Endophthalmitis following cataract surgery and effect of different intracameral antibiotic regimes in Sweden 2011 - 2017. A national registry study.

PURPOSE: To study the incidence, predictive factors, aetiology and visual consequences of postoperative endophthalmitis (PE) in relation to three intracameral antibiotic regimes. SETTING: Swedish National Cataract Register (NCR) entries from 2011 through 2017. DESIGN: Observational retrospective study. METHODS: PE incidence, influencing factors, bacteriology and visual outcome were analyzed with regard to the three major prophylactic IC protocols. RESULTS: The overall incidence of PE was 0.023% or 177 cases in 764 513 cataract procedures. Analyzed per intracameral regime, the rates of PE were 0.024% (126 cases in 514 916 surgeries) for cefuroxime, 0.020% (25 cases in 122 340 surgeries) for moxifloxacin and 0.017% (20 cases in 121 045 surgeries) for combined cefuroxime-ampicillin. Incidences were not statistically significantly different from one another. Gram-positive bacteria caused 89.0% of culture positive cases. Enterococci as pathogens were significantly more frequent with intracameral cefuroxime than with moxifloxacin, p = 0.006 or cefuroxime-ampicillin, p < 0.001, while streptococci other than enterococci were more common with moxifloxacin than with cefuroxime, p < 0.001. Bacterial susceptibility to the given antibiotics was demonstrated in 21.3% of PE cases treated with cefuroxime, which was statistically significantly lower than proportions found with cefuroxime-ampicillin, 60.0%, p = 0.015, or with moxifloxacin, 88.2%, p < 0.001. Visual outcome worse than 20/200 were similar in the groups ranging from 42.0% to 53.7%. CONCLUSION: No statistically significant differences in PE incidence or visual outcome results between treatment groups were demonstrated. However, differences in aetiology and bacterial sensitivity were found between the prophylactic intracameral treatments.

Outcome of cataract surgery in eyes with diabetic retinopathy: a Swedish national cataract register report.

PURPOSE: To analyse if patients with diabetic retinopathy (DR) subjected to cataract surgery differ in outcome compared to patients without DR with regard to best-corrected visual acuity (BCVA), deviation from target refraction, intraoperative difficulties and risk of complications. METHODS: A register-based study from the Swedish National Cataract Register (NCR) during the years 2015-2017 including 358 040 cataract procedures. Patients with other ocular pathology than cataract and DR were omitted from outcome analyses. RESULTS: Diabetic retinopathy was reported in 13 724 of all eyes (3.8%). Preoperative BCVA was significantly worse in DR patients than in patients without DR, 0.54 ± 0.33 compared to 0.40 ± 0.27 (logMAR, mean ± SD, p < 0.001). The same was evident for postoperative BCVA, 0.15 ± 0.25 for DR patients versus 0.06 ± 0.13 (p < 0.001). The improvement in BCVA was slightly better in DR than in non-DR, -0.40 ± 0.32 (logMAR; mean ± SD) versus -0.35 ± 0.27, p < 0.001. The absolute mean biometry prediction error was 0.42 ± 0.50 diopters (D) in DR and 0.43 ± 0.71 D in non-DR patients, p = 0.768. One or more intraoperative difficulties, including mechanical pupil dilation, capsular stain, hooks at capsulorhexis margin or capsular tension ring, had an adjusted odds ratio (OR) of 1.75 (95% confidence interval [CI] 1.61-1.90, p < 0.001) in DR versus non-DR cases and the rate of posterior capsular tears (PCR) had an adjusted OR of 1.76 (95% CI 1.40-2.20, p < 0.001). CONCLUSION: Eyes with DR have inferior pre- and postoperative BCVA compared to non-DR eyes. There is little difference in improvement of BCVA and no difference in absolute mean biometry prediction error. Importantly, intraoperative difficulties and PCRs are almost twice as common in DR patients, strongly indicating that these patients should be managed by experienced surgeons.

Postoperative Endophthalmitis in Immediate Sequential Bilateral Cataract Surgery: A Nationwide Registry Study.

PURPOSE: To report the incidence of postoperative endophthalmitis (PE) after immediate sequential bilateral cataract surgery (ISBCS) in Sweden. DESIGN: Retrospective cohort registry study. PARTICIPANTS: Patient data from 1 457 172 cataract extractions, including 1 364 934 unilateral surgeries and 92 238 ISBCSs. METHODS: Endophthalmitis cases reported to the Swedish National Cataract Register (NCR) during a 16-year period (2002-2017) were analyzed in comparison to all control cases with regard to patient characteristics, surgical technique, and capsule complication. MAIN OUTCOME MEASURE: Incidence and determinants for PE in ISBCS compared with unilateral surgeries. RESULTS: A total of 422 cases of PE were identified in 1 457 172 cataract extractions, yielding an overall incidence of 0.029% (95% confidence interval [CI], 0.0262-0.0317). For unilateral procedures, the rate was 0.0299% (95% CI, 0.0270-0.0328) or 408 cases in 1 364 934 operations, whereas that for ISBCS was 0.0152% (95% CI, 0.0072-0.0231) or 14 incidents in 92 238 operations (P = 0.01). In a logistic regression model including all cataract procedures, nonuse of intracameral (IC) antibiotics (ABs), capsule complication, age 85 years or more, male gender, and ocular comorbidity were found to be independent risk factors for PE. All these parameters were less frequent in ISBCS. Notwithstanding, in the same multivariate analysis, ISBCS in itself was associated with a significantly lower risk for PE. At follow-up, 5 of the 14 PE cases in the ISBCS cohort had a visual acuity (VA) of 20/200 or worse. Of these, one 93-year-old ISBCS patient developed bilateral infection. CONCLUSIONS: After ISBCS in Sweden, PE occurred once in 6600 surgeries. The risk of sustaining a final VA of 20/200 or less was 1 incident in 18 000 operated eyes. When counseling potential ISBCS patients about the risk of PE, it seems reasonable to state that the reported risk in the literature is lower than that with unilateral surgery but not negligible. Precautions remain necessary.

Anti-inflammatory treatment after cataract surgery in Sweden: changes in prescribing patterns from 2010 to 2017.

AIMS: To investigate changes in the prescribing patterns of postoperative eye drops following cataract surgery in Sweden from 2010 to 2017. METHODS: Data from cataract procedures registered in the National Cataract Register during the month of March from 2010 to 2017 were record linked and sent to the Swedish Prescribed Drug Register, which allowed us to determine which eye drops the patients had obtained from 3 months presurgery to 2 weeks post surgery. RESULTS: During the 8-year study period, 54 889 surgeries were registered. Combination treatment with steroid and non-steroidal anti-inflammatory drug (NSAID) eye drops increased from 12% in 2010 to 60% in 2017 (p<0.001) while monotherapy with steroids decreased from 71% in 2010 to 26% in 2017 (p<0.001). Monotherapy with NSAIDs after surgery was fairly stable, at 17% in 2010 and 13% in 2017 (p<0.001). Combination treatment was more frequent in patients with diabetic retinopathy (p<0.001) or age-related macular degeneration (p<0.001), while monotherapy with steroids was more frequent in patients with glaucoma (p<0.001). The proportion of monotherapy or combination therapy varied widely between ophthalmic clinics. The prescription of antibiotic eye drops after surgery also varied greatly between clinics, from 0% to 63%, with a national average of 4.9%. CONCLUSION: There is a change in the prescription pattern of anti-inflammatory eye drops after cataract surgery in Sweden, with less monotherapy and an increasing proportion of patients receiving a combination of steroid and NSAID eye drops.

Three Learning Organizations in Cataract Surgery: The Example of Intracameral Antibiotic Injection.

BACKGROUND: The recent systematic adoption of intracameral antibiotic injection during cataract surgery in Sweden, India, and the US serves as a model for the successful transitioning of local quality improvement initiatives to organization-wide implementation. Although the delivery of eye care in the 3 countries is distinctly organized with differing governances and technological infrastructure, each contains elements of a learning organization (ie, an organization that has adopted a culture of creating, acquiring, and transferring knowledge into practice through system-level and clinician-level change). METHODS: We describe a retrospective and organizational implementation study of intracameral antibiotic injection in Sweden, through the efforts of the National Cataract Registry; in the US by Kaiser Permanente; and in India by the Aravind Eye Hospital System. Leadership structure, training in problem solving, benchmarking, sharing of technical knowledge, and data and workforce engagement are compared. RESULTS: Each of the 3 organizations share the key elements of effective leadership, which values the exchange of ideas in the workforce, training and resourcing for change, and information management in the form of benchmarking and data sharing. In the case of intracameral antibiotic injection, a new technique was identified to improve quality and safety with a reduction in infections as evidence of the success of the programs. CONCLUSION: Committing to a culture of collective learning, and leveraging each stakeholder's personal investment, health-care systems may improve care delivery and set new benchmarks in quality and safety.

A Composite Risk Score for Capsule Complications Based on Data from the Swedish National Cataract Register: Relation to Surgery Volumes.

PURPOSE: To investigate case mix in relation to capsule complication, possible associations between case mix and operation volume, and change in case mix over time. DESIGN: Register-based study. PARTICIPANTS: Swedish patients who underwent cataract surgery between 2007 and 2016. METHODS: Demographics and data on ocular comorbidity, intraoperative difficulties, and capsule complications were registered from 2007 to 2016 and analyzed retrospectively in relation to coded data on individual surgeons' operation volume. Single factor analysis and logistic regression were performed, and a composite risk score was created. MAIN OUTCOME MEASURES: Risk of capsule complication, given as adjusted and composite odds ratio in relation to cataract surgery volume. RESULTS: Preoperative and intraoperative variables significantly associated with capsule complications were best-corrected visual acuity (BCVA) ≤0.1 (decimal, adjusted odds ratio [aOR], 1.82; P < 0.001); pseudoexfoliation (PEX) (aOR, 1.53; P < 0.001); sight-threatening ocular comorbidity other than age-related macular degeneration (AMD), diabetic retinopathy, glaucoma, or cornea guttata (aOR, 1.35; P = 0.006); use of Trypan blue (aOR, 1.76; P < 0.001); mechanical pupil dilation (aOR, 1.36; P = 0.024); and iris hooks at the rhexis margin (aOR, 6.99; P < 0.001). The composite risk score was 3.09 ± 6.40 (mean ± standard deviation) for patients with capsule complication and 1.28 ± 1.66 for uncomplicated procedures (P < 0.001). High-volume cataract surgeons (≥500 procedures yearly) had a significantly lower composite risk score (mean risk score ≤1.28; range, 1.01-2.02) compared with low- and medium-volume cataract surgeons (1.34 ± 0.56; range, 1.00-4.55 and 1.49 ± 0.58; range, 1.01-5.19), respectively. During the period 2007-2016, the proportion of patients aged >88 years, patients with BCVA ≤0.1, and patients with intraoperative difficulties decreased. CONCLUSIONS: Case mix, as calculated from a composite risk score based on preoperative and intraoperative parameters registered in the National Cataract Register (NCR), may contribute to the decrease in capsule complications from 2007 to 2016 and the lower complication rate observed in cases managed by high-volume cataract surgeons.

Treatment of age-related macular degeneration after cataract surgery: a study from the Swedish National Cataract and Macula Registers.

PURPOSE: To characterize pre- and perioperative factors associated with treatment for wet age-related macular degeneration (wet AMD) after cataract surgery. METHODS: This register-based cohort study with data from the Swedish National Cataract Register (NCR) and the Swedish Macula Register (SMR) from 2010 to 2017 compared eyes with and without preoperative AMD that had undergone cataract surgery and was subsequently treated for wet AMD to eyes not treated within the study period. All first-eye surgeries registered in the NCR from 2010 to 2017 and matching eyes found in the SMR that had undergone treatment for wet AMD ≥ 1 year after the cataract procedure were included. Data for cataract surgery date, age and gender, use of a blue-blocking IOL, preoperative visual acuity, ocular comorbidities, posterior capsule rupture and date of AMD treatment initiation were extracted. RESULTS: The only independent factor associated with postoperative treatment of wet AMD in both groups was female gender (67.3% vs. 58.8%, p < 0.001 and 66.4% vs. 60.6%, p = 0.001, respectively). Older age was an independent factor in eyes without preoperative AMD (78.4 ± 6.5 vs. 73.4 ± 9.6 years, p < 0.001). A blue-blocking IOL appeared to decrease the likelihood of subsequent wet AMD treatment slightly but not statistically significant in eyes with preoperative AMD (52.7% vs. 56.8%, p = 0.110). CONCLUSIONS: Some factors (female gender, high age) are associated with undergoing subsequent treatment for wet AMD to a higher extent. If the use of a blue-blocking IOL offers any protection from undergoing AMD treatment after cataract surgery, such an effect must be very small.

Catquest-9SF functioning over a decade - a study from the Swedish National Cataract Register.

BACKGROUND: The Swedish National Cataract Register (NCR) collects data on cataract surgery outcomes during March, including patient-reported outcomes using the Catquest-9SF questionnaire for over 11 years. Previous studies from NCR have shown that the preoperative visual acuity has improved over time. The main purpose of this study was to evaluate the Catquest-9SF Rasch scoring performance in this changing environment. A second purpose was to describe clinical data over the same period for those who completed the questionnaire. METHODS: The performance of the Catquest-9SF was analysed by a separate Rasch analysis for each year, resulting in a preoperative and postoperative score for each participating patient in the annual cohorts. The clinical data and questionnaire scoring were analysed for each year in the period 2008-2018 inclusive. RESULTS: Data were available for 42,023 eyes for 11 annual cohorts (2008-2018). The psychometric properties of the questionnaire were stable during the study period. Person separation (precision) for the whole period was 2.58 and varied between 2.45 and 2.72. The person reliability was 0.87 and varied between 0.86 and 0.88. The targeting of question difficulty to person ability became less accurate over time meaning that the item activities became easier to carry out without difficulty. The average targeting for the whole period was -2.06 and changed from -1.92 in 2008 to -2.31 in 2018. The person score improved both before surgery and after surgery, indicating that patients are undergoing surgery at a more able level and getting better outcomes. The average improvement by surgery decreased from 3.41 logits in 2008 to 3.21 logits in 2018 (p = 0.003). Over time, patient age decreased from 75 to 74 years (p < 0.001) and the proportion of women decreased from 63.9 to 57.9% (p < 0.001). The mean preoperative visual acuity in both the operated eye and the better eye improved over time (0.47 to 0.40 logMAR, p < 0.001 and 0.22 to 0.19 logMAR, p < 0.001, respectively), as did the mean postoperative visual acuity in the operated eye (0.14 to 0.09 logMAR, p < 0.001). CONCLUSIONS: The Catquest-9SF retained stable psychometric properties over this 11-year period although more recent cohorts included slightly younger patients with somewhat better vision.

Visual acuity and intraocular pressure after surgical management of late in-the-bag dislocation of intraocular lenses. A single-centre prospective study.

OBJECTIVES: To describe logarithm of the minimum angle of resolution (logMAR) best corrected visual acuity (BCVA) and intraocular pressure (IOP) after surgical management of late in-the-bag dislocation of the intraocular lens. SUBJECTS/METHODS: In a single-centre prospective study, 165 consecutive cases having surgical correction for late in-the-bag-dislocation of intraocular lenses were analysed. One-year follow-up data of BCVA, IOP and a specially created composite variable designated "IOP issue" which considered IOP ≥ 23 mmHg, ongoing pressure reducing treatment and previous pressure reducing surgery were compared with baseline values. Logistic regression was used to investigate factors with a possible influence on the results. RESULTS: The vast majority, 80% of patients, were operated with an anterior approach with repositioning of the present IOL. Remaining patients were managed with lens exchange via a posterior approach combined with a pars plana vitrectomy (PPV). Baseline BCVA values improved from 0.65 ± 0.48 to 0.32 ± 0.41 (p < 0.001), IOP decreased from 20.12 ± 8.4 to 18.44 ± 5.96 mmHg (p = 0.02) whereas the proportion of cases with a pressure issue remained unchanged, 47.3%, at the 1-year follow-up. Determinants for having a pressure issue at the 1-year follow-up were present a pressure issue at baseline and IOL repositioning with the anterior approach. CONCLUSIONS: Both surgical methods provided similar visual rehabilitation to other techniques described in the literature. However, subjects whose IOL was exchanged in combination with a PPV were at lower risk for an IOP issue at the follow-up.

Cataract Surgery Volumes and Complications per Surgeon and Clinical Unit: Data from the Swedish National Cataract Register 2007 to 2016.

PURPOSE: To investigate the change in proportion of high-volume cataract surgeons during the period 2007 to 2016 and determine the impact of operation volume per surgeon and clinical unit on the rate of capsule complications. DESIGN: Retrospective, register-based study. PARTICIPANTS: Patients undergoing and surgeons performing cataract surgery at Swedish ophthalmologic departments 2007-2016. METHODS: All cataract procedures performed during a 10-year period were analyzed, and the change in operation volume of individual surgeons over time was determined. The yearly incidence of capsule complications was correlated to the operation volume of individual surgeons and clinical units. MAIN OUTCOME MEASURES: The number of cataract procedures yearly per surgeon and clinical unit, proportion of capsule complications, and change over time in operation volume and complication rate. RESULTS: The proportion of high-volume (≥500 procedures yearly) and very high-volume (≥1000 procedures yearly) surgeons increased from 15.0% to 34.0% and 2.1% to 10.9%, respectively (P < 0.001 for both categories). The proportion of all cataract procedures performed by high-volume surgeons was 36.9% in 2007, increasing to 68.1% in 2016. The yearly incidence of capsule complications decreased with increasing number of procedures; from a mean of 2.15% (standard deviation [SD], 3.17) for low-volume surgeons (10-99 procedures/year) to 1.32% (1.28) for medium-volume (100-499 procedures/year) surgeons and 0.59% (0.49) for high-volume surgeons (P = 0.016). Preoperative best-corrected visual acuity was significantly better in eyes operated on by high-volume and very high-volume cataract surgeons; the median best-corrected visual acuity (BCVA) was 0.5 (decimal) compared with a BCVA of 0.4 for patients who had their surgery performed by low- or medium-volume surgeons (overall P < 0.001). No significant difference in rate of capsule complications was seen between clinical units with high or low operation volume (P = 0.804). The overall incidence of capsule complications decreased gradually from 1.5% in 2007 to 0.8% in 2016, and preoperative BCVA increased from 0.46±0.10 (logarithm of the minimum angle of resolution) to 0.40±0.05 (P = 0.030). CONCLUSIONS: There is a strong association of rate of capsule complications with operation volume of individual surgeons but not with operation volume of individual clinical units. The decreased rate of capsule complications seen between 2007 and 2016 may be explained in part by a dramatic increase in the proportion of high-volume cataract surgeons during the period.

Spectacle use after routine cataract surgery and vision-related activity limitation.

PURPOSE: To explore the relationship between acquisition of new spectacles after routine cataract surgery and vision-related activity limitation (VRAL) postoperatively. METHODS: This cohort study with intervention (survey) included 1329 patients in Sweden who had undergone a second-eye cataract surgery during March 2013. Data from the Swedish National Cataract Register were used, including evaluations of VRAL through the Catquest-9SF questionnaire before and 3 months after cataract surgery. Five months after the second-eye surgery, patients completed another five-item questionnaire about spectacle use preoperatively and postoperatively including an item on surgeons' advice about the need for spectacles. These responses were linked to the Rasch-analysed Catquest-9SF data to identify correlations with VRAL. RESULTS: A total of 1239 patients finally participated in the study after excluding those who did not fulfil the inclusion criteria. Patients who were advised about the need for spectacles postoperatively (n = 387) had a greater (p = 0.039) improvement in the postoperative VRAL compared to patients who were not advised (n = 691). Patients who obtained new spectacles postoperatively (n = 512) also had greater improvement (p = 0.032) compared to those who did not (n = 724). CONCLUSION: The average improvements in the VRAL after surgery were significantly higher for patients who obtained new distance spectacles postoperatively and for patients who were informed about the need for spectacles by their practitioners.

Spectacle use after routine cataract surgery: a study from the Swedish National Cataract Register.

PURPOSE: To explore patients' obtaining and use of spectacles after routine cataract surgery. METHODS: The study included 1329 patients who underwent bilateral surgery with the second eye operated during March 2013 at 38 different clinics in Sweden. Five months after the second-eye surgery, patients completed a five-item questionnaire about their spectacle use preoperatively and postoperatively. The responses were linked to data from the registry on multiple variables including postoperative refraction, age and gender. RESULTS: Of the 387 patients who were advised by their surgeons to obtain distance spectacles postoperatively, most did so (77.3%, n = 299), while of the 691 patients who were not so advised, most did not obtain spectacles (78.9%, n = 545). Nevertheless, almost 50% of patients with both spherical and cylindrical errors exceeding 1 dioptre (D) did not obtain new distance spectacles postoperatively, while about 25% of patients with bilateral emmetropia (spherical error <0.5 D, cylinder <1 D) obtained new distance spectacles postoperatively. CONCLUSION: Patients' choices regarding obtaining and using new spectacles postoperatively are strongly correlated with advice given by the surgeon about the need for distance correction. The large difference between groups who were and were not advised to obtain spectacles for distance correction was only partially reflected in the postoperative refractive errors. Similarly, the patterns of preoperative spectacle use and gender or age differences did not explain this difference.

Validation of Catquest-9SF-A Visual Disability Instrument to Evaluate Patient Function After Corneal Transplantation.

PURPOSE: Catquest-9SF is a 9-item visual disability questionnaire developed for evaluating patient-reported outcome measures after cataract surgery. The aim of this study was to use Rasch analysis to determine the responsiveness of Catquest-9SF for corneal transplant patients. METHODS: Patients who underwent corneal transplantation primarily to improve vision were included. One group (n = 199) completed the Catquest-9SF questionnaire before corneal transplantation and a second independent group (n = 199) completed the questionnaire 2 years after surgery. All patients were recorded in the Swedish Cornea Registry, which provided clinical and demographic data for the study. Winsteps software v.3.91.0 (Winsteps.com, Beaverton, OR) was used to assess the fit of the Catquest-9SF data to the Rasch model. RESULTS: Rasch analysis showed that Catquest-9SF applied to corneal transplant patients was unidimensional (infit range, 0.73-1.32; outfit range, 0.81-1.35), and therefore, measured a single underlying construct (visual disability). The Rasch model explained 68.5% of raw variance. The response categories of the 9-item questionnaire were ordered, and the category thresholds were well defined. Item difficulty matched the level of patients' ability (0.36 logit difference between the means). Precision in terms of person separation (3.09) and person reliability (0.91) was good. Differential item functioning was notable for only 1 item (satisfaction with vision), which had a differential item functioning contrast of 1.08 logit. CONCLUSIONS: Rasch analysis showed that Catquest-9SF is a valid instrument for measuring visual disability in patients who have undergone corneal transplantation primarily to improve vision.

Risk factors for endophthalmitis after cataract surgery: Predictors for causative organisms and visual outcomes.

PURPOSE: To investigate visual outcome, bacteriology, and time to diagnosis in groups identified as being at risk for endophthalmitis following cataract surgery. SETTING: Swedish National Cataract Register. DESIGN: A retrospective review of postoperative endophthalmitis and control cases reported from 2002 to 2010. METHODS: Three identified risk groups for endophthalmitis confirmed in previous multivariate models were organized in such a way that the highest level of significance determined the allocation of cases that belonged to more than one group. Control cases of the entire database were arranged in the same manner. RESULTS: Of the 244 endophthalmitis cases occurring in 692 786 surgeries, 148 did not belong to any risk group, whereas the remaining cases were part of the following groups at risk: nontreatment with intracameral antibiotic (n = 22), communication with vitreous (n = 18), and age 85 years or more (n = 56). Cefuroxime was the intracameral antibiotic used in 99% of treated cases. Cases sustaining a communication with vitreous were found to have the worst visual prognosis. Among causative organisms, Gram-positive bacteria were significantly more frequent in cases with a communication with vitreous, whereas staphylococci and Gram-negative results were more common in patients aged 85 years or more than in nonrisk patients. CONCLUSION: Limiting the size of the risk groups by giving a prophylactic intracameral antibiotic to every single patient and by intervening earlier in the course of cataract development appear to be first steps in further reducing the endophthalmitis rate. Adjustments of the intracameral regimen may be advantageous in some risk groups. FINANCIAL DISCLOSURE: None of the authors has any financial or propriety interest in any material or method mentioned.

Changes in intraocular pressure after cataract surgery: analysis of the Swedish National Cataract Register Data.

PURPOSE: To analyze changes in intraocular pressure (IOP) after cataract surgery based on data from the Swedish National Cataract Register (NCR). SETTING: Ophthalmic surgery units in Sweden. DESIGN: Prospective database study. METHODS: Data for 2012 through 2014 were obtained prospectively from the NCR. The outcome register of the NCR has collected data on IOP before and a mean of 37.7 days ± 29.1 (SD) after cataract surgery since 2012. RESULTS: The analyses were based on 20 437 cataract extractions reported during 1 month each year to the outcome registry of the NCR. Cataract surgery was found to reduce IOP by a mean of 1.46 mm Hg, which was statistically significant (P < .001). A larger IOP reduction was seen in cases with a higher preoperative IOP (r = 0.557, P < .001). Older patients and shorter eyes had a greater IOP reduction after surgery (P < .001 and P = .001, respectively). Women had a greater IOP reduction than men (P = .04) When high IOP was given as an indication for surgery, the IOP reduction after cataract surgery was 5.50 mm Hg compared with a reduction of 1.40 mm Hg in patients for whom this indication was not given (P < .001). Patients with glaucoma or pseudoexfoliation (PXF) had a more pronounced IOP reduction than patients without these diagnoses (P < .001). CONCLUSION: Cataract surgery had an IOP-lowering effect, in particular in older patients, women, short eyes, eyes with high preoperative IOP, and eyes with glaucoma or PXF. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.