Stratification of phaco-trabectome surgery results using a glaucoma severity index in a retrospective analysis.

BACKGROUND: To stratify the outcomes of phacoemulsification combined with trabectome surgery using a new glaucoma severity index. METHODS: This is a retrospective, observational cohort study that included open angle glaucoma patients with visually significant cataract that had phacoemulsification combined with trabectome surgery. Exclusion criteria were follow-up less than 12 months, any other surgeries or diagnosis of neovascular or active uveitic glaucoma. Patients were stratified into four groups according to the Glaucoma Index (GI) that incorporated preoperative intraocular pressure (IOP), number of medications and visual field status. The primary outcome measures were IOP reduction and the success rate at 12 months. We examined the relationship between GI group and IOP and medications at one year with a linear regression analysis and survival with log-rank testing. RESULTS: Of 1374 patients, a total of 498 cases with 12 month follow-up were included in the study after applying the exclusion criteria. At one year, IOP of GI groups 1 through 4 was reduced by 2.9 ± 4.4, 3.6 ± 5.0, 3.9 ± 5.3, and 9.2 ± 7.6 mmHg for. Individuals in the next higher GI group had a 1.69 ± 0.2 mmHg larger IOP decrease. The success rate was 98%, 93%, 96% and 88% at one year for GI groups 1 to 4 (p < 0.05). CONCLUSIONS: A substantial IOP reduction was seen in subjects with more advanced glaucoma suggesting that the trabecular meshwork is the primary impediment to outflow and its ablation benefits those eyes relatively more than in mild glaucoma. A larger IOP reduction can be expected in individuals with a higher GI group that indicates a clinically more challenging glaucoma.

Two-year data comparison of ab interno trabeculectomy and trabecular bypass stenting using exact matching.

PURPOSE: To create a balanced comparison of ab interno trabeculectomy (AIT) (Trabectome) and trabecular bypass stenting (TBS) (iStent). SETTING: Eye and Ear Institute, Pittsburgh, Pennsylvania, Ross Eye Institute, Buffalo, New York, and Glaucoma Associates of Texas, Dallas, USA. DESIGN: Retrospective case series. METHODS: The primary outcome measure was an unmedicated intraocular pressure (IOP) of 21 mm Hg or less and the secondary measure was an unmedicated IOP reduction of 20% or more at 2 years. Patients were matched by baseline IOP, number of glaucoma medications, and glaucoma type using exact matching and by age using nearest neighbor matching. Individuals without a close match were excluded. All surgeries were combined with phacoemulsification. RESULTS: One hundred fifty-four AIT eyes and 110 TBS eyes were analyzed. Forty-eight AIT patients were exactly matched with 48 TBS patients. Both groups had a mean baseline IOP of 15.3 mm Hg ± 3.1 (SD). At 24 months, the mean IOP was 13.9 ± 3.3 mm Hg in AIT patients and 16.8 ± 2.8 mm Hg in TBS patients and the mean number of medications was 0.7 ± 1.0 and 1.7 ± 1.2, respectively (both P = .04). At 24 months, the IOP was 21 mm Hg or less without medications in 53% of AIT patients and 16.6% of TBS patients (P < .05). At that time, 17.6% of patients in the AIT group but no patient in the TBS group had an IOP reduction of 20% or more without medication. CONCLUSION: An exact matching comparison of AIT and TBS showed greater IOP reduction with fewer medications after AIT.

Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery.

Increasing prevalence and cost of glaucoma have increased the demand for surgeons well trained in newer, microincisional surgery. These procedures occur in a highly confined space, making them difficult to learn by observation or assistance alone as is currently done. We hypothesized that our ex vivo outflow model is sensitive enough to allow computing individual learning curves to quantify progress and refine techniques. Seven trainees performed nine trabectome-mediated ab interno trabeculectomies in pig eyes (n = 63). An expert surgeon rated the procedure using an Operating Room Score (ORS). The extent of outflow beds accessed was measured with canalograms. Data was fitted using mixed effect models. ORS reached a half-maximum on an asymptote after only 2.5 eyes. Surgical time decreased by 1.4 minutes per eye in a linear fashion. The ablation arc followed an asymptotic function with a half-maximum inflection point after 5.3 eyes. Canalograms revealed that this progress did not correlate well with improvement in outflow, suggesting instead that about 30 eyes are needed for true mastery. This inexpensive pig eye model provides a safe and effective microsurgical training model and allows objective quantification of outcomes for the first time.

Combined analysis of trabectome and phaco-trabectome outcomes by glaucoma severity.

Prior glaucoma severity staging systems were mostly concerned with visual field function and retinal nerve fiber layer, but did not include intraocular pressure or medications to capture resistance to treatment. We recently introduced a simple index that combines pressure, medications, and visual field damage and applied it to stratify outcomes of trabectome surgery. In the analysis presented here, we combined data of trabectome alone and trabectome with same session cataract surgery to increase testing power and chances of effect discovery. This microincisional glaucoma surgery removes the primary resistance to outflow in glaucoma, the trabecular meshwork, and has been mostly used in mild glaucoma. Traditional glaucoma surgeries have a relatively high complication rate and have been reserved for more advanced disease stages. In the analysis presented here we include our data of trabectome combined with cataract surgery. This is a common practice pattern as both occur in the same age group with increasing frequency. For patients in higher glaucoma index (GI) groups, the intraocular pressure (IOP) reduction was 2.34+/-0.19 mmHg more than those in a GI group one level lower while holding everything else constant. Those who had undergone trabectome combined with phacoemulsification had an IOP reduction that was 1.29+/-0.39 mmHg less compared to those with trabectome alone. No statistically significant difference was found between genders and age groups while holding everything else constant. Hispanics had a 3.81+/-1.08 mmHg greater IOP reduction. Pseudoexfoliation and steroid glaucoma patients had an IOP reduction that was greater by 2.91+/-0.56 and 3.86+/-0.81 mmHg, respectively, than those with primary open angle glaucoma. These results suggest a role for trabectome-mediated ab interno trabeculectomy beyond mild forms of glaucoma. Additionally, the multifactorial glaucoma index demonstrates a role in staging patients when comparing glaucoma surgical modalities.

Review and meta-analysis of ab-interno trabeculectomy outcomes.

We analysed all of the PubMed publications on ab-interno trabeculectomy (AIT) with the Trabectome (Neomedix, Irvine, California, USA) to determine the reduction in intraocular pressure (IOP) and medications following the procedure. For IOP outcomes, PubMed was searched for 'trabectome', 'ab interno trabeculotomy' and 'ab interno trabeculectomy' and all available papers retrieved. The meta-analysis used a random-effects model to achieve conservative estimates and assess statistical heterogeneity. To investigate complications, we included all abstracts from the American Glaucoma Society, American Academy of Ophthalmology, American Society of Cataract and Refractive Surgery and the Association for Research in Vision and Ophthalmology. The overall arithmetic mean baseline IOP for standalone Trabectome was 26.71±1.34 mm Hg and decreased by 10.5±1.9 mm Hg (39% decrease) on 0.99±0.54 fewer medications. Defining success as IOP ≤21 with a 20% decrease while avoiding reoperation, the overall average success rate after 2 years was 46±34%. For combined phacoemulsification-Trabectome, the baseline IOP of 21±1.31 mm Hg decreased by 6.24±1.98 mm Hg (27% decrease) on 0.76±0.35 fewer medications. The success rate using the same definition at 2 years was 85±7%. The weighted mean IOP difference from baseline to study endpoint was 9.77 mm Hg (95% CI 8.90 to 10.64) standalone and 6.04 mm Hg (95% CI 4.95 to 7.13) for combined cases. Despite heterogeneity, meta-analysis showed significant and consistent decrease in IOP and medications from baseline to end point in AIT and phaco-AIT. The rate of visually threatening complications was <1%. On average, trabectome lowers the IOP by approximately 31% to a final IOP near 15 mm Hg while decreasing the number of medications by less than one, with a low rate of serious complications. After 2 years, the overall average success rate is 66%.

Coarsened Exact Matching of Phaco-Trabectome to Trabectome in Phakic Patients: Lack of Additional Pressure Reduction from Phacoemulsification.

PURPOSE: To compare intraocular pressure (IOP) after trabectome-mediated ab interno trabeculectomy surgery in phakic patients (T) and trabectome with same session phacoemulsification (PT) using Coarsened Exact Matching. Although phacoemulsification is associated with IOP reduction when performed on its own, it is not known how much it contributes in PT. METHODS: Subjects were divided into phakic T and PT. Exclusion criteria were follow-up for <12 months and additional glaucoma surgery. Demographics were compared by the Mann-Whitney U test and chi-squared test for continuous and categorical variables, respectively. Multiple imputation was utilized to avoid eliminating data with missing values. Groups were then matched using Coarsened Exact Matching based on age, race, type of glaucoma, baseline IOP, and number of preoperative glaucoma medications. Univariate linear regression was used to examine IOP reduction after surgery; those variables that were statistically significant were included in the final multivariate regression model. RESULTS: A total of 753 cases were included (T: 255, PT: 498). When all variables except for age were kept constant, there was an additional IOP reduction of 0.05±0.01 mmHg conferred for every yearly increment in age. Every 1 mmHg increase in baseline IOP correlated to an additional IOP reduction of 0.80±0.02 mmHg. Phacoemulsification was not found to be a statistically significant contributor to IOP when comparing T and PT (p≥0.05). T had a 21% IOP reduction to 15.9±3.5 mmHg (p<0.01) while PT had an 18% reduction to 15.5±3.6 mmHg (p<0.01). Number of medications decreased (p<0.01) in both groups from 2.4±1.2 to 1.9±1.3 and from 2.3±1.1 to 1.7±1.3, respectively. CONCLUSION: Phacoemulsification does not make a significant contribution to postoperative IOP or number of medications when combined with trabectome surgery in phakic patients.

Glaucoma Surgery Calculator: Limited Additive Effect of Phacoemulsification on Intraocular Pressure in Ab Interno Trabeculectomy.

PURPOSE: To compare intraocular pressure (IOP) reduction and to develop a predictive surgery calculator based on the results between trabectome-mediated ab interno trabeculectomy in pseudophakic patients versus phacoemulsification combined with trabectome-mediated ab interno trabeculectomy in phakic patients. METHODS: This observational surgical cohort study analyzed pseudophakic patients who received trabectome-mediated ab interno trabeculectomy (AIT) or phacoemulsification combined with AIT (phaco-AIT). Follow up for less than 12 months or neovascular glaucoma led to exclusion. Missing data was imputed by generating 5 similar but non-identical datasets. Groups were matched using Coarsened Exact Matching based on age, gender, type of glaucoma, race, preoperative number of glaucoma medications and baseline intraocular pressure (IOP). Linear regression was used to examine the outcome measures consisting of IOP and medications. RESULTS: Of 949 cases, 587 were included consisting of 235 AIT and 352 phaco-AIT. Baseline IOP between groups was statistically significant (p≤0.01) in linear regression models and was minimized after Coarsened Exact Matching. An increment of 1 mmHg in baseline IOP was associated with a 0.73±0.03 mmHg IOP reduction. Phaco-AIT had an IOP reduction that was only 0.73±0.32 mmHg greater than that of AIT. The resulting calculator to determine IOP reduction consisted of the formula -13.54+0.73 × (phacoemulsification yes:1, no:0) + 0.73 × (baseline IOP) + 0.59 × (secondary open angle glaucoma yes:1, no:0) + 0.03 × (age) + 0.09 × (medications). CONCLUSIONS: This predictive calculator for minimally invasive glaucoma surgery can assist clinical decision making. Only a small additional IOP reduction was observed when phacoemulsification was added to AIT. Patients with a higher baseline IOP had a greater IOP reduction.

Dietary factors and the risk of glaucoma: a review.

Glaucoma is an optic neuropathy characterized by a progressive typical pattern of optic neurodegeneration and visual field loss. A relatively high proportion of glauctomatous individuals admit to interest in dietary modification in an attempt to manage their disease. Heavy caffeine consumption appears to have a transient effect on increasing intraocular pressure (IOP). This effect may be clinically insignificant for nonglaucomatous individuals, but the association warrants clinical consideration in those with the disease. Studies investigating the relationship between self-reported antioxidant intake and risk of glaucomatous disease have reported conflicting results. Preliminary studies investigating the relationship between self-reported glaucoma diagnosis and consumption of the oxidants calcium and iron suggest a possible relationship indicating increased risk of the disease with increased consumption of these dietary factors. Initial reports in the literature suggest a potential role for dietary modification in the treatment of glaucomatous optic neuropathy. Further study, with randomized controlled trials, may be necessary to further characterize these relationships.

OCT for glaucoma diagnosis, screening and detection of glaucoma progression.

Optical coherence tomography (OCT) is a commonly used imaging modality in the evaluation of glaucomatous damage. The commercially available spectral domain (SD)-OCT offers benefits in glaucoma assessment over the earlier generation of time domain-OCT due to increased axial resolution, faster scanning speeds and has been reported to have improved reproducibility but similar diagnostic accuracy. The capabilities of SD-OCT are rapidly advancing with 3D imaging, reproducible registration, and advanced segmentation algorithms of macular and optic nerve head regions. A review of the evidence to date suggests that retinal nerve fibre layer remains the dominant parameter for glaucoma diagnosis and detection of progression while initial studies of macular and optic nerve head parameters have shown promising results. SD-OCT still currently lacks the diagnostic performance for glaucoma screening.

Bilateral central serous chorioretinopathy associated with estrogen modulator diindolylmethane.

Central serous chorioretinopathy (CSCR) is an idiopathic disease associated with states of hypercortisolism that causes fluid to collect under the retina resulting in visual impairment. The authors describe an otherwise healthy female patient who presented with headaches and blurry vision after a 2-month history of excessive daily consumption of diindolylmethane (DIM), an over-the-counter estrogen modulator medication used to treat facial acne. Imaging demonstrated asymmetric, bilateral CSCR with active leakage in the left eye. She was instructed to discontinue DIM and reported that visual improvement began 2 weeks after, with resolution to baseline after 8 weeks.