeculotomy.