How to Predict Intraocular Pressure Reduction after Cataract Surgery? A Prospective Study.

Purpose/Aim: To evaluate the best formula to predict intraocular pressure (IOP) reduction after cataract surgery. Materials and methods: In this prospective longitudinal study, we included consecutive patients with or without glaucoma, either with open or with narrow angles but without peripheral anterior synechiae, who underwent phacoemulsification. Clinical factors and anterior segment parameters measured with optical biometry and optical coherence tomography were evaluated as preoperative predictors for IOP reduction at 6 months postoperatively. To find the best combinations of predictors, model selection was conducted using least absolute selection and shrinkage operator regression with cross-validation. Results: A total of 156 eyes from 109 patients were enrolled. The mean age of the patients was 74.89 (±8.54) years and the average preoperative IOP was 15.6 (±3.68) mmHg with 0.7 (range 0-4) glaucoma medications. The mean IOP reduction after phaco was 3.1 (±2.49) mmHg at postoperative month 6. After multivariate analysis, preoperative IOP (ß = 0.49 [0.4-0.59] P < .0001), gonioscopy score (ß = -0.14 [-0.23 to -0.06] P = .0001), anterior chamber depth (ß = -0.85 [-1.64 to -0.07] P = 0.033), lens thickness (LT) (ß = 0.87 [0.12-1.62] P = .024), and angle open distance 750 (ß = -2.2 [-3.96 to -0.44] P = 0.014) were associated with IOP reduction. The best formula to correlate with IOP reduction was -4.76 + (0.46 × preoperative IOP) - (0.42 × LT) - (0.1 × gonioscopy score) - (0.66 × glaucoma status). Conclusion: Different formulas were developed and were able to improve the predictive value of the preoperative IOP. When used in combination, these formulas may help the clinician to know how much IOP reduction to expect after cataract surgery at 6 months postoperatively.

Corneal Endothelial Cell Density and Morphology After Phacoemulsification in Patients With Primary Open-Angle Glaucoma and Cataracts: 2-Year Results of a Randomized Multicenter Trial.

PURPOSE: To evaluate corneal endothelial cell density (ECD) and morphology 2 years after phacoemulsification in subjects from the COMPASS trial (ClinicalTrials.gov, NCT01085357) who had mild-to-moderate primary open-angle glaucoma and visually significant cataracts. METHODS: The central corneal endothelium was evaluated by serial specular microscopy at 0 to 24 months. ECD, coefficient of variation, and percentage of hexagonal cells were evaluated by a central image analysis reading center and central corneal thickness (CCT) was evaluated by ultrasound pachymetry. RESULTS: Of 131 subjects who underwent routine phacoemulsification, analyzable endothelial images at 24 months were available for 126 subjects (96.2%). Mean ± SD central ECD at baseline was 2453 ± 359 cells/mm, decreasing by 10% ± 14% to 2195 ± 517 cells/mm at 3 months (P < 0.001) but stabilizing thereafter with mean endothelial cell loss (ECL) from baseline to 24 months of 9% ± 13% (P < 0.001). Twelve (9.5%) and 10 (7.9%) subjects experienced >30% ECL at 12 and 24 months, respectively. Neither coefficient of variation nor percentage of hexagonal cells changed significantly from baseline at any time point. Mean CCT was similar at baseline (550 ± 35 µm) and at 12 months (551 ± 37 µm) and 24 months (555 ± 35 µm). Age was significantly associated with ECL after cataract surgery (P = 0.02), but baseline intraocular pressure, number of glaucoma medications, and CCT were not. Similar results were observed in patients who underwent CyPass micro-stent implantation accompanying phacoemulsification. CONCLUSIONS: Phacoemulsification in eyes with mild-to-moderate primary open-angle glaucoma results in early ECL, with ECD stabilizing after 3 months and no effect on other endothelial stress markers up to 2 years postoperatively.

Post-phacoemulsification iris changes in eyes with glaucoma or glaucoma suspect status.

PURPOSE: This prospective study used anterior segment optical coherence tomography (AS-OCT) to determine how phacoemulsification (phaco) changes iris parameters in eyes with glaucoma or glaucoma suspect status. METHODS: Using Visante AS-OCT (Carl Zeiss Meditec AG), the following pre- and post-phaco parameters were measured: IT750 = iris thickness at 750 µm from the scleral spur; IT2000 = iris thickness 2000 µm from the scleral spur; ITCM = the maximum iris thickness at the middle one third of the iris; ICURV = iris curvature; IAREA = iris area; and pupil size = pupil diameter (mm). Only high-quality images with an identifiable scleral spur were included, and only the nasal quadrant was analyzed. A single glaucoma specialist analyzed the parameters according to the Zhongshan Angle Assessment Program (ZAAP, Guangzhou, China). Multivariate analysis was performed using mixed effects regression correcting for age, gender, and ethnicity. RESULTS: 89 subjects and 110 eyes were included in this study. The mean age of subjects was 74.83 {+/-} 8.69 years old. Most common diagnoses were POAG and glaucoma suspect (23% and 52%, respectively), and 16% of subjects had an LPI. In multivariate analysis of AS-OCT parameters, decreases in IT750, IT2000, ITCM, ICURV, and pupil size were statistically significant (p<0.05). CONCLUSIONS: After phacoemulsification, eyes with glaucoma as well as glaucoma suspect eyes have thinner irises and smaller pupils. This may lead to less iris-mediated aqueous outflow obstruction, providing support for early phacoemulsification glaucoma treatment. TRANSLATIONAL RELEVANCE: Our AS-OCT imaging findings may guide clinical practice as iris parameters become increasingly relevant in preoperative phaco planning.

Novel Gonioscopy Score and Predictive Factors for Intraocular Pressure Lowering After Phacoemulsification.

PURPOSE: To evaluate a novel gonioscopy score as a potential predictor for intraocular pressure (IOP) reduction after cataract surgery. MATERIALS AND METHODS: This was a prospective study that included consecutive patients with or without glaucoma, either with open or narrow angles but without peripheral anterior synechiae, who underwent phacoemulsification. Eyes with intraoperative complications and secondary glaucoma were excluded. A preoperative gonioscopy score was created, summing the Shaffer gonioscopy grading in 4 quadrants (range, 0 to 16). To determine variables associated with IOP change at 6 months, univariate and multivariate linear mixed-effects regression analysis was performed adjusting for age, sex, and preoperative IOP. RESULTS: In total, 188 eyes from 137 patients were enrolled. The mean age of the patients was 75.0 (±8.5) years and the average preoperative IOP was 15.6 (±3.6) mm Hg with 0.7 (range, 0 to 4) glaucoma medications. The mean IOP reduction after phacoemulsification was 3.0 (±2.6) mm Hg at postoperative month 6. After multivariate analysis, preoperative IOP [ß=0.49 (0.41-0.58), P<0.0001], gonioscopy score [ß=-0.17 (-0.24 to -0.09), P<0.0001], anterior chamber depth (ACD) [ß=-0.88 (-1.64 to -0.14), P=0.02], and IOP/ACD ratio [ß=0.45 (0.07 to 0.83) P=0.021] were associated with IOP reduction at 6 months. CONCLUSIONS: Preoperative predictors for IOP reduction after cataract surgery were preoperative IOP, ACD, gonioscopy score, and IOP/ACD ratio. The IOP/ACD ratio and gonioscopy score can be easy parameters to obtain and may help clinicians to estimate the IOP reduction after phacoemulsification.

The role of phacoemulsification in glaucoma therapy: A systematic review and meta-analysis.

Cataract extraction is a safe and effective surgery that has been performed in its modern form for several decades. Many studies have noted that cataract extraction could also have a clinically significant role in the control of comorbid glaucoma. Lens extraction decreases the pressure within the eye, and intraocular pressure (IOP) is the only controllable risk factor in glaucoma proven to be effective. A systematic analysis of current evidence is needed to establish strong practice patterns and identify areas where further research is required. We performed systematic review and meta-analysis of the clinical data to estimate the net effect of cataract surgery on IOP. A total of 37 treatment arms from 32 different studies from January 1997 to January 2017 were included. IOP reduction was highly correlated across follow-up periods. For angle-closure glaucoma, results showed an IOP decrease of -6.4 mmHg (95% CI: -9.4 to -3.4) at final follow-up (12 months and longer). For the open-angle glaucoma group, there was an overall IOP change of -2.7 mmHg (95% CI -3.7 to -1.7) from baseline. For pseudoexfoliation glaucoma further research is needed to reach an adequate evidence-based conclusion. The influence of inherent sources of bias, including loss to follow-up, washout and medication use, and lack of a control group, was evaluated numerically. These sources of bias pulled the IOP estimate in opposite directions and are therefore unlikely to affect the main conclusions substantially. Future prospective clinical trials, including other outcomes such as quality of life, clinical severity information, and cost-effectiveness analysis, are needed to determine the role of phacoemulsification alone within the glaucoma treatment algorithm.

Predictors of Intraocular Pressure After Phacoemulsification in Primary Open-Angle Glaucoma Eyes with Wide Versus Narrower Angles (An American Ophthalmological Society Thesis).

PURPOSE: To assess if narrower-angle status and anterior segment optical coherence tomography (AS-OCT) parameters can predict intraocular pressure (IOP) drop in primary open-angle glaucoma (POAG) patients after cataract surgery. METHODS: This was a prospective case series of consecutive cataract surgery patients with POAG and no peripheral anterior synechiae (PAS) using a standardized postoperative management protocol. Preoperatively, patients underwent gonioscopy and AS-OCT. The same glaucoma medication regimen was resumed by 1 month. Potential predictors of IOP reduction included narrower-angle status by gonioscopy and angle-opening distance (AOD500) as well as other AS-OCT parameters. Mixed-effects regression adjusted for use of both eyes and other potential confounders. RESULTS: We enrolled 66 eyes of 40 glaucoma patients. The IOP reduction at 1 year was 4.2±3 mm Hg (26%, P<.001) in the narrower-angle group vs 2.2±3 mm Hg (14%, P<.001) in the wide-angle group (P=.027 for difference), as classified by gonioscopy. By AOD500 classification, the narrower-angle group had 3.4±3 mm Hg (21%, P<.001) reduction vs 2.5±3 mm Hg (16%, P<.001) in the wide-angle group (P=.031 for difference). When the entire cohort was assessed, iris thickness, iris area, and lens vault were correlated with increasing IOP reduction at 1 year (P<.05 for all). CONCLUSIONS: In POAG eyes, cataract surgery lowered IOP to a greater degree in the narrower-angle group than in the wide-angle group, and parameters relating to iris thickness and area, as well as lens vault, were correlated with IOP reduction. These findings can guide ophthalmologists in their selection of cataract surgery as a potential management option.

Trabecular Meshwork Height in Primary Open-Angle Glaucoma Versus Primary Angle-Closure Glaucoma.

PURPOSE: To determine if trabecular meshwork (TM) height differs between primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) eyes. DESIGN: Prospective, cross-sectional clinical study. METHODS: Adult patients were consecutively recruited from glaucoma clinics at the University of California, San Francisco, from January 2012 to July 2015. Images were obtained from spectral-domain optical coherence tomography (Cirrus OCT; Carl Zeiss Meditec, Inc, Dublin, California, USA). Univariate and multivariate linear mixed models comparing TM height and glaucoma type were performed to assess the relationship between TM height and glaucoma subtype. Mixed-effects regression was used to adjust for the use of both eyes in some subjects. RESULTS: The study included 260 eyes from 161 subjects, composed of 61 men and 100 women. Mean age was 70 years (SD 11.77). There were 199 eyes (123 patients) in the POAG group and 61 eyes (38 patients) in the PACG group. Mean TM heights in the POAG and PACG groups were 812 ± 13 µm and 732 ± 27 µm, respectively, and the difference was significant in univariate analysis (P = .004) and in multivariate analysis (ß = -88.7 [24.05-153.5]; P = .008). CONCLUSION: In this clinic-based population, trabecular meshwork height is shorter in PACG patients compared to POAG patients. This finding may provide insight into the pathophysiology of angle closure and provide assistance in future diagnosis, prevention, and management of the angle-closure spectrum of disorders.

Anterior segment parameters as predictors of intraocular pressure reduction after phacoemulsification in eyes with open-angle glaucoma.

PURPOSE: To evaluate intraocular pressure (IOP) change after cataract surgery in eyes with open-angle glaucoma (OAG) and its relationship to angle and anterior segment parameters measured by anterior segment optical coherence tomography (AS-OCT). SETTING: University of California, San Francisco, California, USA. DESIGN: Prospective case series. METHODS: Eyes were placed into a narrow-angle group or open-angle group based on gonioscopy grading. Biometric parameters were measured using AS-OCT (Visante) preoperatively, and IOP 4 months after surgery was obtained. The IOP change and its relationship to AS-OCT parameters were evaluated. RESULTS: Eighty-one eyes of 69 patients were enrolled. The mean age of the patients was 76.8 years. The preoperative IOP was 15.02 mm Hg on 1.89 glaucoma medications. The average mean deviation of preoperative visual field was -4.58 dB. The mean IOP reduction was 2.1 mm Hg (12.8%) from a preoperative mean of 15.0 mm Hg. The IOP reduction was significantly greater in eyes with narrow angles than in eyes with open angles (20.4% versus 8.0%) (P = .002). In multivariate analysis, preoperative IOP (ß = -0.53, P < .001, R2 = 0.40), angle-opening distance at 500 mm (ß = 5.83, P = .02, R2 = 0.45), angle-opening distance at 750 mm (ß = 5.82, P = .001, R2 = 0.52), and lens vault (ß = -0.002, P = .009, R2 = 0.47) were associated with IOP reduction postoperatively. CONCLUSION: In eyes with OAG, IOP reduction after cataract surgery was greater in eyes with narrower angles. Preoperative IOP, angle-opening distance, and lens vault were predictors for IOP reduction.

Association between self-reported bupropion use and glaucoma: a population-based study.

PURPOSE: To investigate the relationship between self-reported bupropion use and self-reported glaucoma in a nationally representative sample of the US population. METHODS: This cross-sectional study included 6760 participants in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2008, age ≥40 years, who responded to a question regarding their glaucoma status. Participants were interviewed regarding the use of prescription medications, and those ascertained as having used bupropion were further divided into groups based on duration of usage. Other relevant information, including demographics, comorbidities and health-related behaviours, was obtained via interview. Multivariate logistic regression was performed to determine the OR and 95% CIs for association between bupropion use and prevalent glaucoma. Covariates in the final multivariate model included parameters associated with glaucoma at p<0.1: age, gender, ethnicity and annual income. RESULTS: 453 participants self-reported a diagnosis of glaucoma, and 108 reported bupropion medication use. Participants who reported using bupropion for more than 1 year had decreased odds of self-reporting a diagnosis of glaucoma (unadjusted OR=0.5, 95% CI 0.01 to 0.52; adjusted OR=0.1, 95% CI 0.01 to 0.81) compared with those not using bupropion or using it for less than a year. CONCLUSIONS: Bupropion use, particularly for an extended period of time, may be associated with a reduced risk of glaucomatous disease.

Erratum: Predictors of Intraocular Pressure After Phacoemulsification in Primary Open-Angle Glaucoma Eyes with Wide Versus Narrower Angles (An American Ophthalmological Society Thesis).

[This corrects the article on p. T6 in vol. 115, PMID: 29147104.].

Classification of diabetic retinopathy and diabetic macular edema.

The global incidence and prevalence of diabetes mellitus (DM) have reached epidemic proportions. Estimates indicate that more than 360 million people will be affected by DM by 2030. All of these individuals will be at risk of developing diabetic retinopathy (DR). It is extremely important to categorize, classify and stage the severity of DR in order to establish adequate therapy. With proper management more than 90% of cases of visual loss can be prevented. The purpose of the current paper is to review the classification of DR with a special emphasis on the International Clinical Disease Severity Scale for DR. This new classification is simple to use, easy to remember and based on scientific evidence. It does not require specialized examinations such as optical coherence tomography or fluorescein angiography. It is based on clinical examination and applying the Early Treatment of Diabetic Retinopathy Study 4:2:1 rule.