Two-Year Performance and Safety Results of the MINIject Supraciliary Implant in Patients With Primary Open-Angle Glaucoma: Meta-Analysis of the STAR-I, II, III Trials.

PURPOSE: To evaluate the performance and safety of minimally invasive glaucoma surgery with a supraciliary drainage device (MINIject; iSTAR Medical, Wavre, Belgium) in primary open-angle glaucoma (POAG) as a stand-alone procedure. DESIGN: Meta-analysis. METHODS: At 11 sites in Colombia, France, Germany, India, Panama, and Spain, 82 patients were treated in 3 prospective, multicenter, interventional, nonrandomized trials (STAR-I, II, III). Data were pooled in a meta-analysis of up to 2 years of follow-up postimplantation. The main outcome measures were mean relative and absolute reduction in diurnal intraocular pressure (IOP) compared to baseline. Secondary outcomes included patients with IOP ≤18 mmHg, patients with IOP reduction ≥20%, number of IOP-lowering medications, adverse events, and endothelial cell density loss. RESULTS: At the 2-year follow-up (n = 66), mean IOP was reduced from 23.8 ± 3.3 mmHg at baseline to 14.4 ± 4.5 mmHg (-39.3%; P < 0.0001). An IOP reduction of ≥20% was achieved in 89.4% of patients, with 84.8% having an IOP ≤18 mmHg. IOP-lowering medications were reduced from a mean of 2.4 ± 1.1 to 1.4 ± 1.4 (P < 0.0001), with 37.9% of patients being medication-free at 2 years. Mean endothelial cell density loss at 2 years was 6.2 ± 9.1% compared to baseline and no patient had a loss >30%. CONCLUSIONS: This meta-analysis demonstrates the favorable safety and efficacy profile of a supraciliary device implanted in a stand-alone, ab-interno procedure in patients with mild-to-moderate POAG. The data demonstrate that MINIject is a safe and effective, bleb-free treatment option for patients requiring low target IOP up to 2 years.

Hydrus microstent for the treatment of primary open-angle glaucoma: overview of its safety and efficacy.

INTRODUCTION: Minimally invasive glaucoma surgeries (MIGS) are now a consolidated reality in many surgical units. The Hydrus Microstent is one of several MIGS devices bypassing trabecular outflow and had excellent results over the years. This article aims to review the key features of the Hydrus Microstent in terms of design, efficacy, and safety. AREAS COVERED: The present review analyses the main characteristics of the device by evaluating the technical and physical details of its functioning. The evidence that supports a clinical decision summarizes the most influential clinical trials and the most accurate systematic reviews. EXPERT OPINION: The Hydrus device has been extensively studied regarding biocompatibility and outflow potential. The subsequent clinical studies have been well-built and proved that the device effectively reduces intraocular pressure (IOP) and the eyedrop load. The device covers almost a quarter of Schlemm's canal circumference, offering at least two advantages: cannulating the Schlemm's canal provides evidence that the device has been implanted correctly; covering a larger area potentially allows to target multiple collector channels or at least areas of active outflow. This scaffold may prove more effective in naïve patients or subjects who used antiglaucoma eyedrops for a limited period, as the prolonged use of hypotonic medications has been associated with the surgical failure of ab interno microhook trabeculotomy.

Safety and Efficacy of Ab Interno XEN 45 Gel Stent in Patients with Glaucoma and High Myopia.

This study reports on the safety and efficacy of Xen 45 in patients with glaucoma and high myopia. It was a retrospective study including patients with high myopia (>6D) who underwent Xen implant with 2 years of follow-up. The primary outcome was to report the incidence of hypotony (IOP ≤ 5 mmHg) and hypotony-related complications. Patients with high myopia treated with mitomycin-C-augmented trabeculectomy were included as a control group. We included 14 consecutive patients who underwent Xen implant (seven eyes) and trabeculectomy (seven eyes). The mean myopia was -14.71 ± 5.36 and -15.07 ± 6.11 in the trabeculectomy and Xen groups, respectively (p > 0.05). The success rate and the mean IOP at 1 and 2 years from the intervention were statistically comparable between the two groups. The group undergoing trabeculectomy showed a higher incidence of hypotony (six eyes (85.71%) vs. two eyes (28.57%)) and hypotony maculopathy (three eyes (42.86%) vs. zero eyes (0%)) and required more postoperative procedures. Patients with high myopia were at higher risk of hypotony-related complications after trabeculectomy. The Xen implant can achieve an IOP control comparable to trabeculectomy with a significantly better safety profile and can be considered as an option for the management of patients with high myopia and glaucoma.

A New and Easier Approach to Preserflo MicroShunt Implantation.

PRESERFLO™ MicroShunt is a new minimally invasive glaucoma surgical (MIGS) device, implanted with an ab externo approach, which drains the aqueous humor to the subconjunctival space. It has been designed as a safer and less invasive approach for treating medically uncontrolled primary open-angle glaucoma (POAG) patients. The classic way of MicroShunt implantation involves different key steps, which includes creating a small scleral pocket with a 1mm blade; passing a 25-gauge (25G) needle through the scleral pocket into the anterior chamber (AC); and subsequently flushing the stent with a 23-gauge (23G) thin-wall cannula. However, sliding the needle into the scleral pocket can create false passages, thus making the device's threading more difficult. The purpose of the current paper is to propose a simplified implantation approach. Our method proposes to make the scleral tunnel by using directly the 25G needle and, at the limbus, this 25G needle is used to slightly depress the sclera and enter into the AC. The MicroShunt is subsequently assembled on a 23G cannula mounted on a 1mL syringe. The syringe can then be used to flush the device. Outflow can thus be confirmed immediately by seeing drops of aqueous humor leaking from the external opening of the stent. This new approach may have different potential advantages, such as better control of the site of entry, avoids wrong passages, reduces or eliminates the risk of aqueous humor sideway flow, facilitates a parallel path to the iris plane, and it is faster.

XEN® Gel Stent: A Comprehensive Review on Its Use as a Treatment Option for Refractory Glaucoma.

The XEN Gel Microstent is a subconjunctival microinvasive glaucoma surgical device developed with the aim of improving the predictability and safety profile of bleb-forming glaucoma surgical procedures. The stent is a hydrophilic tube composed of a porcine gel cross-linked with glutaraldehyde with good stability and biocompatibility with minimal tissue reaction. This device has demonstrated promising outcomes with fewer risks compared to traditional surgeries. The aim of the review is to present early studies on different designs of the XEN Gel Stent, to summarize different surgical techniques of implantation and to analyze more comprehensively the results, complications and rates of needling of the commercially available device (Xen 45). The review will address separately special cases (PXG, UVG, ICE, congenital glaucoma) and describe small series and case reports.

European study of the efficacy of a cross-linked gel stent for the treatment of glaucoma.

PURPOSE: To investigate the efficacy and safety of a cross-linked gel stent (XEN45) with or without cataract surgery in the treatment of glaucoma patients. SETTING: Five university hospitals. DESIGN: Prospective multicenter clinical trial. METHODS: Patients with glaucoma inadequately controlled by treatment or poor compliance or intolerance to topical therapy were included. Patients were divided into those who had an implant only (Solo Group; phakic and pseudophakic patients) and those who had an implant combined with cataract surgery (Combo Group). Differences in mean intraocular pressure (IOP) and number of medications between the baseline preoperative visit and study end (12 months), and the rate of qualified and complete success, were evaluated. RESULTS: The Solo Group comprised 115 glaucoma patients (43 phakic and 72 pseudophakic) and the Combo Group comprised 56 patients. Compared with baseline, mean IOP (23.9 ± 7.6 to 15.5 ± 3.9) and number of medications (3.0 ± 1.1 to 0.5 ± 1.0) decreased significantly at 12-month follow-up (P < .001 for both). A >20% and >30% reduction in IOP from baseline was achieved by 72.3% and 52.6% of patients, respectively. IOP at 1 week postoperatively was a predictor of success, and the needling rate was inversely correlated with early postoperative IOP. The number of preoperative medications and patient age were not significantly associated with failure. CONCLUSIONS: Insertion of a cross-linked gel stent alone or combined with phacoemulsification might be effective and safe in the treatment of open-angle glaucoma, with a substantial reduction in IOP and number of medications.

Long-term titrated IOP control with one, two, or three trabecular micro-bypass stents in open-angle glaucoma subjects on topical hypotensive medication: 42-month outcomes.

PURPOSE: Evaluate long-term outcomes after one, two, or three trabecular micro-bypass stents implanted in a standalone procedure in eyes with open-angle glaucoma taking ocular hypotensive medication. PATIENTS AND METHODS: Prospective randomized ongoing study of 119 subjects (109 with 42-month follow-up) with open-angle glaucoma, preoperative intraocular pressure (IOP) 18-30 mmHg on one to three glaucoma medications, and unmedicated (post-washout) IOP 22-38 mmHg. Subjects were randomized to receive one (n=38), two (n=41), or three (n=40) iStent trabecular micro-bypass stents in a standalone procedure. Postoperatively, IOP was measured with medication and annually following washout. Data included IOP, medications, gonioscopy, pachymetry, visual field, visual acuity, adverse events, and slit-lamp and fundus examinations. RESULTS: Preoperative mean medicated IOP was 19.8±1.3 mmHg on 1.71 medications in one-stent eyes, 20.1±1.6 mmHg on 1.76 medications in two-stent eyes, and 20.4±1.8 mmHg on 1.53 medications in three-stent eyes. Post-washout IOP prior to stent implantation was 25.0±1.2, 25.0±1.7, and 25.1±1.9 mmHg in the three groups, respectively. Postoperatively, Month 42 medicated IOP was 15.0±2.8, 15.7±1.0 and 14.8±1.3 mmHg in the three groups, and post-washout IOP (Months 36-37) was 17.4±0.9, 15.8±1.1 and 14.2±1.5 mmHg, respectively. IOP reduction ≥20% without medication was achieved in 89%, 90%, and 92% of one-, two-, and three-stent eyes, respectively, at Month 12; and in 61%, 91%, and 91% of eyes, respectively, at Month 42. The need for additional medication remained consistent at Months 12 and 42 in multi-stent eyes (four two-stent eyes and three three-stent eyes at both time points), whereas it increased in single-stent eyes (four eyes at Month 12 versus 18 eyes at Month 42). Safety parameters were favorable in all groups. CONCLUSION: The standalone implantation of either single or multiple iStent® device(s) produced safe, clinically meaningful IOP and medication reductions through 42 months postoperatively, with incrementally greater and more sustained reductions in multi-stent eyes.

Treatment of refractory uveitic macular edema: results of a first and second implant of long-acting intravitreal dexamethasone.

PURPOSE: The purpose of this study was to report the functional and anatomical outcomes of a prospective study resulting from repeated dexamethasone intravitreal implants in patients with uveitic refractory macular edema. METHODS: Twelve eyes of 9 patients with intermediate and posterior noninfectious inflammatory uveitis complicated with refractory macular edema were regularly reviewed after a dexamethasone intravitreal implant. Patients were examined at baseline, 30, 90, 135, and 180 days with best-corrected visual acuity (BCVA), complete slit-lamp examination, intraocular pressure (IOP), optical coherence tomography, and fluorescein angiography. After 6 months of follow-up, eyes were reassessed to receive a second implant. RESULTS: BCVA significantly improved when comparing the baseline values after the first and second implant (16.2 and 25.8 letters, respectively, 9.6 letters improvements, p<0.05). BCVA was better after the second implant compared to the first one throughout the follow-up, but without statistical significance. Mean central macular thickness (CMT) was 446.3±129.9 µm at baseline and was significantly reduced until day 135 (p<0.05). CMT reductions after the second injection showed a similar pattern, though differences were not statistically significant. Cataract progression was observed in 4 of 8 phakic eyes (50%) after the first implant, and in 2 of 3 phakic eyes following the second implant, with 1 eye requiring cataract surgery. One eye developed an IOP >30 mmHg 30 days after the second implant, treated topically. CONCLUSION: Repeated dexamethasone intravitreal implants in uveitic patients with refractory macular edema can be used effectively in a clinical setting with an acceptable safety profile.

Evaluation of a Schlemm canal scaffold microstent combined with phacoemulsification in routine clinical practice: Two-year multicenter study.

PURPOSE: To evaluate the efficacy and the safety of a new Schlemm canal scaffold microstent (Hydrus) combined with cataract surgery in routine clinical practice. SETTINGS: Clinics in Italy, Poland, and the United Kingdom. DESIGN: Retrospective case series. METHODS: Clinical outcomes in patients with primary open-angle glaucoma who had combined phacoemulsification and microstent implantation were analyzed. Data (intraocular pressure [IOP], number of glaucoma medications, incidence of complications) were collected preoperatively and postoperatively through 24 months. RESULTS: Ninety-two eyes were included. Six patients had previous glaucoma surgeries. Sixty-seven patients completed a 2-year follow-up. The mean baseline IOP was 19.4 mm Hg ± 4.4 (SD). The mean IOP was 15.5 ± 2.7 mm Hg at 1 year and 15.7 ± 2.5 mm Hg at 2 years (P < .001). The IOP reduction was correlated with the baseline IOP (R2 = 0.72). The mean number of glaucoma medications was 2.1 ± 1.0 preoperatively, decreasing significantly at 1 year (0.6 ± 1.0) and 2 years (0.7 ± 1.0) (P < .001). At 2 years, 64% of patients were medication free. In patients with an IOP of 18 mm Hg or higher preoperatively, the reduction in IOP and in the number of medications was higher. Two patients required microstent repositioning intraoperatively. One patient was treated with an argon laser for microstent obstruction, and 1 patient had a trabeculectomy at 18 months. CONCLUSION: This microstent combined with cataract surgery safely and effectively reduced the IOP and medication use in a routine clinical practice setting with results comparable to those in previously published controlled clinical trials.

Hydrus microstent compared to selective laser trabeculoplasty in primary open angle glaucoma: one year results.

BACKGROUND: To compare the reduction of intraocular pressure (IOP) and glaucoma medications following selective laser trabeculoplasty (SLT) versus stand-alone placement of the Hydrus microstent, a microinvasive glaucoma surgery device. DESIGN: Prospective interventional case-series. University practice. PARTICIPANTS: Fifty six eyes (56 patients) with uncontrolled primary open-angle glaucoma. METHODS: Patients received either SLT (n = 25) or Hydrus implantation (n = 31) in two centres. Patients were evaluated at baseline and 1, 7 days, 1, 3, 6 and 12 months after surgery. MAIN OUTCOME MEASURES: Intraocular pressure and number of glaucoma medications variations inter-groups and intra-groups. RESULTS: There were no significant differences at baseline between groups, but the mean deviation was worse in the Hydrus group (-8.43 ± 6.84 dB, confidence limits (CL)-2.8/-3.3 vs.-3.04 ± 0.65 dB, CL-6/-10.8; P < 0.001). After 12 months, there was a significant decrease in IOP and medications in the Hydrus group compared with baseline values. In the SLT group, only the decrease in IOP was significant. There was 3-fold greater reduction in medication use in the Hydrus group compared with SLT (-1.4 ± 0.97 vs.-0.5 ± 1.05, P = 0.001). 47% of patients were medication free at 12 months in the Hydrus group (4% in the SLT group). No complications were recorded in the SLT group. In the Hydrus group, three patients experienced a temporary reduction of visual acuity post-operatively, and two patients had post-operative IOP spikes that resolved within one week. CONCLUSIONS: Both SLT and Hydrus implantation reduced IOP without serious adverse events. Hydrus implantation led to a significant and further reduction in medication dependence at 12 months.

Microperimetric Assessment after Epiretinal Membrane Surgery: 4-Year Follow-Up.

Purpose. To investigate retinal function using microperimetry in patients affected by idiopathic epiretinal membrane (iERM) and cataract who underwent combined surgery: 4-year follow-up. Design. Prospective, interventional case series. Methods. 30 eyes of 30 consecutive patients with iERM and age-related cataract underwent 25-gauge vitrectomy and cataract surgery. At baseline, 90 and 180 days, and 1 and 4 years, we examined retinal mean sensitivity (MS), retinal mean defect (MD), fixation stability, and frequency of microscotomas using MP1 microperimetry. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) using a spectral domain optical coherence tomography (SD-OCT) were also performed. Results. All patients completed 1-year follow-up, while 23 patients reached last follow-up. Baseline MS and MD (10.48 ± 4.17 and -9.18 ± 4.40 dB) significantly changed at one year (12.33 ± 3.66 and -7.49 ± 3.31 dB, p < 0.01), at four years (14.18 ± 3.46 and -4.66 ± 2.85, p < 0.01), and between one and four years (p < 0.01) after surgery. Compared to baseline, CRT and BCVA significantly changed at one year and remained stable at four years. No variations were observed in fixation stability and frequency of microscotomas compared to baseline. Conclusions. Long-term follow-up using microperimetry seems useful to evaluate patients after iERM surgery: retinal sensitivity changes even when BCVA and CRT remain stable.

Prospective, randomized study of one, two, or three trabecular bypass stents in open-angle glaucoma subjects on topical hypotensive medication.

PURPOSE: To assess the safety and efficacy of one, two, or three trabecular microbypass stents in eyes with primary open-angle glaucoma (OAG) not controlled on ocular hypotensive medication. A total of 119 subjects were followed for 18 months postoperatively. MATERIALS AND METHODS: Subjects with medicated intraocular pressure (IOP) 18-30 mmHg and postmedication-washout baseline IOP 22-38 mmHg were randomized to implantation of one, two, or three stents. Ocular hypotensive medication was to be used if postoperative IOP exceeded 18 mmHg. RESULTS: A total of 38 subjects were implanted with one stent, 41 subjects with two stents, and 40 subjects with three stents. Both month 12 IOP reduction ≥20% without ocular hypotensive medication vs baseline unmedicated IOP and month 12 unmedicated IOP ≤18 mmHg were achieved by 89.2%, 90.2%, and 92.1% of one-, two-, and three-stent eyes, respectively. Furthermore, 64.9%, 85.4%, and 92.1% of the three respective groups achieved unmedicated IOP ≤15 mmHg. Over the 18-month follow-up period, medication was required in seven one-stent subjects, four two-stent subjects, and three three-stent subjects. At 18 months, mean unmedicated IOP was 15.9±0.9 mmHg in one-stent subjects, 14.1±1.0 mmHg in two-stent subjects, and 12.2±1.1 mmHg in three-stent subjects. Month 18 IOP reduction was significantly greater (P<0.001) with implantation of each additional stent, with mean differences in reduction of 1.84 mmHg (95% confidence interval 0.96-2.73) for three-stent vs two-stent groups and 1.73 mmHg (95% confidence interval 0.83-2.64) for two-stent vs one-stent groups. Adverse events through 18 months were limited to cataract progression with best-corrected visual acuity loss and subsequent cataract surgery. CONCLUSION: In this series, implantation of each additional stent resulted in significantly greater IOP reduction with reduced medication use. Titratability of stents as a sole procedure was shown to be effective and safe, with sustained effect through 18 months postoperatively in OAG not controlled with medication.

A Comparison of Endothelial Cell Loss in Combined Cataract and MIGS (Hydrus) Procedure to Phacoemulsification Alone: 6-Month Results.

Purpose. To compare the corneal endothelial cell loss after phacoemulsification, alone or combined with microinvasive glaucoma surgery (MIGS), in nonglaucomatous versus primary open angle glaucoma (POAG) eyes affected by age-related cataract. Methods. 62 eyes of 62 patients were divided into group 1 (n = 25, affected by age-related cataract) and group 2 (n = 37, affected by age-related cataract and POAG). All patients underwent cataract surgery. Group 2 was divided into subgroups A (n = 19, cataract surgery alone) and B (n = 18, cataract surgery and MIGS). Prior to and 6 months after surgery the patients' endothelium was studied. Main outcomes were CD (cell density), SD (standard deviation), CV (coefficient of variation), and 6A (hexagonality coefficient) variations after surgeries. Results. There were no significant differences among the groups concerning preoperative endothelial parameters. The differences in CD before and after surgery were significant in all groups: 9.1% in group 1, 17.24% in group 2A, and 11.71% in group 2B. All endothelial parameters did not significantly change after surgery. Conclusions. Phacoemulsification determined a loss of endothelial cells in all groups. After surgery the change in endothelial parameters after MIGS was comparable to the ones of patients who underwent cataract surgery alone.

Prospective unmasked randomized evaluation of the iStent inject (®) versus two ocular hypotensive agents in patients with primary open-angle glaucoma.

PURPOSE: The purpose of this study was to compare outcomes of subjects with open-angle glaucoma (OAG) not controlled on one medication who underwent either implantation of two iStent inject (®) trabecular micro-bypass devices or received medical therapy consisting of a fixed combination of latanoprost/timolol. PATIENTS AND METHODS: Of 192 subjects who qualified for the study and were enrolled, 94 were randomized to surgery with implantation of two iStent inject(®) devices in the treated eye and 98 to receive medical therapy. RESULTS: At the month 12 visit, 94.7% of eyes (89/94) in the stent group reported an unmedicated intraocular pressure (IOP) reduction of ≥20% versus baseline unmedicated IOP, and 91.8% of eyes (88/98) in the medical therapy group reported an IOP reduction ≥20% versus baseline unmedicated IOP. A 17.5% between-group treatment difference in favor of the iStent inject group was statistically significant (P=0.02) at the ≥50% level of IOP reduction. An IOP ≤18 mmHg was reported in 92.6% of eyes (87/94) in the iStent inject group and 89.8% of eyes (88/98) in the medical therapy group. Mean (standard deviation) IOP decreases from screening of 8.1 (2.6) mmHg and 7.3 (2.2) mmHg were reported in the iStent inject and medical therapy groups, respectively. A high safety profile was also noted in this study in both the iStent inject and medical therapy groups, as measured by stable best corrected visual acuity, cup-to-disc ratio, and adverse events. CONCLUSION: These data show that the use of iStent inject is at least as effective as two medications, with the clinical benefit of reducing medication burden and assuring continuous treatment with full compliance to implant therapy as well as having a highly favorable safety profile.

Phacoemulsification versus phacoemulsification with micro-bypass stent implantation in primary open-angle glaucoma: randomized double-masked clinical trial.

PURPOSE: To compare phacoemulsification alone and phacoemulsification with micro-bypass stent implantation in eyes with primary open-angle glaucoma. SETTING: Instituto di Fisiopatologia Clinica, Clinica Oculistica, Universita' di Torino, Torino, Italy. METHODS: In this prospective double-masked randomized clinical trial, patients had phacoemulsification alone (control group) or phacoemulsification with iStent implantation (combined group). Primary outcomes were intraocular pressure (IOP) and reduction in medication use over 15 months and IOP after a 1-month washout of ocular hypotensive agents (ie, 16 months postoperatively). RESULTS: The baseline IOP was similar between groups (combined group: 17.9 mm Hg +/- 2.6 [SD]; control group: 17.3 +/- 3.0 mm Hg) (P = .512). Three patients in the control group were lost to follow-up. The mean IOP was 14.8 +/- 1.2 mm Hg in the combined group and 15.7 +/- 1.1 mm Hg in the control group at 15 months and 16.6 +/- 3.1 mm Hg and 19.2 +/- 3.5 mm Hg, respectively, after washout; the IOP was statistically significantly lower in the combined group than in the control group at both time points (P = .031 and P = .042, respectively). At 15 months, the mean number of medications was lower in the combined group than in the control group (0.4 +/- 0.7 and 1.3 +/- 1.0, respectively; P = .007), as was the proportion of patients on ocular hypotensive medication (33% and 76%, respectively). CONCLUSIONS: Phacoemulsification with stent implantation was more effective in controlling IOP than phacoemulsification alone; the safety profiles were similar.

Magnetic resonance imaging and Orbscan assessment of the anterior chamber.

PURPOSE: To evaluate the correlation between white-to-white (WTW) distance as assessed by Orbscan II (Bausch & Lomb) and high-resolution magnetic resonance imaging (MRI) sulcus-sulcus (S-S) measures and to analyze the correlation between age and anterior chamber parameters. SETTING: Istituto per la Ricerca e la Cura del Cancro, Candiolo, Torino, Italy. METHODS: Eighty-eight patients had MRI with a 1.5 Tesla imager (GE Medical Systems) using a 3-inch circular coil. T1 weighted fast spin-echo scans were performed on the axial plane. Orbscan II was also used to measure WTW distance, K, anterior chamber depth (ACD), and lens curvature. One eye was randomly selected for analysis. Measures were compared using Spearman correlation, paired Student t test, and analysis of variance (ANOVA; post hoc: Scheffé). Intersession variability was performed in 10 patients. Ten MRI images were randomly selected and measured by 2 operators in a masked fashion (intrasession variability). RESULTS: Intersession and intrasession correlation was good for MRI (r = 0.89 and r = 0.92, respectively), and intersession was good for Orbscan (r = 0.91). When comparing Orbscan II and MRI results, the ACD was well correlated and not significantly different, whereas the S-S and the WTW measures were not correlated and significantly different. Lens thickness and lens diameter were directly correlated with age; S-S, WTW, lens curvature, and ACD were inversely correlated with age. CONCLUSIONS: Current methods of measuring the WTW were poorly correlated with anatomical measures. The S-S diameter and other anterior chamber structures significantly change with age, which could give rise to potential problems with posterior chamber phakic intraocular lens sizing position.