Aqueous shunt implantation in glaucoma

Treatment Outcomes Comparing the Paul and Baerveldt Glaucoma Implants After One Year of Follow-Up

PRCIS

In reducing intraocular pressure (IOP), Paul (PGI) and Baerveldt (BGI) glaucoma implants are safe and effective in patients with glaucoma.

OBJECTIVE

To compare efficacy and safety profiles of the PGI and BGI in the treatment of medically uncontrolled glaucoma at 1 year of follow-up.

METHODS

Retrospective analysis of patients implanted with a PGI or BGI with a minimum of 12 months follow-up. The primary outcome was surgical success defined as IOP ≥6 and ≤18 mm Hg and at least 20% IOP reduction from baseline. Secondary outcomes included IOP measurements, number of medications, and complications.

RESULTS

Twenty-three patients implanted with PGI and 27 with BGI were included. At last visit (12 mo), mean IOP had decreased from 23.7 ± 6.9 to 0.1 ± 2.9 mm Hg in the PGI group versus 26 ± 7.3 to 10.4 ± 4.9 mm Hg with the BGI ( P < 0.001 for both comparisons). Overall qualified success rates were similar between groups (PGI 91% vs BGI 89%, P = 0.784). IOP was significantly lower in the PGI at week 1 and month 1 of follow-up versus the BGI (13.6 ± 6.1 vs 20.1 ± 7.4; 14.6±3.8 vs 21.2 ± 5.8 mm Hg; P < 0.002 for both) with a lower number of medications (1.57 ± 1.47 vs 2.52 ± 1.16 at mo 1, P = 0.015). Most complications were minor and similar in both groups.

CONCLUSION

Both PGI and BGI are safe and effective in reducing IOP in patients with glaucoma, with similar success rates.

Intraluminal Suture Placement for Management of Hypotony After Glaucoma Drainage Device Surgery

PRCIS

Intraluminal 3-0 Supramid stent placement can be an effective long-term solution for hypotony after glaucoma drainage device surgery. This procedure may obviate the need for conjunctival dissection. In some cases, additional procedures are required.

PURPOSE

To describe the utility of implantation of a multifilament polyamide suture (Supramid) in the tube lumen to reverse hypotony after glaucoma drainage device (GDD) surgery.

PATIENTS

Patients who underwent tube revision with intraluminal placement of a 3-0 Supramid stent, with or without external ligature, to manage hypotony following GDD surgery between January 2010 and October 2020.

METHODS

Resolution of hypotony was defined as IOP >5 mm Hg and the absence of hypotony-related structural abnormalities. Overall success was the absence of failure criteria (IOP ≤5 mm Hg, >21 mm Hg, or <20% reduction below baseline IOP after 3 months for 2 consecutive study visits; additional glaucoma surgery; or loss of light perception), with or without adjunctive ocular hypotensive therapy.

RESULTS

Nine eyes of 9 patients underwent placement of a 3-0 Supramid stent with a resolution of hypotony in all eyes with a mean follow-up duration of 33.3 ±24.0 months. Overall success was achieved in 7 of 9 eyes. Four eyes required intervention after stent placement: 1 eye required selective laser trabeculoplasty followed by replacement of the original stent with a shorter 3-0 Supramid suture and external ligature; 1 eye underwent revision for tube exposure; and 2 eyes underwent laser suture lysis to release an external suture ligature.

CONCLUSIONS

In cases of hypotony after GDD, particularly when it is desirable to reduce the extent of additional conjunctival dissection, intraluminal placement of a 3-0 Supramid stent via an intracameral approach can be an effective long-term solution. Postoperative adjustments were required in many cases.

Application of Silicone in Ophthalmology: A Review

This paper reviews the latest trends and applications of silicone in ophthalmology, especially related to intraocular lenses (IOLs). Silicone, or siloxane elastomer, as a synthetic polymer, has excellent biocompatibility, high chemical inertness, and hydrophobicity, enabling wide biomedical applications. The physicochemical properties of silicone are reviewed. A review of methods for mechanical and in vivo characterization of IOLs is presented as a prospective research area, since there are only a few available technologies, even though these properties are vital to ensure medical safety and suitability for clinical use, especially if long-term function is considered. IOLs represent permanent implants to replace the natural lens or for correcting vision, with the first commercial foldable lens made of silicone. Biological aspects of posterior capsular opacification have been reviewed, including the effects of the implanted silicone IOL. However, certain issues with silicone IOLs are still challenging and some conditions can prevent its application in all patients. The latest trends in nanotechnology solutions have been reviewed. Surface modifications of silicone IOLs are an efficient approach to further improve biocompatibility or to enable drug-eluting function. Different surface modifications, including coatings, can provide long-term treatments for various medical conditions or medical diagnoses through the incorporation of sensory functions. It is essential that IOL optical characteristics remain unchanged in case of drug incorporation and the application of nanoparticles can enable it. However, clinical trials related to these advanced technologies are still missing, thus preventing their clinical applications at this moment.

Updates on the Diagnosis and Management of Glaucoma

Glaucoma is the leading cause of blindness throughout the world (after cataracts); therefore, general physicians should be familiar with the diagnosis and management of affected patients. Glaucomas are usually categorized by the anatomy of the anterior chamber angle (open vs narrow/closed), rapidity of onset (acute vs chronic), and major etiology (primary vs secondary). Most glaucomas are primary (ie, without a contributing comorbidity); however, several coexisting ophthalmic conditions may serve as the underlying etiologies of secondary glaucomas. Chronic glaucoma occurs most commonly; thus, regular eye examinations should be performed in at-risk patients to prevent the insidious loss of vision that can develop before diagnosis. Glaucoma damages the optic nerve and retinal nerve fiber layer, leading to peripheral and central visual field defects. Elevated intraocular pressure (IOP), a crucial determinant of disease progression, remains the only modifiable risk factor; thus, all current treatments (medications, lasers, and operations) aim to reduce the IOP. Pharmacotherapy is the usual first-line therapy, but noncompliance, undesirable adverse effects, and cost limit effectiveness. Laser and surgical treatments may lower IOP significantly over long periods and may be more cost effective than pharmacotherapy, but they are plagued by greater procedural risks and frequent treatment failures. Traditional incisional procedures have recently been replaced by several novel, minimally invasive glaucoma surgeries with improved safety profiles and only minimal decreases in efficacy. Minimally invasive glaucoma surgeries have dramatically transformed the surgical management of glaucoma; nevertheless, large, randomized trials are required to assess their long-term efficacy.

Outcomes of Anterior Chamber, Sulcus, and Pars Plana Glaucoma Drainage Device Placement in Glaucoma Patients

Purpose

To assess outcomes of anterior chamber (AC), sulcus, and pars plana (PP) glaucoma drainage device (GDD) placement in glaucoma patients. Patients and Methods. Retrospective evaluation of glaucoma patients who underwent GDD insertion in the AC, sulcus, or PP at Massachusetts Eye and Ear between November 2016 and May 2021. Patients who received AC, sulcus, and pars plana tubes were selected using simple random sampling, and the first 40 patients meeting inclusion criteria were analyzed. Main outcome measures were cumulative success probabilities from Kaplan-Meier (KM) analyses, intraocular pressure (IOP), medication burden, and complication rates.

Results

The PP group had a larger proportion of Ahmed GDDs and was younger on average with less severe glaucoma compared to patients with AC or sulcus tubes. The PP group had a higher proportion of mixed-mechanism glaucoma and lower proportion of primary open-angle glaucoma. With success defined as IOP reduction ≥20% and 5 < IOP ≤ 21 mm Hg, the Kaplan-Meier cumulative success probabilities for all three GDD locations were not significantly different. No significant differences were found in complication rates between all groups after 3 months. Patients with PP GDD had significantly lower medication burden than those with AC or sulcus GDDs up to 1.5 years postoperatively (1.7 ± 1.1, 3.0 ± 1.4, and 2.8 ± 1.2 for PP, AC, and sulcus, respectively; P=0.017).

Conclusion

PP GDDs may be more effective in lowering medication burden than AC or sulcus tubes without compromising long-term safety.

Primary outcomes of Baerveldt glaucoma implants with a modified technique to control intraocular pressure in different cases of glaucoma

INTRODUCTION

To describe the outcomes of Baerveldt glaucoma implants implanted via a modified technique with regard to early intraocular pressure (IOP) reduction in cases of uncontrolled glaucoma.

METHODS

The medical records of patients who had Baerveldt glaucoma implants of 350 or 250 mm² implanted via a modified technique and were followed up for a period of at least 6 months were reviewed. The primary outcome measures were the mean IOP and number of glaucoma medications at each visit. We evaluated complete success rates at 1 day, 1 week and 1 month, defined as IOP values [Formula: see text] 5 mmHg and ≤ 21 mmHg prior to ligature rupture.

RESULTS

A total of 42 eyes had Baerveldt glaucoma implants and met the inclusion criteria. The mean preoperative intraocular pressure (IOP) was 34.2 ± 11.2 mmHg. The postoperative mean IOP values were 15.1 mmHg ± 8.8 (p < 0.05), 17.7 ± 7.1 mmHg (p < 0.05), 12.3 ± 4.0 mm Hg (p < 0.05) at 1 day, 1 month, and 6 months, respectively. The rate of complete success on the first day was 78%, at the first month was 69%, and at 6 months was 95.2%. The number of glaucoma medications used was significantly lower at 6 months (P =  < 0.001).

CONCLUSION

The modified surgical technique using Baerveldt implants enables a safe, effective, and reliable IOP control in early postoperative patients with uncontrolled glaucomas.

Analysis of Efficacy and Safety of Pediatric Ahmed Glaucoma Valve (FP8) in Advanced Age Populations

PRECIS

The FP8 glaucoma valve was demonstrated to be reasonably safe with reliable results in an advanced age patient population.

PURPOSE

As life expectancy increases, a growing number of patients with glaucoma are of an advanced age. There are little to no data looking at glaucoma surgical treatment options in patients over the age of 85. Our study describes the safety and efficacy of the FP8 Ahmed glaucoma valve in this patient population.

MATERIALS AND METHODS

This was a retrospective study of patients over 85 years of age undergoing FP8 Ahmed glaucoma valve implantation. Preoperative age, sex, intraocular pressure (IOP), and number of glaucoma medications were recorded. Primary outcome variables were IOP and number of medications. Secondary outcome variables included any intraoperative or postoperative complications.

RESULTS

Mean IOP preoperatively was 26 mm Hg on an average of 3 glaucoma medications (n=56). IOP was significantly reduced at all time points in follow-up for an overall reduction of 42% at 1 year and 46% at 2 years. Mean IOP at 1 year follow-up was 15 mm Hg and 14 mm Hg at 2 years follow-up. Glaucoma medications were reduced from a mean of 3 preoperatively to 2 postoperatively.

CONCLUSIONS

Implantation of an FP8 Ahmed glaucoma valve is a relatively safe procedure to achieve satisfactory IOP and decreased reliance on glaucoma medications in an advanced age population.

Comparison of complications after Ahmed versus Baerveldt implant in glaucoma patients: one year follow-up

AIM

To compare surgical results of the Ahmed and Baerveldt implant procedures in glaucoma patients at 1y follow-up at Jakarta Eye Center (JEC) Eye Hospitals.

METHODS

This cohort retrospective study was conducted on glaucoma patients aged ≥18y who had undergone Ahmed and Baerveldt implant surgery. Intraocular pressure (IOP), visual acuity, glaucoma medication, success rate, early and late postoperative complications, and the number of resurgeries were analyzed.

RESULTS

A total of 351 eyes in the Ahmed group and 94 eyes in the Baerveldt group were included in this study. At 1y follow-up, the mean IOP was found to be significantly lower in the Baerveldt group (13±4.47 mm Hg) compared to the Ahmed group (15.02±5.73 mm Hg; P=0.025). Glaucoma medication was required in both the Ahmed and Baerveldt groups (58.92% vs 71.67%). Comparable success rate was found in both groups. The Ahmed group revealed a complete and qualified success of 86.82%, and failure of 13.17%. Similarly, the Baerveldt group showed complete and qualified success in 87.75% and failure in 12.25% cases. In the Ahmed group, 11.97% early complications, 26.06% late complications and 9.97% resurgeries were observed. In comparison, in the Baerveldt group, 23.40% early complications, 30.95% late complications and 11.70% resurgeries were observed.

CONCLUSION

Both groups of glaucoma implants show significant IOP reduction, however, the Baerveldt implant group demonstrates greater IOP reduction with more failure rates and complications than the Ahmed implant group.

Health-related quality of life in Ahmed FP7, and Baerveldt 250 and 350 patients compared with medical controls

PURPOSE

To compare health-related quality of life (HRQoL) in patients with Ahmed FP7 (FP7), Baerveldt 250 (B250) and Baerveldt 350 (B350) glaucoma drainage device (GDDs), and medically treated controls.

METHODS

This was a prospective cohort study from August 2017 to July 2019. The NEI 25-Item Visual Function Questionnaire (VFQ-25), the Adult Strabismus-20 questionnaire (AS-20) and the Diplopia Questionnaire were conducted ≥30 days postoperatively in GDD patients, on enrolment for controls. Age, sex, treatment type, visual acuity, mean deviation and diplopia were evaluated for association with HRQoL RESULTS: Of the 128 GDD patients enrolled, 35 (27.3%) had FP7, 32 (25.0%) had B250 and 61 (47.7%) had B350. In univariate analysis, decreased HRQoL was associated with younger age (r² range 0.042-0.071), diplopia (r² range 0.039-0.119), GDD treatment (r² range 0.023-0.103), lower visual acuity (r² range 0.021-0.215) and worse mean deviation (r² range 0.029-0.131). All GDD groups had lower HRQoL subscores than the controls. HRQoL scores were lower compared with controls among B350 patients for AS-20 Self-perception subscale, B250 and B350 for Reading and General Function subscales, and FP7 and B350 for VFQ-25 Visual Functioning subscale. There were no significant differences among the GDDs.

CONCLUSIONS

Glaucoma patients with a younger age, diplopia, lower visual acuity, worse mean deviation or a GDD had lower HRQoL. Those with B350 had lower self-perception scores, consistent with previous reports in the literature. This subscale was not diminished in FP7 or B250, so the decreased self-perception scores may be due to greater visibility or awareness of the B350.

Tube Length Adjustment and Tube Trimming Technique in Refractory Glaucoma

Secondary glaucoma may develop after vitreoretinal surgery as it is a known risk factor for its development. When the risk factors are more than one, for instance along with neovascular glaucoma (NVG), the secondary glaucoma may become recalcitrant and very difficult to manage. Surgical intervention is often warranted to control intraocular pressure (IOP) and prevent progressive glaucomatous damage in patients with refractory glaucoma, and glaucoma drainage implant may be preferred as the primary choice. We describe a patient who develop secondary glaucoma after vitrectomy and silicone oil (SO) injection due to unresolved vitreous hemorrhage in proliferative diabetic retinopathy (PDR) and subsequent NVG. Baerveldt glaucoma implant (BGI) was carried out and placed in the superotemporal quadrant with longer anterior chamber tube placement to prevent escape of SO through the tube. Qualified success was achieved with additional one fixed-drug combination (FDC). However, 3 years later, the tube was blocked by the iris tissue at the inferior edge of the pupil. Tube trimming was performed efficiently using a simple technique. The distal end of the tube was pulled out of the anterior chamber through a paracentesis just next to the tube entrance and trimmed to the appropriate length. More than a year after the surgery, IOP was still well controlled with the same FDC. Unfortunately, the visual acuity could not be recovered due to advanced PDR.

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.

Monitoring and management of the patient with pseudoexfoliation syndrome: current perspectives

Pseudoexfoliation syndrome (PES) is a complex and age-related systemic disorder characterized by the progressive accumulation and granular deposition of pseudoexfoliative material in various intraocular and extraocular tissues. The diagnosis of PES is so important because it is a major risk factor for complications during cataract surgery and the most frequent cause of secondary glaucoma. In addition to ocular complications, PES is related with numerous systemic abnormalities, for which the list is growing steadily. Therefore, management and monitoring of patients with PES are crucial. The aim of this paper was to review current perspectives on monitoring patients with PES and addressing management of ocular and systemic associations of this clinically important and biologically fascinating disease.