Current practice of trabeculectomy in a cohort of experienced glaucoma surgeons in Australia and New Zealand.

BACKGROUND/OBJECTIVES: To evaluate current routine trabeculectomy technique preferences among Australian and New Zealand Glaucoma Society surgeons regularly performing trabeculectomy surgery. SUBJECTS/METHODS: Survey of experienced surgeons who perform trabeculectomy. RESULTS: Forty-nine surgeons (33 male:16 female) participated in the survey. Trabeculectomy was performed as day surgery (39/47, 83.0%) under local anesthesia (44/47, 93.6%). The surgical techniques most commonly used were a corneal traction suture (44/47, 93.6%), fornix-based conjunctival flap (43/47, 91.5%) and half-thickness scleral flap (38/47, 81.0%). Mitomycin C antifibrotic agent was used in routine cases by 45/46 (97.8%) surgeons. Surgeons applied the antifibrotic agent under the Tenon layer with a pledget (36/46, 78.2%) with a concentration of 0.02% (37/46, 80.4%) for 2 (11/46, 23.9%) or 3 min (30/46, 65.2%). The Kelly (26/46, 56.5%) and the Khaw Descemet (19/46, 41.3%) punches were used to perform the sclerostomy. Most surgeons performed a peripheral iridectomy in all phakic patients (46/47, 97.9%), but less commonly in pseudophakic patients (34/47, 72.3%). Techniques for closure of the limbal conjunctival edge were quite varied with a combination of suturing including purse string (21/47, 57.4%), wing (20/47, 42.6%) and horizontal mattress sutures (33/47, 70.2%). Surgeons reviewed their routine patients four times in the first month (29/47, 61.7%) and continued the postoperative topical steroids for 3-4 months (28/47, 59.6%). CONCLUSIONS: Although a wide range of techniques for trabeculectomy exists among surgeons, there are consistent procedures currently in use to optimize patient outcomes. This report will assist surgeons in choosing which surgical techniques fit their best practice.

Glaucoma Drainage Device Technique in a Cohort of Experienced Glaucoma Surgeons in Australia and New Zealand.

PRéCIS:: Glaucoma drainage devices (GDD) by Australian and New Zealand glaucomatologists are implanted superotemporally under a peribulbar anesthesia without the use of mitomycin C. Intraluminal stents and tube fenestration are utilized and covered with a scleral graft. PURPOSE: To evaluate current practice patterns of surgical techniques for GDD among Australia and New Zealand Glaucoma Society members routinely performing GDD surgery. METHODS: Survey of surgeons who performed more than 20 GDD in past 5 years. RESULTS: Surgeon participation rate was 31/32 (96.8%). The most common surgical techniques were Baerveldt GDD (24/32, 77.4%), superotemporal placement (31/31, 100%), and peribulbar anesthesia (21/31, 67.7%). Mitomycin C antimetabolite was used routinely by 9/31 surgeons (29.0%). Most surgeons employed intraluminal stents (23/31, 74.2%) with tube fenestrations (19/31, 61.3%). GDD was placed behind the recti muscles (27/31, 87.1%) and secured with nylon (8/0, 9/0 or 10/0) by 29/31 (93.6%). Most common sclerostomy techniques for tube insertion was a 23-G needle passed ab externo (18/31, 58.1%). Tube placement was in the sulcus (11/31, 35.5%) for pseudophakic patients. The external portion of the tube was most commonly covered with a full-thickness scleral patch graft (21/31, 67.7%). Majority of surgeons (21/31, 67.7%) reviewed patients 3 to 4 times in the first month. CONCLUSIONS: Although a wide range of practice patterns for GDD implantation exists among Australia and New Zealand Glaucoma Society surgeons, there are consistent techniques currently in use to optimize patient outcomes. This report can help surgeons seeking to improve outcomes and minimize complications when trialing the different surgical options.

Compound heterozygote myocilin mutations in a pedigree with high prevalence of primary open-angle glaucoma.

PURPOSE: To describe the phenotype of ocular hypertension and primary open-angle glaucoma in a family with individuals compound heterozygote for Gln368STOP and Thr377Met myocilin (MYOC) mutations. METHODS: Family members of the proband underwent comprehensive ocular clinical examination and DNA sequencing for MYOC mutations. RESULTS: A 34-year-old woman with marked ocular hypertension was found to carry Gln368STOP and Thr377Met MYOC mutations. Three other siblings carried both mutations, while one carried Gln368STOP alone. Three of five siblings had received treatment for ocular hypertension or early glaucoma, with the average age of diagnosis 28 years; one required trabeculectomy at age 27. The mother of the proband was found to be a carrier for Gln368STOP alone, which indicates that her offspring with both Gln368STOP and Thr377Met carry variants on opposing alleles. CONCLUSIONS: This pedigree is the first report with individuals compound heterozygote for the two most common glaucoma-causing MYOC variants. The combination of mutations manifests a more severe phenotype than either alone. Identification of gene changes associated with glaucoma within the family has enabled unaffected members to stratify their risk of future disease and institute closer monitoring and early treatment.

Deconstructing the mechanisms of angle closure with anterior segment optical coherence tomography.

BACKGROUND: To illustrate the common mechanisms of angle closure by observing the changes following a laser iridotomy and then cataract surgery with anterior segment optical coherence tomography. DESIGN: Retrospective interventional case series. PARTICIPANTS: Four patients with iridotrabecular contact. METHODS: The anterior chamber was imaged in different lighting conditions prior to and following a laser iridotomy and then cataract surgery. The images were superimposed on each other, using the interscleral spur line as a common baseline. MAIN OUTCOME MEASURES: Qualitative and quantitative analysis of the changes of the iris and the drainage angle. RESULTS: Iridotrabecular contact was seen in dark conditions in all patients. Iridotrabecular contact related to pupil block was abolished after a laser iridotomy. Persistent iridotrabecular contact following a laser iridotomy, due to a lens-induced mechanism, was abolished after cataract surgery. Iridotrabecular contact that persisted after a laser iridotomy and cataract surgery was due to a 'pure' plateau iris syndrome or peripheral anterior synechiae. These treatments lowered the height of the iris plane in the region posterior to the trabecular meshwork. CONCLUSION: Following a laser iridotomy and cataract surgery, there is posterior movement of the iris plane away from the trabecular meshwork, but iridotrabecular contact can persist due to the ciliary processes or peripheral anterior synechiae. These changes show that the risk of iridotrabecular contact depends on the height of the iris plane relative to the trabecular meshwork and the degree of physiologic pupil dilation, and that angle closure can be a multi-mechanism disease rather than a pure one.

The concave iris in pigment dispersion syndrome.

OBJECTIVE: To visualize the changes of the iris contour in patients with pigment dispersion syndrome after blinking, accommodation, and pharmacologic miosis using anterior segment optical coherence tomography. DESIGN: Observational case series. PARTICIPANTS: A total of 33 eyes of 20 patients with pigment dispersion syndrome. METHODS: Each eye was imaged along the horizontal 0- to 180-degree meridian using the Visante Anterior Segment Imaging System (Carl Zeiss Meditec, Dublin, CA). Scans were performed at baseline and after focusing on an internal fixation target for 5 minutes, forced blinking, accommodation, and pharmacologic miosis with pilocarpine 2%. MAIN OUTCOME MEASURES: Quantitative analysis of the changes in the iris configuration. RESULTS: After 5 minutes of continual fixation, the iris became planar with the mean ± standard deviation curvature decreasing from 214 ± 74 µm to 67 ± 76 µm (P < 0.05). The iris remained planar in all patients with pigment dispersion syndrome after forced blinking, but the iris concavity recovered to 227 ± 113 µm (P = 0.34) and 238 ± 119 µm (P = 0.19) with the -3.0 and -6.0 diopter lenses, respectively. Pilocarpine-induced miosis caused the iris to assume a planar configuration in all subjects. CONCLUSIONS: This study shows that the iris in pigment dispersion syndrome assumes a planar configuration when fixating and that the concavity of the iris surface is not restored by blinking. Accommodation restored the iris concavity, suggesting that the posterior curvature of the iris in pigment dispersion syndrome is induced and probably maintained, at least in part, by accommodation.

The role of the lens in pigment dispersion syndrome.

In patients with pigment dispersion syndrome, changes of the iris configuration can occur with accommodation, blinking, miotics, and following a laser iridotomy. This observational case series looks at the changes following cataract surgery in 3 eyes with signs of pigment dispersion, symptomatic cataracts, and no previous laser iridotomy that were imaged with optical coherence tomography. The iris was concave posteriorly in dark and light lighting conditions, and became flat following an uncomplicated cataract operation. This may be explained by the elimination of iridolenticular contact, which contributes to the mechanism of reverse pupil block. These iris changes suggest the lens plays an important role in the mechanism of pigment dispersion.

The role of the lens in pigment dispersion syndrome.

In patients with pigment dispersion syndrome, changes of the iris configuration can occur with accommodation, blinking, miotics, and following a laser iridotomy. This observational case series looks at the changes following cataract surgery in 3 eyes with signs of pigment dispersion, symptomatic cataracts, and no previous laser iridotomy that were imaged with optical coherence tomography. The iris was concave posteriorly in dark and light lighting conditions, and became flat following an uncomplicated cataract operation. This may be explained by the elimination of iridolenticular contact, which contributes to the mechanism of reverse pupil block. These iris changes suggest the lens plays an important role in the mechanism of pigment dispersion.

Efficacy and safety of bimatoprost as replacement for latanoprost in patients with glaucoma or ocular hypertension: a uniocular switch study.

PURPOSE: To assess the efficacy and safety of switching patients from bilateral latanoprost to bimatoprost in 1 eye while maintaining latanoprost in the fellow eye. PATIENTS AND METHODS: This prospective, open-label, multicenter, uniocular (within-eye control) study was conducted from March 2005 to February 2007; 105 patients with glaucoma or ocular hypertension were enrolled. At baseline, patients using bilateral latanoprost were switched to bimatoprost treatment in 1 eye (study eye) and continued latanoprost treatment in the fellow eye (control eye). At 12 weeks, patients were offered bilateral bimatoprost for 12 additional weeks. RESULTS: At week 12, the mean difference in intraocular pressure (IOP) from baseline was -3.0 mm Hg in study eyes and -1.6 mm Hg in control eyes, which equates to a further -1.4 mm Hg (95% confidence limits: -1.9, -0.9) reduction in IOP in study eyes compared with control eyes (P<0.0001). Overall, 27% (28/104) more study eyes had > or = -2.5 mm Hg reduction in IOP than control eyes (P<0001). At week 24, the mean difference in IOP from baseline was -2.8 mm Hg for study eyes and for control eyes that had switched to bimatoprost. Conjunctival hyperemia occurred more frequently and was more severe in bimatoprost-treated eyes at week 12 than at baseline (P<0.001). No patients withdrew from treatment because of conjunctival hyperemia. CONCLUSIONS: Clinically, these data suggest that switching patients from latanoprost to bimatoprost may result in further improvement in IOP control.

Anatomical changes of the anterior chamber angle with anterior-segment optical coherence tomography.

OBJECTIVE: To examine the anatomical changes of the anterior chamber angle in the eyes of white patients using anterior-segment optical coherence tomography. METHOD: An observational study of 122 white patients was performed to examine the changes of the iris and the anterior angle chamber using anterior-segment optical coherence tomography. Images were compared between healthy eyes of different age groups and patients with eyes having newly diagnosed ocular hypertension or glaucoma in different lighting conditions, using the interscleral spur line as a reproducible baseline. RESULTS: In light illumination, the iris plane was posterior to the interscleral spur line and the iris was usually flat in 91.7% of healthy eyes in young persons. In 85.0% of healthy eyes in older persons and 92.5% of eyes in the group with ocular hypertension and glaucoma, the iris plane was anterior to the interscleral spur line and the iris was usually curved forward. In the dark lighting conditions, the pupil was dilated and the iris plane was more anterior, with narrowing or loss of the angle recess. Iridotrabecular contact was present in 67.5% of healthy eyes in older persons and 77.6% of patients with ocular hypertension or glaucoma. CONCLUSION: The risk of iridotrabecular contact depends on the height of the iris plane relative to the trabecular meshwork and the degree of physiological dilation of the pupil. Open or narrow angles may become closed in dark lighting conditions, which can lead to the diagnosis of angle-closure glaucoma being missed.

Australia and New Zealand survey of antimetabolite and steroid use in trabeculectomy surgery.

AIM: To assess the pattern of use of antimetabolites and steroids in trabeculectomy surgery among consultant ophthalmologists in Australia and New Zealand. METHOD: A postal questionnaire of 25 questions regarding current glaucoma practices and antimetabolite and steroid use in trabeculectomy surgery was sent to all practicing Australian and New Zealand Fellows of the Royal Australia and New Zealand College of Ophthalmologists in July 2005. The second half of the survey consisted of questions on the number of trabeculectomies performed per year, topical steroid use, the type of antimetabolite used, and assessment of factors that may influence the decision to use them. The results were cross-tabulated according to state/country, years practicing, type of practice, and being a glaucoma subspecialist (GSS). RESULTS: The overall response rate was 78% (627 out of 808). Ninety-one percent stated that they managed glaucoma of which 65% stated that they perform trabeculectomy surgery and 16% considered themselves as a GSS. In 2004, 75% of ophthalmologists performed less than 10 trabeculectomies. Sixty-one percent used an antimetabolite in trabeculectomy surgery of which 5-fluorouracil was used 51% (intraoperatively) and 24% (postoperatively). Mitomycin C was used in 12% and 0.2 mg/mL was the most commonly used concentration for 2 or 3 minutes. Fifty-four percent used postoperative steroids in a primary trabeculectomy for 1 to 2 months with 48% of GSSs using it for 2 to 3 months. Forty-eight percent to 96% would use an antimetabolite in patients with risk factors for conjunctival scarring. CONCLUSIONS: This survey shows a wide range of the use of antimetabolites and steroids in trabeculectomy surgery with 5-fluorouracil being most commonly used. GSSs and young ophthalmologists would use antimetabolites more often and postoperative steroids for longer. This survey allows ophthalmologists to compare their own practices with those of their colleagues in Australia and the United Kingdom.

Australia and New Zealand survey of glaucoma practice patterns.

BACKGROUND: To evaluate current glaucoma practices among consultant ophthalmologists in Australia and New Zealand. METHODS: A postal questionnaire of 25 questions regarding current glaucoma practices and the use of antimetabolites and steroids in trabeculectomy surgery was sent to all practising Australian and New Zealand Fellows of the Royal Australian and New Zealand College of Ophthalmologists (as of June 2005). This paper looked at glaucoma practice patterns and consisted of questions on demographic data, the definition of glaucoma, intraocular pressure measurements, central corneal thickness, gonioscopy, optic disc assessment, preferred first-line glaucoma medications and laser trabeculoplasty. RESULTS: The overall response rate was 78% (627 out of 808). Ninety-one per cent stated that they managed glaucoma of which 12% considered themselves as a glaucoma subspecialist. Eighty-two per cent of ophthalmologists defined glaucoma as an optic neuropathy and 66% measured the intraocular pressure themselves. Pachymetry was routinely measured by 37%. When performing gonioscopy, 56% did this (more than 50% of the time) but only 13% repeated it. Fifty-eight per cent assessed the optic disc by objective means and 18% used this to follow glaucoma patients. Eighty-two per cent preferred a prostaglandin analogue as first-line treatment of primary open angle glaucoma and 79% did less than 10 argon laser trabeculoplasties in 2004. CONCLUSIONS: This survey shows a wide range of glaucoma practice patterns among Australian and New Zealand ophthalmologists. Gonioscopy (initial and repeat) and objective assessment of the optic disc were poorly done.