Abstract
Background
Combined cataract and glaucoma surgeries are common in patients diagnosed with both visually significant cataract and uncontrolled intraocular pressure (IOP). Although phacoemulsification with Ahmed glaucoma valve (phaco-AGV) implantation and phacoemulsification with trabeculectomy (phaco-trab) are established surgical options, limited data are available on their long-term comparative outcomes, particularly in large patient cohorts.
Methodology
A retrospective cohort study involving 249 eyes of patients who underwent either phaco-AGV (n = 120) or phaco-trab (n = 129) procedures at a tertiary eye center was conducted. Patients were followed for up to 6 years after surgery. The primary outcome measure was surgical success, defined as an IOP between 6 and 21 mmHg with or without glaucoma medications and without further glaucoma surgery or light perception vision loss. Secondary outcomes included IOP level, number of glaucoma medications, best-corrected visual acuity (BCVA), and postoperative complications. Surgical outcomes were analyzed using Kaplan‒Meier survival curves, and chi‒square and ANOVA tests were used to assess differences between the two groups.
Results
At the final follow-up, the cumulative probability of surgical success was slightly greater in the phaco-trab group than in the phaco-AGV group (59.9% vs. 40.1%, P < 0.001). The mean IOP was significantly lower in both groups at the final follow-up than at baseline (p < 0.001), with comparable final IOP levels. The mean number of glaucoma medications was significantly lower in the phaco-trab group than in the phaco-AGV group (p < 0.05). Postoperative complications were more frequent in the phaco-AGV group (32.5%) than in the phaco-trab group (16.3%) (p = 0.003). Visual acuity improvements were comparable between the groups.
Conclusion
Both the phaco-AGV and phaco-trab procedures effectively reduced IOP and improved visual acuity in patients with coexisting cataract and glaucoma. However, phaco-trab was associated with a lower rate of postoperative complications and required fewer long-term glaucoma medications. These findings suggest that while both procedures are viable options, phaco-trab, compared with phaco-AGV, may offer a more favorable risk‒benefit profile across an extended follow-up.
Keywords: Glaucoma, Combined glaucoma surgery, Long-term surgical outcomes, Cataract-Glaucoma surgery, Tube shunt implantation, Intraocular pressure control
Introduction
Glaucoma is a progressive optic neuropathy characterized by optic nerve damage and visual field loss, often leading to irreversible blindness if left untreated, and affects more than 70 million individuals worldwide [1]. The primary goal of glaucoma management is to reduce intraocular pressure (IOP), as elevated IOP is a major risk factor for the development and progression of the disease. While pharmacological treatments such as eye drops are typically the first line of therapy, surgical interventions are often necessary for patients who do not adequately respond to or cannot tolerate medical treatment [2, 3].
Trabeculectomy and glaucoma drainage device (GDD) surgery are two common surgical procedures used to lower IOP in patients with glaucoma. Notably, the intraoperative and postoperative use of antifibrotic agents such as mitomycin C (MMC) and 5-fluorouracil (5-FU) has significantly increased success rates [4]. Longer-term sequelae observed after trabeculectomy include cataract formation and progression [5]. The risk of developing cataract increases with advanced age regardless of surgical intervention [5]. The most common indications for GDD implantation include failed trabeculectomy or a good likelihood of trabeculectomy surgery failure (e.g., in uveitic and aphakic patients) [6]. The aim of both procedures is to improve aqueous outflow and lower IOP to prevent further damage to the optic nerve and preserve vision.
Cataract extraction (CE) is among the most commonly performed surgical procedures worldwide and is highly effective at restoring visual function and improving quality of life [7]. CE significantly decreases IOP in all forms of glaucoma, including primary open angle glaucoma (POAG), although the mechanisms are not entirely understood [7]. In patients with both glaucoma and cataract, concurrent cataract extraction (phacoemulsification) is often considered during glaucoma surgery to address both conditions simultaneously [7].
The decision to combine cataract surgery with glaucoma surgery, specifically trabeculectomy or GDD, is influenced by several factors, including the severity of both conditions, patient preferences, surgeon expertise, and the potential impact on visual outcomes and postoperative complications. While there is a growing body of literature on the outcomes of trabeculectomy and GDD surgery as standalone procedures, few studies have directly compared the effectiveness of these interventions with that of concurrent phacoemulsification, or such studies have had short-term follow-up periods [8, 9].
Understanding the effects of trabeculectomy and GDD surgery with concurrent phacoemulsification is crucial for optimizing treatment strategies and improving outcomes for patients with coexisting glaucoma and cataract. Consequently, the aim of this research is to bridge the existing knowledge gap and to compare complete success, qualified success and failure between phaco-trabeculectomy (phaco-trab) and phacoemulsification with GDD.
Methods
A retrospective chart review was performed to include all patients aged 18 years and older who underwent combined phacoemulsification with either trabeculectomy (phaco-trab group) or Ahmed glaucoma valve (AGV) (phaco-AGV group) implantation in one or both eyes at our hospital between 2014 and 2023. The AGV is the most common glaucoma drainage device (GDD) implanted at our center. Clinical and demographic data were collected using a structured collection sheet. The variables extracted included patient age, sex, ocular history, type of surgery performed, type of tube implant (AGV), IOP, anterior chamber (AC) depth, glaucoma medication usage, and glaucoma severity.
The inclusion criteria were patients who were of either sex, aged 18 years or older, who underwent cataract extraction with either trabeculectomy or AGV surgery during the defined study period and who were diagnosed with any form of glaucoma. Only patients with complete medical records and a minimum of six months of postoperative follow-up were included. Patients were excluded if they required reoperation within the first three months following the initial procedure, had follow-up periods of less than six months, underwent GDD implantation with a tube other than the AGV, or underwent additional concurrent ocular surgeries at the time of the cataract and glaucoma procedure, such as corneal grafts or retinal surgery.
The anticipated sample size was approximately 100 eyes in each surgical arm. Descriptive statistics were used to summarize baseline demographics, glaucoma diagnosis, severity, and preoperative IOP. Continuous variables are reported as means with standard deviations, whereas categorical variables are presented as frequencies and percentages. Between-group comparisons were performed with Student’s t test for continuous variables and the chi-square test for categorical variables.
The surgical outcomes were defined as follows: complete success was achieved when the IOP was ≤ 21 mmHg without the need for additional glaucoma medications; qualified success referred to an IOP ≤ 21 mmHg with the use of medications; and failure was defined as an IOP > 21 mmHg or ≤ 5 mmHg despite medication and was confirmed at two consecutive follow-up visits spaced at least one week apart. The choice of 21 mmHg as the primary success criterion is based on its widespread acceptance in clinical guidelines, as it is considered a safe threshold to minimize the risk of glaucomatous damage while avoiding complications from overly low IOP [10, 11]. Research has shown that maintaining IOP at or below 21 mmHg significantly reduces the progression of glaucoma and preserves vision in most patients [11].
Intraoperative antimetabolite use was standardized across all patients who underwent phaco-trab. A concentration of 5-fluorouracil (5-FU) at 0.2–0.5 mg/mL was applied for 2–3 min during surgery to prevent excessive scarring and promote successful trabeculectomy. The same exposure time and concentration were used in all the cases to ensure consistency across the cohorts. Postoperative interventions, such as bleb needling or 5-FU injections, were also noted in the phaco-trab group. Patients who developed insufficient filtering blebs or experienced elevated IOP despite initial surgery were considered for bleb needling or 5-FU injections.
Mean IOP and BCVA were calculated at various postoperative time points and are represented graphically across time. To address the longitudinal structure of the data and handle missing observations, linear mixed-effects models were employed to assess changes in IOP and BCVA across follow-up periods to account for repeated measures and intereye correlations. Because baseline values differed among procedures, the percentage change in IOP from baseline to one year after surgery was computed and compared using Student’s t tests. Additionally, Kaplan–Meier survival analyses were performed to estimate the time to reoperation for each surgical procedure, and survival curves were plotted with 95% confidence intervals. Statistical significance was indicated by p < 0.05.
Results
The study sample was composed of 249 patients with a mean age of 61.97 ± 12.61 years, and 57.8% were males. The baseline visual acuity was 1.28 ± 1.29 logMAR, based on data from 246 participants (98.8%). The average IOP was 25.76 ± 10.19 mmHg (n = 248), and the participants used an average of 3.47 ± 1.28 glaucoma medications (n = 247). The most common comorbidities were diabetes mellitus (55.0%) and hypertension (50.2%), followed by dyslipidemia (10.8%) and asthma (9.6%). Approximately 27.3% of the participants were otherwise healthy. The majority of our patients were categorized as having advanced disease (73.9%), while 16.1% had moderate disease and 7.6% had mild disease (Table 1).
Table 1.
Baseline demographics and clinical characteristics of all participants. (n = 249)
| Demographic | Count (%) | Mean ± SD | |
|---|---|---|---|
| Age (years) | 249 (100.0) | 61.97 ± 12.61 | |
| Sex | Male | 144 (57.8) | |
| Female | 105 (42.2) | ||
| Baseline characteristics | |||
| Visual acuity (logMAR) | 246 (98.8) | 1.28 ± 1.29 | |
| Intraocular pressure | 248 (99.6) | 25.76 ± 10.19 | |
| Number of glaucoma medications | 247 (99.2) | 3.47 ± 1.28 | |
| Comorbidity | Not known to have medical illness | 68 (27.3) | |
| HTN | 125 (50.2) | ||
| DM | 137 (55.0) | ||
| Dyslipidemia | 27 (10.8) | ||
| Asthma | 24 (9.6) | ||
| Severity | Mild | 19 (7.6) | |
| Moderate | 40 (16.1) | ||
| Advanced | 184 (73.9) | ||
| Follow-up mean ± SD | 3.34 ± 1.36 | ||
logMAR Logarithm of minimum angle of resolution; HTN Hypertension; DM Diabetes mellitus; and SD Standard deviation
At baseline, significant differences were observed between the phaco-AGV (n = 120) and phaco-trab (n = 129) groups. The mean age was significantly lower in the phaco-AGV group (59.22 ± 14.53) than in the phaco-trab group (64.53 ± 9.91; p < 0.001). No significant differences in sex or operated eye (left or right eye) were detected between the groups. The baseline IOP was significantly greater in the phaco-AGV group than in the phaco-trab group (28.01 ± 11.18 vs. 23.64 ± 8.68; p < 0.001), whereas visual acuity showed a nonsignificant trend toward worse vision in the phaco-AGV group (p > 0.05). The prevalence of hypertension was significantly greater in the phaco-trab group than in the phaco-AGV group (p = 0.037), whereas dyslipidemia was significantly greater in the phaco-AGV group (p < 0.001). There were more cases of secondary open angle glaucoma (SOAG), primary congenital glaucoma (PCG), and pseudoexfoliation glaucoma (PXFG) and higher prevalences of POAG and angle closure glaucoma in the phaco-trab group than in the phaco-AGV group (p < 0.001). The phaco-AGV group had a significantly greater proportion of patients with no prior ocular surgery, while various procedures, such as selective laser trabeculoplasty (SLT), cyclophotocoagulation (CPC) and pars plana vitrectomy (PPV), were more common in the phaco-trab group (p < 0.001). There was a greater tendency for advanced cases in the phaco-trab group (56.0%) than in the phaco-AGV group (44.0%), although the difference was not statistically significant (p = 0.055) (Table 2).
Table 2.
Baseline demographics and clinical characteristics of glaucoma patients who underwent phacoemulsification and trabeculectomy or phacoemulsification and Ahmed glaucoma valve implantation
| Characteristic | Phaco-AGV (n = 120) | Phaco-trab (n = 129) | p-Value | |
|---|---|---|---|---|
| Count (%) | Count (%) | |||
| Age (years), mean ± SD | 59.22 ± 14.53 | 64.53 ± 9.91 | < 0.001 | |
| Sex | Male | 76 (52.8) | 68 (47.2) | 0.090 |
| Female | 44 (41.9) | 61 (58.1) | ||
| Eye | OD | 58 (47.9) | 63 (52.1) | 0.937 |
| OS | 62 (48.4) | 66 (51.6) | ||
| Intraocular pressure, mean ± SD | 28.01 ± 11.18 | 23.64 ± 8.68 | < 0.001 | |
| Visual acuity by LogMAR, mean ± SD | 1.44 ± 1.31 | 1.13 ± 1.27 | 0.061 | |
| Follow-up, mean ± SD | 3.25 ± 1.22 | 3.38 ± 1.32 | 0.326 | |
| Comorbidity | Medical-free | 33 (48.5) | 35 (51.5) | 0.948 |
| HTN | 52 (41.6) | 73 (58.4) | 0.037 | |
| DM | 70 (51.1) | 67 (84.9) | 0.311 | |
| Dyslipidemia | 26 (96.3) | 1 (3.7) | < 0.001 | |
| Asthma | 9 (37.5) | 15 (62.5) | 0.270 | |
| Type of glaucoma | SOAG | 20 (87.0) | 3 (13.0) | < 0.001 |
| ACG | 60 (50.0) | 60 (50.0) | ||
| PCG | 7 (100.0) | 0 (0.0) | ||
| POAG | 15 (34.1) | 29 (65.9) | ||
| PXFG | 15 (30.6) | 34 (69.4) | ||
| Other | 3 (60.0) | 2 (40.0) | ||
| Number of glaucoma medications, mean ± SD | 3.50 ± 1.58 | 3.45 ± 0.92 | 0.758 | |
| Types of previous ocular interventions on the operated eye* | No previous surgery | 65 (45.5) | 78 (54.5) | 0.369 |
| Selective laser trabeculoplasty | 3 (21.4) | 11 (78.6) | 0.053 | |
| Laser peripheral iridotomy | 25 (37.3) | 42 (62.7) | 0.045 | |
| CPC | 9 (90.0) | 1 (10.0) | 0.008 | |
| Pars plana vitrectomy | 10 (100.0) | 0 (0.0) | < 0.001 | |
| Deep sclerectomy | 3 (100.0) | 0 (0.0) | 0.110 | |
| Bleb revision | 6 (100.0) | 0 (0.0) | 0.012 | |
| Other | 7 (100.0) | 0 (0.0) | 0.006 | |
| Severity | Mild | 13 (68.4) | 6 (31.6) | 0.055 |
| Moderate | 23 (57.5) | 17 (42.5) | ||
| Advanced | 81 (44.0) | 103 (56.0) | ||
Phaco-AGV Phacoemulsification and Ahmed glaucoma valve implantation group; Phaco-trab Phacoemulsification and trabeculectomy group; HTN Hypertension; DM Diabetes mellitus; SD Standard deviation; SOAG Secondary open angle glaucoma; POAG Primary open glaucoma; PCG Primary congenital glaucoma; ACG Angle closure glaucoma; PXFG Pseudoexfoliation glaucoma; CPC denotes cyclophotocoagulation; and denotes pars plana vitrectomy
p < 0.05 is statistically significant.
*The count and percentage reflect history of ocular surgeries among patients in each group. Percentages are calculated by row, representing the proportion of patients in each group. As patients may have undergone multiple interventions, the total count may exceed the number of cases
At the six-year follow-up, both groups demonstrated a sustained reduction in IOP and in the number of glaucoma medications. At 1 month after surgery, the mean IOP decreased to approximately 15 mmHg in both groups, with patients in the phaco-trab group requiring significantly fewer medications than patients in the phaco-AGV group did (0.07 vs. 0.68, respectively; p < 0.001). This trend continued at 3 and 6 months, with the phaco-trab group maintaining a greater reduction in medications (p < 0.001; Fig. 1). IOP remained similar between groups across most time points. Compared with the phaco-AGV group, the phaco-trab group consistently achieved better visual acuity outcomes, which reached statistical significance at some postoperative visits at six months or later (Table 3). By the 4th and 5th years, differences in visual acuity and number of medications narrowed, with patients in both groups requiring approximately 2–2.5 medications (Table 3). There was no significant difference in IOP between the groups at any long-term time point, suggesting similar efficacy for controlling pressure. Both surgical approaches led to a significant reduction in IOP and medication use by 12 months after surgery (Table 4, Fig. 5). In the phaco-AGV group, the IOP decreased from 27.98 ± 11.13 to 16.29 ± 6.26 mmHg (p < 0.001), and the number of medications decreased from 3.54 ± 1.55 to 1.65 ± 1.45 (p < 0.001) (Table 4). In the phaco-trab group, similar improvements were observed, with the IOP decreasing from 23.32 ± 8.70 to 14.96 ± 5.39 mmHg (p < 0.001) and the use of medications decreasing from 3.46 ± 0.85 to 1.38 ± 1.48 (p < 0.001) (Table 4). Although visual acuity slightly improved in both groups, the changes were not statistically significant over the one-year period (Table 3).
Fig. 1.
Differences in intraocular pressure between the groups
Table 3.
Changes in visual acuity, intraocular pressure, and number of glaucoma medications used at different time points in glaucoma patients who underwent phacoemulsification and trabeculectomy or phacoemulsification and Ahmed glaucoma valve implantation
| Postoperative finding | N | Phaco-AGV (n = 120) | Phaco-trab (n = 129) |
p Value | |||
|---|---|---|---|---|---|---|---|
| n | mean ± SD | n | mean ± SD | ||||
| Baseline | VA (logMAR) | 219 | 107 | 1.45 ± 1.35 | 112 | 1.17 ± 1.34 | < 0.001 |
| IOP (mmHg) | 222 | 110 | 27.98 ± 11.13 | 112 | 23.32 ± 8.70 | < 0.001 | |
| Number of glaucoma medications | 222 | 110 | 3.54 ± 1.55 | 112 | 3.46 ± 0.85 | 0.235 | |
| 1 Month | VA (logMAR) | 239 | 117 | 2.16 ± 8.35 | 122 | 0.96 ± 1.40 | 0.120 |
| IOP (mmHg) | 242 | 119 | 15.03 ± 7.52 | 123 | 14.92 ± 7.39 | 0.908 | |
| Number of glaucoma medications | 243 | 119 | 0.68 ± 1.03 | 124 | 0.07 ± 0.36 | < 0.001 | |
| 3 Months | VA (logMAR) | 197 | 99 | 1.95 ± 8.97 | 98 | 0.94 ± 1.21 | 0.269 |
| IOP (mmHg) | 196 | 98 | 16.38 ± 6.32 | 98 | 15.03 ± 5.47 | 0.111 | |
| Number of glaucoma medications | 197 | 99 | 1.45 ± 1.29 | 98 | 0.42 ± 0.97 | < 0.001 | |
| 6 Months | VA (logMAR) | 182 | 94 | 1.21 ± 1.41 | 88 | 0.53 ± 0.60 | < 0.001 |
| IOP (mmHg) | 187 | 98 | 16.65 ± 7.16 | 89 | 15.20 ± 6.19 | 0.138 | |
| Number of glaucoma medications | 187 | 98 | 1.61 ± 1.45 | 89 | 0.92 ± 1.30 | < 0.001 | |
| 12 Months | VA (logMAR) | 222 | 109 | 1.29 ± 1.77 | 113 | 0.80 ± 2.11 | 0.061 |
| IOP (mmHg) | 223 | 110 | 16.29 ± 6.26 | 113 | 14.96 ± 5.36 | 0.089 | |
| Number of glaucoma medications | 223 | 110 | 1.65 ± 1.45 | 113 | 1.36 ± 1.48 | 0.139 | |
| 2 Years | VA (logMAR) | 184 | 97 | 1.01 ± 0.97 | 87 | 0.57 ± 0.64 | < 0.001 |
| IOP (mmHg) | 187 | 99 | 15.40 ± 5.93 | 88 | 15.20 ± 5.13 | 0.812 | |
| Number of glaucoma medications | 187 | 99 | 2.08 ± 1.51 | 88 | 1.75 ± 1.53 | 0.138 | |
| 3 Years | VA (logMAR) | 140 | 78 | 1.31 ± 1.02 | 62 | 0.63 ± 0.74 | < 0.001 |
| IOP (mmHg) | 141 | 78 | 16.18 ± 6.93 | 63 | 15.10 ± 5.10 | 0.303 | |
| Number of glaucoma medications | 142 | 79 | 2.15 ± 1.54 | 63 | 2.10 ± 1.54 | 0.828 | |
| 4 Years | VA (logMAR) | 114 | 58 | 1.20 ± 0.96 | 56 | 0.64 ± 0.78 | < 0.001 |
| IOP (mmHg) | 114 | 58 | 15.38 ± 6.01 | 56 | 14.86 ± 5.21 | 0.622 | |
| Number of glaucoma medications | 114 | 58 | 2.36 ± 1.48 | 56 | 2.36 ± 1.48 | 0.986 | |
| 5 Years | VA (logMAR) | 67 | 35 | 1.21 ± 0.96 | 32 | 0.84 ± 0.85 | 0.100 |
| IOP (mmHg) | 67 | 35 | 15.31 ± 6.46 | 32 | 14.09 ± 5.83 | 0.421 | |
| Number of glaucoma medications | 67 | 35 | 2.43 ± 1.60 | 32 | 2.47 ± 1.41 | 0.914 | |
| 6 Years | VA (logMAR) | 47 | 28 | 1.32 ± 1.03 | 19 | 0.81 ± 0.86 | 0.085 |
| IOP (mmHg) | 47 | 28 | 14.57 ± 6.01 | 19 | 12.79 ± 5.90 | 0.320 | |
| Number of glaucoma medications | 47 | 28 | 2.79 ± 1.55 | 19 | 2.53 ± 1.39 | 0.560 | |
VA Visual acuity; logMAR Logarithm of the minimum angle of resolution; IOP denotes intraocular pressure; Phaco-AGV the phacoemulsification and Ahmed glaucoma valve implantation group; Phaco-trab denotes the phacoemulsification and trabeculectomy group; and SD denotes standard deviation
p < 0.05 is statistically significant
Table 4.
Comparison of parameters in baseline and one year by the two phaco groups
| Parameter | n | Baseline | 12 months | P value |
|---|---|---|---|---|
| mean ± SD | mean ± SD | |||
| Phaco-AGV | ||||
| VA | 107 | 1.45 ± 1.35 | 1.30 ± 1.78 | 0.434 |
| IOP | 110 | 27.98 ± 11.13 | 16.29 ± 6.26 | < 0.001 |
| Anti-glaucoma medications | 110 | 3.54 ± 1.55 | 1.65 ± 1.45 | < 0.001 |
| Phaco-Trab | ||||
| VA | 112 | 1.17 ± 1.34 | 0.81 ± 2.12 | 0.114 |
| IOP | 112 | 23.32 ± 8.70 | 14.96 ± 5.39 | < 0.001 |
| Anti-glaucoma medications | 112 | 3.46 ± 0.85 | 1.38 ± 1.48 | < 0.001 |
Fig. 5.
Glaucoma medications
The incidence of complications was markedly greater in the phaco-AGV group than in the phaco-trab group. A total of 42 patients experienced complications (Figs. 2, 3, 4, 5), with 95.2% occurring in the phaco-AGV group (p < 0.001). Among complications, choroidal detachment was the most common complication in the phaco-AGV group (11 cases), followed by corneal decompensation (7 cases), both of which were rarely seen or absent in the phaco-trab group. Notably, 98.4% of phaco-trab patients had no complications, compared with only 66.7% in the phaco-AGV group, underscoring the significant safety advantage of trabeculectomy (p < 0.001) (Table 5).
Fig. 2.
Comparison of overall failure rates at 6 years after surgery between glaucoma patients who underwent phacoemulsification and trabeculectomy or phacoemulsification and Ahmed glaucoma valve implantation
Fig. 3.
Comparison of glaucoma medications between the two groups at six years after surgery
Fig. 4.
Comparison between preoperative and postoperative IOP between the phaco-AGV and phaco-trab groups at different follow-up times
Table 5.
Comparison of the incidence of complications between glaucoma patients who underwent phacoemulsification and trabeculectomy or phacoemulsification and Ahmed glaucoma valve implantation
| Had complication | N | Phaco-AGV (n = 120) | Phaco-Trab (n = 129) | p Value |
|---|---|---|---|---|
| Count (%) | Count (%) | |||
| Yes | 42 | 40 (95.2) | 2 (4.8) | < 0.001 |
| No | 207 | 80 (38.6) | 127 (61.4) | |
| Type of complications | ||||
| None | 207 | 80 (66.7) | 127 (98.4) | < 0.001 |
| Choroidal detachment | 13 | 11 (9.2) | 2 (1.6) | |
| Corneal decompensation | 7 | 7 (5.8) | 0 (0.0) | |
| Hyphema | 7 | 7 (5.8) | 0 (0.0) | |
| Hypertensive phase | 6 | 6 (5.0) | 0 (0.0) | |
| Leak | 6 | 6 (5.0) | 0 (0.0) | |
| Retinal detachment | 1 | 1 (0.8) | 0 (0.0) | |
| Corneal Epithelial defect | 3 | 3 (2.5) | 0 (0.0) | |
| Descemet detachment | 2 | 2 (1.7) | 0 (0.0) | |
| Exposed plate | 1 | 1 (0.8) | 0 (0.0) | |
| Microbial keratitis | 1 | 1 (0.8) | 0 (0.0) | |
| Wound burned | 1 | 1 (0.8) | 0 (0.0) | |
| Stage of complication | ||||
| Early (≤ 6 weeks) | 35 | 34 (97.1) | 1 (2.9) | 0.309 |
| Late (> 6 weeks) | 7 | 6 (85.7) | 1 (14.3) | |
Phaco-AGV denotes the phacoemulsification and Ahmed glaucoma valve implantation group; Phaco-trab denotes the phacoemulsification and trabeculectomy group; and RD denotes retinal detachment
Fisher’s exact test; p < 0.05 is statistically significant
Table 6 presents a comparative analysis of the postoperative outcomes between the phaco-AGV and phaco-trab procedures across multiple time points. At 1 month after surgery, the rate of complete success was significantly greater in the phaco-trab group (59.9%) than in the phaco-AGV group (40.1%) (p < 0.001). This trend was consistently observed at 3 months (78.5% vs. 21.5%, respectively) and 6 months (68.4% vs. 31.6%, respectively) (all p < 0.001), favoring the phaco-trab group. Although the complete success rates remained higher in the phaco-trab group up to 12 months, the difference was not statistically significant (p = 0.100). At subsequent follow-up visits (2 to 6 years), the differences between groups diminished further, with no statistically significant differences observed in complete success, qualified success, or failure rates (all p > 0.05). The convergence in complete success rates between the two groups at 2–6 years may be attributed to factors such as bleb scarring or other long-term complications associated with trabeculectomy.
Table 6.
Comparison of postoperative overall success between glaucoma patients who underwent phacoemulsification and trabeculectomy or phacoemulsification and Ahmed glaucoma valve implantation
| Postoperative overall success | N | Phaco-AGV (n = 120) | Phaco-Trab (n = 129) | p Value | |
|---|---|---|---|---|---|
| n | n | ||||
| 1 Month | Complete | 242 | 67 (40.1) | 100 (59.9) | < 0.001 |
| Qualified | 34 (94.4) | 2 (5.6) | |||
| Failure | 18 (46.2) | 21 (53.8) | |||
| 3 Months | Complete | 194 | 20 (21.5) | 73 (78.5) | < 0.001 |
| Qualified | 57 (78.1) | 16 (21.9) | |||
| Failure | 19 (67.9) | 9 (32.1) | |||
| 6 Months | Complete | 187 | 24 (31.6) | 52 (68.4) | < 0.001 |
| Qualified | 53 (63.1) | 31 (36.9) | |||
| Failure | 21 (77.8) | 6 (22.2) | |||
| 12 Months | Complete | 223 | 32 (40.0) | 48 (60.0) | 0.100 |
| Qualified | 60 (53.6) | 52 (46.4) | |||
| Failure | 18 (58.1) | 13 (41.9) | |||
| 2 Years | Complete | 187 | 21 (45.7) | 25 (54.3) | 0.525 |
| Qualified | 65 (54.6) | 54 (45.4) | |||
| Failure | 13 (59.1) | 9 (40.9) | |||
| 3 Years | Complete | 141 | 16 (59.3) | 11 (40.7) | 0.799 |
| Qualified | 49 (53.3) | 43 (46.7) | |||
| Failure | 13 (59.1) | 9 (40.9) | |||
| 4 Years | Complete | 114 | 10 (55.6) | 8 (44.4) | 0.910 |
| Qualified | 41 (49.4) | 42 (50.6) | |||
| Failure | 7 (53.8) | 6 (46.2) | |||
| 5 Years | Complete | 67 | 7 (58.3) | 5 (41.7) | 0.444 |
| Qualified | 24 (48.0) | 26 (52.0) | |||
| Failure | 4 (80.0) | 1 (20.0) | |||
| 6 Years | Complete | 47 | 5 (71.4) | 2 (28.6) | 0.884 |
| Qualified | 20 (57.1) | 15 (42.9) | |||
| Failure | 3 (60.0) | 2 (40.0) | |||
Phaco-AGV denotes the phacoemulsification and Ahmed glaucoma valve implantation group; Phaco-trab denotes the phacoemulsification and trabeculectomy group.
p < 0.05 is statistically significant
Discussion
This study evaluated the long-term outcomes of phaco-AGV and phaco-trab. Additionally, this study evaluated intraocular pressure (IOP) control, drug usage, and visual acuity. Compared with similar studies in the literature, this study presents longer follow-up data. For example, the current study evaluated 249 patients for an average of six years. The main objective was to determine whether either combined technique, i.e., phaco-AGV or phaco-trab, offers better survival and efficacy in terms of both cataract surgery outcomes and glaucoma management.
At baseline, notable differences were detected between the groups. The Phaco-AGV group had a substantially younger mean age and higher baseline IOP than the Phaco-trab group did. These findings are in agreement with earlier research indicating that individuals with more severe glaucoma could experience greater baseline IOP, which may warrant the implantation of an AGV (a type of GDD) [12, 13]. These results concur with those reported by Weinreb et al., i.e., GDDs such as the AGV are usually indicated for patients with advanced glaucoma [14]. Furthermore, customized treatment strategies such as phaco-trab are often needed on the basis of patient characteristics such as systemic comorbidities (e.g., hypertension and diabetes), as these variables might affect surgical results and postoperative healing [15, 16].
In the current study, patients in both groups experienced statistically significant reductions in IOP and glaucoma medication usage, findings that are consistent with results reported in the literature [8, 17–19]. In a study by Hashemian et al., in both the phaco-AGV and phaco-trab groups, there were notable decreases in IOP and the use of glaucoma medications [17]. This was especially notable in our study during the first three months after surgery and was consistent at all follow-up points. Patients in the phaco-trab group had better IOP control and needed fewer glaucoma medications after surgery. Given that trabeculectomy is an inherently more effective filtering surgery, this outcome may represent the faster and more sustained impact on IOP control it has over GDDs, which occasionally need more time to stabilize IOP [8, 18, 19].
The Tube versus Trabeculectomy (TVT) Study was a multicenter randomized clinical trial that compared Baerveldt tube shunt surgery to trabeculectomy with MMC (mitomycin C) in glaucoma patients with prior intraocular surgery. Over 5 years, the study revealed that compared with trabeculectomy, tube shunts had a higher success rate (70% vs. 52%), led to a similar reduction in IOP, and resulted in fewer early postoperative complications [20].
In the current study, over the 6-year follow-up period, patients in both groups maintained similar levels of IOP control, but patients in the phaco-trab group consistently required fewer medications, which is important for patient quality of life. These findings concerning medication reduction concur with those of previous studies, which demonstrated that compared with tube implantation, trabeculectomy with cataract surgery resulted in a more sustained reduction in medication use [20, 21].
Although patients in both groups experienced an effective reduction in IOP, patients in the phaco-AGV group required slightly more medications after surgery, and patients in both groups experienced similar rates of vision loss. This study revealed that trabeculectomy is more reliable for long-term outcomes in this patient population. This difference is likely attributable to the superior aqueous outflow achieved by trabeculectomy, which typically leads to more consistent IOP control without the need for additional medication [22].
In the current study, patients in both groups experienced postoperative improvements in vision, with patients in the phaco-trab group achieving better visual outcomes at later follow-up points. The difference in visual acuity was most pronounced at the 6-month and 1-year follow-ups, favoring the phaco-trab group. However, at the 2–6-year follow-up, the visual acuity results in both groups were similar, suggesting that the early visual acuity advantage of phaco-trab converged with time. Several potential reasons for poorer visual outcomes in the phaco-AGV group include higher complication rates (choroidal detachment and corneal decompensation), greater disease severity, and preexisting comorbidities. This outcome is consistent with the results of a similar study by Tham et al., who reported better visual outcomes in patients who underwent combined phaco-trabeculectomy procedures than in patients who underwent phaco-AGV [23]. This observation could be due to the lower rate of complications such as choroidal detachment and corneal decompensation in the trabeculectomy group, leading to better long-term visual outcomes [23].
In the current study, the incidence of complications was notably greater in the phaco-AGV group, with a significant proportion of patients experiencing choroidal detachment and corneal decompensation, which were rarely observed in the phaco-trab group. The 7 cases of corneal decompensation in the phaco-AGV group warrants further clarification. Tube location (anterior chamber vs. sulcus vs. pars plana) is a critical determinant of endothelial health and corneal survival. The standard tube placement technique involved positioning the tube in the anterior chamber, as per our institutional protocol. Among the 7 cases of corneal decompensation, 5 occurred in eyes with anterior chamber tube placement. The complication-free rate in the phaco-trab group was an impressive 98.4% and is not consistent with the findings of Gedde et al., who reported higher rates of major complications with trabeculectomy than with tube implantation surgeries [24]. The higher complication rate in the phaco-AGV group is consistent with the known risks associated with tube implantation surgeries, such as a higher likelihood of postoperative choroidal detachment and corneal decompensation, particularly in patients with advanced glaucoma or significant ocular surface disease [25, 26]. These findings suggest that while an AGV may offer excellent IOP control in the short term, it is associated with an increased risk of complications that may adversely affect long-term visual prognosis.
When comparing the postoperative success rates across both groups at various time points, phaco-trab consistently demonstrated better complete success rates in the first year, which was statistically significant at 1 month, 3 months, and 6 months after surgery. However, by 12 months, the postoperative success rates between the groups were similar, and in the subsequent years (2 to 6 years), the success rates between the groups converged. These findings indicate that while trabeculectomy may yield superior early postoperative results, the long-term outcomes of the two surgical techniques appear to be similar, with both procedures maintaining acceptable levels of IOP control and a reduction in medications. The survival rates and success rates in this study are consistent with those of other studies comparing combined surgeries in which both combined phaco-trabeculectomy and phaco-tube surgeries resulted in similar long-term survival rates for IOP control, although trabeculectomy yielded better early results [27, 28].
Llaneras et al. [29] performed a comparison between phaco-tube (Baerveldt tube) and phaco-trab procedures, with key differences compared with our study, e.g., a smaller sample size (90 patients) and a 3-year follow-up period. Additionally, while the study by Llaneras et al. and our study found similar IOP control between groups, Llaneras et al. reported a lower rate of surgical failure in the phaco-tube group (6.7%) than in the phaco-trab group (32.8%) at 3 years, a finding that contrasts with the results of our study, in which the difference in surgical success diminished over time. Notably, an Ahmed glaucoma valve was used in our phaco-tube group, whereas Llaneras et al. used a Baerveldt tube, which may explain the variations in complication rates. In their study, the incidence of postoperative complications was higher in the phaco-tube group (47% vs. 33% for phaco-trab), similar to our findings, in which the phaco-AGV group had significantly more complications than the phaco-trab group did. Taken together, the results of both studies highlight phaco-trab as a safer option, with fewer complications and better outcomes in terms of visual acuity and medication use, although our study offers additional long-term insights and a larger patient cohort.
The retrospective nature of this research naturally restricts the capacity to make causal deductions and could introduce bias into data collection and analysis. The lack of randomization also poses a major constraint, as it could create disparities between the groups that are not thoroughly considered. The comprehensiveness of the findings is further limited by the lack of visual field or quality of life outcomes, as these are key criteria for evaluating the general success of glaucoma operations. Additionally, the research might be subject to referral or selection bias because the enrolled patients might not adequately represent the whole population. The discussion of the results, especially the superiority of phaco-trab, may be overemphasized without fully considering the baseline distinctions between the groups, such as the presence of more complex and refractory glaucoma cases in the phaco-AGV group. Variations in postoperative outcomes could have been caused by these underlying differences, which should be more fully explored in the interpretation of the data.
Conclusion
In conclusion, both phaco-AGV and phaco-trab are effective surgical approaches for combined cataract and glaucoma surgery, with both techniques offering substantial reductions in IOP and medication use over a 6-year period. While phaco-trab demonstrated superior short-term visual acuity improvements and a lower incidence of complications, phaco-AGV resulted in comparable long-term IOP control and reductions in medications. The choice of surgery should therefore be individualized, with careful consideration given to glaucoma severity, patient comorbidities, and the risk of postoperative complications. Future studies with larger sample sizes and longer follow-up periods are necessary to further elucidate the long-term benefits and risks of these two surgical approaches.
Author contributions
A.A and N,A and B.A Did the data collection B.A and I.A Wrote the main manuscript All authors reviewed the manuscript.
Funding
No funding
Data availability
No datasets were generated or analysed during the current study.
Declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Footnotes
Publisher's Note
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
No datasets were generated or analysed during the current study.