Intermediate-term Outcome and Success of Superior Versus Inferior Ahmed Glaucoma Valve Implantation:

Superonasal vs Inferonasal Subconjunctival Gel Stent Placement in Patients with Glaucoma

Aim and background

To compare the safety and efficacy of subconjunctival gel stent implantation in the superonasal (SN) vs inferonasal (IN) quadrants in the treatment of glaucoma.

Materials and methods

Patients with a history of IN (n = 29) or SN, (n = 96) gel stent placement with ≥3 months of follow-up were included. Intraocular pressure (IOP) and the number of glaucoma medications were collected preoperatively and postoperatively at months 1, 3, 6, and 12. Safety measures included the number of bleb needlings, complication rate, and additional surgeries.

Results

Mean baseline IOP was 32.4 ± 11.7 mm Hg in the IN group and 21.6 ± 9.2 mm Hg in the SN group (p < 0.01). IOP was similar between groups at 3 months (IN = 15.8, SN = 15.6, p = 0.45), 6 months (IN = 17.4, SN = 15, p = 0.13), and 12 months (IN = 17.9, SN = 14.7, p = 0.15) follow-up. The number of glaucoma medications was also similar at 3 months (p = 0.31), 6 months (p = 0.24), and 12 months (p = 0.39) follow-up. Bleb needling rates were similar with 51.7% (15/29) in the IN group vs 42.7% (41/96) in the SN group (p = 0.39) and subjects requiring further surgery were 17.2% (5/29) in the IN group vs 24.0% (23/96) in the SN group (p = 0.45).

Conclusion

Both IN and SN subconjunctival gel stent placements provide favorable safety and efficacy when treating open-angle glaucoma, with a meaningful decrease in medication use and IOP.

Clinical significance

Implantation of the subconjunctival gel stent in the IN quadrant is an effective and safe alternative to superior implantation in refractory glaucoma.

How to cite this article

Vander Zee BL, Wilson C, Berdahl JP, et al. Superonasal vs Inferonasal Subconjunctival Gel Stent Placement in Patients with Glaucoma. J Curr Glaucoma Pract 2024;18(2):63-67.

Management of a recurrent encapsulated bleb with a cost-effective non-valved glaucoma drainage device

Despite the advancements in the surgical management of glaucoma, childhood glaucoma remains a challenging surgical disease worldwide. An early adolescent boy with primary congenital glaucoma, status after glaucoma drainage device (GDD) implantation, on maximum medical therapy, was presented with a swelling in the superotemporal orbital region. The patient had undergone an uneventful GDD implantation 2 years prior to presentation. A similar swelling, which was diagnosed to be a Tenon's cyst, had been excised on three earlier occasions. Given that the repeat capsular excision would also have the same likelihood of failure, and poor intraocular pressure control, a non-valved, cost-effective Aurolab aqueous drainage implant (AADI, Aurolab, Madurai, India) implantation was done inferonasally. In this patient, AADI proved to be a safe and effective alternative for the known GDDs.

Outcomes of XEN Gel Stent Implantation in the Inferonasal Quadrant after Failed Trabeculectomy

Aim and objective

To evaluate the efficacy and safety of XEN stent implantation in the inferonasal quadrant after prior failed trabeculectomy.

Materials and methods

Fourteen open-angle glaucoma patients with prior failed trabeculectomy were recruited to this retrospective study. Implantation of the stent was performed as a stand-alone procedure. The mean follow-up duration was 14.2 months. Best-corrected visual acuity, intraocular pressure (IOP), number of medications, complications, and the requirement for additional procedures were among the outcome measures recorded.

Results

Mean IOP reduced by 49.3% from 24.14 ± 2.74 mm Hg preoperatively to 12.23 ± 2.89 mm Hg at month 12 (p < 0.001). Medication usage reduced from 3.71 ± 0.47 medications preoperatively to 1.31 ± 1.55 at month 12 (p = 0.003). Adverse events included transient slight intracameral hemorrhage (5 eyes, 35.7%), second trabeculectomy required (2 eyes, 14.3%), and numerical hypotony (IOP <5 mm Hg, in 3 cases, 21.4%), all of which resolved spontaneously. Six eyes (42.8%) required postoperative bleb needling to further reduce IOP. There were no cases of vision loss, stent exposure, hypotony, lower eyelid malposition, bleb dysesthesia, or bleb-related infection.

Conclusion

XEN gel stent implantation in the inferonasal quadrant can be considered a viable surgical option for patients with a history of previously failed trabeculectomy requiring further IOP lowering.

Clinical significance

To the best of our knowledge, this is the first case series describing the outcome of inferonasal implantation of XEN gel stent following failed trabeculectomy.

How to cite this article

Düzgün E, Olgun A, Karapapak M, et al. Outcomes of XEN Gel Stent Implantation in the Inferonasal Quadrant after Failed Trabeculectomy. J Curr Glaucoma Pract 2021;15(2):64–69.

Surgical Outcomes of Superotemporal Versus Inferonasal Placement of Aurolab Aqueous Drainage Implant in Refractory Pediatric Glaucoma

PURPOSE

We sought to describe the outcomes of the Aurolab aqueous drainage implant (AADI) placed in the superotemporal (ST) versus the inferonasal (IN) quadrant in pediatric eyes with refractory glaucoma.

DESIGN

Retrospective comparative interventional case series.

METHODS

This was a retrospective study of patients ≤18 years of age who underwent AADI implantation and completed a minimum of 2-year follow-up. The choice of the quadrant depended upon the amount of scarring and conjunctival mobility. Cumulative success at 2 years was defined as intraocular pressure (IOP) ≤21 mm Hg or reduced by ≥20% below baseline on 2 consecutive follow-up visits after 3 months, IOP ≤5 mm Hg on 2 consecutive follow-up visits after 3 months, reoperation for glaucoma or a complication, or loss of light perception vision.

RESULTS

A total of 144 patients (144 eyes) underwent AADI placement, including 48 eyes (33%) in the IN and 96 eyes (67%) in the ST quadrants. The IOP was significantly higher in the IN group (17.5 ± 7.4 mm Hg vs 13.7 ± 6.2 mm Hg, P = .005) with a greater number of medications (1.5 ± 1.0 vs 0.8 ± 0.9, P = .001) after 2 years of follow-up. Cumulative success rates at 2 years were 50.7% (95% confidence interval 35.4%-63.9%) in the IN group and 65.6% (95% confidence interval 56.5%-75.7%) in the ST group (P = .15). Complications occurred more frequently in the IN group, with significantly more tube exposure (12% vs 0%, P = .05).

CONCLUSIONS

Placement of the AADI in the ST quadrant has better IOP-related outcomes and is a safer surgical option in pediatric eyes compared with the IN quadrant. It may be prudent to avoid AADI in the IN quadrant in children unless the ST location is not a viable option.

Comparison of outcomes between Aurolab aqueous drainage implant placed in the superotemporal versus inferonasal quadrant

Aim

To determine the outcomes of Aurolab aqueous drainage implant (AADI) placed in the superotemporal versus the inferonasal quadrant in adult eyes with refractory glaucoma.

Methods

This was a retrospective study of eyes that had AADI placement and completed a minimum of 2-year follow-up. The choice of the quadrant was at the surgeon’s discretion and mainly depended on the amount of scarring and conjunctival mobility. The cumulative failure rate of the AADI was defined as intraocular pressure (IOP) >21 mm Hg or not reduced by 20% below baseline on two consecutive follow-up visits after 3 months, IOP ≤5 mm Hg on two consecutive follow-up visits after 3 months, reoperation for glaucoma or a complication, or loss of light perception vision.

Results

We included 84 eyes with AADI in the inferonasal quadrant versus 69 eyes in the superotemporal quadrant. A significant drop in IOP was seen in both groups (18.4±10.4 mm Hg in the inferonasal group vs 17.7±11.1 mm Hg in the superotemporal group; p=0.63) at 3-month follow-up and this was maintained until last follow-up. Best-corrected visual acuity, IOP, number of IOP-lowering medications and complications were similar between the two groups at all time points. The cumulative success rate at 2-year follow-up without IOP-lowering medications was 57.1% (47.1%–68.1%) in the inferonasal group and 50.7% (39.8%–63.1%) in the superotemporal group (p=0.47).

Conclusions

Inferonasal AADI placement appears to be an equally safe and effective surgical option compared with superotemporal AADI placement and may be helpful in certain clinical situations.

Pars plana Ex-Press mini shunt for management of persistent glaucoma in vitrectomized eyes: A novel technique

PURPOSE

To evaluate the safety and efficacy of a novel approach to implant Ex-Press mini shunt via the pars plana under a scleral flap in pseudophakic or aphakic, vitrectomized patients with secondary refractory glaucoma.

METHODS

A prospective interventional case series of three patients with secondary glaucoma after pars plana vitrectomy. Intraocular pressure was not controlled by silicone oil removal, if the patient was siliconized, nor the maximum medical treatment. Ex-Press mini shunt via the pars plana was implanted. We evaluated the control of intraocular pressure and the development of intraoperative and postoperative complications.

RESULTS

During 1-year follow-up, control of intraocular pressure was achieved; 14, 15, and 15 mmHg at the 3 months, and 15, 15, and 16 mmHg at the 6 months in our three cases without antiglaucoma treatment and 16, 16, and 18 with single antiglaucoma medication at 1 year. Blebs were posterior and diffuse. No complications were encountered intraoperatively or postoperatively. Ultrasound biomicroscopy showed suprachoroidal posterior lake of fluid as an additional filtration route without any choroidal or retinal complication.

CONCLUSION

Implantation of Ex-Press mini shunt via the pars plana in aphakic or pseudophakic, vitrectomized eyes is a promising, safe, and effective technique in patients with secondary glaucoma.

ADVERSE EVENTS OF THE ARGUS II RETINAL PROSTHESIS: Incidence, Causes, and Best Practices for Managing and Preventing Conjunctival Erosion

PURPOSE

To analyze and provide an overview of the incidence, management, and prevention of conjunctival erosion in Argus II clinical trial subjects and postapproval patients.

METHODS

This retrospective analysis followed the results of 274 patients treated with the Argus II Retinal Prosthesis System between June 2007 and November 2017, including 30 subjects from the US and European clinical trials, and 244 patients in the postapproval phase. Results were gathered for incidence of a serious adverse event, incidence of conjunctival erosion, occurrence sites, rates of erosion, and erosion timing.

RESULTS

Overall, 60% of subjects in the clinical trial subjects versus 83% of patients in the postapproval phase did not experience device- or surgery-related serious adverse events. In the postapproval phase, conjunctival erosion had an incidence rate of 6.2% over 5 years and 11 months. In 55% of conjunctival erosion cases, erosion occurred in the inferotemporal quadrant, 25% in the superotemporal quadrant, and 20% in both. Sixty percent of the erosion events occurred in the first 15 months after implantation, and 85% within the first 2.5 years.

CONCLUSION

Reducing occurrence of conjunctival erosion in patients with the Argus II Retinal Prosthesis requires identification and minimization of risk factors before and during implantation. Implementing inverted sutures at the implant tabs, use of graft material at these locations as well as Mersilene rather than nylon sutures, and accurate Tenon's and conjunctiva closure are recommended for consideration in all patients.

Partial thickness cornea tissue from small incision lenticule extraction: A novel patch graft in glaucoma drainage implant surgery

OBJECTIVE

The aim of the present study was to observe the feasibility and effect of cornea slice acquired from femtosecond laser surgery, small incision lenticule extraction (SMILE) as patch graft for the prevention of drainage tube exposure and to compare with the sclera.

METHODS

The research is a prospective comparative randomized study. Patients who received Ahmed glaucoma valve implantation surgery from August 2015 to January 2017 at the Xiamen Eye Center were randomly divided into 2 groups. Group A (corneal group) included 131 cases (135 eyes), receiving the 3 layers of allogeneic cornea slices as graft. Group B (scleral group) included 124 cases (127 eyes), using the sclera as allograft. The appearance, graft, conjunctiva melting, and tube exposure were the primary observation points.

RESULTS

After followed up for 6 to 20 months, a thinner appearance was seen in 3 eyes (2.2%) in the corneal graft group and 7 eyes (5.5%) in the scleral group. Conjunctiva melted and drainage tube exposed in 0 eyes (0%) in the corneal graft group and 2 eyes (1.6%) in the scleral group. One eye needed repair surgery. There was no statistical difference between the 2 groups (P > .05). After surgery, the intraocular pressure was reduced significantly in both groups (P < .05). The white sclera slice could be seen under the conjunctiva, thereby affecting the cosmetic appearance.

CONCLUSION

The cornea slice acquired from SMILE surgery can effectively prevent drainage tube exposure. Moreover, it is easy to acquire, safe, and cheaper, giving the patient a better cosmetic appearance.

Quantification of the Posterior Cornea Using Swept Source Optical Coherence Tomography

Purpose

We define optical coherence tomography (OCT) measurement parameters of the corneal endothelium/Descemet's membrane (DM) complex and peripheral transition zone (TZ) and describe these measurements in an ethnically Chinese population.

Methods

OCT images of the anterior segment and iridocorneal angle were obtained from 129 healthy Chinese subjects (129 eyes), aged 40 to 81 years. The scleral spur (SS) and Schwalbe's line (SL) were identified in each image. Endothelium/DM diameter, referred to as endothelial arc length (EAL), is the SL-to-SL distance. The SS-to-SL distance encompasses the TZ and trabecular meshwork (TM). Since the TZ cannot be visualized by OCT, a ratio of TZ-to-TZ+TM width was calculated from scanning electron microscopy (SEM) images obtained from 5 cadaveric corneas. The SS-to-SL distance was multiplied by this ratio to approximate in vivo TZ width.

Results

From SEM measurements, the relationship TZ = 0.20*(TZ+TM) was determined. From OCT measurements, mean EAL was 12.15 ± 0.58 mm and mean TZ width was 156 ± 20 μm. For eyes with horizontal and vertical images, vertical EAL was significantly greater than horizontal EAL (P = 0.03).

Conclusions

Corneal endothelium/DM diameter and TZ width can be obtained from OCT images. Although only combined TZ+TM is visualized on OCT, TZ width can be reasonably approximated.

Translational Relevance

Emerging procedures, like endothelial cell injection and DM transplantation (DMT), require accurate measurements of endothelium/DM size for preoperative planning. Size of the TZ, which may contain progenitor cells, also could contribute to endothelial regeneration in these procedures.

Upper Eyelid Splitting to Facilitate the Insertion of Glaucoma Drainage Devices

PURPOSE

To describe a new application for vertical splitting of the upper eyelid, a technique traditionally used for orbital access, to facilitate glaucoma drainage device (GDD) implantation in patients with poor surgical exposure.

METHODS

Case series.

CASES

We present a case of Möbius syndrome with complete restriction of the extraocular muscles, followed by a case of cicatricial narrowing of the palpebral fissures due to chronic allergic dermatitis. Both patients had severe, medically uncontrolled glaucoma, but poor surgical exposure precluded implantation of a GDD. Both cases underwent vertical splitting of the upper eyelid, which allowed for adequate exposure of the superior globe quadrants and successful implantation of a GDD.

CONCLUSIONS

A variety of congenital or acquired conditions result in narrowing of the palpebral fissure or restriction of extraocular motility. When these patients have concurrent advanced glaucoma, inadequate surgical exposure can impede necessary surgical intervention. Use of a vertical upper eyelid split technique allows for access to the superior globe and facilitates implantation of a GDD.

Aqueous shunts for glaucoma

BACKGROUND

Aqueous shunts are employed to control intraocular pressure (IOP) for people with primary or secondary glaucomas who fail or are not candidates for standard surgery.

OBJECTIVES

To assess the effectiveness and safety of aqueous shunts for reducing IOP in glaucoma compared with standard surgery, another type of aqueous shunt, or modification to the aqueous shunt procedure.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 8), MEDLINE Ovid (1946 to August 2016), Embase.com (1947 to August 2016), PubMed (1948 to August 2016), LILACS (Latin American and Caribbean Health Sciences Literature Database) (1982 to August 2016), ClinicalTrials.gov (www.clinicaltrials.gov); searched 15 August 2016, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 15 August 2016. We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 15 August 2016. We also searched the reference lists of identified trial reports and the Science Citation Index to find additional trials.

SELECTION CRITERIA

We included randomized controlled trials that compared various types of aqueous shunts with standard surgery or to each other in eyes with glaucoma.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results for eligibility, assessed the risk of bias, and extracted data from included trials. We contacted trial investigators when data were unclear or not reported. We graded the certainty of the evidence using the GRADE approach. We followed standard methods as recommended by Cochrane.

MAIN RESULTS

We included 27 trials with a total of 2099 participants with mixed diagnoses and comparisons of interventions. Seventeen studies reported adequate methods of randomization, and seven reported adequate allocation concealment. Data collection and follow-up times varied.Four trials compared an aqueous shunt (Ahmed or Baerveldt) with trabeculectomy, of which three reported one-year outcomes. At one-year, the difference in IOP between aqueous shunt groups and trabeculectomy groups was uncertain (mean difference (MD) 2.55 mmHg, 95% confidence interval (CI) -0.78 to 5.87; 380 participants; very low-certainty evidence). The difference in logMAR visual acuity was also uncertain (MD 0.12 units, 95% CI -0.07 to 0.31; 380 participants; very low-certainty evidence). In two trials, the difference in visual field score was uncertain (MD -0.25, 95% CI -1.91 to 1.40; 196 participants; very low-certainty evidence). The mean number of antiglaucoma medications was higher in the aqueous shunt group than the trabeculectomy group in one trial (MD 0.80, 95% CI 0.48 to 1.12; 184 participants; low-certainty evidence). The effect on needing additional glaucoma surgery was uncertain between groups in two trials (risk ratio (RR) 0.24, 95% CI 0.04 to 1.36; 329 participants; very low-certainty evidence). In one trial, fewer total adverse events were reported in the aqueous shunt group than the trabeculectomy group (RR 0.59, 95% CI 0.43 to 0.81; 212 participants; very low-certainty evidence). No trial reported quality-of-life outcomes at one-year follow-up.Two trials that compared the Ahmed implant with the Baerveldt implant for glaucoma found higher mean IOP in the Ahmed group at one-year follow-up (MD 2.60 mmHg, 95% CI 1.58 to 3.62; 464 participants; moderate-certainty evidence). The difference in logMAR visual acuity was uncertain between groups (MD -0.07 units, 95% CI -0.27 to 0.13; 501 participants; low-certainty evidence). The MD in number of antiglaucoma medications was within one between groups (MD 0.35, 95% CI 0.11 to 0.59; 464 participants; moderate-certainty evidence). More participants in the Ahmed group required additional glaucoma surgery than the Baerveldt group (RR 2.77, 95% CI 1.02 to 7.54; 514 participants; moderate-certainty evidence). The two trials reported specific adverse events but not overall number of adverse events. Neither trial reported visual field or quality-of-life outcomes at one-year follow-up.One trial compared the Ahmed implant with the Molteno implant for glaucoma over two-year follow-up. Mean IOP was higher in the Ahmed group than the Molteno group (MD 1.64 mmHg, 95% CI 0.85 to 2.43; 57 participants; low-certainty evidence). The differences in logMAR visual acuity (MD 0.08 units, 95% CI -0.24 to 0.40; 57 participants; very low-certainty evidence) and mean deviation in visual field (MD -0.18 dB, 95% CI -3.13 to 2.77; 57 participants; very low-certainty evidence) were uncertain between groups. The mean number of antiglaucoma medications was also uncertain between groups (MD -0.38, 95% CI -1.03 to 0.27; 57 participants; low-certainty evidence). The trial did not report the proportion needing additional glaucoma surgery, total adverse events, or quality-of-life outcomes.Two trials compared the double-plate Molteno implant with the Schocket shunt for glaucoma; one trial reported outcomes only at six-month follow-up, and the other did not specify the follow-up time. At six-months, mean IOP was lower in the Molteno group than the Schocket group (MD -2.50 mmHg, 95% CI -4.60 to -0.40; 115 participants; low-certainty evidence). Neither trial reported the proportion needing additional glaucoma surgery, total adverse events, or visual acuity, visual field, or quality-of-life outcomes.The remaining 18 trials evaluated modifications to aqueous shunts, including 14 trials of Ahmed implants (early aqueous suppression versus standard medication regimen, 2 trials; anti-vascular endothelial growth factor agent versus none, 4 trials; corticosteroids versus none, 2 trials; shunt augmentation versus none, 3 trials; partial tube ligation versus none, 1 trial; pars plana implantation versus conventional implantation, 1 trial; and model M4 versus model S2,1 trial); 1 trial of 500 mm² Baerveldt versus 350 mm² Baerveldt; and 3 trials of Molteno implants (single-plate with oral corticosteroids versus single-plate without oral corticosteroids, 1 trial; double-plate versus single-plate, 1 trial; and pressure-ridge versus double-plate with tube ligation, 1 trial).

AUTHORS' CONCLUSIONS

Information was insufficient to conclude whether there are differences between aqueous shunts and trabeculectomy for glaucoma treatment. While the Baerveldt implant may lower IOP more than the Ahmed implant, the evidence was of moderate-certainty and it is unclear whether the difference in IOP reduction is clinically significant. Overall, methodology and data quality among existing randomized controlled trials of aqueous shunts was heterogeneous across studies, and there are no well-justified or widely accepted generalizations about the superiority of one surgical procedure or device over another.

Partial thickness corneal tissue as a patch graft material for prevention of glaucoma drainage device exposure

Background

To protect from erosion of the tube in glaucoma drainage device (GDD), the tube is covered by a biologic tissue which is roofed by the conjunctiva. Sclera, pericardium, dura mater and cornea are available as a patch graft. Drawbacks of some of these materials may include high cost and poor appearance. The purpose of this study is to report the long-term outcomes of partial thickness corneal grafts to cover the tube and prevent its exposure, in GDD surgeries.

Methods

This was a retrospective review of all patients who underwent Ahmed glaucoma valve implantation and had a minimum follow-up of 12 months. The tube was covered by a 300-micron partial thickness corneal graft taken either from a previous Descemet stripping endothelial keratoplasty procedure or cut from a whole corneal graft button unsuitable for keratoplasty.

Results

Forty-four patients (45 eyes, mean follow-up of 27.6 ± 11.4 months) were enrolled. The partial thickness corneal grafts maintained clarity throughout follow-up with satisfactory cosmetic results. Mild conjunctival retraction occurred in 4 eyes (8.9 %) between 1 and 12 months after the surgery. Corneal graft melting occurred in 3 (6.7 %) eyes. Tube exposure and additional surgery to re-patch or suture the conjunctiva over the tube was needed in 1 (2.2 %) eye. None of the patients had graft infection or immunologic rejection.

Conclusions

Partial thickness corneal grafts have favorable long-term outcome as a patch for GDD tubes with low rates of tube exposure and other complications.

Glaucoma drainage devices: risk of exposure and infection

PURPOSE

To identify risk factors for device exposure and intraocular infection following implantation of a glaucoma drainage device.

DESIGN

Retrospective case series.

METHODS

The medical records of adult patients undergoing glaucoma drainage device implantation at an academic medical center between 2000 and 2010 were reviewed. Main outcome measures included device exposure and intraocular infection.

RESULTS

Seven hundred and sixty-three cases were identified. These included 702 primary implants (ie, the first drainage device implanted into an eye) and 61 sequential implants. Among 702 primary implants, there were 41 cases of exposure (5.8%). None of the potential risk factors were statistically significant. Implant location was found to be a marginally significant risk factor. The exposure rates for inferior and superior implants were 12.8% (5 of 39) and 5.4% (36 of 663), respectively (P = .056). The highest rate of exposure for primary implants occurred in the inferior-nasal quadrant (17.2%, 5 of 29). The rate of exposure for sequential devices was 13.1% (8 of 61), with the highest rate also found in the inferior-nasal quadrant (20%, 5 of 25). Of 49 total exposures, 8 were associated with intraocular infection (16.3%). Exposures over inferior implants were more likely to be associated with infection than exposures over superior implants (41.7% vs 8.1%; P = .0151).

CONCLUSION

Implant location approached, but did not reach, statistical significance as a risk factor for exposure. Exposures over inferior implants place patients at a higher risk of infection than superior exposures. More studies are needed to identify modifiable risk factors for device exposure.

Surgical outcomes of superior versus inferior glaucoma drainage device implantation

PURPOSE

To compare the safety and intraocular pressure (IOP) lowering efficacy of initial glaucoma drainage device (GDD) implantation performed at the superior versus inferior limbus.

METHODS

A retrospective chart review was conducted to identify patients with glaucoma who had undergone initial Baerveldt GDD surgery at the inferior limbus for uncontrolled IOP. All eyes of patients had a minimum of 6 months of postoperative follow-up. These eyes were frequency-matched to eyes with initial Baerveldt GDD implantation performed at the superior limbus, within 5 years of age and 6 months of follow-up. Baseline demographic and clinical information, as well as preoperative and postoperative IOP, visual acuity, and number of antiglaucoma medications were extracted. Failure was defined as IOP>21 mm Hg or not reduced by 20% below baseline on 2 consecutive follow-up visits after 3 months, IOP≤5 mm Hg on 2 consecutive follow-up visits after 3 months, reoperation for glaucoma, or loss of light perception vision. Statistical methods consisted of Student t tests, χ test, and Kaplan-Meier time to failure analysis.

RESULTS

Fifty eyes (17 inferior, 33 superior) of 43 patients were enrolled. Mean postoperative follow-up in both groups were similar (mean 26.2±15.2 mo for inferior and 23.9±10.43 mo for superior, P=0.54). Trabeculectomy had been performed previously in 8/17 (47%) and 11/33 (33%) eyes (P=0.34) with inferior and superior implants, respectively. Mean preoperative IOP (mm Hg) in the superior group (26±11) was significantly higher (P=0.02) when compared with the inferior group (21±7). Success rates were similar (P>0.05) between the inferior and superior GDD groups during the study period, with 64.7% and 75.8% classified as successful at 1-year of follow-up and 43.1% and 65.7% at 2 years of follow-up, respectively. There was no difference in cumulative proportions of eyes failing between the groups (P=0.20, log-rank test). The mean postoperative IOP and number of antiglaucoma medications were similar (all P>0.05) in both groups during the first 2 years of postoperative follow-up. The frequency and types of postoperative complications in both the groups were similar. The 36-month cumulative reoperation rates for IOP control were 33.8% and 9.1%, respectively, in the inferior and superior GDD groups (P=0.04 log-rank test).

CONCLUSIONS

No differences were observed in the overall success rates of initial GDD implantation performed at the superior and inferior limbus in this cohort. However, inferior GDD implantation was associated with a greater incidence of reoperation for IOP control.

Hypertensive phase and early complications after Ahmed glaucoma valve implantation with intraoperative subtenon triamcinolone acetonide

Objective

To evaluate intraoperative subtenon triamcinolone acetonide (TA) as an adjunct to Ahmed glaucoma valve (AGV) implantation.

Design

Retrospective comparative case series.

Participants

Forty-two consecutive cases of uncontrolled glaucoma undergoing AGV implantation: 19 eyes receiving intraoperative subtenon TA and 23 eyes that did not receive TA.

Methods

A retrospective chart review was performed on consecutive pseudophakic adult patients with uncontrolled glaucoma undergoing AGV with and without intraoperative subtenon TA injection by a single surgeon. Clinical data were collected from 42 eyes and analyzed for the first 6 months after surgery.

Main outcome measures

Primary outcomes included intraocular pressure (IOP) and number of glaucoma medications prior to and after AGV implantation. The hypertensive phase (HP) was defined as an IOP measurement of greater than 21 mmHg (with or without medications) during the 6-month postoperative period that was not a result of tube obstruction, retraction, or malfunction. Postoperative complications and visual acuity were analyzed as secondary outcome measures.

Results

Five out of 19 (26%) TA cases and 12 out of 23 (52%) non-TA cases developed the HP (P=0.027). Mean IOP (14.2±4.6 in TA cases versus [vs] 14.7±5.0 mmHg in non-TA cases; P=0.78), and number of glaucoma medications needed (1.8±1.3 in TA cases vs 1.6±1.1 in the comparison group; P=0.65) were similar between both groups at 6 months. Although rates of serious complications did not differ between the groups (13% in the TA group vs 16% in the non-TA group), early tube erosion (n=1) and bacterial endophthalmitis (n=1) were noted with TA but not in the non-TA group.

Conclusions

Subtenon TA injection during AGV implantation may decrease the occurrence of the HP but does not alter the ultimate IOP outcome and may pose increased risk of serious complications within the first 6 months of surgery.

[Current surgical methods for advanced glaucoma]

The author summarizes the most effective types of glaucoma surgery in advanced glaucoma. In high pressure advanced glaucoma a low target intraocular pressure is to be set. The most effective method of reaching this target pressure level is mitomycin C trabeculectomy combined with effective pre- and postoperative antiinflammatory treatment. However, in several cases glaucoma filtering surgery gradually fails due to increased episcleral fibrosis. In these cases use of long-tube glaucoma drainage devices is recommended. In Hungary use of the Ahmed implant has provided favourable clinical outcome even in the most complicated, high pressure, advanced glaucoma cases. Modern types of surgical treatment of advanced glaucoma need to be known by non-ophthalmologist physicians for more than a decade. This may help them to propose the optimal treatment modality to their glaucoma patients.

Clinical outcomes of Ahmed Glaucoma valve in posterior segment versus anterior chamber

PURPOSE

To compare the intermediate-term intraocular pressure (IOP) control and complication profile of the Ahmed Glaucoma Valve (AGV) implanted posteriorly through the pars plana in eyes undergoing concurrent pars plana vitrectomy (PPV) with device implantation in the anterior chamber (AC) in nonvitrectomized eyes.

METHODS

: We retrospectively reviewed the medical records of 31 case eyes (30 patients) with refractory glaucoma that underwent posterior implantation of AGV after complete PPV and compared them to 31 control eyes (31 patients) with refractory glaucoma that underwent implantation of AGV in the AC. Case-control patients were matched one-to-one on the basis of principal glaucoma diagnosis. All surgeries were performed at 1 institution using a silicone-plate device. Success was defined as intraocular pressure (IOP)≥ 5 mm Hg and ≤ 21 mm Hg with or without glaucoma medications at final follow-up, no additional glaucoma surgery, no removal of the implant, and no loss of light perception.

RESULTS

The average follow-up was 20.9 months (range, 6 to 54 mo) for the posterior group and 20.5 months (range, 4 to 48 mo) for the anterior group. The reduction in IOP was similar in both groups at all postoperative time points. The number of postoperative glaucoma medications in both groups was not statistically different at final follow-up. Success rates at final follow-up were identical, 83.9% in both groups, and Kaplan-Meier survival curve analysis showed no significant difference between the 2 groups (P=0.96). Postoperative complications were similar between the 2 groups, except there were more instances of early postoperative flat AC in the anterior group than the posterior group (P=0.01).

CONCLUSIONS

The AGV can similarly control IOP in the majority of cases, whether the tube is placed in the posterior segment after PPV or in the AC of nonvitrectomized eyes.