Short-term anterior chamber inflammation in phacoemulsification with and without Ex-Press glaucoma implant

Abstract

Purpose:

The aim of this study was to investigate the incidence of clinically significant anterior chamber inflammation in a combined surgery, namely, phacoemulsification and Ex-Press miniature glaucoma device implantation, compared to phacoemulsification alone.

Methods:

A retrospective comparative study of a consecutive series of 210 participants above 18 years of age diagnosed with significant cataract and who required glaucoma surgery, namely, Ex-Press miniature glaucoma device implantation or cataract alone in one or both eyes. All were operated on by a single experienced glaucoma surgeon in a single medical center. A total of 231 eyes were included in this study. All cases underwent an uneventful surgery and were examined the day following the surgery for visual acuity, intraocular pressure, and signs of excessive anterior chamber inflammation (Standardization of Uveitis Nomenclature grading ⩾ 3).

Results:

The combined group included 55 eyes of 51 patients, of whom 15 (27.3%) demonstrated excessive anterior chamber inflammation. The phacoemulsification group included 176 eyes of 159 patients, of whom 12 (6.7%) demonstrated excessive anterior chamber inflammation. Visual acuity and intraocular pressure measurements showed no statistically significant difference between the two groups.

Conclusion:

The Ex-Press glaucoma device is efficient, safe, and known for its inert nature. However, combination of this procedure with phacoemulsification surgery might result in a condition encouraging excessive inflammation, which eventually could lead to excessive anterior chamber inflammations if not treated vigorously. Emphasizing and recognizing the risks, especially in glaucoma patients, is important.

Keywords

Combined surgery Ex-Press phacoemulsification inflammation glaucoma

Introduction

The Ex-Press glaucoma implant is a small, non-valved device that was designed to lower intraocular pressure (IOP) as an alternative to trabeculectomy and shows good IOP reduction with a relatively good safety profile.¹ Unlike trabeculectomy, there is no iridectomy, no trabecular tissue excision, and no sclerectomy performed during the implantation of the Ex-Press device.

Compared to the previous technique of implantation with no flap,^2–8 placing the device under a partial thickness sclera flap has minimized the rates of adverse effects such as hypotony and erosion through the conjunctiva.^9–14 Moreover, Ex-Press implantation combined with phacoemulsification cataract surgery has recently gained more popularity and shows favorable results.¹⁵

Despite previous reports that Ex-Press may be associated with less postoperative inflammation when compared to trabeculectomy,^16,17 it had come to our attention that in clinical practice, combining Ex-Press implantation with phacoemulsification may be associated with higher rates of short-term postoperative high-grade inflammation. Therefore, the purpose of the current study was to compare the prevalence of short-term high-grade postoperative inflammation in patients undergoing phacoemulsification combined with Ex-Press implantation to phacoemulsification alone.

Subjects and methods

This study was approved by the institutional review board. This retrospective comparative study included consecutive series of eyes treated with phacoemulsification combined with Ex-Press surgery miniature glaucoma device (combined group) compared with phacoemulsification alone (phacoemulsification group).

Eligible patients above 18 years of age requiring cataract surgery alone or combined with glaucoma surgery were included. Patients meeting any of the following criteria were excluded: intraoperative complications, previous glaucoma surgery, history of uveitis, or corneal pathology as it precludes accurate IOP assessment.

Data collected included the following: demographics, ocular history, pre- and postoperative visual acuity (VA), applanation tonometry, and full slit-lamp biomicroscopy including fundoscopy.

Surgical technique

All procedures were performed by a single experienced glaucoma surgeon (B.T.) using a standardized under-the-sclera technique. Prior to the operation, the operated eye of all patients received the following: tropicamide 0.5% (Mydramide; Dr. Fischer, Israel), phenylephrine hydrochloride 2.5% (Efrin; Dr. Fischer), and cyclopentolate 1% (Colircusi Cicloplejico; Cusi, Spain) for mydriasis. Additional preoperative topical medications included the following: oxybuprocaine hydrochloride 0.4% (Localin; Dr. Fischer), dexamethasone 0.1% + neomycin sulfate 0.5% (Dethamycin; Teva, Israel), and diclofenac sodium 1% (Voltaren; Novartis, France). Patients had their periorbital skin cleansed with Iodiflor soap containing povidone iodine 7.5% (Floris, Israel) and a solution of iodine 10% (Vitamed Pharmaceutical Industries, Israel). Thereafter, the conjunctiva was topically disinfected using povidone iodine 4% (Pov-Eyeodine; Concept, Israel), and finally, for topical anesthesia, lidocaine hydrochloride 2% (Esracain Jelly; Rafa Laboratories, Israel) was applied before the operation. The surgical field was covered with a disposable sterilized surgical drape (Sion Biotext, Israel). For the combined surgery, sub-conjunctival anesthesia of bupivacaine–adrenaline 0.5% (Marcaine Adrenaline, Sweden) and lidocaine hydrochloride 2% (Esracain Injection, Rafa Laboratories) were injected and a fornix-based conjunctival flap was created. A wound-modulating agent, namely, mitomycin C 0.02% (MMC; Mitomycin; Kyowa Hakko Kirin Co., Ltd, Japan), was applied to the scleral bed for 1 min and then copiously irrigated with balanced salt solution (Balanced sterile saline solution; Beaver-Visitec International, Italy). A 50% thickness trapezoidal scleral flap was constructed and advanced anteriorly into the cornea. A 25-gauge needle was used to penetrate the anterior chamber. At this stage, phacoemulsification cataract surgery was performed using the identical procedure as for the group of patients who underwent cataract surgery alone; a clear corneal incision using a 3.2-mm keratome was followed by insertion of a viscoelastic (Sodium hyaluronate solution 1.4%; Bio-Hyalur; Biotech Ophthalmics, India) into the anterior chamber. Thereafter, a continuous curvilinear capsulorhexis, hydrodissection, and phacoemulsification were completed. Routinely, a foldable hydrophobic acrylic intraocular lens (IOL; SeeLens AF; Hanita Lenses, Israel) was inserted in the posterior chamber. In cases of small pupils, the surgeon routinely performed small pupil phacoemulsification surgery without the use of pupil expansion devices. After cataract surgery was completed, an Ex-Press glaucoma device (P-50; Alcon, Inc., USA) was inserted into the anterior chamber through the entrance created previously.

The scleral flap was sutured at its two corners by a 10-0 nylon suture (Black monofilament; Alcon, Inc.). The conjunctival flap was advanced and sutured at its two extremities by a 10-0 nylon suture. Cefuroxime sodium (Zinacef 750 mg/50 mL; GlaxoSmithKline, Italy) was injected into the anterior chamber for patients of both groups.

Postoperative treatment

Following surgery, all patients of both groups were prescribed ciprofloxacin 0.3% (Ciloxan; Alcon-Couvreur, Belgium) five times a day and a combined ophthalmic suspension containing dexamethasone 0.1%, neomycin sulfate 3500 IU/mL, and polymyxin B sulfate 6000 IU/mL (Maxitrol; Alcon-Couvreur) four times a day. All patients had their first postoperative evaluation on the day following surgery. Excessive anterior chamber inflammation was defined as Standardization of Uveitis Nomenclature grading ⩾ 3 (more than 26 cells counted with the slit lamp set to maximum intensity and both the width and length of the beam at 1 mm).¹⁸

Statistical analysis

Statistical analysis included paired t-test for testing the differences between pre- and post-surgery assessment for IOP and VA parameters. A p-value less than 0.05 was considered as statistically significant.

Results

A total of 231 eyes of 210 patients were included in this study. The combined group included 55 eyes of 51 patients and the phacoemulsification group included 176 eyes of 159 patients. Additional data regarding age and gender are detailed in Table 1 and show no statistically significant difference. There was a similar amount of pseudoexfoliation in the combined (23%) and phacoemulsification groups (13%) (p = 0.10). All of the cases of the phacoemulsification-alone group were placed in the capsular bag except for three cases where the IOL was placed in the anterior chamber. All of the cases in the combined group had the IOL placed in the capsular bag.

Table 1.

Demographic data for phacoemulsification and combined groups.

	Phacoemulsification(N = 159)	Combined(N = 51)
Age (years)
Mean ± SD	71.11 ± 9.80	71.31 ± 8.66
Min.	41	52
Max.	90	89
Gender (%)
Male	68 (42.7)	32 (62.7)
Female	91 (57.3)	19 (37.3)

SD: standard deviation.

In the combined group, 15 eyes of 55 (27.3%) cases were diagnosed with short-term postoperative high-grade inflammation. In the phacoemulsification group, 12 eyes of 176 (6.7%) cases were diagnosed with high-grade inflammation (p < 0.001) (Figure 1).

Pre- and postoperative mean VA of both groups is expressed in LogMAR (Table 2). Comparison of VA between cases diagnosed with and without short-term postoperative high-grade inflammation yielded no statistically significant difference (Table 2). Nevertheless, a comparison of IOP measurements was found to be statistically significant due to higher values in the phacoemulsification group compared to the combined group regardless of whether or not there was high-grade inflammation (Table 3).

Table 2.

Pre- and postoperative VA of both groups with and without short-term postoperative high-grade inflammation.

Postoperative high-grade inflammation	VA (LogMAR), mean ± SD	Phacoemulsification	p-value	Combined	p-value	p*
Yes	Preoperative	0.31 ± 0.28		0.28 ± 0.19
	Postoperative	0.24 ± 0.24		0.35 ± 0.12
	Pre/post changes	−0.07 ± 0.37	0.53	0.07 ± 0.18	0.17	0.32
No	Preoperative	0.27 ± 0.26		0.34 ± 0.26
	Postoperative	0.41 ± 0.24		0.49 ± 0.27
	Pre/post changes	0.14 ± 0.33	<0.001	0.15 ± 0.30	0.004	0.53

VA: visual acuity; SD: standard deviation.

p* = comparing VA changes between the two groups.

Table 3.

Pre- and postoperative IOP of both groups with and without postoperative high-grade inflammation.

Postoperative high-grade inflammation	IOP (mmHg), mean ± SD	Phacoemulsification	p-value	Combined	p-value	p*
Yes	Preoperative	15.33 ± 1.72		19.13 ± 4.36
	Postoperative	17.42 ± 6.69		12.73 ± 4.91
	Pre/post changes	2.08 ± 6.63	0.30	−6.40 ± 6.43	0.002	0.004
No	Preoperative	15.21 ± 2.3		21.45 ± 8.28
	Postoperative	16.70 ± 5.08		13.75 ± 4.35
	Pre/post changes	1.49 ± 5.32	<0.001	−7.70 ± 9.55	<0.001	<0.001

IOP: intraocular pressure; SD: standard deviation.

p* = comparing IOP changes between the two groups.

Additional variables such as pseudoexfoliation or type of glaucoma did not significantly influence the development of postoperative high-grade inflammation.

Discussion

In this study comparing combined phacoemulsification with Ex-Press, the combined group demonstrated a more significant reduction in IOP at the expense of a significantly higher prevalence of postoperative high-grade inflammation.

The Ex-Press glaucoma implant is a well-accepted miniature glaucoma device aimed to lower the IOP. Previous publications have shown the device’s efficacy and relatively lower rates of postoperative complications when compared to the classic trabeculectomy.¹⁹ Due to safety and relatively less demand for a high-skill surgical technique, this device has recently also gained popularity as a procedure combined with cataract extraction.

The incidence of postoperative short-term high-grade inflammation appeared to be surprisingly higher in the combined group. However, neither VA nor IOP was dramatically affected. Despite appropriate preventive treatment, a high-grade inflammatory reaction could potentially inflict damage to vital anterior segment structures such as the trabecular meshwork, resulting in its dysfunction.²⁰ Therefore, especially in patients with glaucoma, identifying the risk factors for developing such a high-grade inflammatory reaction and minimizing its probable causes is important. Perhaps, more intensive perioperative anti-inflammatory treatment is warranted in such a combined procedure.

Previous studies evaluating risk factors for excessive anterior segment inflammation following cataract surgery have reported both preoperative factors (diabetes mellitus, pseudoexfoliation syndrome (PXF), history of uveitis, and glaucoma)²¹ and intraoperative factors (inadequate flushing of phacoemulsification and irrigation/aspiration hand pieces, use of enzymatic cleansers, preserved epinephrine, skin prep agents, powdered gloves, and complicated surgery).^22,23 Therefore, in the current study, numerous additional causes may have potentially contributed to the high-grade inflammation. During the phacoemulsification technique in both groups, substances used prior, during, or following surgery were similar in the two groups. Moreover, the procedures were performed by the same surgeon using the same operating room and surgical instruments. While the phacoemulsification step is nearly identical between the two groups, in the combined group, there are several additional factors that may be the cause or the trigger of a high-grade inflammatory reaction. The rate of pupil stretching/manipulation which is a potential cause of significant inflammation was not recorded in this study. Therefore, this may have been a factor that contributed to the difference in inflammation between both groups as PXF, which is associated with small pupils, was more common in the combined group (23% vs 13%, p = 0.10).

MMC applied as a part of the glaucoma device implantation has been previously reported as a cause of inflammation.²⁴ The two-step surgery, namely, phacoemulsification combined with Ex-Press implantation, involves the use of similar substances to the phacoemulsification group (other than MMC) but with extended exposure due the Ex-Press implantation stage.²² Furthermore, when compared to the phacoemulsification group, the additional surgical trauma in the combined group may result in further uveal irritation with a consequential inflammatory reaction.

The Ex-Press glaucoma device is safe and known for its inert nature.^25–27 In the current study, the high-grade inflammation was not associated with significantly higher (or lower) IOP in the combined group. However, this procedure combined with phacoemulsification surgery might result in a condition predisposing to increased postoperative inflammation. Further studies are warranted to elaborate on the mechanisms that may be involved in this process.

In summary, performing combined surgery, namely, phacoemulsification with Ex-Press surgery miniature glaucoma device implantation, might increase the risk for short-term postoperative inflammation when compared to phacoemulsification procedure alone.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

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