Outcomes of Inferonasal Baerveldt Glaucoma Drainage Implant Surgery

Ahmed Glaucoma Valve Implantation to Reduce Intraocular Pressure: Updated Perspectives

Trabeculectomy and glaucoma drainage device implantation are the most commonly performed glaucoma surgeries worldwide. Although trabeculectomy is the gold standard, at the present time there is an increase in the use of glaucoma drainage devices. The Ahmed glaucoma valve is one of the most widely used glaucoma drainage devices worldwide. Corneal endothelial cell loss and eventually corneal decompensation is one of the serious complication of glaucoma drainage device implantation. To avoid this, drainage tube can be inserted into the ciliary sulcus instead of the anterior chamber, especially in eyes with high risk for corneal decompensation. Tube/plate exposure, hypertensive phase, endophthalmitis, cataract formation, diplopia and ocular hypotony are the other potential complications that can develop after Ahmed glaucoma valve implantation.

Racial Disparities Affecting Black Patients in Glaucoma Diagnosis and Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Racial Disparities Affecting Black Patients In Glaucoma Diagnosis And Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Differences in the Surgical Outcomes of Glaucoma Surgery in Patients of African Caribbean Descent

PURPOSE

People of African Caribbean Descent (ACD) have a higher prevalence of glaucoma compared to people of European Descent (ED) and there is uncertainty if treatment outcomes are equivalent between the two groups. To assess surgical failure rates comparing ACD with ED focusing on trabeculectomy, aqueous shunt implantation, non-penetrating filtering surgery (NPFS), and minimally invasive glaucoma surgery (MIGS) by performing a systematic review in accordance with the PRISMA guidelines and to determine whether there is any evidence in to show a difference in success rates based on race.

METHODS

A systematic review of articles using the CENTRAL, Ovid MEDLINE, PubMed, EMBASE, and ClinicalTrials.gov databases was completed. Additional studies were identified by contacting clinical experts and searching bibliographies. All retrospective and prospective studies on trabeculectomy, aqueous shunt implantation, NPFS, and MIGS that included at least 20% ACD were included. Two review authors independently screened search results for eligibility and inclusion and extracted the data using pre-determined fields.

RESULTS

A total of 76 studies were identified for inclusion in the review. Glaucoma surgical outcomes in ACD appear to be poorer compared to ED overall, particularly for trabeculectomy. Data on NPFS are limited, but the studies completed thus far demonstrate surprisingly good results for ACD, particularly when compared to ED, who have significantly lower pre-operative IOPs. Evidence from studies investigating aqueous shunts does not suggest that ACD have poorer outcomes than ED. There is not enough data on MIGS to provide a significant conclusion.

CONCLUSION

In a population where trabeculectomy may no longer be the gold standard, sufficiently powered studies assessing surgical outcomes in aqueous shunts, NPFS, and MIGS are needed to guide clinicians.

Outcomes of inferonasal glaucoma drainage device surgery in the management of childhood glaucoma

PURPOSE

To evaluate indications and postoperative outcomes of inferonasal Ahmed and Baerveldt glaucoma drainage devices (GDDs) in pediatric glaucoma.

METHODS

This retrospective study included patients ≤18 years of age at inferonasal GDD placement, from June 2013 to September 2021. Demographic information, indications, and outcomes were recorded. Successful eyes had intraocular pressure (IOP) ≥5 and ≤21 mm Hg or (in severe cases, where entry IOP was ≤21 mm Hg) 20% below preoperative values without additional IOP-lowering surgery or vision-threatening complications.

RESULTS

A total of 68 eyes of 52 patients were included. Mean age was 9.8 ± 5.8 years. Most common diagnoses included primary congenital glaucoma (n = 28 eyes [41%]) and glaucoma following cataract surgery (n = 12 eyes [18%]). Success rates by Kaplan-Meier survival analysis (95% CI) at 1, 2, 3, and 5 years were 62.2% (49.4-72.7), 49.0% (36.3-60.6), 36.8% (24.0-49.8), and 31.9% (18.5-44.5), respectively. Surgical failure was associated with Ahmed (vs Baerveldt) GDD (HR = 3.2; P = 0.002) and inferonasal site as initial (vs subsequent) GDD received (HR = 2.2; P = 0.048). Twenty-five eyes (36.7%) had at least one complication. Although vision-threatening complications were uncommon (n = 2 eyes [3%]), less severe complications were relatively common and included new/worsened strabismus (n = 9 patients [17%]), corneal edema (n = 6 eyes [9%]), lens opacities (n = 4 [6%]), tube or patch graft exposure (n = 3 [4%]), tube blockage (n = 2 eyes [3%]), and other (n = 8 eyes [12%]).

CONCLUSIONS

In this study cohort, inferonasal GDDs for childhood glaucoma had modest success, with frequent though rarely vision-threatening complications.

A Review on Glaucoma Drainage Devices and its Complications

Glaucoma is one of the leading causes of blindness in the world. It is an ocular disorder that may have multiple etiologies and which can present as optic neuropathy and increased intraocular pressure (IOP), but in some cases like normotensive glaucoma, the IOP may remain normal. Its gradually progressive nature makes it important for early diagnosis; although the loss of vision is slow, lost vision can't be restored. Glaucoma drainage implant surgeries are an increasingly popular option in recent days in complicated cases of glaucoma where the previous trabeculectomy had failed and medical management was not responsive. Glaucoma drainage devices (GDD) are of various designs; they are implanted according to the patient condition and surgeons' preference. There are complications after the implantation of a GDD like hypotony, endophthalmitis, migration of the plate, extrusion, erosion of the mucous membrane, etc. In the market, there are various drainage devices present, but some of them are frequently used and popular.

In this article, we will discuss some most commonly used GDDs and their complications. Among these, four are the most popular: Molteno, Baerveldt, Krupin, and Ahmed. The failure rate of the GDD is low. In many studies, it has been noted that only half of the GDD remains functional after five years. Therefore, further studies are still being conducted to refine the biomaterials, techniques, and shape of the GDD. The technique of surgery is also very much crucial in the success of GDD implantation. The glaucoma type is an essential factor in deciding the treatment, and the outcome of the surgery also depends on it.

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.

Management of hypotony-related maculopathy after combined phacoemulsification and trabeculectomy: January consultation #1

A 59-year-old man with mild to moderate pigmentary glaucoma was referred for management of hypotony-related maculopathy 3 years after combined phacoemulsification and trabeculectomy in his right eye. His ocular history is significant for retinal detachment in the right eye that was surgically treated with a pars plana vitrectomy and scleral buckle 5 years prior to the current presentation and 1 year prior to his combined phacoemulsification-trabeculectomy procedure. After trabeculectomy, he reportedly had a wound leak with hypotony and choroidal effusion. The patient was referred to a second surgeon who performed a bleb revision with a pericardial patch graft, but the patient had a severe intraocular pressure (IOP) spike in the immediate postoperative period requiring suture removal. This resulted in recurrent hypotony with maculopathy. A second bleb revision with pericardial patch graft was performed but was not successful in raising the IOP out of the single digits or in resolving the maculopathy. Accordingly, the patient was referred for further assessment. At presentation, the patient's corrected distance visual acuity was 20/100 in the right eye and 20/20 in the left eye. Applanation tonometry IOP was 4 mm Hg and 16 mm Hg for the right and left eyes, respectively. Central corneal thickness was 609 μm in the right eye and 574 μm in the left eye. The right pupil was noted to be slightly irregular with a relative afferent pupillary defect. Slitlamp examination of the right eye was notable for a moderately elevated, Seidel test-negative bleb, and deep anterior chamber. The left eye had a Krukenberg spindle and mild nuclear sclerotic cataract but was otherwise unremarkable. Fundus examination of the right eye was notable for significant macular folds with edematous nerve fiber layer (NFL) and optic nerve. The left optic nerve and fundus examination were unremarkable. Gonioscopy revealed open angles with dense trabecular meshwork pigment in both eyes. There was a nicely patent superior sclerostomy in the right eye. There was no cyclodialysis cleft. Optical coherence tomography (OCT) of the macula showed chorioretinal folds and NFL edema in the right eye and was normal in the left eye (Figure 1JOURNAL/jcrs/04.03/02158034-202101000-00022/figure1/v/2021-01-04T143903Z/r/image-tiff). The OCT of the optic nerve in the right eye was distorted secondary to the chorioretinal folds, whereas the left eye was notable for mild superior thinning of the NFL (Figure 2JOURNAL/jcrs/04.03/02158034-202101000-00022/figure2/v/2021-01-04T143903Z/r/image-tiff). Humphrey visual field revealed a superior nasal step in the right eye (Figure 3JOURNAL/jcrs/04.03/02158034-202101000-00022/figure3/v/2021-01-04T143903Z/r/image-tiff). Axial lengths were 25.33 mm and 26.53 mm in the right and left eye, respectively; it is notable that the right eye had a shorter axial length despite the scleral buckle, which demonstrates the degree of axial shortening from hypotony (Figure 4JOURNAL/jcrs/04.03/02158034-202101000-00022/figure4/v/2021-01-04T143903Z/r/image-tiff). What would be your approach for managing this patient's hypotony? Does the fact that the referring surgeon had performed 2 failed bleb revision procedures prior to referral influence your approach? Given that a previous attempt at revision resulted in an extreme IOP spike would you also recommend a glaucoma procedure? If so, what procedure would you perform? Would you do it coincident with the revision or in a staged procedure later on an as-needed basis?

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.

Strabismus After Ahmed Glaucoma Valve Implantation

PURPOSE

Most reports of strabismus after glaucoma drainage device implantation study larger devices and rarely note the incidence of strabismus after Ahmed glaucoma valve (AGV) implantation. It is unknown if the pattern of strabismus is similar with smaller devices. We investigated characteristics of strabismus after AGV implantation.

DESIGN

Retrospective review.

METHODS

Institutional study of 732 patients at our institution undergoing AGV implantation between 2013 and 2018. Rate and characteristics of strabismus were the primary outcome; age, gender, and location of AGVs were also analyzed.

RESULTS

We identified 29 patients who developed new-onset strabismus postoperatively after initial AGV implantation, for 4% incidence of strabismus. Twenty-one (72%) of these had diplopia. AGVs were implanted superotemporally in 21, superonasally in 5, inferotemporally in 1, and inferonasally in 2. Three patients were esotropic, 11 were exotropic, 4 had hypertropia, 2 had hypotropia, and 9 patients had combined horizontal/vertical strabismus (esotropia/hypotropia [n = 1] or exotropia/hypertropias [n = 8]). Exotropia was the most common type of strabismus in both the superotemporal and superonasal (60%) AGV groups. Superotemporal AGVs were more commonly associated with ipsilateral hypertropia (43%) than superonasal AGVs. Treatments included strabismus surgery (n = 14), prisms (n = 6), or an occlusive lens (n = 1).

DISCUSSION

In the largest single-center series of patients undergoing initial AGV implantation, the overall incidence of postoperative strabismus was 4%. This is comparable to strabismus incidence following implantation of other types of glaucoma drainage devices, even larger devices. The possibility of this complication should be discussed with patients prior to surgery.

Management of strabismus related to infantile glaucoma: Case series

OBJECTIVE

To evaluate the different modalities of treatment of the strabismus related to infantile glaucoma, its complications, and results.

METHODS

The clinical history of 7 patients with infantile glaucoma which required strabismus surgical treatment were analyzed. Age at onset of glaucoma, type of glaucoma, glaucoma surgeries, type of strabismus, strabismus surgical treatment and postoperative results were studied.

RESULTS

Four patients required strabismus surgery, two were treated with botulinum toxin and one required both. Primary congenital glaucoma was the most common (71,42%), 14,28% had an anterior segment dysgenesis and 14,28% had secondary glaucoma. Regarding strabismus, 4 patients had exotropia and 3 had esotropia. The main difficulty involved the management of the conjunctiva and the filtering blebs.

CONCLUSION

Strabismus is a frequent complication in infantile glaucoma. The management of these patients should be individualized. In our case series, treatment of strabismus improved eye alignment. Surgery should be the mainstay of treatment while preserving the conjunctiva and interfere the less with glaucoma surgeries. Botulinum toxin is a reasonable option when conservative treatment is needed.

Comparison of surgical outcomes between sulcus and anterior chamber implanted glaucoma drainage devices

PURPOSE:

This retrospective case-control cross-sectional study compared the outcomes of sulcus placement of glaucoma drainage devices (GDD) versus traditional anterior chamber (AC) to test the hypothesis that sulcus placement results in fewer complications whilst maintaining similar efficacy.

METHODS:

This study included 45 patients in the sulcus group and 60 patients in the anterior chamber (AC) group who had undergone surgery from January 2014 to December 2017. Data were collected on pre-operative demographics, operative details and post-operative intraocular pressure and complications. The IOP, number of medications and complications between the two groups was compared. A P value of <5% was considered statistically significant.

RESULTS:

The sulcus group had significantly lower overall complications compared to the AC group with a comparable IOP decrease between groups. There were significantly lower rates of hyphaema in the sulcus (3 cases) compared to AC group (17 cases) (P < 0.05). Severe or late complications (implant exposure, corneal decompensation, endophthalmitis, poor vision, choroidal hemorrhage and cornea edema) were significantly lower in the sulcus group [2 eyes; 4.4%] compared to the AC group [13 eyes; 21.7%] (P < 0.05). The sulcus group required fewer medications during the follow-up period.

CONCLUSION:

Sulcus implantation of GDD resulted in less postoperative hyphaema and severe complications compared to AC implantation. Our findings concur with the literature that sulcus implantation is safe and effective for controlling IOP for various types of glaucoma. The long-term effects of endothelial cell loss for sulcus versus AC implantation require further evaluation.

Management of strabismus related to infantile glaucoma: Case series

OBJECTIVE

To evaluate the different modalities of treatment of the strabismus related to infantile glaucoma, its complications, and results.

METHODS

The clinical history of 7 patients with infantile glaucoma which required strabismus surgical treatment were analyzed. Age at onset of glaucoma, type of glaucoma, glaucoma surgeries, type of strabismus, strabismus surgical treatment and postoperative results were studied.

RESULTS

Four patients required strabismus surgery, two were treated with botulinum toxin and one required both. Primary congenital glaucoma was the most common (71,42%), 14,28% had an anterior segment dysgenesis and 14,28% had secondary glaucoma. Regarding strabismus, 4 patients had exotropia and 3 had esotropia. The main difficulty involved the management of the conjunctiva and the filtering blebs.

CONCLUSION

Strabismus is a frequent complication in infantile glaucoma. The management of these patients should be individualized. In our case series, treatment of strabismus improved eye alignment. Surgery should be the mainstay of treatment while preserving the conjunctiva and interfere the less with glaucoma surgeries. Botulinum toxin is a reasonable option when conservative treatment is needed.

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.

Otago Glaucoma Surgery Outcome Study: Examining the Development of Strabismus Causing Diplopia in Patients Who Have Received Molteno Implant Surgery

OBJECTIVE

To evaluate the development of postoperative strabismus causing diplopia in patients who received Molteno implant surgery for the treatment of glaucoma.

METHODS

The Otago Glaucoma Surgery Outcome study (OGSOS) was used to select cases who had undergone Molteno implant surgery to examine the effect on the development of strabismus causing diplopia. Information was collected on treatments provided to correct motility disturbance, and their success, in this retrospective non-comparative study.

RESULTS

32 cases (3.3%) were found to have developed diplopia following the Molteno implant surgery from a total of 977 cases. Of these, the strabismus in 23 cases was described in sufficient detail to permit clinical categorization. Most (19/23) demonstrated an exodeviation, hyperdeviation, or a combination thereof, although 2/6 cases with superonasal plate location demonstrated a hypodeviation. Diplopia generally resolved spontaneously (20/32 cases). Treatment was required in eight cases, usually conservative and successful (6/8 cases), but strabismus surgery was required in two cases, and was unsuccessful.

CONCLUSIONS

This study found a low incidence of diplopia developing post-Molteno implant surgery. Strabismus features suggested a restrictive etiology, and spontaneous recovery was common (62.5%). Surgical correction proved unsuccessful - confirming persistent postoperative diplopia after Molteno implant surgery to be a rare but surgically challenging complication.

Clinical outcome of a nonvalved Aurolab aqueous drainage implant in posterior segment versus anterior chamber

Purpose

To evaluate the outcome of a nonvalved Aurolab aqueous drainage implant (AADI) in the management of refractory glaucoma.

Methods

Retrospective case series of patients with refractory glaucoma underwent AADI implantation in posterior segment (PS group) or anterior chamber (AC group) with minimum follow-up of 1 year. Primary outcome criterion was success, defined as intraocular pressure (IOP) <18 or >6 mm Hg or IOP reduced to <20% from baseline, for two consecutive visits after 3 months. Failure was defined as inability to meet IOP criteria, any additional glaucoma surgery, loss of light perception, and implant explantation. Secondary outcome criteria compared groups based on mean IOP, mean glaucoma medication use, best-corrected visual acuity, and complications at each postoperative visit.

Results

In the AC and PS group of 64 patients, 32 tubes each were placed. Preoperative mean IOP was 37.41 ± 8.6 and 43.38 ± 10.3 mm Hg in AC and PS, respectively. Postoperatively IOP reduced to 14.22 ± 4.9 and 15.21 ± 8.1 mm Hg in AC and PS groups, respectively (P < 0.001). Preoperative mean antiglaucoma medication changed from 2.56 ± 0.9 and 3.44 ± 0.5 to 1.03 ± 0.9 and 1.67 ± 0.5 in AC and PS, respectively, postoperatively (P < 0.001). No significant change in VA was noted in either group. At 12 months, success rate was 84% in AC group and 72% in PS group, with PS group having 2.63 times higher hazard (risk) of failure than AC group.

Conclusion

AADI implantation in PS or AC is a safe and effective method for IOP control in refractory glaucoma with its low cost being of significance in developing countries.

Intermediate-term outcomes of Aurolab aqueous drainage implant in refractory paediatric glaucoma

Aim

To report the intermediate-term outcomes of Aurolab aqueous drainage implant (AADI) surgery in paediatric eyes with refractory glaucoma.

Methods

Case records of patients below 18 years, who underwent AADI surgery between 2012 and 2015 with >2 years follow-up, were analysed. The intraocular pressure (IOP), visual acuity, number of antiglaucoma medications, complications and resurgery if any were recorded at baseline, day 1and then at months 1, 3, 6, 9, 12, 18, 24 and at the last visit. Failure was defined as IOP >18 mm Hg or not reduced by at least 30% below baseline, IOP ≤5 mm Hg on two consecutive follow-up visits after 3 months, reoperation for a complication or loss of light perception vision.

Results

101 eyes of 101 patients were included with a mean age of 10.4±4.7 years at the time of surgery and a mean follow-up of 40.9±15.1 months. Glaucoma following cataract surgery was the most common type of glaucoma (n=31, 30%), followed by primary congenital glaucoma (n=29, 29%). The cumulative probability of failure was 15.8% (95% CI 10.1% to 24.5%) at 1 year, 22.7% (95% CI 15.7% to 32.2%) at 2 years, 42.5% (95% CI 32.6% to 53.9%) at 3 years and 62.1% (95% CI 49.5% to 74.8%) at the 4 years time point.

Conclusion

The AADI showed excellent success until 2 years after surgery in paediatric eyes after which failure rates increased. Further prospective studies with longer follow-up are required to evaluate the long-term success of the AADI for paediatric glaucomas.

Plate size reduction surgery for the Baerveldt 350-mm2 glaucoma implant for postoperative motor disturbance: A case report

RATIONALE

Diplopia due to ocular motility disturbance is a common complication after glaucoma drainage device (GDD) surgery. The treatment options include prescription prism glasses, strabismus surgery or GDD removal. However, to the best of our knowledge, GDD size reduction surgery has not been reported.

PATIENT CONCERNS AND DIAGNOSES

An 83-year-old woman diagnosed with primary open angle glaucoma was referred to Tsukazaki Hospital due to uncontrolled intraocular pressure (IOP) in December 2015. We performed an EXPRESS shunt surgery on both eyes in January 2016 and a needling procedure on the left eye in May 2017. Thereafter, because IOP in her left eye remained high, we performed Baerveldt 350-mm implantation in her inferotemporal area by placing the tube at the sulcus on December 3, 2017. The next day, 4Δ hypertropia (HT) was detected in the left eye in alternate cover testing in primary gaze, and diplopia in the inferotemporal direction was demonstrated. Although IOP was controlled well between 15 and 20 mmHg in her left eye, diplopia did not improve.

INTERVENTIONS

Three weeks later, we performed a plate size reduction surgery for the Baerveldt 350-mm implant. In this procedure, we cut and removed the plates placed beneath the lateral rectus muscle and inferior rectus muscle, which were thought to be responsible for diplopia.

OUTCOMES

Diplopia improved subjectively, but there was no drastic objective change. We prescribed prism glasses (3Δ base down for the left eye) for remaining mild diplopia. On January 21, 2019, significant objective improvement (2Δ HT with less ocular motor dysfunction demonstrated in the Hess chart) was finally observed.

LESSONS

Early plate size reduction surgery, which was not immediately but ultimately effective in improving motor disturbance in our case, could be a potential option to relieve operation-induced motor disturbance. However, notably, tube shunt surgery has the risk of motility disturbances, which might require additional treatment.

Comparison of two prototypes of a magnetically adjustable glaucoma implant in rabbits

Glaucoma drainage devices are used in surgical glaucoma therapy. Success of controlling the intraocular pressure is limited due to fibrous implant encapsulation and fibrin coating on the implant which lead to drainage obstructions. An innovative implant with a magnetically adjustable valve was developed. The valve opening of the implant should eliminate inflammatory products from the outflow area and affect fibrous tissue formation to achieve a sufficient long-term aqueous humour outflow. Lifting of this valve should disturb cell adhesion by exerting mechanical forces. Before testing this hypothesis, the flow characteristics of glaucoma drainage devices, especially the outflow resistance by regular IOP, should be considered in a pilot study, as they are important in preventing too low postoperative intraocular pressure known as ocular hypotony. Therefore, two prototypes of the innovative implant differing in their valve area design were examined regarding their flow characteristics in a limited animal experiment lasting two weeks. Ten healthy New Zealand White rabbits were divided into two groups (A & B) with different implanted prototypes. Daily, tonometry and direct ophthalmoscopy were performed to assess the intraocular pressure and the inflammatory reaction of the eye. After two weeks, the rabbits were euthanised to evaluate the initially histological inflammatory reaction to the implant. In group A, one case of hypotony emerged. When considering the entire observation period, a highly statistically significant difference between the intraocular pressure in the operated eye and that in the control eye was detected in group A (p < 0.0001) in contrast to group B (p = 0.0063). The postoperative inflammatory signs decreased within two weeks. Histologically, a typical but low level foreign body reaction with macrophages and lymphocytes as well as mild to moderate fibrosis was seen after the short experimental period. Based on our tonometric results, prototype B seems to be the system of choice for further research assessing its long-term function and biocompatibility.

Incidence of Conjunctival Exposure following Drainage Device Implantation in Patients with Glaucoma

Purpose

To evaluate prior studies including a glaucoma drainage device and to describe the timing and incidence of conjunctival exposure. A meta-analysis of previously published articles.

Methods

Articles included were prospective, single cohort, or comparative parallel design, with a mean treatment period of at least 3 months and at least 30 patients per treatment arm. We limited our analysis to studies that evaluated the most common devices, including Ahmed, Baerveldt, and Molteno.

Results

We included 38 studies containing 45 treatment arms (16 Ahmed, 12 Baerveldt, and 17 Molteno). These studies included 3,105 patients and 3,255 eyes with an average follow-up of 26.1±3.3 months. The overall incidence of exposure was 2.0±2.6% (n=64) of eyes with an average exposure/month of 0.09±0.14%. There was no significant correlation between study length and incidence of exposure (p=0.11), although multivariate regression analysis identified length of follow-up as a risk factor for exposure (p=0.001). Among individual drainage devices, there was no significant difference in the incidence of exposure (p=0.22) or percent exposure per month (p=0.18). In addition, no difference existed in the incidence of exposure between sizes for the Baerveldt 250, 350 or 500 mm (p=0.7), number of plates for the Molteno Single or Double (p=0.3), nor between the composition of the Ahmed Silicone or Polypropylene (p=0.7).

Conclusions

This study suggests that tube exposure of glaucoma implants is unusual and the incidence does not differ between the Ahmed, Baerveldt, and Molteno implants. However, exposure appears to occur at any time within the first 5 years following implantation.

Strabismus After Ocular Surgery

Many types of ocular surgery can cause diplopia, including eyelid, conjunctival, cataract, refractive, glaucoma, retinal, and orbital surgery. Mechanisms include direct injury to the extraocular muscles from surgery or anesthesia, scarring of the muscle complex and/or conjunctiva, alteration of the muscle pulley system, mass effects from implants, and muscle displacement. Diplopia can also result from a loss of fusion secondary to long-standing poor vision in one eye or from a decompensation of preexisting strabismus that was not recognized preoperatively. Treatment, which typically begins with prisms and is followed by surgery when necessary, can be challenging. In this review, the incidence, mechanisms, and treatments involved in diplopia after various ocular surgeries are discussed. [J Pediatr Ophthalmol Strabismus. 2017;54(5):272-281.].

Strabismus surgery outcomes in eyes with glaucoma drainage devices

PURPOSE

To report strabismus surgery outcomes in eyes with prior implantation of glaucoma drainage devices (GDD).

METHODS

The medical records of patients who underwent strabismus surgery for ocular misalignment that developed after implantation of a GDD over a 13-year period at a single institution were examined retrospectively. Patient characteristics, deviation types, preoperative measurements, surgical procedures, and postoperative measurements were analyzed.

RESULTS

Of the 16 patients included, 14 had exotropia (34^Δ ± 16^Δ) and 11 had vertical deviations (15^Δ ± 7^Δ), of which 9 had concurrent exotropia and vertical deviations. Preoperatively, 9 patients had diplopia. The surgical approach was tailored to address the deviation most noticeable to the patient-horizontal, vertical, or both if the vertical component could be addressed by horizontal muscle supra- or infraplacement. Three patients underwent simultaneous horizontal and vertical surgery. All patients underwent strabismus surgery on an eye with a GDD. Surgical motor success (defined as horizontal deviation ≤10^Δ, vertical ≤4^Δ) was achieved in 42% of horizontal and 57% of vertical deviations. Postoperatively 74% of deviations decreased by ≥50% in magnitude. Diplopia resolved in 50% of patients who presented with preoperative diplopia. One patient had intraoperative bleb perforation, but none had postoperative hypotony at any follow-up visit. Only 2 required a second strabismus surgery.

CONCLUSIONS

Strabismus surgery with preservation of the filtering bleb following implantation of a glaucoma drainage device is a low risk procedure that can improve ocular alignment and related symptoms, despite a low motor success rate by standard criteria.

Diplopia in Medically and Surgically Treated Patients with Glaucoma

PURPOSE

To report the prevalence, type, and cause of diplopia in medically and surgically treated patients with glaucoma.

DESIGN

Cohort study.

PARTICIPANTS

A total of 195 adult patients with glaucoma treated in a glaucoma referral practice.

METHODS

A total of 195 adult patients with glaucoma who had undergone surgical or medical management were prospectively enrolled. Forty-seven patients had undergone glaucoma drainage device (GDD) surgery (Baerveldt 350, Baerveldt 250 [Abbott Medical Optics, Abbott Park, IL], or Ahmed FP7 [New World Medical Inc, Rancho Cucamonga, CA]), 61 patients had undergone trabeculectomy, and 87 patients were medically treated. All patients completed the Diplopia Questionnaire to assess diplopia. We defined the presence of diplopia as "sometimes," "often," or "always" in distance straight ahead or reading positions on the Diplopia Questionnaire. A chart review was performed jointly by a strabismus specialist and a glaucoma subspecialist to characterize the type and cause of the diplopia.

MAIN OUTCOME MEASURES

Frequency, type, and cause of diplopia.

RESULTS

Diplopia was reported in 41 of 195 medically and surgically treated patients (21%) with glaucoma. Binocular diplopia due to the glaucoma procedure was present in 11 of 47 patients (23%) after GDD (95% confidence interval, 12-38), which was significantly greater than in patients after trabeculectomy (2/61 [3%]; 95% confidence interval, 0.4-11; P = 0.002). The most common type of strabismus associated with binocular diplopia due to glaucoma surgery was hypertropia (10/11 GDD cases, 2/2 trabeculectomy cases). Monocular diplopia was found in a similar proportion of medically treated, post-trabeculectomy, and post-GDD cases (4/87 [5%], 4/61 [7%], and 2/47 [4%], respectively). Binocular diplopia not due to surgery was found in similar proportions of GDD, trabeculectomy, and medically treated cases (3/47 [6%], 5/61 [8%], and 10/87 [11%], respectively).

CONCLUSIONS

Diplopia may be under-recognized in medically and surgically treated patients with glaucoma, and standardization of ascertaining patient symptoms using the Diplopia Questionnaire may be useful in these patients. Diplopia was more commonly seen after GDD than trabeculectomy, typically a noncomitant restrictive hypertropia. The prevalence of monocular diplopia and binocular diplopia unrelated to glaucoma surgery was similar among medical and surgical groups. It is important to counsel patients on the higher occurrence of diplopia associated with GDD surgery.

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.

Diplopia after glaucoma drainage device implantation

PURPOSE

To determine incidence of diplopia after glaucoma drainage device (GDD) surgery and to report treatment outcomes.

METHODS

Financial claims data were used to identify patients who underwent GDD surgery (CPT [Current Procedural Terminology] 66180) at the Bascom Palmer Eye Institute from January 2, 1991, through December 31, 2005. After a second claims data search, the medical records of patients diagnosed with diplopia (International Classification of Diseases, 9th Revision code 368.2) and those who underwent extraocular muscle surgery (CPT-4 code 67311-67335) after GDD implantation were reviewed retrospectively.

RESULTS

A total of 2,661 patients underwent GDD surgery during the study period. Charges were submitted for 59 patients for strabismus surgery or office visits relating to diplopia. Of these, 27 patients were excluded because medical records did not document diplopia or included pre-existing diplopia, cranial nerve palsy, or diplopia attributed to another ocular procedure. The remaining 32 patients developed diplopia secondary to GDD. Superotemporal quadrant GDDs were identified in 23 eyes and inferonasal quadrant placement in 9 eyes. The 1-year cumulative incidence of diplopia was 1.4%. No patient developed diplopia after 1 year. The mean follow-up after diagnosis for patients with diplopia was 48 ± 27 months (range, 1-124 months). The mean time of onset of diplopia after GDD implantation was 66 ± 62 days, with median onset of 42 days (range, 8-278 days). Treatment of diplopia included prisms in 17 cases (53.1%), no treatment in 13 (40.6%), other therapies in 2 (6.3%), and surgery after prismatic treatment failed in 3 (9.4%).

CONCLUSIONS

The incidence of diplopia after GDD surgery is low, and most patients are treated with prisms.

Imaging of glaucoma drainage devices

Previously reserved for patients with refractory glaucoma, glaucoma drainage devices (GDDs) are being used more frequently as a primary treatment option. Several types of GDDs are currently manufactured, only one of which is radiopaque. Knowledge of their typical imaging appearance in addition to pertinent background information is therefore vital for radiologists. We present a case of bilateral glaucoma drainage devices and briefly review the surgical aspect of implantation.

Update on aqueous shunts

Medicare claims data and surveys of the American Glaucoma Society membership show that aqueous shunts are being increasingly utilized in the surgical management of glaucoma. New clinical trials data have identified differences in the efficacy and safety of shunts in common use. Recent studies have reported comparable results with trabeculectomy and aqueous shunts in similar patient groups. Intraoperative and postoperative complications may develop with aqueous shunt surgery related to the implantation of a foreign material. Several modifications in surgical technique have been directed toward improving surgical success, reducing complications, and optimizing efficiency and cost.

Glaucoma tube shunt implantation through the ciliary sulcus in pseudophakic eyes with high risk of corneal decompensation

PURPOSE

To summarize our clinical experience with implanting Baerveldt glaucoma tube shunts through the ciliary sulcus in eyes with a posterior chamber intraocular lens and shallow anterior chambers, corneal transplants, guttata or edema.

PATIENTS AND METHODS

A retrospective interventional nonrandomized noncomparative case series. Main outcome measure was postoperative corneal status. Secondary outcome measures included postoperative intraocular pressure (IOP), visual acuity and complications.

RESULTS

Thirty-six eyes of 32 patients were identified through chart review. Follow-up period was 21.8+/-16.6 months (mean+/-standard deviation, range: 4.0 to 58.5 mo). At final visit, all 23 preoperative clear native corneas and 6 of 7 corneal transplants remained clear. Thus, of the 30 preoperative clear corneas, only 1 decompensated. Preoperative IOP was 27.9+/-11.8 mm Hg (range: 12 to 59 mm Hg), reduced postoperatively to 10.1+/-3.9 mm Hg (range: 2 to 21 mm Hg, P=0.0001), a reduction of 58.2%+/-19.3% (range: 5.0% to 95.4%). Final IOP was >or=5 and <or=21 mm Hg in 33 of 36 eyes (91.7%). It was lowered by 30% or more in 34 of 36 eyes (94.4%).

CONCLUSIONS

Although previously published studies demonstrated a significant risk of corneal decompensation after angle or pars plana tube implantation, our clinical experience suggests that ciliary sulcus tube implantation in eyes with a posterior chamber intraocular lens is a safe and effective procedure even in eyes with high risk of corneal decompensation.

Ahmed glaucoma valve surgical outcomes in eyes with and without silicone oil endotamponade

PURPOSE

To compare the results of Ahmed glaucoma valve (AGV) implantation in eyes containing silicone oil to those without silicone oil.

METHODS

This was a multicenter, retrospective, comparative study of 94 eyes in 94 patients with mean follow-up of 2 years, comparing surgical outcomes in eyes with silicone oil (N=47) to matched patients without silicone oil (N=47). Success was defined as intraocular pressure (IOP) of >/=6 and </=21 mm Hg and 20% reduction of IOP from preoperative level, with or without glaucoma medicines, and without further glaucoma surgery or loss of light perception.

RESULTS

The mean IOP and number of medications at the last follow-up were comparable between the 2 groups (P=0.26 and P=0.12). The cumulative probability of success by life-table analysis was 85% at 6 months, 80% at 1 year, 70% at 2 and 3 years, and 47% at 4 years in silicone oil group, and 100% at 6 months and 1 year, and 76% at 2, 3, and 4 years in the control group (P=0.03). Complications were similar in the 2 groups (P=0.663). The duration of postoperative topical steroid use was significantly longer in the silicone oil group (P=0.0003). Silicone oil was identified as a risk factor for surgical failure by the Cox hazard model (risk ratio=3.43; P=0.04).

CONCLUSIONS

The AGV can control the IOP in the majority of eyes after pars plana vitrectomy and silicone oil injection. However, the presence of silicone oil is associated with increased risk of surgical failure in eyes treated with the AGV.

Motility disturbances in the tube versus trabeculectomy study during the first year of follow-up

PURPOSE

To describe the preoperative and postoperative motility disturbances encountered in the Tube Versus Trabeculectomy (TVT) Study during the first year of follow-up.

DESIGN

Multicenter randomized clinical trial.

METHODS

settings: Seventeen clinical centers. population: Patients 18 to 85 years old who had previous trabeculectomy and/or cataract surgery and uncontrolled glaucoma with intraocular pressure > or =18 mm Hg and < or =40 mm Hg on maximum tolerated medical therapy. interventions: 350-mm(2) Baerveldt glaucoma implant or trabeculectomy with mitomycin C (MMC). main outcome measures: Preoperative and postoperative evaluation of ocular motility and diplopia.

RESULTS

Motility disturbances were detected in 55 patients (28%) at baseline. New-onset persistent diplopia was reported in 5 patients (5%) in the tube group and no patients in the trabeculectomy group at 1 year (P = .06). A new postoperative motility disturbance developed or worsened in 7 patients (9.9%) in the tube group and no patients in the trabeculectomy group during the first year of follow-up (P = .005). Postoperative motility disturbances were also associated with increasing age (P < .001) and right eye surgery (P = .044).

CONCLUSIONS

Preoperative motility disturbances were common among patients in the TVT Study. New postoperative motility disturbances were more frequent following tube shunt surgery than trabeculectomy with MMC after 1 year of follow-up.

Modern concepts in antiglaucomatous implant surgery

BACKGROUND

Antiglaucomatous implant surgery is a continously evolving field in glaucoma treatment.

METHODS

A literature search with the terms "glaucoma implant surgery", "aqueous shunts" and "glaucoma drainage devices" was carried out, especially giving prominence to innovative surgical developments in glaucoma implant surgery and to recently established clinical evidence on traditional shunt surgery.

RESULTS

Episcleral glaucoma drainage devices have recently proven their efficacy in large studies. Longterm data about their clinical efficacy and their risk/safety profile are sufficiently available. New antiglaucomatous devices try to target alternative drainage routes, for example trabecular or uveoscleral outflow. Valid longterm data from prospective randomized clinical trials are not available for these devices as yet.

CONCLUSIONS

Although valid data on clinical application of the new glaucoma implants are not available as yet, profound knowledge about their theoretical concept and their practical management is obligatory for all glaucoma clinicians.