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

Predictors of intraocular pressure response and survival after phacoemulsification for glaucomatous eyes in the IRIS registry (Intelligent Research in Sight)

This retrospective cohort study describes the real-world incidence and maintenance of clinically meaningful intraocular pressure (IOP) reduction ("response") following stand-alone phacoemulsification for 667,987 eyes with suspected or confirmed glaucoma in the IRIS Registry (Intelligent Research in Sight) from 1/1/2013-9/30/2019. Intraocular pressure responders had ≥ 20% IOP reduction in daily mean IOP from baseline on two consecutive postoperative visits. We declared failure if a responder no longer maintained ≥ 20% IOP reduction. The estimated IOP responder rate was 41.3% by Kaplan-Meier analysis. Multivariate analysis demonstrated relationships between IOP response and baseline IOP (hazard ratio (HR) (95% confidence interval)) 1.48 (1.48-1.49), per 3 mmHg, P < 0.0001), age (HR 1.14 (1.13-1.14), per 10 years, P < 0.0001), male sex (HR 1.13 (1.12-1.15), P < 0.0001), prostaglandin analogue (HR 0.88 (0.87-0.90), P < 0.0001), and Rho-kinase inhibitor use (HR 1.50 (1.32-1.70), P = 0.01). Fifty percent of IOP responders failed at a median time of 14.3 months. Multivariate analysis demonstrated relationships between failure and baseline IOP (HR 0.75 (0.75-0.76), per 3 mmHg, P < 0.0001), nitric oxide donating prostaglandin (HR 1.78 (1.46-2.18), P < 0.0001) and Rho-kinase inhibitor use (HR 1.73 (1.43-2.09), P < 0.0001). Clinicians may counsel glaucoma patients with risk factors on whether to anticipate an IOP response and its expected duration after stand-alone phacoemulsification.

Refining glaucoma diagnosis and treatment in cataract surgery candidates: contribution of preoperative OCT retinal nerve fiber layer

PURPOSE

To evaluate the clinical significance of preoperative spectral domain optical coherence tomography (OCT) of the retinal nerve fiber layer (RNFL) thickness in identifying glaucoma and better managing patients scheduled for routine cataract surgery.

SETTING

Department of Ophthalmology, Shaare Zedek Medical Center, Jerusalem, Israel.

DESIGN

Retrospective cohort study.

METHODS

Consecutive patients scheduled for cataract surgery were enrolled from February 2022 to August 2022. Participants underwent routine OCT RNFL studies which were evaluated by a glaucoma specialist. Findings were compared with those of preoperative fundus biomicroscopic examinations conducted by the referring ophthalmologist. The main outcomes were the incidence of newly detected glaucoma based on OCT RNFL findings and the consequent changes in patient management.

RESULTS

In total, 486 patients met the inclusion criteria of whom 112 (23%) had abnormal RNFL. 31 patients (6.4%) had abnormal OCT RNFL findings attributed to comorbidities other than glaucoma, and 81 patients (16.7%) were suspected to have glaucoma based on their OCT RNFL findings, from which 44 patients (9%) were newly diagnosed with glaucoma or as glaucoma suspects, resulting in management modifications that included routine glaucoma follow-up (25 patients, 5.1%), initiation of intraocular pressure-lowering treatment (12 patients, 2.5%), and conversion to combined cataract-glaucoma surgery (7 patients, 1.4%).

CONCLUSIONS

OCT RNFL for cataract surgery candidates proved valuable in detecting glaucoma that had not been revealed by standard fundus biomicroscopic examination. The additional information provided by OCT RNFL can potentially enhance patient management and optimize outcomes.

Corneal endothelial cell loss and intraocular pressure following phacoemulsification using a new viscous-cohesive ophthalmic viscosurgical device

PURPOSE

To compare results of two ophthalmic viscosurgical devices (OVDs)-Viscoat (a dispersive OVD, Alcon) and FR-Pro (a viscous-cohesive OVD, Rayner), in phacoemulsification surgery.

METHODS

A prospective randomized controlled study. Patients undergoing phacoemulsification were randomly assigned to receive one of the two OVDs. Exclusion criteria were age under 40, preoperative endothelial cell count (ECC) below 1,500 cells/mm2 and an eventful surgery. The primary outcome was change in ECC from baseline to postoperative month one and month three. Secondary outcomes were the difference between ECC at postoperative month one and month three, changes in IOP and occurrence of an IOP spike ≥ 30 mmHg after surgery.

RESULTS

The study included 84 eyes-43 in the Viscoat group and 41 in the FR-Pro group. Mean cell density loss at month one and month three was 17.0 and 19.2%, respectively, for the Viscoat group and 18.4 and 18.8%, respectively, for the FR-Pro group, with no statistically significant difference between the groups (p = 0.772 and p = 0.671, respectively). The mean ECC difference between the month one and month three visits was 50.5 cells/mm2 and was not statistically significant (p = 0.285). One eye in each group had an IOP spike ≥ 30 mmHg, both normalized by postoperative week one.

CONCLUSIONS

Viscoat and FR-Pro have comparable results following phacoemulsification surgery, suggesting that while FR-Pro is not a dispersive OVD, its endothelial cell protection may be comparable to one, perhaps due to the addition of sorbitol. Furthermore, a one-month follow-up of ECC seems sufficient in such trials.

Changes in Intraocular Pressure and Anterior Chamber Parameters Following Cataract Surgery, Vitrectomy, and Combined Surgery

PURPOSE

The aim of this study is to investigate changes in intraocular pressure (IOP) and anterior-segment parameters before and after cataract surgery, vitrectomy, and combined surgery.

METHODS

The records of patients who had undergone cataract surgery (cataract group), vitrectomy (vitrectomy group), or combined cataract surgery and vitrectomy (combined group) at our hospital were retrospectively examined. The vitrectomy group consisted of pseudophakic eyes. IOP and anterior-segment measurements, including anterior chamber depth (ACD), angle opening distance (AOD), trabecular-iris angle (TIA), and trabecular-iris space area (TISA), were measured using swept-source anterior-segment optical coherence tomography before and 6 months after surgery in 41, 15, and 40 eyes, respectively.

RESULTS

In the cataract and combined groups, there was a decrease in IOP (cataract group: from 15.8 to 13.4 mmHg, p <0.001; combined group: from 15.8 to 14.2 mmHg, p = 0.002) and an increase in the central corneal thickness after surgery (p <0.001). The ACD increased in all groups, with a smaller increase in the vitrectomy group (p <0.03). Postoperative AOD, TIA, and TISA were significantly increased in the cataract and combined groups (p <0.02). Higher preoperative IOP and larger IOP reduction after surgery were correlated with smaller preoperative AOD, TISA, and TIA in cataract and combined groups (p <0.034). A small preoperative ACD was related to smaller preoperative AOD, TISA, TIA (r > 0.649, p <0.001), and postoperative IOP reduction in the cataract and combined groups (r = 0.377, p = 0.018 and r = 0.559, p = 0.001, respectively).

CONCLUSIONS

Compared to the vitrectomy group, the cataract and combined groups showed reduced postoperative IOP and increased AOD, TISA, and TIA. In these two groups, patients with shallower preoperative ACDs showed greater changes in IOP after surgery. Changes in IOP after surgery are thought to be related to changes in the anterior segment caused by the removal of the crystalline lens.

Intraocular Pressure Changes Following Stand-Alone Phacoemulsification: An IRISɌ Registry Analysis

PURPOSE

To describe real-world intraocular pressure (IOP) changes following stand-alone cataract surgery by comparing postoperative IOP to phakic fellow eyes.

DESIGN

Retrospective clinical cohort study.

METHODS

A total of 1,334,868 patients (336,060 with glaucoma and 998,808 without glaucoma) in the IRIS® Registry (Intelligent Research in Sight) underwent stand-alone phacoemulsification from 1 January 2013 to 30 September 2019 with a fellow eye that had subsequent cataract surgery. Postoperative daily mean IOP was compared between surgical and control eyes from postoperative day 1 to 90. A generalized linear model determined when the postoperative daily mean IOP stabilized to calculate a final mean IOP, which was then compared to baseline IOP.

RESULTS

Postoperative daily mean IOP was initially greater for surgical than for control eyes because of an early postoperative IOP spike. By postoperative day 13, postoperative daily mean IOP was significantly lower for surgical than for control eyes every day through postoperative day 90 (P < .001). There was a mean (SD) decrease from baseline to final mean IOP of 1.55 (3.52) mm Hg or 7.79% for all surgical eyes, 1.91 (3.93) mm Hg or 8.89% for surgical eyes with glaucoma, and 1.37 (3.28) mm Hg or 7.24% for surgical eyes without glaucoma, respectively. There was a statistically significant decrease from baseline to the final mean IOP for all surgical eyes, surgical eyes without glaucoma, and all categories of pre-glaucoma and glaucoma (P < .0001 for all, excluding uveitic glaucoma [P = .0016]).

CONCLUSIONS

Eyes both with and without glaucoma that underwent stand-alone phacoemulsification had a significant decrease in IOP through the 90-day postoperative period compared to baseline and phakic fellow eyes.

Kahook Dual-Blade Goniotomy with and without Phacoemulsification in Medically Uncontrolled Glaucoma

Purpose

To evaluate the 2-year efficacy and safety of Kahook dual-blade (KDB) goniotomy in patients with medically uncontrolled glaucoma.

Methods

This was a retrospective case-series study of 90 consecutive patients with primary open-angle glaucoma (POAG) or pseudoexfoliation glaucoma (PEXG) that underwent KDB goniotomy alone (KDB-alone group) or KDB goniotomy in combination with phacoemulsification (KDB-phaco group) during 2019-2020. All patients were uncontrolled on three or more medications. Surgical success was defined as an IOP reduction ≥20% and/or a reduction of one or more medications at 24 months. We also report IOP levels and number of medications from baseline to 24 months, as well as the need for further glaucoma interventions.

Results

At 24 months, mean IOP had reduced from 24.8±8.3 to 15.0±5.3 mmHg in the KDB-alone group (P<0.001) and from 22.3±5.8 to 13.9±3.0 mmHg in the KDB-phaco group (P<0.001). Medications had reduced from 3.5±0.6 to 3.1±0.9 in the KDB-alone group (P=0.047) and from 3.3±0.5 to 2.3±1.1 in the KDB-phaco group (P<0.001). An IOP reduction ≥20% and/or a reduction with one or more medications was achieved by 47% of eyes in the KDB-alone group and by 76% of eyes in the KDB-phaco group. Eyes with PEXG and POAG responded equally well to the success criteria. During the 24-month follow-up, additional glaucoma surgery or transscleral photocoagulation was performed in 28% of eyes in the KDB-alone group and in 12% of eyes in the KDB-phaco group.

Conclusion

In patients with medically uncontrolled glaucoma, KDB had a significant IOP-lowering effect after 24 months, but success rates were higher when KDB was performed in combination with cataract surgery compared to stand-alone treatment.

Real-World Outcomes of Glaucoma Filtration Surgery Using Electronic Health Records: An Informatics Study

PRCIS

Utilizing an automated pipeline for data extraction from electronic health records provides real-world information on the success of various glaucoma procedures, with tube shunt implantation associated with increased failure rates compared with trabeculectomy.

BACKGROUND

We aimed to evaluate the long-term survival of glaucoma surgeries using an automated pipeline for extraction of outcomes from electronic health records.

METHODS

A retrospective observational study from a single academic center. Patients undergoing trabeculectomy, Ex-PRESS shunt, Baerveldt, and Ahmed tube shunt insertion from 2009 to 2018 were identified from electronic health record procedure codes. Patient characteristics were identified from structured and unstructured fields using a previously validated natural language processing pipeline.

RESULTS

Five hundred twelve patients underwent 711 glaucoma surgeries: 287 trabeculectomies, 47 Ex-PRESS shunts, 274 Baerveldt and 103 Ahmed tube implantations. The Median follow-up was 359 days. The mean baseline IOP was 24.4 mm Hg (SD 10.9), and 73.1% were on ≥3 medications. Compared with trabeculectomy, tube shunt surgery had a higher risk of failure (Baerveldt: Hazard Ratio (HR) 1.44, 95% CI 1.02 to 2.02; Ahmed: HR 2.01, 95% CI 1.28 to 3.17). Previous glaucoma surgery was associated with increased failure (≥2 previous surgeries: HR 2.74, 95% CI 1.62 to 4.64), as were fewer baseline medications (<3 medications: HR 2.96, 95% CI 2.12 to 4.13) and male sex (HR 1.40, 95% CI 1.03 to 1.90). At 1 year, tube shunt patients had a 2.53 mm Hg ( P =0.002) higher IOP compared with trabeculectomy patients.

CONCLUSIONS

Baerveldt and Ahmed tube shunt implantation was associated with increased failure compared with trabeculectomy. Fewer baseline medications, previous glaucoma surgeries, and male sex were also risk factors for failure. These results demonstrate the utility of applying an informatics pipeline to electronic health records to investigate key clinical questions using real-world evidence.

Repeatability of Corneal Hysteresis Measurements in Glaucoma Patients During Routine Follow Up and After Cataract Surgery

PRCIS

Corneal hysteresis (CH) measurements are relatively stable during routine follow up of glaucoma patients over an intermediate time frame. Cataract surgery does not change the CH significantly after an average follow up of 6 months.

PURPOSE

The aim was to assess the repeatability of CH measurements in glaucoma patients over time, during routine follow up and after cataract surgery.

MATERIALS AND METHODS

Retrospective analysis of patients records in a glaucoma clinic where routine measurements by the Ocular Response Analyzer were done. Patients with at least 2 CH measurements were included. Repeatability was assessed using the intraclass correlation coefficient (ICC).

RESULTS

A total of 164 eyes (87 patients) were included. Twenty-eight of them had measurements before and after cataract surgery with mean follow up time of 29.64±9.63 weeks. There was no evidence for a difference in CH between the before and after cataract surgery measurements (ICC=0.79, 95% confidence interval: 0.60-0.89). In the remaining 136 eyes, without any surgical treatment between measurements, there was moderate agreement among the repeated CH measurements (ICC=0.64, 95% confidence interval: 0.61-0.82) with mean time of 32.06±25.32 weeks between first and last measurement.

CONCLUSION

CH measurements in glaucoma patients were repeatable over a 6-month period during routine follow up or following cataract surgery. These findings suggest that the intraocular pressure reduction following cataract surgery is unlikely to be because of a change in this biomechanical property.

Cataract extraction and intraocular pressure-lowering agents delivery: A nationwide French study between 2005 and 2017

PURPOSE

Cataract and glaucoma are among the leading causes of blindness worldwide in older people, and they are often concomitant. To assess topical intraocular (IOP)-lowering agents delivery changes after cataract extraction.

MATERIAL AND METHODS

Longitudinal matched exposed-unexposed study from the French national healthcare database from January 1, 2005 to January 1, 2017. We compared individuals using topical IOP-lowering agents who underwent bilateral cataract extraction with individuals matched on IOP-lowering agents load, age, and sex who did not undergo cataract extraction. IOP-lowering agents number of drops was assessed 12 months before the first cataract extraction and compared with number of drops 12 months after the second cataract extraction.

RESULTS

About 1194 individuals treated with IOP-lowering agents were included, 597 exposed to bilateral cataract extraction and 597 unexposed to any surgery (total mean age 74.8 ± 8.3 years; 69.0% women). Mean IOP-lowering agents delivery at baseline was 1.4 daily drops in both groups. The mean number of drops decreased greater in the exposed than unexposed group (-25.5% vs -3.5%; p < 0.0001). Overall, 159 (26.6%) and 48 (8.0%) individuals in the exposed and unexposed groups interrupted medication (p < 0.0001).

CONCLUSIONS

A decrease of around one quarter of IOP-lowering agents delivery was observed after cataract extraction in the present real-life study with a longstanding interruption observed in one quarter of patients. Phacoemulsification as a standalone procedure reduces IOP-lowering agents delivery in ocular hypertension and glaucoma.

Profile of Glaucoma in the Eastern Region of Saudi Arabia: A Retrospective Study

Background:

Glaucomas remain asymptomatic until severe, indicating that the actual number of affected individuals may be higher than those diagnosed.

Objective:

To study the clinical patterns of glaucoma cases in the Eastern Province of Saudi Arabia.

Patients and Methods:

This retrospective study was conducted at King Fahd Hospital of the University, Al-Khobar, and Dhahran Eye Specialist Hospital, Dhahran, Saudi Arabia. The medical records of all patients with glaucoma who visited these hospitals from January 2015 to December 2018 were critically reviewed. Data regarding patients' demographic characteristic, clinical data and their medical and surgical management techniques were collected and analyzed.

Results:

A total of 999 patients were included, of which 52.9% were males, 94.8% were Saudi, and the mean age was 58.8 years. Bilateral involvement was observed in 82.3% of cases. Primary open-angle glaucoma (POAG) was the most prevalent type of glaucoma (27.7%), followed by secondary glaucomas (26.7%), primary angle-closure glaucoma (PACG) (18.2%), primary congenital glaucoma (2.7%), and juvenile open-angle glaucoma (2.2%), which were the most frequent glaucoma subsets.

Conclusion:

The study population was most affected by POAG, secondary glaucomas and PACG. Knowledge regarding prevalence of glaucoma is important to plan services, allocate resources, and prevent blindness.

Learning Curve and One-Year Outcome of XEN 45 Gel Stent Implantation in a Swedish Population

Purpose

Evaluation of 1-year-outcome of XEN 45 gel stent surgery in a Swedish cohort with regard to clinical success, complications, and learning curve.

Patients and Methods

This was a retrospective study of glaucoma patients undergoing glaucoma XEN-stent surgery alone or combined with phacoemulsification between December 2015 and May 2017. Intraocular pressure (IOP), number of medical agents, and adverse events were assessed. Clinical success rate was defined as achieving individual target pressure with/without medication.

Results

A total of 113 eyes were included in the final statistics. Mean age was 70.8±11.8 years. Primary open angle glaucoma (POAG) accounted for 46.9% and exfoliative glaucoma (PEXG) for 40.7%. Mean preoperative IOP was 23.8±6.2 mmHg and mean number of agents 3.4. After 1 year, mean IOP was reduced to 16.1±4.7 mmHg and medication to 1.34 substances on average. Failure rate at 1-year follow-up was 34% with no significant difference between POAG and PEXG. There was a trend of higher success rate for combined cases (P=0.116). Stents with malpositioned or curved appearance had significantly worse outcome. The failure rate of the most productive surgeon dropped from 33% to 10% from the first implantations. Temporary hypotony (19.5%) and choroidal detachment (9.7%) were the most common complications. Blockage of the inner stent lumen was common (8.8%), with a high proportion of failure.

Conclusion

XEN-stent surgery is a surgical option in uncontrolled glaucoma in both POAG and PEXG. A XEN-stent can reduce both IOP and the number of antiglaucoma medications needed. The learning curve is significant and stent positioning is crucial for optimal results. Combined XEN-cataract surgery is not inferior to stand-alone procedures. The long-time effectiveness is still to be proven.

Microinvasive glaucoma surgery: A review of 3476 eyes

Microinvasive glaucoma surgery (MIGS) is a potentially safer and more efficacious method studied in patients with mild-to-moderate open-angle glaucoma requiring less invasive treatment goals; however, the literature on MIGS must be thoroughly evaluated. We conducted a review of MIGS by searching MEDLINE, EMBASE, and Cochrane CENTRAL. Primary efficacy indicators were reductions in intraocular pressure and topical medication use postoperatively. While all comparative randomized controlled trials assessing MIGS in English peer-reviewed journals were included, only observational studies with a target follow-up of at least one year and a high priority score were analyzed, resulting in a total of 3476 eyes across 20 trials. The mean age was 69.5 ± 2.9 years, 53.7% were female, and 77.4% were Caucasian. One study had last follow-up at less than one year, fifteen studies had follow-up extending 1-2 years, and four had longer than two years of follow-up. A pattern of more significant intraocular pressure and medication reduction was observed in patients who underwent MIGS (n = 2170) relative to control (n = 1306) interventions. iStent had the most literature supporting its efficacy, followed by Hydrus. The most common adverse events after MIGS implantation included stent obstruction, inflammation, and subsequent surgical intervention. Surgical complication rates and efficacy are favorable after MIGS. This review helps to consolidate the high-quality evidence that exists for various MIGS procedures and to identify gaps where further research is needed.

Intraocular Pressure Changes after Cataract Surgery in Patients with and without Glaucoma: An Informatics-Based Approach

PURPOSE

To evaluate changes in intraocular pressure (IOP) after cataract surgery among patients with or without glaucoma using automated extraction of data from electronic health records (EHRs).

DESIGN

Retrospective cohort study.

PARTICIPANTS

Adults who underwent standalone cataract surgery at a single academic center from 2009-2018.

METHODS

Patient information was identified from procedure and billing codes, demographic tables, medication orders, clinical notes, and eye examination fields in the EHR. A previously validated natural language processing pipeline was used to identify laterality of cataract surgery from operative notes and laterality of eye medications from medication orders. Cox proportional hazards modeling evaluated factors associated with the main outcome of sustained postoperative IOP reduction.

MAIN OUTCOME MEASURES

Sustained post-cataract surgery IOP reduction, measured at 14 months or the last follow-up while using equal or fewer glaucoma medications compared with baseline and without additional glaucoma laser or surgery on the operative eye.

RESULTS

The median follow-up for 7574 eyes of 4883 patients who underwent cataract surgery was 244 days. The mean preoperative IOP for all patients was 15.2 mmHg (standard deviation [SD], 3.4 mmHg), which decreased to 14.2 mmHg (SD, 3.0 mmHg) at 12 months after surgery. Patients with IOP of 21.0 mmHg or more showed mean postoperative IOP reduction ranging from -6.2 to -6.9 mmHg. Cataract surgery was more likely to yield sustained IOP reduction for patients with primary open-angle glaucoma (hazard ratio [HR], 1.19; 95% confidence interval, 1.05-1.36) or narrow angles or angle closure (HR, 1.21; 95% confidence interval, 1.08-1.34) compared with patients without glaucoma. Those with a higher baseline IOP were more likely to achieve postoperative IOP reduction (HR, 1.06 per 1-mmHg increase in baseline IOP; 95% confidence interval, 1.05-1.07).

CONCLUSIONS

Our results suggest that patients with primary open-angle glaucoma or with narrow angles or chronic angle closure were more likely to achieve sustained IOP reduction after cataract surgery. Patients with higher baseline IOP had increasingly higher odds of achieving reduction in IOP. This evidence demonstrates the potential usefulness of a pipeline for automated extraction of ophthalmic surgical outcomes from EHR to answer key clinical questions on a large scale.

Corneal Biomechanical Changes After Uneventful Phacoemulsification in Patients With Type 2 Diabetes Mellitus and Patients Without Diabetes

PURPOSE

To compare corneal biomechanical changes after uneventful phacoemulsification cataract surgery between type 2 diabetic (DM) and nondiabetic patients.

METHODS

Forty-four diabetic (44 eyes) and 44 (44 eyes) age and sex-matched non-DM controls with age-related cataract were enrolled in this prospective observational study. Corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc) were evaluated by using the ocular response analyzer; central corneal thickness was recorded by using the Pentacam HR. Patients were evaluated preoperatively and 1 and 6 months after surgery.

RESULTS

In the DM group, CH was observed to be significantly lower than preoperative value (9.8 ± 1.5 mm Hg) at 1 month (9.4 ± 1.2 mm Hg, P = 0.040), but not at the 6-month follow-up (9.6 ± 1.6 mm Hg, P = 0.437),whereas it did not change significantly in the non-DM group (preoperative 9.8 ± 1.3 mm Hg vs. 1 month 9.6 ± 1.1 mm Hg vs. 6 months 10.1 ± 1.1 mm Hg, P > 0.05). CRF was significantly lower than the preoperative values at 1 and 6 months in both groups (P ≤ 0.001). Postoperative CH change was significantly associated with preoperative CH (P < 0.001), preoperative IOPcc (P = 0.004), and IOPcc change (P < 0.001), whereas CRF change was only correlated with preoperative CRF (P < 0.001). There was a significant postoperative IOPcc reduction 6 months after surgery (P < 0.001) in both DM and non-DM groups; however, central corneal thickness was not found to significantly change in the postoperative period (P > 0.05).

CONCLUSIONS

This study showed that phacoemulsification causes a significant and persistent decrease in intraocular pressure and CRF in both groups, whereas CH recovered to preoperative values, although more slowly in patients with diabetes.

Predictive factors for the IOP reduction in phacocanaloplasty with suprachoroidal drainage

PURPOSE

Although the pressure-reducing effect of cataract surgery alone is not very high, it is often cited in the literature. Some authors describe predictive factors correlated with the IOP (intraocular pressure) reduction: in particular noteworthy are age, axial length, preoperative pressure level and the ratio of preoperative pressure/anterior chamber depth. The aim of this study was to determine the applicability of these predictive factors to phacocanaloplasty with suprachoroidal drainage. Setting Eye Clinic Sulzbach Germany.

DESIGN

Retrospective study with a 12-month follow-up, including patients that underwent phacocanaloplasty with suprachoroidal drainage between 2012 and 2014.

METHODS

Preoperatively, baseline information was collected (including age, diagnosis, medication), and the patients underwent a basic examination and optical biometry. To investigate the relationship between preoperative parameters and the IOP reduction, Pearson's correlation analysis and linear regression were used. Patients with missing data pre- or postoperatively were excluded from the analysis.

RESULTS

The study comprised 89 patients. Mean preoperative IOP was 23.0 ± 5.3 mmHg with 4.0 different antiglaucomatous eye drops. After 12 months, IOP was reduced to 12.1 ± 1.4 mmHg with a median medication of 0.0. The preoperative IOP and the ratio of preoperative IOP/anterior chamber depth were identified as predictive factors. There was no influence of axial length and anterior chamber depth.

CONCLUSION

Unlike in cataract surgery, anterior chamber depth and axial length have no influence on the pressure reduction caused by phacocanaloplasty. However, a strong predictive factor is the preoperative pressure level. The higher the preoperative IOP, the greater the postoperative pressure reduction.

Pneumotonometer Accuracy Using Manometric Measurements after Radial Keratotomy, Clear Corneal Incisions and Lamellar Dissection in Porcine Eyes

Purpose/Aim of the study: Measured intraocular pressure (IOP) after corneal incisions may not be reflective of the true IOP because of changes in corneal biomechanical properties. The purpose of this study is to investigate the effect of various corneal incisions on pneumotonometer accuracy in enucleated porcine eyes.Materials and Methods: A pneumotonometer was used to measure IOP (IOPp) at manometrically controlled pressure levels of 10, 20, 30 and 40 mmHg in enucleated porcine eyes. IOP measurements at each level were repeated after one of the following corneal incisions: radial keratotomy (8 eyes), lamellar dissection (10 eyes), clear cornea standard phacoemulsification incisions (10 eyes). The pneumotonometer error, defined as the difference between IOPp and manometric pressure (IOPm), was calculated for each pressure level. The error before the corneal incisions was compared to the error after the corneal incisions to assess the accuracy of the pneumotonometer.Results: The pneumotonometer underestimates true IOP at all pressure levels, both before and after the corneal procedures. There was a statistically significant greater underestimation of IOP after radial keratotomy incisions at pressure levels of 20, 30 and 40 mmHg (p = .013, 0.004, and 0.002, respectively). There was no statistically significant difference in the amount of pneumotonometer underestimation error after lamellar dissection or standard cataract incisions.Conclusion: The pneumotonometer underestimates true IOP in enucleated porcine eyes at all pressure levels between 10-40 mmHg. Radial keratotomy incisions caused a statistically significant greater underestimation error in pneumotonometry measurements at pressures of 20-40 mmHg. Lamellar dissection and clear corneal cataract incisions did not cause an additional error in pneumotonometry measurements in enucleated porcine eyes.

Miniaturization in Glaucoma Monitoring and Treatment: A Review of New Technologies That Require a Minimal Surgical Approach

In the management of glaucoma, recent and upcoming innovations have the potential to contribute to both the efficacy of intraocular pressure (IOP) monitoring and the number of available treatment options. These new devices and procedures have two things in common: they are part of the trend in medicine towards miniaturization, and they require a limited surgical procedure to become effective. This review focuses on the Eyemate (Argos) intraocular sensor, which offers a new way to reliably measure 24 h IOP, and on intraocular sustained release systems for pharmacological glaucoma therapy. It also briefly reflects on the miniature implants currently used in minimally invasive glaucoma surgery (MIGS).

Intraocular Pressure (IOP) Change and Frequency of IOP Spike After Cataract Surgery in Normal-tension Glaucoma: A Case-Control Study

PURPOSE

To evaluate the early-postoperative intraocular pressure (IOP) changes and frequency of IOP spike after cataract surgery in normal-tension glaucoma (NTG) eyes and to compare them with those of nonglaucomatous eyes.

MATERIALS AND METHODS

This was a case-control study. We reviewed the medical records of patients who had undergone cataract surgery. One-to-one (1:1) case matching was performed, each matched set consisting of 1 NTG and 1 nonglaucomatous eye as the control eye. Comparisons between those 2 groups were performed. Specifically, IOP was measured preoperatively and 1 day, 1, 2, and 4 weeks postoperatively. The incidence of IOP spike was evaluated according to the criteria of IOP higher than 21, 25, 30 mm Hg, higher than 5, 10 mm Hg over baseline IOP, and 50% above preoperative IOP.

RESULTS

A total of 298 eyes (149 NTG eyes and 149 control eyes) were enrolled. Preoperative IOP did not show any significant difference between the 2 groups (P=0.687). IOP significantly decreased in both the NTG and control groups [P<0.001, repeated-measures analysis of variance (ANOVA)]. No significant differences in this regard were detected between the 2 groups (P=0.618, repeated-measures ANOVA). When IOP spike was evaluated according to the 6 criteria, the frequencies were <3% at any timepoint. There was no significant difference between the 2 groups.

CONCLUSIONS

In both the NTG and control groups, IOP gradually decreased in the early-postoperative period after cataract surgery, and there was no significant difference between the 2 groups. The frequency of IOP spike was <5% in both the NTG group and the control group.

Comparison of variation of intraocular pressure in noncontact tonometry in patients subjected to phacoemulsification and trabeculectomy with phacoemulsification

OBJECTIVE

Evaluate the pattern of intraocular pressure (IOP) variations through the pneumatic tonometer, between two specific surgical techniques, and the possible variables that may influence the behavior of this pressure.

METHODS

Retrospective cross-sectional study carried out through the review of electronic medical records of a private ophthalmological reference hospital in the city of Goiânia, Goiás, Brazil, from 2012 to 2016, comprising of a sample of 550 eyes. The analyzed variables were, age, gender, IOP, axis, pachymetry, anterior chamber depth, and axial length.

RESULTS

In the end, the study consisted of 231 eyes, represented by 179 patients. Of these, 182 eyes were operated on by isolated cataract surgery, with a mean age of 72.0±9.5 years. The combined surgery represented a total of 49 eyes, 34 patients with a mean age of 71.9±8.14 years. There was statistical significance (P<0.05) in correlating the pre- and postoperative IOP values in the 24-hour, 7-, 15-day, and 12-month postoperative periods.

CONCLUSION

A standard of variation of IOP was found through the pneumatic tonometer in both surgical techniques, but a more significant reduction was observed in combined surgery than in isolated cataract surgery, and further studies with a greater epidemiological impact are required for confirmation of this conclusion.

Changes of intraocular pressure after cataract surgery in myopic and emmetropic patients

To investigate the intraocular pressure (IOP) changes after cataract surgery, and its relationship with refractive conditions.IOP after phacoemulsification with intraocular lens (IOL) implantation was retrospectively reviewed. Patients were classified into 3 groups by refractive conditions: emmetropia, mild to moderate myopia, and high myopia. Basic information was collected including age, sex, place of IOL, and operating surgeon, with IOP and refractive conditions measured before surgery, and 1, 7, 30, and 90 days after surgery.The study comprised 353 eyes from 353 patients, of which 175 were emmetropia, 130 were mild to moderate myopia, and 48 were high myopia. A lower IOP than baseline was observed at 7, 30, and 90 days after surgery in emmetropic and mild to moderate myopia, while in high myopia, IOP was instable from 1 to 30 days, and reduced only in 90 days after surgery. Changes of IOP was more significant from 1 to 7 days in emmetropic and mild to moderate myopic patients, but from 30 to 90 days in high myopia. Patients over 75 showed a lower IOP at each follow-up than patients younger and female showed a higher baseline IOP than male. Different surgeons might influence the IOP fluctuation at first 90 days but not the final IOP.All patients with different refractive conditions showed a remarkably lower IOP at 90 days after cataract surgery. However, high myopia lowered the speed of IOP reduction, which might be explained by the anatomical changes of eye structure.

Changes in Ocular Hypotensive Drug Usage for Glaucoma Treatment After Cataract Surgery: A Nationwide Population-based Study in Taiwan

PURPOSE

The aims of this study were to observe the changes in the demand for prescriptions of ocular hypertensive drug (OHD) after cataract surgery, to investigate patterns of change in the required OHD amount in open-angle glaucoma (OAG) and angle-closure glaucoma (ACG) cases, and to determine the associated factors related to the change.

MATERIALS AND METHODS

This population-based cohort study using the Taiwan National Health Insurance Research Database enrolled patients with glaucoma who underwent bilateral cataract surgeries within 2 years between 2001 and 2012. The major dependent variables were the total amounts of OHDs prescribed within 1 year before the first cataract surgery and 1 year after the second cataract surgery. We compared the overall change in the required OHD amount before and after cataract surgery and further explored potential factors affecting the change.

RESULTS

Among the 440 patients, there were more cases of ACG than OAG (68.6% vs. 31.4%). The total OHD amount prescribed reduced significantly after cataract surgery in patients with OAG (median, from 12 to 6 bottles before and after the surgery, P<0.0001) and ACG (median, from 10 to 3 bottles, P<0.0001), and the reduction was sustained for 5 years. The reduction was significantly larger in patients with ACG and higher demand for OHD (P=0.0157). Among the OAG cases, the reduction was significantly larger in patients who were female individuals (P=0.0138), treated in clinics (P=0.0305), and exhibited high demand for OHD (P=0.0282).

CONCLUSIONS

The prescriptions of OHDs by glaucoma patients reduced considerably after cataract surgery. Although the reduction proportion of the demand for OHD after cataract surgery was significantly larger in patients with ACG than in those with OAG, the reduction was sustained for 5 years in both types of glaucoma.

A comparison between patients with epiphora and cataract of the activity limitations they experience in daily life due to their visual disability

PURPOSE

The objective of this study was to compare patients with epiphora and cataract in terms of the activity limitations they experience in daily life due to their visual disability and to validate the use of the Catquest-9SF questionnaire for epiphora patients.

METHODS

Seventy-two consecutively encountered adult patients with confirmed lacrimal obstruction and listed for dacryocystorhinostomy (DCR) or lacrimal intubation at the St. Erik Eye Hospital, Stockholm, Sweden, completed the Catquest-9SF questionnaire, which measures activity limitations in daily life due to visual disability. The psychometric qualities of the Catquest-9SF results obtained from this group of patients were evaluated by Rasch analysis. Rasch analysis was further employed to convert the ordinal raw data to a Rasch score for comparison with the preoperative scores of patients registered in the Swedish National Cataract Register (NCR) during March 2013.

RESULTS

The Catquest-9SF exhibited good psychometric qualities when investigating epiphora patients, with the exception of a misfit for Item 4, the item regarding facial recognition. On the Rasch scale (-5.43 = no activity limitations to +5.01 = severe activity limitations), the mean score for epiphora patients was -0.82 while for patients listed for 1st eye and 2nd eye cataract surgery it was -0.17 and -0.76, respectively. An equivalence test confirmed that the reported visual disability of epiphora patients was not significantly different from visual disability reported by patients waiting for 2nd eye cataract surgery.

CONCLUSION

The Catquest-9SF is a valid measure of visual disability in patients with epiphora. Epiphora patients experience visual disability to the same degree as patients awaiting 2nd eye cataract surgery.

Effect of phacoemulsification on intraocular pressure in patients with primary open angle glaucoma and pseudoexfoliation glaucoma

AIM

To compare the effect of phacoemulsification on intraocular pressure (IOP) in patients with primary open angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG).

METHODS

A retrospective comparative case series conducted at the Glaucoma Department at the Association to Prevent Blindness in Mexico. The study enrolled consecutive patients having phacoemulsification with intraocular lens (IOL) implantation and a diagnosis of POAG or PXG. Data about IOP values and number of glaucoma medications used was collected at baseline, 1, 3, 6 and 12mo postoperatively.

RESULTS

The study enrolled 88 patients (88 eyes). After phacoemulsification, there was a statistically significant reduction in IOP values and glaucoma medications use compared to baseline in both POAG and PXG patients (P<0.001). In the POAG group, a 20% decrease in IOP values was evidenced, and a 56.5% reduction in the number of medications used at the one-year follow-up. The PXG group showed a 20.39%, and a 34.46% decrease in IOP and number of medications used, respectively. A significant difference in the mean ΔIOP (postoperative changes in IOP) was evidenced between groups (P=0.005). The reduction of the postsurgical IOP mean values in both groups, the POAG group showed a greater reduction in IOP values compared to the PXG group.

CONCLUSION

In both types of glaucoma, phacoemulsification cataract surgery can result in a significant IOP reduction (20%) over a 12mo follow-up period. The number of medications used is also significantly reduced up to 12mo after surgery, especially in the PXG group.

Genetics, Diagnosis, and Monitoring of Pseudoexfoliation Glaucoma

Recent studies have shed new light on the genetic factors underlying pseudoexfoliation syndrome, growing our understanding of the role of the lysyl oxidase-like 1 (LOXL1) gene and its various polymorphisms as well as identifying new genetic associations. Recent years have brought new insight on how these genetic factors interact with other factors, including environmental, to confer risk to individuals and populations worldwide. All of these findings may hold importance to the screening, diagnosis, and monitoring of pseudoexfoliation and may also help lead to the identification of novel therapeutic targets. This review serves as an update on the recent trends and findings in pseudoexfoliation syndrome.

24-h monitoring devices and nyctohemeral rhythms of intraocular pressure

Intraocular pressure (IOP) is not a fixed value and varies over both the short term and periods lasting several months or years. In particular, IOP is known to vary throughout the 24-h period of a day, defined as a nyctohemeral rhythm in humans. In clinical practice, it is crucial to evaluate the changes in IOP over 24 h in several situations, including the diagnosis of ocular hypertension and glaucoma (IOP is often higher at night) and to optimize the therapeutic management of glaucoma. Until recently, all evaluations of 24-h IOP rhythm were performed using repeated IOP measurements, requiring individuals to be awakened for nocturnal measurements. This method may be imperfect, because it is not physiologic and disturbs the sleep architecture, and also because it provides a limited number of time point measurements not sufficient to finely asses IOP changes. These limitations may have biased previous descriptions of physiological IOP rhythm. Recently, extraocular and intraocular devices integrating a pressure sensor for continuous IOP monitoring have been developed and are available for use in humans. The objective of this article is to present the contributions of these new 24-h monitoring devices for the study of the nyctohemeral rhythms. In healthy subjects and untreated glaucoma subjects, a nyctohemeral rhythm is consistently found and frequently characterized by a mean diurnal IOP lower than the mean nocturnal IOP, with a diurnal bathyphase - usually in the middle or at the end of the afternoon - and a nocturnal acrophase, usually in the middle or at the end of the night.