New options for combined cataract and glaucoma surgery

Crystalline lens nuclear age prediction as a new biomarker of nucleus degeneration

BACKGROUND

The crystalline lens is a transparent structure of the eye to focus light on the retina. It becomes muddy, hard and dense with increasing age, which makes the crystalline lens gradually lose its function. We aim to develop a nuclear age predictor to reflect the degeneration of the crystalline lens nucleus.

METHODS

First we trained and internally validated the nuclear age predictor with a deep-learning algorithm, using 12 904 anterior segment optical coherence tomography (AS-OCT) images from four diverse Asian and American cohorts: Zhongshan Ophthalmic Center with Machine0 (ZOM0), Tomey Corporation (TOMEY), University of California San Francisco and the Chinese University of Hong Kong. External testing was done on three independent datasets: Tokyo University (TU), ZOM1 and Shenzhen People's Hospital (SPH). We also demonstrate the possibility of detecting nuclear cataracts (NCs) from the nuclear age gap.

FINDINGS

In the internal validation dataset, the nuclear age could be predicted with a mean absolute error (MAE) of 2.570 years (95% CI 1.886 to 2.863). Across the three external testing datasets, the algorithm achieved MAEs of 4.261 years (95% CI 3.391 to 5.094) in TU, 3.920 years (95% CI 3.332 to 4.637) in ZOM1-NonCata and 4.380 years (95% CI 3.730 to 5.061) in SPH-NonCata. The MAEs for NC eyes were 8.490 years (95% CI 7.219 to 9.766) in ZOM1-NC and 9.998 years (95% CI 5.673 to 14.642) in SPH-NC. The nuclear age gap outperformed both ophthalmologists in detecting NCs, with areas under the receiver operating characteristic curves of 0.853 years (95% CI 0.787 to 0.917) in ZOM1 and 0.909 years (95% CI 0.828 to 0.978) in SPH.

INTERPRETATION

The nuclear age predictor shows good performance, validating the feasibility of using AS-OCT images as an effective screening tool for nucleus degeneration. Our work also demonstrates the potential use of the nuclear age gap to detect NCs.

Hydrogel Sealant for Closure of Clear Corneal Incisions in Combined Glaucoma Procedures

Purpose

The purpose of this study is to determine whether ReSure hydrogel sealant is superior to standard suture for closure of clear corneal incisions in the setting of combined glaucoma procedures.

Setting

Glaucoma Department, Duke University Eye Center.

Design

This is a retrospective case series. Subjects studied were patients in a 6-year period undergoing combined phacoemulsification and glaucoma surgery. All cases were performed by the same surgeon. Wound closure methods correlated with discrete timeframes, as ReSure replaced suture midway through the study period, thereby establishing sutured closure as an analogous control group.

Methods

All cases included a phacoemulsification procedure requiring a 2.4 mm clear corneal incision. Upon completion of the phacoemulsification portion of the case, the wound was closed with either ReSure hydrogel or standard 10–0 suture closure. The researchers assessed the rate of Seidel-positive corneal wound leak on postoperative day one.

Results

In all cases employing ReSure, no wound leak was observed at postoperative day one. Within the suture group, 3 cases showed Seidel positivity of the corneal incision. This equates to a statistically significant difference in wound leak frequency of 2.04% (P = 0.012); confidence interval, 0.21 to 5.82.

Conclusion

ReSure was able to maintain closure 100% of the time over hundreds of combined cases. Suture, though the standard of practice, did not perform to this level, presenting with 3 cases of spontaneous wound leak. We conclude that ReSure is highly effective and superior to suture in closure of clear corneal incisions in combined glaucoma procedures.

Cyclophotocoagulation under Microscopy Combined with Phacoemulsification for Primary Angle-Closure Glaucoma

The purpose of this study was to evaluate the safety and efficacy of cyclophotocoagulation under microscopy combined with phacoemulsification in patients with primary chronic angle-closure glaucoma. We retrospectively reviewed the results of cyclophotocoagulation under microscopic direct vision combined with phacoemulsification in 35 eyes (35 patients) with primary chronic angle-closure glaucoma and coexisting visually significant cataracts, treated between January 2017 and April 2020 at the glaucoma unit of the affiliated Changshu Hospital of Xuzhou Medical University. All patients were followed up for at least 12 months postoperatively. The preoperative to postoperative changes in best-corrected visual acuity (BCVA), intraocular pressure (IOP), number of antiglaucoma medications, and surgery-associated complications were recorded. The BCVA improved from 1.15 ± 0.91 logMAR preoperatively to 0.86 ± 0.82 logMAR at the final postoperative examination (Z = −3.62, P < 0.0001). The mean IOP was 36.63 ± 13.50 mmHg preoperatively and 15.14 ± 3.19 mmHg at the final examination (Z = −5.16, P < 0.0001). The number of antiglaucoma drugs was significantly reduced from 2.23 ± 0.55 preoperatively to 0.54 ± 0.86 at the final postoperative examination (Z = −5.26, P < 0.0001). The absolute value of the mean defect and retinal nerve fiber layer thickness at the last follow-up postoperatively were significantly reduced compared to preoperative values (Z = −3.35, P=0.001; Z = −4.56, P < 0.001, respectively). One patient experienced an explosive suprachoroidal hemorrhage during the operation. The sclera was incised at the corresponding site of the intraoperative hemorrhage. The operation was continued once there was no active bleeding, and the outcome was satisfactory. None of the patients required additional surgery to treat complications. Thus, cyclophotocoagulation under microscopic direct vision combined with phacoemulsification can be performed safely for the management of primary angle-closure glaucoma.

Endoscopic Cyclophotocoagulation Combined with Phacoemulsification Increases Risk of Persistent Anterior Uveitis Compared to Phacoemulsification Surgery Alone

PURPOSE

To evaluate if the addition of endoscopic cyclophotocoagulation (ECP) to uncomplicated phacoemulsification cataract extraction increases the risk of persistent anterior uveitis (PAU) compared to phacoemulsification alone.

PATIENTS AND METHODS

Retrospective analysis of patients who had either phacoemulsification alone or combined with endoscopic cyclophotocoagulation from January 1, 2014 to December 31, 2017. Visual acuity, intraocular pressure, presence of anterior chamber cells, and steroid usage were analyzed pre- and post-operatively. Patient eyes with a history of uveitis, autoimmune disease, complicated cataract surgery, combined surgery other than ECP, and less than 3 months of follow-up were excluded.

RESULTS

This study consisted of 4423 eyes from 2903 patients, meeting the inclusion criteria (phacoemulsification only group n=4242 and phacoemulsification/ECP group n=181 eyes). PAU developed in 14.9% in the phacoemulsification with ECP group compared to 1.7% who had phacoemulsification alone. White patients had a 17.9 (95% CI: 7.8-41.1, p<0.0001) increased odds of developing persistent anterior uveitis with a combined procedure compared to phacoemulsification only, while Non-white patients had a 5.8 (95% CI: 2.8-12.1, p<0.0001) increased odds. Despite the higher odds ratio in White patients, this group had a significantly lower rate of PAU compared to Non-white patients after phacoemulsification/ECP.

CONCLUSION

The addition of endoscopic cyclophotocoagulation to phacoemulsification significantly increases the risk of developing PAU in the post-operative period compared to phacoemulsification alone.

Combined Phacoendoscopic Cyclophotocoagulation versus Combined Phacotrabeculectomy in the Management of Coexisting Cataract and Glaucoma: A Comparative Study

Purpose

To compare the surgical outcome of combined phacoemulsification and endoscopic cyclophotocoagulation (phacoECP) versus combined phacoemulsification and mitomycin C-augmented trabeculectomy (phacoTbx) in patients with coexisting glaucoma and visually significant cataract.

Methods

A retrospective review of 89 eyes of 89 patients who received phacoECP (N=49) and phacoTbx (N=40) was carried out at a tertiary eye center in Hong Kong. The minimum follow-up period was 6 months. Criterion of success was reduction of IOP at least 30% or absolute IOP of 15 mmHg or below without (complete success) or with (qualified success) antiglaucomatous medication.

Results

PhacoTbx had more reduction of antiglaucomatous medication (4 vs 1, P < 0.001). At postoperative year one, there was more IOP reduction for phacoTbx than phacoECP (8 mmHg vs 3 mmHg, P=0.012). The one-year complete success rate was also higher for phacoTbx (46.2% vs 8.2%, P < 0.001), while qualified success was comparable between the 2 groups (74.4% vs 73.5%, P=0.925). Operation time was shorter for phacoECP (37 vs 73 minutes, P < 0.001). The number of postoperative follow-up visits was less (6 vs 11.5, P < 0.001) for phacoECP. Additional surgical procedures were more common in phacoTbx (55% vs 0%, P < 0.001). There was no postoperative cystoid macula edema, hypotony, or endophthalmitis reported in both groups.

Conclusions

PhacoECP is significantly less effective than phacoTbx in reduction of both IOP and number of antiglaucomatous medications for patients with medically uncontrolled glaucoma and cataract. Its complete success rate is also significantly lower than that of phacoTbx. With its comparable qualified success, shorter operation time, less number of postoperative visits, and secondary surgical intervention, phacoECP may still have a role in very selected cases.

Phacoemulsification combined with deep sclerectomy augmented with mitomycin and amniotic membrane implantation in chronic primary open angle glaucoma with cataract

OBJECTIVE

The aim of this study was to determine the safety and efficacy of combined phacoemulsification plus Intraocular lens (IOL) implantation with deep sclerectomy augmented with mitomycin C (MMC) and sub-flap implantation of amniotic membrane for the management of uncontrolled, chronic, primary open-angle glaucoma patients.

METHODS

This prospective study included 41 patients with chronic, primary, open-angle glaucoma and cataract uncontrolled with medical treatment who underwent combined phacoemulsification augmented with mitomycin C (MMC) application and amniotic membrane implantation under the scleral flap. Intraocular pressure (IOP), visual acuity, glaucoma medications, stabilization of visual field, complications, and viability of the success rate were assessed a 36-month follow-up period.

RESULTS

The mean age of cases was 54.8 ± 5.3 years. Sixty-one percent of cases were males, and 39% were females. The mean IOP decreased from 23.8 ± 1.8 mmHg preoperatively to 16.8 ± 2.3 mmHg postoperatively. The overall success rate was 97.5, 95, and 92.7% in the first, second, and third year, respectively. The overall success rate was 90% in the first year, but that decreased to 85.3 and 78% in the second and third year, respectively. Qualified success was 7.5, 10, and 14.7% in the first, second, and third year, respectively. Failure was recorded as 2.5, 5, and 7.3% in the first, second, and third year, respectively. IOP reduction was sustained through the follow-up period. Visual acuity improved from 0.13 ± 0.06 to 0.9 ± 0.07 (p < 0.001). The visual field improved significantly in the first assessment, from 14.0 ± 2.7 preoperatively to 12.6 ± 2.6 at three months postoperatively (p < 0.001), after which it became stable for the remainder of the follow-up period. One hundred percent of cases were on three anti-glaucoma drugs preoperatively, while postoperatively, 12.2% were on three drugs, 4.2% were on two drugs, and 82.9% were controlled without anti-glaucoma treatment. There were minor postoperative complications all of which were minor, such as a spike in the post-operative IOP and the formation of fibrinous material in the anterior chamber, both of which were treated medically without any adverse effects on the final results.

CONCLUSION

Amniotic membrane implantation in conjunction with MMC application may be an effective alternative to expensive implants in deep sclerectomy combined with phacoemulsification, and this approach can be used safely in advanced cases.

Glaucoma Suspect: Diagnosis and Management

Glaucoma suspect is a diagnosis reserved for individuals who do not definitively have glaucoma at the present time but have characteristics suggesting that they are at high risk of developing the disease in the future based on a variety of factors. This review provides a practical approach to individuals classified as glaucoma suspects caused by one or more of the following risk factors or indicators of disease: ocular hypertension, optic nerve features suggestive of glaucoma, visual field abnormalities, and other characteristics placing them at greater risk than the average population. In addition to diagnostic considerations, this overview provides information on therapeutic approaches to the glaucoma suspect.

Use of Various Glaucoma Surgeries and Procedures in Medicare Beneficiaries from 1994 to 2012

PURPOSE

Determine how procedural treatments for glaucoma have changed between 1994-2012.

DESIGN

Retrospective, observational analysis.

PARTICIPANTS

Medicare Part B beneficiaries.

METHODS

We analyzed Medicare fee-for-service paid claims data between 1994-2012 to determine the number of surgical/laser procedures performed for glaucoma in the Medicare population each year.

MAIN OUTCOME MEASURES

Number of glaucoma-related procedures performed.

RESULTS

Trabeculectomies in eyes without previous scarring decreased 52% from 54 224 in 1994 to 25 758 in 2003, and a further 52% to 12 279 in 2012. Trabeculectomies in eyes with scarring ranged from 9054 to 13 604 between 1994-2003, but then decreased 48% from 11 018 to 5728 between 2003-2012. Mini-shunts done via an external approach (including ExPRESS [Alcon Inc, Fort Worth, TX]) increased 116% from 2718 in 2009 to 5870 in 2012. The number of aqueous shunts to the extraocular reservoir increased 231% from 2356 in 1994 to 7788 in 2003, and a further 54% to 12 021 in 2012. Total cyclophotocoagulation procedures increased 253% from 2582 in 1994 to 9106 in 2003, and a further 54% to 13 996 in 2012. Transscleral cyclophotocoagulations decreased 45% from 5978 to 3268 between 2005-2012; over the same period, the number of endoscopic cyclophotocoagulations (ECPs) increased 99% from 5383 to 10 728. From 2001 to 2005, the number of trabeculoplasties more than doubled from 75 647 in 2001 to 176 476 in 2005, but since 2005 the number of trabeculoplasties decreased 19% to 142 682 in 2012. The number of laser iridotomies was fairly consistent between 1994-2012, increasing 9% over this period and ranging from 63 773 to 85 426. Canaloplasties increased 1407% from 161 in 2007 to 2426 in 2012. Between 1994-2012, despite a 9% increase in beneficiaries, the total number of glaucoma procedures and the number of glaucoma procedures other than laser procedures decreased 16% and 31%, respectively.

CONCLUSIONS

Despite the increase in beneficiaries, the number of glaucoma procedures performed decreased. Glaucoma procedures demonstrating a significant increase in use include canaloplasty, mini-shunts (external approach), aqueous shunt to extraocular reservoir, and ECP. Trabeculectomy use continued its long-term downward trend. The continued movement away from trabeculectomy and toward alternative intraocular pressure-lowering procedures highlights the need for well-designed clinical trials comparing these procedures.

A review of the iStent(®) trabecular micro-bypass stent: safety and efficacy

There is a significant demand for procedures that can effectively treat glaucoma with low risk and good visual outcomes. To fill this void, procedures termed “minimally invasive glaucoma surgery”, are gaining in popularity. This review will focus on the safety and efficacy of one such minimally invasive glaucoma surgery procedure, the trabecular micro-bypass stent. This stent is intended to lower intraocular pressure by directly cannulating Schlemm’s canal and thereby enhancing aqueous outflow. Recent randomized controlled trials and case series have demonstrated the micro-bypass stent to be a relatively safe procedure, with limited complications and no serious adverse sequelae. The most common complication across all studies was stent obstruction or malposition, which generally did not result in any adverse outcome in vision or pressure control. In addition, increased rates of hypotony, choroidal hemorrhage, or infection were not seen with the micro-bypass stent in comparison to cataract surgery alone.

Cataract surgery and intraocular pressure

Cataract surgery is one of the most performed surgeries in the developed world. In addition to its significant impact on visual acuity, phacoemulsification has been hailed as a potential intraocular pressure (IOP)-lowering procedure. While current evidence suggests an overall significant and sustained decrease in IOP to exist after cataract surgery, the specific ocular characteristics that could help predict which patients are likely to benefit from this IOP-lowering effect remain unclear. This definition is important in glaucoma patients if this surgery is to be used in the treatment for this disease. Our review aims to summarize the literature on the subject, depicting possible mechanisms behind this IOP decrease, which type of patients are more likely to benefit from this surgery for IOP-lowering purposes and ultimately help optimizing disease management for the increasing number of patients with concomitant glaucoma and cataract.