Intraocular pressure changes following topical ocular hypotensive medications washout.

BACKGROUND: To review the changes in intraocular pressure (IOP) following topical hypotensive medications washout in patients with primary open angle glaucoma (POAG), ocular hypertension (OHT) and uveitic glaucoma (UG)/OHT. METHODS: The study included 120 patients with POAG, OHT and UG recruited from prospective clinical trials between February 2013 and July 2017. We excluded 20 eyes with IOP of ≤21 mm Hg, 11 eyes with previous incisional surgery and 17 eyes with incomplete data. UG eyes with active inflammation and on steroid treatment were excluded. Participants underwent a 1-month washout period from topical ocular hypotensive medications before IOP phasing. Comparisons were made between pre/post-washout IOP, and highest-recorded (peak) and post-washout IOP. RESULTS: A total of 110 eyes with POAG, 33 eyes with OHT and 43 eyes with UG were included for analysis. The mean pre-washout IOP was 18.1±3.3 mm Hg in POAG, 18.8±3.3 mm Hg in OHT and 17.9±8.8 mm Hg in UG; the mean post-washout IOP was 26.6±4.8 mm Hg, 26.4±3.9 mm Hg, 23.1±10.1 mm Hg in POAG, OHT and UG, respectively. The mean increase in IOP after washout was significantly lower in UG compared with POAG and OHT eyes (p=0.01). The percentage of eyes with post-washout IOP <22 mm Hg was 12.7% in POAG, 6.1% in OHT and 51.2% in UG. CONCLUSION: Active inflammation and steroid treatment contributes to elevated IOP in uveitis. Therefore, IOP may revert to normal once inflammation subsides. We recommend ocular hypotensive treatment washout to be considered in UG eyes that have IOP under control in the absence of recurrence of uveitis.

Effect of high-intensity focused ultrasound (HiFU) treatment on intraocular pressure and aqueous humour dynamics: 12 -months results.

PURPOSE: High intensity focused ultrasound (HiFU) is a cyclodestructive therapy for controlling intraocular pressure (IOP) in glaucoma. The mechanism of action is thought to be through destruction of the ciliary epithelium as well as increased uveoscleral outflow. We reviewed the change in aqueous humour dynamics parameters including aqueous humour flow rate, tonographic outflow facility (TOF) and uveoscleral outflow at 12 months. PATIENTS AND METHODS: This is a prospective observational study. Consecutive patients with open angle glaucoma (OAG) or ocular hypertension (OHT) requiring further IOP lowering were enroled in the study between August 2016 and January 2017. Patients were commenced on medication washout period prior to baseline and twelve months' visit. RESULTS: Sixteen patients (OAG) in the treatment group underwent assessment at twelve months follow up. Mean age was 63.1 ± 11 years. Eleven patients were African/Caribbean and 5 were Caucasian. Nine patients were female and 7 were male. Mean post-washout IOP was reduced by 21% (28.3 ± 5.7 at baseline vs 22.4 ± 8.4 mmHg at 12 months, p = 0.04). Aqueous humour flow rate was reduced by 16% at twelve months (2.40 ± 0.6 at baseline vs 2.02 ± 0.6 µl/min at 12 months, p = 0.0493). There was no statistically significant change in the TOF (0.12 ± 0.09 at baseline vs 0.08 ± 0.05 µl/min/mmHg at 12 months, p = 0.08) or uveoscleral outflow (0.6 ± 1.3 at baseline vs 1.3 ± 0.85 µl/min at 12 months, p = 0.15). CONCLUSION: In this study, we demonstrated that the observed IOP reduction was likely due to aqueous humour flow rate reduction. The TOF and uveoscleral outflow were not detectibly changed.

The Effect of High-Intensity Focused Ultrasound on Aqueous Humor Dynamics in Patients with Glaucoma.

PURPOSE: To investigate the effects of high-intensity focused ultrasound (HiFU) on aqueous humor dynamics in patients with glaucoma. DESIGN: Comparative, nonrandomized, interventional study. PARTICIPANTS: Adult patients with a diagnosis of open-angle glaucoma or ocular hypertension with suboptimal intraocular pressure (IOP) control despite maximum medical treatment who required further IOP optimization. METHODS: All patients underwent comprehensive ophthalmic examination before aqueous humor dynamics study measurements, including fluorophotometry and digital Schiøtz tonography. All patients received 6 seconds of HiFU therapy. Aqueous humor dynamics studies were repeated 3 months after the treatment (patients had 4-week washout from their glaucoma medication before their aqueous humor dynamics study measurements at baseline and the 3-month visit). MAIN OUTCOME MEASURES: Intraocular pressure, facility of topographic outflow, aqueous flow rate, and uveoscleral outflow. RESULTS: Thirty eyes of 30 patients were included in the study. At the 3-month postoperative visit, the mean postwashout IOP was reduced by 16% (31.7±5.3 vs. 26.6±4.8 mmHg, P = 0.004), and aqueous flow rate was decreased by 15% (2.07±0.73 vs. 1.77±0.55 µl/min, P = 0.05) from baseline. Neither the tonographic outflow facility nor the uveoscleral outflow was significantly different from baseline. There is a 20% risk of treatment failure (those who needed further glaucoma surgical intervention) within 1 month after a single HiFU treatment (n = 6). Only 25 patients (80%) were able to undergo post-treatment washout measurements, and in these eyes, only 26.6% of eyes achieved >20% IOP reduction at 3 months compared with baseline. CONCLUSIONS: We investigated the aqueous humor dynamics effects of a cyclodestructive procedure and specifically HiFU in patients with uncontrolled open-angle glaucoma on maximum tolerated medical therapy. High-intensity focused ultrasound reduced IOP 3 months postoperatively by 16% and aqueous flow decreased by 15% without any significant effect on tonographic outflow facility and uveoscleral outflow.

Predictors of selective laser trabeculoplasty success in open angle glaucoma or ocular hypertension: does baseline tonography have a predictive role?

BACKGROUND: The determinants of success of selective laser trabeculoplasty (SLT) in treatment-naïve patients with open angle glaucoma (OAG) and ocular hypertension (OHT) have not been understood fully. Therefore, we have conducted this study to explore the predictors of success. METHODS: This is a retrospective review of a pre-existing database of patients who had received primary SLT at St Thomas' Hospital, London, UK. Patients with OAG and OHT who had received primary 360° SLT treatment and had reliable baseline tonographic outflow facility (TOF) with minimum of 1 year of follow-up were included. Univariate and multivariate analyses were performed to find the determinants of success. RESULTS: One hundred and seventy-four patients between August 2006 and February 2010 had received primary 360° SLT treatment and had baseline TOF measurement. Of these, 72 subjects fulfilled the eligibility criteria. In multivariate regression analysis, the only variable associated with success was baseline intraocular pressure (IOP) (R2=0.32, beta=-0.51, p<0.001, 95% CI -2.02 to -0.74). CONCLUSION: To our knowledge, this is the only study investigating the pretreatment TOF (measured with electronic Shiøtz tonography) and IOP as determinants of success 12 month's post-360° SLT in treatment-naïve patients with OAG and OHT. This study demonstrated that pretreatment IOP (and not TOF) is the only determinant of success after primary SLT therapy.

Aqueous Humor Dynamics in Uveitic Eyes.

PURPOSE: To investigate aqueous humor dynamics in uveitic eyes. DESIGN: Cross-sectional study. PARTICIPANTS: Patients with recurrent (≥3 attacks) anterior uveitis (now quiescent) and being treated for glaucoma or ocular hypertension (OHT) (Group 1), previous recurrent anterior uveitis (≥3 attacks) without glaucoma or OHT (Group 2), and normal subjects with no ocular problems and IOP < 21 mm Hg at screening (control group; Group 3). METHODS: Patients had one-off measurements. Group 1 patients who were on antihypertensives were washed out for a 4-week period, prior to their study measurements. Main outcome measures were tonographic outflow facility, aqueous humor flow rate, and uveoscleral outflow. RESULTS: One hundred and one patients were screened between February 2014 and February 2017. Nine patients did not meet the inclusion criteria. Groups 1 and 3 each included 30 patients, and Group 2 included 32 patients. The mean intraocular pressure was higher in Group 1 compared to the others (25 ± 10.2 mm Hg in Group 1 vs 16 ± 2.7 mm Hg in Group 2 vs 16 ± 2.2 mm Hg in Group 3, P < .001). The tonographic outflow facility was lower in Group 1 compared to the others (0.18 ± 0.1 µL/min/mm Hg in Group 1 vs 0.25 ± 0.1 µL/min/mm Hg in Group 2 vs 0.27 ± 0.1 µL/min/mm Hg in Group 3, P = .005). However, aqueous humor flow rate was not statistically different (2.47 ± 0.9 µL/min in Group 1 vs 2.13 ± 0.9 µL/min in Group 2 vs 2.25 ± 0.7 µL/min in Group 3, P = .3). There was also no significant difference in calculated uveoscleral outflow. CONCLUSION: This is the first aqueous humor dynamics study in patients with uveitic glaucoma/OHT and recurrent anterior uveitis compared with age-matched controls. We have demonstrated that the elevated intraocular pressure seen in the uveitic glaucoma/OHT eyes (3-6 attacks) was due to reduced tonographic outflow facility. The aqueous humor flow rate was not detectibly different, nor did the calculated uveoscleral outflow demonstrate any discernible difference. However, the exact mechanism remains to be elucidated.

Effect of phacoemulsification on facility of outflow.

PURPOSE: Phacoemulsification has been shown to reduce intraocular pressure (IOP). The mechanism of action is thought to be via increased trabecular outflow facility. However, studies on the relationship between phacoemulsification and outflow facility have been inconsistent. This study intended to examine the change in electronic Schiotz tonographic outflow facility (TOF) and IOP measurements following phacoemulsification. METHODS: Patients who were due to undergo a standard clear corneal incision phacoemulsification with intraocular lens (IOL) implantation, at St Thomas' Hospital, were invited to participate in this study. IOP was measured using Goldmann's applanation tonometer, and TOF was measured by electronic Schiotz tonography at baseline and at 3, 6 and 12 months postoperatively. RESULTS: Forty-one patients were recruited. Tonography data for 27 patients were reliable and available at all time points. Eleven cases had primary open angle glaucoma and cataract, while 16 patients had cataract only. Mean IOP reduced at every time point postoperatively significantly compared with baseline. TOF improved significantly after cataract extraction at all time points (baseline of 0.14±0.06 vs 0.18±0.09 at 3 months, P=0.02 and 0.20±0.09 at 6 months, P=0.003, 0.17±0.07 µL/min mmHg at 12 months, P=0.04). Five contralateral eyes of patients with cataracts only who did not have any intraocular surgery during the follow-up period were used as comparison. Their IOP and TOF did not change significantly at any postoperative visits. CONCLUSION: This is the first study using electronic Schiotz tonography with documented anterior chamber depth and gonioscopy after modern cataract surgery (CS) with phacoemulsification and IOL implantation. We demonstrated that phacoemulsification increases TOF and this fully accounts for the IOP reduction following CS. ISTCRN REGISTRATION NUMBER: ISRCTN04247738.

Aqueous outflow facility after phacoemulsification with or without goniosynechialysis in primary angle closure: a randomised controlled study.

BACKGROUND: Goniosynechialysis (GSL) to remove peripheral anterior synechiae (PAS) alongside standard cataract surgery has potential theoretical advantages, Published randomised trials, however, have not shown conclusive functional benefits and aqueous outflow changes following GSL are unknown. This study aimed to compare electronic Shiøtz tonographic aqueous outflow facility (TOF) following phacoemulsification with or without GSL in patients with primary angle closure (PAC) and PAC glaucoma. Secondary outcomes were changes in intraocular pressure (IOP) and use of glaucoma medications. METHODS: Prospective randomised pilot study of 26 patients on glaucoma medication, with ≥90° PAS and significant lens opacity. Patients were randomised 1:1 to receive phacoemulsification with intraocular lens (IOL) implantation only (phaco) or phacoemulsification with IOL plus GSL (phaco-GSL). RESULTS: Fourteen patients were randomised to phaco-GSL and 12 to phaco alone. TOF increased with phaco-GSL from 0.099±0.07 µL/min/mm Hg to 0.194±0.07, µL/min/mm Hg, p=0.0006, while the phaco group showed no significant change. IOP reduced in both groups, but reduced significantly more following phaco-GSL (46.0%) compared with phaco alone (27.6%, p=0.04). Medication use and extent of PAS only reduced with phaco-GSL, from 0.923±0.86 to 0.384±0.18 medications, p=0.0279, and from 249.2±83.4 to 110.8±53.9° PAS, 6 months postoperatively. No serious adverse events occurred in either group. CONCLUSIONS: Eyes randomised to both surgical groups had similar and good outcomes at 6 months in this pilot study. However, only eyes undergoing GSL combined with standard phacoemulsification had significantly increased TOF, reduced glaucoma medication dependence and PAS postoperatively. GSL should therefore be considered in such patients. TRIAL REGISTRATION NUMBER: NCT00719290, Results.