Transconjunctival suturing of the scleral flap for overfiltration with hypotony maculopathy after trabeculectomy

Objective: To assess the efficacy of transconjunctival suturing of the scleral flap in improving hypotony maculopathy resulting from overfiltration after trabeculectomy.Design: Retrospective review.Participants: 35 eyes of 33 patients.Methods: Patients underwent transconjunctival scleral flap suturing for hypotony maculopathy following trabeculectomy using mitomycin C. The scleral flap was sutured through the conjunctiva as an outpatient clinic procedure using a spatulated needle with a 10-0 nylon suture.Results: The average age of the patients was 67.5 (SD 4.80, range 39-83) years, and 52% patients were male. The average duration of hypotony prior to transconjunctival suturing of the flap was 108.0 (SD 68.3) days. The median intraocular pressure (IOP) before suturing was 3 mm Hg, and the median IOP 6 months after the procedure was 9 mm Hg (p < 0.0001). The median best-corrected visual acuity (BCVA) before transconjunctival suturing of the scleral flap was 20/100, and the median BCVA 6 months after the procedure was 20/30 (p < 0.0001). Compared with visual acuity before suturing the average gain in BCVA was 4.9 (SD 0.8) lines.Conclusions: Transconjunctival suturing of the trabeculectomy scleral flap is an effective treatment to raise IOP and improve visual loss from hypotony maculopathy after trabeculectomy with overfiltering blebs.     

Factors that influence intraocular pressure after cataract surgery in primary glaucoma

Objective: We sought to find predictive factors for favourable postoperative intraocular pressure (IOP) after cataract surgery in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).Study Design: Retrospective evaluation of patients who had undergone cataract surgery.Participants: Forty-eight patients with POAG and 48 patients with PACG.Methods: Various clinical factors were evaluated retrospectively in 96 patients. All patients had undergone standard 2.75-3.5 mm limbal incision cataract surgery. Clinical parameters in patients with successful postoperative IOP courses were compared with those in unsuccessful patients. Success was defined as an IOP between 6 and 21 mm Hg, with fewer antiglaucoma medications needed compared with before surgery, and no need of additional glaucoma surgery.Results: In POAG, eyes with a highest preoperative IOP of <31 mm Hg or those being treated with <3 antiglaucoma medications before surgery had a significantly higher probability of success. In PACG, the probability of success was significantly higher if the highest preoperative IOP was <42 mm Hg, the number of antiglaucoma medications before surgery was <3, or the areas of peripheral anterior synechiae were <4 clock hours.Conclusions: Primary small-incision cataract surgery using phacoemulsification and foldable intraocular lens implantation may be the procedure of choice in patients with medically controlled glaucoma and coexisting visually significant cataracts, considering the highest preoperative IOP and number of antiglaucoma medications in POAG and PACG, and the area of peripheral anterior synechiae in PACG.     

Comparison of trabeculectomy with Ex-PRESS miniature glaucoma device implanted under scleral flap

PURPOSE: To evaluate the Ex-PRESS miniature implant (Model R 50) placed under partial-thickness scleral flap compared with standard trabeculectomy. METHODS: In this retrospective comparative series of 100 eyes, we compared 50 eyes in 49 patients treated with the Ex-PRESS miniature glaucoma implant under a scleral flap with 50 matched control eyes in 47 patients treated with trabeculectomy. Success was defined as intraocular pressure (IOP) > or =5 mm Hg and < or =21 mm Hg, with or without glaucoma medications, without further glaucoma surgery or removal of implant. Early postoperative hypotony was defined as IOP <5 mm Hg during the first postoperative week. RESULTS: The average follow-up was 10.8 months (range 3.5 to 18) for the Ex-PRESS group and 11.2 months (range 3 to 15) for the trabeculectomy group. Although the mean IOP was significantly higher in the early postoperative period in the Ex-PRESS group compared with the trabeculectomy group, the reduction of IOP was similar in both groups after 3 months. The number of postoperative glaucoma medications in both groups was not significantly different. Kaplan-Meier survival curve analysis showed no significant difference in success between the 2 groups (P=0.594). Early postoperative hypotony and choroidal effusion were significantly more frequent after trabeculectomy compared with Ex-PRESS implant under scleral flap (P<0.001). CONCLUSIONS: The Ex-PRESS implant under a scleral flap had similar IOP-lowering efficacy with a lower rate of early hypotony compared with trabeculectomy.     

Comparison of trabeculectomy and Ex-PRESS implantation in fellow eyes of the same patient: a prospective, randomised study

Purpose

To compare intraocular pressure (IOP) over time after standard trabeculectomy vsEx-PRESS implantation in patients with bilateral primary open-angle glaucoma (POAG).

Design

Prospective, randomised study.

Patients and methods

This study included adult patients with bilateral POAG necessitating surgery. Each patient underwent trabeculectomy in one eye and Ex-PRESS implantation under a scleral flap in the other eye according to randomised contralateral allocations. Efficacy was assessed by IOP values and success rates (IOP threshold and/or need for topical glaucoma medication) during 30 months. Statistical analysis included Generalised Estimate Equation and Cox Survival models, and paired t-tests.

Results

Thirty eyes of 15 patients were studied for a mean of 23.6 months (SD, ±6.9). At the last follow-up visit, mean pre-operative IOP decreased from 31.1 (±14.2) to 16.2 (±1.5) mm Hg after trabeculectomy, and from 28.1 (±9.0) to 15.7 (±1.8) mm Hg after Ex-PRESS implantation (P=0.001). The mean number of anti-glaucoma medicines prescribed at the last follow-up decreased from 3.7 pre-operatively (both groups) to 0.9 after trabeculectomy vs0.3 after Ex-PRESS implantation (P=0.001). Complete success rates (5P=0.0024). Postoperative complications were more frequent after trabeculectomy (33%) compared with Ex-PRESS (20%), with four trabeculectomy eyes (27%) needing postoperative interventions, compared with none with Ex-PRESS.

Conclusions

Trabeculectomy and Ex-PRESS implantation provided similar IOP control, but the Ex-PRESS group had a lower rate of complications, fewer postoperative interventions, and needed less glaucoma medications.     

Risk factors for a postoperative intraocular pressure spike after phacoemulsification

Background: The aim of our study was to examine several potential risk factors for intraocular pressure (IOP) spikes 2 to 3 hours after phacoemulsification.Methods: 50 eyes of 50 consecutive patients undergoing uncomplicated phacoemulsification under topical anesthesia were included in this prospective study. The following variables were recorded:preoperative IOP, nuclear colour,cortical lens opacity,posterior subcapsular lens opacity,patient age;and presence or absence of preexisting glaucoma.Results: The mean IOP at each time interval was as follows: preoperatively, 14.5 (SD 3.4) mm Hg; 2-3 hours postoperatively, 23.1 (7.0) mm Hg; and 24 hours postoperatively, 17.0 (6.0) mm Hg. The postoperative IOP was significantly higher than baseline at 2-3 hours (p < 0.001) and at 24 hours (p = 0.002). Overall there were 10 cases (20%) of IOP spikes 2-3 hours postoperatively. Higher mean baseline IOP was significantly associated with postoperative IOP spikes (p = 0.013). Patient age, sex, operating surgeon, absolute phacoemulsification time, lens nuclear colour, cortical opacity, and posterior opacity were not significantly different between groups with or without an IOP spike (p > 0.05).Interpretation: Patients with high IOP at the preoperative assessment are more likely to have IOP spikes after surgery and should be scheduled at the start of the operating list. In a day-case setting with restricted opening hours, postoperative checks in those patients at risk of IOP spikes can then coincide with the time IOP reaches its peak.     

Implantation of a miniature glaucoma device under a scleral flap

PURPOSE: To test the safety and efficacy of the Ex-PRESS miniature glaucoma device when it is implanted under a scleral flap instead of under the conjunctiva as it was originally suggested. PATIENTS AND METHODS: Between November 2000 and February 2003, the Ex-PRESS implant was inserted in 24 eyes of 23 patients with severe open angle glaucoma. Sixteen eyes of the 24 (66%) had had previous failed filtering surgery. The remaining 8 eyes (33%) were high risk for failures cases. A 5 x 5 mm limbal-based, 50% depth, scleral flap was raised into clear cornea. The Ex-PRESS implant was inserted into the anterior chamber under the scleral flap at the limbus. The scleral flap was securely sutured back, as is done in trabeculectomy operations. RESULTS: The intraocular pressure was significantly reduced from 27.2 +/- 7.1 mm Hg pre-operatively to 14.5 +/- 5.0 mm Hg at 12 months (n = 21) and 14.2 +/- 4.2 mm Hg at 24 months (n = 8). Postoperatively, only two patients needed anti-glaucoma medications to keep the IOP below 21 mm Hg. CONCLUSIONS: The Ex-PRESS device was found to be safe and effective with few complications when it is implanted under a scleral flap even in the high-risk patients studied.     

Comparison of dynamic contour tonometry and Goldmann applanation tonometry following penetrating keratoplasty

Objective: To evaluate dynamic contour tonometry (DCT) versus Goldmann applanation tonometry (GAT) intraocular pressure (IOP) measurements in eyes that underwent penetrating keratoplasty (PKP).Design: Prospective, cross-sectional, observational study.Participants: Thirty-one eyes of 28 patients were examined after PKP.Methods: All eyes had undergone PKP with interrupted sutures. The postoperative period was more than 1 year for 25 eyes and less than 1 year for 6. Sutures were removed based on corneal topography and refraction. IOP was measured by both DCT and GAT methods and was correlated to the number of remaining sutures.Results: IOP readings were successfully obtained in 25/31 (80.6%) with DTC and in 21/31 (67.7%) with GAT (p = 0.25). In eyes with fewer than 4 remaining sutures, both methods were successful. In eyes with more than 4 sutures, the success rates of DCT and GAT were 66.7% and 44.4%, respectively (p = 0.18). In PKPs with a postoperative period of more than 1 year, the success rates of DCT and GAT were 96% and 84%, respectively (p = 0.16). In 20 eyes, both methods measured the IOP. The mean IOP obtained by DCT (16.6 [SD 2.8] mm Hg) was higher than the mean IOP obtained from GAT (15.1 [SD 3.6] mm Hg). The IOPs from the 2 instruments correlated significantly (p < 0.05) and the mean difference was 1.5 mm Hg.Conclusions: The success rate in measuring IOP with DCT and GAT did not show any statistically significant difference. Both methods were less effective measuring the IOP after recent PKPs and regrafts. However, DCT seemed to be superior to GAT in corneas with more than 4 remaining sutures and in PKPs performed more than 1 year earlier. The absolute values of IOP were higher with DCT than with GAT.     

Can preoperative anterior chamber angle width predict magnitude of intraocular pressure change after cataract surgery?

Objective: To determine whether preoperative anterior chamberangle width,capturedbyanteriorsegment optical coherence tomography (AS-OCT), can be a predictor of intraocular pressure (IOP) change following cataract surgery.Design: Prospective comparative observational study.Participants: Fifty-three eyes of 53 patients awaiting cataract surgery were included.Methods: Measurement of anterior chamber angle width and IOP using AS-OCT and Goldmann’s applanation tonometry, respectively, were performed before and 6 months after phacoemulsification and intraocular lens implantation. Preoperative and postoperative measurements were compared using paired t test. The prediction rule defined success as ≥20% IOP reduction from the baseline preoperative IOP measurement. Multivariate regression analysis was performed to assess the association of postoperative IOP with independent variables, including age, sex, systemic hypertension, diabetes mellitus, glaucoma, and preoperative anterior chamber angle width.Results: Data were collected from 32 females and 21 males with visually significant cataract. Mean age was 73.3 (SD 8.2) years. Mean IOP dropped from 15.1 (SD 3.l)mm Hg to 12.8 (SD 2.5) mm Hg (p < 0.0001) after cataract extraction. Mean anterior chamber angle width increased from 24.7° (SD 7.1°) to 38.1° (SD 6.0°) after surgery (p < 0.001). Multivariate regression analysis did not identify preoperative variables to be significantly associated with ≥20% postoperative IOP reduction.Conclusions: Cataract surgery results in significant and sustained mean reductions in IOP and concurrent increases in anterior chamber angle width for a period of at least 6 months after surgery. However, measurements of the preoperative anterior chamber angle width did not predict the IOP-lowering effect of cataract surgery.     

Intravitreal bevacizumab and aqueous shunting surgery for neovascular glaucoma: safety and efficacy

Objective: To study the safety and efficacy of intravitreal injection of bevacizumab followed by aqueous shunting tube surgery for the management of neovascular glaucoma (NVG).Study Design: A prospective, non-randomized study with a historical control group.Participants: Twenty eyes of 20 patients with intractable NVG were treated with intravitreal injection of bevacizumab followed by aqueous shunting surgery (IVB group). A historical group of 10 NVG eyes treated with panretinal photocoagulation followed by aqueous shunting surgery without bevacizumab injection was used for comparison (PRP group).Methods: Injection of bevacizumab (1.25 mg/0.05 mL) was performed under topical anesthesia. An Ahmed valve was implanted in all cases after 1-2 weeks. In the IVB group, 10 eyes received postoperative panretinal photocoagulation (subgroup IA), and 10 eyes were followed without further photocoagulation (subgroup IB). Minimum follow-up was I year or when failure was diagnosed.Results: Mean preoperative intraocular pressure (IOP) was 46.5 mm Hg in the IVB group and 49.2 mm Hg in the PRP group (p = 0.5). After bevacizumab injection, iris neovessels regressed markedly. The final IOP after aqueous shunting tube surgery was 18.8 mm Hg in the IVB group and 15.9 mm Hg in the PRP group (p = 0.2). Postsurgical complications were comparable between the groups. The success rate was 85% and 70% in the 2 groups, respectively. Two eyes were considered failures, and 3 required repeated bevacizumab injections in subgroup IB as compared with I in subgroup IA.Conclusion: Intravitreal bevacizumab is a useful preparatory step to safely and effectively implant an aqueous shunting tube in NVG. Panretinal photocoagulation after bevacizumab injection promotes the success rate of aqueous shunt surgery by permanent ablation of the ischemic retina.     

A trial of topical prednisolone acetate before intravitreal triamcinolone acetonide decreases intraocular pressure spikes

Objective: To compare adverse intraocular pressure (IOP) spikes in patients receiving intravitreal triamcinolone acetonide (IVTA) in 2 cohorts: (i) patients who underwent a topical prednisolone acetate trial (PAT) without incurring a short-term IOP rise, and (ii) control patients who did not undergo a PAT.Design: Retrospective cohort study.Participants: Charts of all patients who underwent any intravitreal injection during the study period were reviewed (n = 1150).Methods: Patients in the PAT group received a 6-week course of prednisolone acetate 1% 4 times per day and had an IOP that did not rise above 25 mm Hg or above 8 mm Hg over the IOP in the contralateral eye. Patients undergoing a PAT and having a short-term IOP rise were not studied. Control patients did not receive a PAT. All patients received 12-20 mg of IVTA. Patients were followed for a minimum of 6 weeks and follow-up lasted for I year or until intraocular surgery or another IVTA injection was performed.Results: There were 97 patients in the PAT cohort and 75 control patients. Patients in the PAT cohort had a lower proportional rise between maximum IOP and baseline (43%) compared with controls (64%) (p = 0.035). Patients in the PAT group also had a lower risk of incurring a 40% (p = 0.05), 60% (p = 0.0I8), and 100% (p = 0.045) increase in maximum IOP (vs baseline) compared with controls and were less likely to require glaucoma filtration surgery (p = 0.035).Conclusions: Patients undergoing a PAT who did not have a subsequent short-term IOP rise had a lower risk of severe IOP spikes after IVTA compared with those patients receiving IVTA but not having undergone a PAT.     

Intraocular pressure adjusted for central corneal thickness as a screening tool for open-angle glaucoma in an at-risk population

Objective: Evaluation of intraocular pressure (IOP) adjusted for central corneal thickness (CCT) screening for open-angle glaucoma (OAG) in an at-risk population.Study Design: Community-based screening clinic.Participants: Three hundred and forty-nine persons of black race, or >50 years of age, or with a positive family history of glaucoma.Methods: Ophthalmological examination including Goldmann applanation tonometry, ultrasonographic corneal pa-chymetry, and visual field testing. Glaucomatous optic nerve damage with visual field loss was the gold standard. IOP was adjusted for CCT based on 3 nomograms. Results were compared with screening using unadjusted IOP. Outcome measures included sensitivity, specificity, areas under the receiver operating characteristic (ROC) curves, positive and negative predictive values (PPVs and NPVs), as well as positive and negative likelihood ratios.Results: No significant difference in CCT was found between those with glaucoma (560 [SD 37] µm, n = 31) and those without (557 [SD 35] um, n = 233). Screening adjusted IOPs for glaucoma with an IOP > 21 mm Hg resulted in PPVs of 23.8% to 25% and NPVs of 89.3% to 89.6%, similar to preadjustment values. Areas under the ROC curves varied from 0.544 to 0.571 post adjustment from the initial value of 0.574.Conclusions: IOP adjusted for CCT is unlikely to improve tonometry as a screening tool for OAG in an at-risk population.     

Rescue of an extending capsulorrhexis by creating a midway tangential anterior capsular flap: a novel technique in 22 eyes

Objective: To show how an extending capsulorrhexis can be rescued by a midway tangential capsular flap in order to achieve an uneventful phacoemulsification.Design: Consecutive case series.Participants: Twenty-two eyes of 22 patients with extending capsulorrhexis treated at the Farabi Eye Hospital, Tehran.Methods: First, a tangential capsular opening was created on the border of the presumed continuous curvilinear capsulorrhexis just midway between the beginning of the capsulorrhexis and the edge of the extending capsulor-rhexis, to make a tangential flap of the anterior capsule. Second, the centre of this new flap was grasped and pulled centripetally until the edges of the new flap joined the edges of the extending flap to complete the capsulorrhexis.Results: The technique was successfully performed in all cases, leading to an uneventful phacoemulsification.Conclusions: Midway tangential capsular flap is a safe and effective technique to rescue an extending capsulorrhexis and leads to an uneventful phacoemulsification.     

Long term effect on IOP of a stainless steel glaucoma drainage implant (Ex-PRESS) in combined surgery with phacoemulsification

AIM: To evaluate the efficacy and safety of a stainless steel miniature glaucoma drainage device (Ex-PRESS R50) for the surgical treatment of primary open angle glaucoma (POAG) and cataract when combined with phacoemulsification. METHODS: Clinical, prospective, multicentre, single treatment arm, non-randomised, non-masked study. The Ex-PRESS device was implanted at the limbus under a conjunctival flap. Phacoemulsification cataract extraction and in the bag IOL implantation were performed through clear cornea temporally. Primary outcome: IOP change; secondary outcomes: side effects and VA changes. RESULTS: 26 eyes of 25 patients were implanted with the device. The mean (SD) follow up was 23.9 (10.4) months and the mean age was 75.1 (7.1) years. 17/26 eyes have more than 3 years of follow up. One case was discontinued because of device removal, one because of death, and three were lost to follow up. Efficacy: preoperative IOP was 21 (4) mm Hg; at 1, 2, and 3 years IOP was 15.3 (3.1) mm Hg (35% reduction), 16.6 (2.7) mm Hg (29% reduction), and 16 (2.6) mm Hg (22% reduction) respectively. Kaplan-Meyer determined overall success rate (IOP < or = 21 mm Hg at the last visit with or without medications) as 76.9%. The number of antiglaucoma medications was reduced by 95% at year 1. Only six patients (23%) were taking IOP lowering treatment at their last visit, five with one medication and one with two medications. Side effects: early postoperative complications were clinically mild and included six cases of hypotony (IOP <5 mm Hg), three cases of hyphaema (<2 mm) with no clinically significant further effects. Long term complications were two cases (7.7%) of device rotation (one treated by reposition) and three cases (11.5%) of conjunctival erosion at 2 and 3 years. CONCLUSIONS: The Ex-PRESS implant, combined with phacoemulsification cataract extraction, is clinically safe and effective, maintaining in the long term a large reduction in IOP and in the number of antiglaucoma medications.     

Delayed in-the-bag implantation of intraocular lens

Objective: To report delayed in-the-bag intraocular lens (IOL) implantation for patients who had undergone simultaneous phacoemulsification and vitreoretinal surgery.Design: Interventional case series.Participants: Delayed IOL implantation surgery was performed for 3 patients who had undergone simultaneous phacoemulsification and scleral buckling or vitrectomy surgery.Methods: The medical records of each patient, including the surgical findings and final refraction status, were reviewed retrospectively.Results: Successful in-the-bag IOL implantation surgeries without capsular tear were achieved 3 to 5 months after the initial surgeries. The postoperative refractive error ranged from plano to −1.00 D.Conclusions: Successful in-the-bag IOL implantation and satisfactory refraction were achieved in patients who had undergone simultaneous phacoemulsification and scleral buckling or vitrectomy surgery.     

Biomechanical considerations: evaluating scleral reinforcement materials for pathological myopia

Objective: Scleral biomechanical weakness and thinness are known to be one of the main factors in the pathogenesis of progressive myopia. Posterior scleral reinforcement surgery remains the rational treatment for pathological myopia. We tested the biomechanical properties of 3 types of scleral reinforcement materials (artificial pericardium, human sclera, and all-dermal matrix) in an attempt to select the ideal material for the reinforcement of pathologic sclera.Design: Experimental study.Participants: Forty-five adult Japanese white rabbits.Methods: Animals were equally divided into 3 groups. For each group, 1 type of material was surgically implanted at the back of the globe. We harvested samples after 10 months of implantation, tested the elasticity modulus for both reinforced sclera and unreinforced control sclera, and assessed data by t test methods. Statistically significant differences were considered when p < 0.05.Results: Rabbit sclera reinforced by artificial pericardium or human sclera showed significant increases in the elasticity modulus compared with control eyes. However, the rabbit sclera reinforced by all-dermal matrix showed no significant difference in the elasticity modulus compared with normal controls.Conclusions: The analysis of biomechanical considerations in scleral reinforcement materials presented here is a very helpful method to choose the best materials for treatment of myopia. Of all materials tested, the artificial pericardium and human foreign-body sclera provided the best biomechanical characteristics.     

Evaluation of Ahmed glaucoma valve implantation through a needle-generated scleral tunnel in Mexican children with glaucoma

Purpose:

To evaluate the results and extrusion rates of the Ahmed glaucoma valve (AGV) implantation through a needle-generated scleral tunnel, without a tube-covering patch, in children.

Materials and Methods:

A retrospective review of the charts of 106 Mexican children implanted with 128 AGVs operated between 1994 and 2002, with the needle track technique, at our institution, with at least six months follow up was done. Main outcome measures were intraocular pressure (IOP) control, tube extrusions or exposure and other complications.

Results:

Kaplan-Meier analysis demonstrated a 96.9% survival rate at six months, 82.4% at one year, 78.7% at two years, 70% at three years and 41.6% at four years. Total success at the last follow-up (IOP between 6 and 21 mm Hg without medications) was achieved in 30 eyes (23.5%), 58 eyes (45.3%) had qualified success (only topical hypotensive drugs) and 40 eyes (31.3%) were failures. The mean pre- and post-operative IOP at the last follow up was 28.4 mmHg (SD 9.3) and 14.5 mmHg (SD 6.3), respectively. No tube extrusions or exposures were observed. Tube-related complications included five retractions, a lens touch and a transitory endothelial touch. The risk of failure increased if the eye had any complication or previous glaucoma surgeries.

Conclusion:

Medium-term IOP control in Mexican children with glaucoma can be achieved with AGV implantation using a needle-generated tunnel, without constructing a scleral flap or using a patch to cover the tube. There were no tube extrusions, nor any tube exposures with this technique.     

Does the use of trypan blue during phacoemulsification affect the intraocular pressure?

Objective: The purpose of the study was to evaluate the effect of trypan blue on intraocular pressure (IOP) after small-incision cataract surgery.Design: Prospective, randomized study.Participants: Fifteen patients (30 eyes) with bilateral, dense, age-related cataracts.Methods: Patients with glaucoma, ocular hypertension, exfoliation, pigment dispersion syndrome, history of uveitis, recent use of topical or systemic steroids, and previous ocular surgery were excluded. The patients were randomly assigned to receive trypan blue during cataract surgery for enhancing capsulorrhexis in 1 of their eyes, while in the other eye, trypan blue was not used. Cataract surgery was performed in an identical fashion in both eyes, with a sutureless posterior limbal incision, phacoemulsification, and implantation of a foldable intraocular lens. The same viscoelastic (sodium hyaluronate) was used in all cases and was thoroughly aspirated at the end of the procedure. All patients received a single dose of 250 mg acetazolamide 8 hours after surgery. No other antiglaucomatous agent was used during surgery or postoperatively. The intraocular pressure (IOP) was measured preoperatively and at 24 hours, 1 week, 1 month, and 3 months postoperatively.Results: IOP values were similar in both groups at all 4 postoperative measurements. There was no statistically significant difference in postoperative IOP values between the eyes in which trypan blue was used and the control eyes.Conclusions: The use of trypan blue during small-incision cataract surgery does not have any effect on IOP during the immediate and early postoperative period.     

Transconjunctival suture adjustment for initial intraocular pressure control after trabeculectomy

PURPOSE: In an experimental human eye model of trabeculectomy, scleral flap suture adjustment allows predictable control of intraocular pressure (IOP). This approach had not previously been described in clinical use; we present a case series with the application of this technique. METHODS: A prospective, non-comparative interventional case series of consecutive patients undergoing trabeculectomy. Forty trabeculectomies were performed using a 3 mm x 4 mm scleral flap with two apical adjustable 10-0 nylon sutures under a fornix-based conjunctival flap. Intraoperatively the scleral flap sutures were tied tightly to appose the edges of the flap. All trabeculectomies were augmented with antimetabolite intraoperatively. On day one, patients with an IOP greater than 15 mm Hg had their suture tension adjusted to lower their IOP to a target range (10 to 15 mm Hg). Major outcome measures were IOP before and after adjustment and success at last follow-up (IOP < or = 15 mm Hg on no glaucoma medication and no clinically significant complications) without and with adjunctive needling. Other outcomes measured were postoperative complications, bleb needling, final bleb morphology, and visual acuity change from pre-operation to final follow-up. RESULTS: Average day one IOP was 14.8 mm Hg (standard deviation (SD) 7.8). Fourteen patients had a day one IOP over 15 mm Hg and underwent suture adjustment, lowering IOP to between 10 and 15 mm Hg. (Mean post adjustment IOP was 10.7 mm Hg (SD 3.6)). One patient had a conjunctival tear intraoperatively. Four patients had transient wound leaks. No patients had shallow anterior chambers. All but four had diffuse blebs at last follow-up. Success rate without any further surgical intervention was 75%, and success rate with adjunctive needling was 100%. The mean duration of follow-up was 6.3 months (range 1-12 months). CONCLUSION: The approach of tying scleral flap sutures tightly with transconjunctival adjustment of sutures if the IOP is greater than 15 mm Hg on day one allows excellent control of early postoperative IOP.     

Canadian Glaucoma Study: 1. Study design, baseline characteristics, and preliminary analyses

Background: The Canadian Glaucoma Study is a multicentred, prospective longitudinal study designed to study a variety of systemic risk factors for the progression of open-angle glaucoma under a standardised interventional protocol for intraocular pressure (IOP) control.Methods: Newly or previously diagnosed patients with early to moderate open-angle glaucoma were recruited consecutively from 5 hospital-based university departments. Baseline parameters, including an assessment of peripheral vasospasm, haematologic, coagulation, and immunopathologic variables were obtained. Newly diagnosed patients were targeted for a ≥30% reduction in IOP, whereas previously diagnosed patients entered the study at a physician-defined target IOP. After baseline examinations, patients were followed at 4-month intervals with standard automated perimetry, short-wavelength automated perimetry, and confocal scanning laser tomography, and at 28-32-month intervals with stereo disc photography. If the patient had visual field progression with standard automated perimetry, a further ≥20% reduction in IOP was mandated. A standardized IOP treatment protocol, ranging from topical monotherapy to filtration surgery, was implemented.Results: A total of 258 patients (130 men and 128 women, median age 65.0 years) were enrolled. Baseline median values for visual acuity, visual field mean deviation, untreated IOP, and refractive error were 0.10 logMAR, −4.04 dB, 25.0 mm Hg, and 0.00 D, respectively. Approximately 30% of the patients were hypertensive, 16% had cardiovascular disease, 9% thyroid disease, 9% diabetes, 14% migraine, and 19% were smokers.The median follow-up was 5.3 years, with 148 (57.0%) and 51 (19.8%) patients completing ≥5 and ≥7 years follow-up, respectively. The cumulative visual field progression rate at 2,4,6, and 8 years was 11.3%, 21.5%, 33.1%, and 43.5%, respectively.Interpretation: We describe the study design and baseline patient characteristics of the Canadian Glaucoma Study and present some preliminary results. This long and close followup of a large group of patients will reveal the importance of several systemic factors for the progression of glaucoma.     

Medical control of intraocular pressure with brinzolamide 1% after phacoemulsification

Background: To compare the effectiveness of only 1 drop of topical brinzolamide 1% with dosing every 12 hours and with no ocular hypotensive medication following clear corneal phacoemulsification surgery.Methods: This prospective, randomized, double-blind study was composed of 60 eyes of 60 patients who underwent uneventful clear corneal phacoemulsification surgery under topical anesthesia. There were no intraoperative complications. Eyes were randomized to receive only 1 drop of topical brinzolamide 1% immediately after surgery, 1 drop of brinzolamide 1% every 12 (q12h) hours starting immediately after speculum removal, or no ocular hypotensive medication (control group). Intraocular pressure (IOP) was measured preoperatively and at 4 to 6 hours and 18 to 24 hours postoperatively by a Perkins tonometer.Results: Preoperative IOP was not significantly different among the 3 groups. IOPs of both the brinzolamide 1 drop group (p = 0.000) and the brinzolamide q12h group (p = 0.001) were significantly lower than those of the control group at 4 to 6 hours postoperatively. The same result was observed at 18 to 24 hours postoperatively in the brinzolamide q12h group (p = 0.001) but not the brinzolamide 1 drop group (p = 0.489). The brinzolamide q12h group had significantly lower IOP compared with the brinzolamide 1 drop group (p = 0.000) at 18 to 24 hours postoperatively. None of the eyes in the medication groups, but 1 eye (5%) in the control group, had postoperative IOP elevation ≥30 mm Hg at 4 to 6 hours; such an elevation was not encountered at postoperative 18 to 24 hours. Preoperative to postoperative IOP increase of >5 mm Hg at 4 to 6 hours postoperatively was seen in 4 (20%), 4 (20%), and 14 (70%) eyes in the brinzolamide 1 drop group, the brinzolamide q12h group, and the control group, respectively.Interpretation: The current study reveals that 1 drop of brinzolamide 1% is sufficient to control IOP within the first 4 to 6 hours following uneventful phacoemulsification, whereas 12-hour dosing is necessary for prolonged control of IOP.