Stabilization of refractive error and associated factors following small incision phacoemulsification cataract surgery.

BACKGROUND: Accumulating evidence suggests that refractive stabilization occurs rapidly following small incision cataract surgery. Nonetheless, many guidelines still suggest waiting four to 6 weeks before prescribing corrective lenses. This study was undertaken to supplement the existing literature regarding refractive stabilization, and evaluate multiple contributing factors that could dissuade clinicians from confidently correcting refractive error in the early post-operative course following routine cataract surgeries. METHODS: Adult patients undergoing phacoemulsification cataract surgery with uncomplicated surgeries and post-surgical courses at the Calgary Ophthalmology Centre (Calgary, Alberta, Canada) were included in this prospective observational case series. Exclusion criteria included known corneal dystrophies, infectious keratitis, complicated surgery or toric/multifocal IOLs. Data was collected at weekly intervals for a total of 6 weeks. Collected data included autorefraction, visual acuity, corneal pachymetry, and effective lens position. RESULTS: One hundred six eyes of 104 patients were included in this study. Post-operative sphere, cylinder and spherical equivalent were not significantly different at any post-operative week compared with week six, and 80-86% of patients were within 0.5D of last follow-up spherical equivalent at any week. The secondary outcomes of central corneal thickness, effective lens position and visual acuity did, however, exhibit significant differences between early post-operative weeks and last follow-up values. CONCLUSIONS: These data suggest that refractive error can be effectively measured and corrected as early as one-week post-operatively in the majority of patients, though other measures of post-operative stability including central corneal thickness, effective lens position and visual acuity can require up to 4 weeks to stabilize. Thus a conservative and pragmatic approach may be to wait until 4 weeks post-operatively prior to obtaining refractive correction following uncomplicated phacoemulsification cataract surgery.

Ocular surface tolerability of prostaglandin analogs and prostamides in patients with glaucoma or ocular hypertension.

INTRODUCTION: There has been increased attention on the potential impact of the preservative benzalkonium chloride (BAK) on the ocular surface. This study compared the ocular surface tolerability of once-daily bimatoprost 0.01% and latanoprost 0.005% (both preserved with 0.02% BAK), and travoprost 0.004% preserved with sofZia™. METHODS: A randomized, multicenter (15 sites), investigator-masked study enrolled patients with open-angle glaucoma or ocular hypertension who had received latanoprost monotherapy for at least 1 month. Patients were randomized to oncedaily bimatoprost (n = 56), travoprost (n = 53), or latanoprost (n = 55) monotherapy for 3 months. Follow-up visits were at weeks 1, 4, and 12. The primary outcome measure was physician-graded conjunctival hyperemia (scale 0 to 3) at week 12. Secondary outcomes included corneal staining (scale 0 to 3) and tear break-up time (TBUT). RESULTS: There were no significant differences in mean (standard deviation [SD]) outcome measures including conjunctival hyperemia (bimatoprost: 0.48 [0.52], travoprost: 0.49 [0.52], latanoprost: 0.51 [0.54]), corneal staining (bimatoprost: 0.31 [0.49], travoprost: 0.25 [0.46], latanoprost: 0.24 [0.45]), or TBUT (bimatoprost: 9.7 s [6.1], travoprost: 9.5 s [5.8], latanoprost: 9.8 s [5.0]) among subjects at latanoprost-treated baseline (P ≥ 0.664). At week 12, there were no significant differences in conjunctival hyperemia (bimatoprost: 0.42 [0.48], travoprost: 0.46 [0.44], latanoprost: 0.44 [0.57]), corneal staining (bimatoprost: 0.31 [0.45], travoprost: 0.32 [0.48], latanoprost: 0.22 [0.30]), or TBUT (bimatoprost: 9.7 s [5.7], travoprost 9.7 s [5.0], latanoprost: 9.3 s [4.0]) among the treatment groups (P ≥ 0.379). At week 1, there was a statistically significant among-group difference in mean change from baseline in hyperemia (+0.04, bimatoprost; +0.20, travoprost; 0.00, latanoprost; P = 0.018). There were no statistically significant among-group differences in mean corneal staining, mean TBUT, or change from baseline at any visit. CONCLUSIONS: Despite preservative differences, there were no significant differences in objective clinical measures of ocular surface tolerability after 3 months of treatment with bimatoprost (with 0.02% BAK), travoprost (with sofZia), and latanoprost (with 0.02% BAK).

Effectiveness of dorzolamide­timolol (COSOPT) in patients who were treatment naive for open-angle glaucoma or ocular hypertension: the COSOPT first-line study.

PURPOSE: The aim of this study was to assess the effectiveness of dorzolamide-timolol (DT) in the management of open-angle glaucoma (OAG) and ocular hypertension. METHODS: An open-label, 12-week, multicenter, Canadian study was conducted. Patients with untreated OAG or ocular hypertension received DT for 12 weeks to reduce intraocular pressure (IOP). If target IOP was not reached after the first 6-week treatment period, a prostaglandin (PG) (latanoprost) was added for the remaining 6 weeks. Primary outcome measures were changes in IOP from baseline to 6 and 12 weeks of treatment, and secondary outcome measures included the proportion of patients achieving target IOP and the proportion of patients achieving therapeutic response defined as a reduction of 5.0 mmHg or 20% in IOP from baseline. IOP values were the mean of 2 measures taken before and at least 2 h after patients administered the study medication. RESULTS: A total of 164 patients were enrolled. Mean [standard deviation (SD)] population age was 63.0 (12.3) years and 53.0% of the patients were men. At week 6, the mean (SD) absolute and percent change in IOP for the total population was (-11.1) (4.9) and (-36.4)% (13.9%), respectively, and 92.1% of the patients achieved a reduction in IOP of at least 5 mmHg. Therapeutic target was achieved by 136 (82.9%) patients (DT subgroup) at 6 weeks, whereas 28 (17.1%) patients were changed to a combination therapy of DT and latanoprost [DT plus PG (DT & PG) subgroup]. Between weeks 6 and 12, DT was effective in sustaining the IOP within therapeutic target, whereas addition of latanoprost reduced the IOP of the DT & PG subgroup by an additional 6.3 mmHg or 22.1% (20.1%). At week 12, patients in the DT subgroup experienced a clinically and statistically significant mean (SD) decrease in IOP from a baseline of 12.2 mmHg or 40.4% (11.9%) (P < 0.001), whereas these values corresponded to 13.4 mmHg and 39.7% (15.7%) (P < 0.001), respectively, in the DT & PG subgroup. The proportion of patients who achieved therapeutic response during the entire 12-week study period was over 82%. Treatment-related adverse events (AEs) were reported by 19 (14.0%) patients in the DT subgroup and by 6 (21.4%) patients in the combination subgroup. Eye disorders and nervous system disorders were among the most common treatment-related AEs in both subgroups. No serious AEs were reported during the study period. CONCLUSION: DT alone and DT in combination with a PG are effective in significantly reducing IOP in patients with untreated OAG or ocular hypertension. The treatment was safe and well tolerated with a low incidence of AEs.

Multiple bilateral iridociliary cysts: ultrasound biomicroscopy and clinical characteristics.

BACKGROUND: To describe the utility of ultrasound biomicroscopy in diagnosing multiple bilateral iridociliary cysts and to determine the clinical significance of this condition. METHODS: A retrospective review of 73 patients referred for ultrasound biomicroscopy who were found to have bilateral iridociliary cysts. RESULTS: Seventy-three patients were identified who demonstrated 2 or more cysts in 1 eye and at least 1 in the other with ultrasound biomicroscopy. A solitary iris elevation was the most common reason for referral (84.9%). There were 44 patients for whom sufficient follow-up data were available, with a mean follow-up of 40.4 months. Clinical sequelae included 1 case of sectoral cataract (2.3%) and 4 cases of cyst-related glaucoma (9.1%). INTERPRETATION: Multiple bilateral iridociliary cysts is a common condition with occasional clinical significance. Ultrasound biomicroscopy is a valuable technique in diagnosing this condition. Patients who have significant angle compromise should be followed and treated as required for glaucoma.

Postmortem microscopic evaluation and clinical correlation of a pseudophakic eye with pseudoexfoliation and loss of zonular support.

We describe a pseudophakic patient with pseudoexfoliation who developed late intraocular lens (IOL) instability manifested by pseudophakodonesis, a change in refraction, and loss of glaucoma control. The patient subsequently required glaucoma surgery that was complicated by vitreous loss. Preoperative ultrasound biomicroscopy (UBM) failed to provide useful information regarding the zonular status. The patient died as a result of a malignancy, and the eye was donated for research. Anatomical evaluation confirmed the clinical impression of IOL placement in the bag and zonular laxity. Postmortem UBM helped explain some of the technical difficulties in examining zonules in the pseudophakic state.

Ultrasound biomicroscopy for the assessment of zonules after ocular trauma.

PURPOSE: To evaluate the role of ultrasound biomicroscopy (UBM) as a method for assessing the zonules after trauma to the anterior segment. These patients might develop traumatic cataract or glaucoma requiring surgery. If occult zonular defects can be identified preoperatively, this might lead to a modified surgical technique and improved outcomes. DESIGN: Retrospective observational case series. PARTICIPANTS: Fifty-nine patients who were referred for UBM after anterior segment trauma. METHODS: UBM examinations were performed using the Humphrey Instruments Ultrasound Biomicroscope equipped with a 50-mHz transducer. A plastic eyecup filled with 2% methylcellulose solution was used in each case. The chart and UBM images of all anterior segment trauma patients examined between 1995 and 2000 were reviewed. The age, gender, and mechanism of injury were recorded for each patient. Follow-up data were obtained from the referring physician in patients who subsequently underwent ocular surgery. MAIN OUTCOME MEASURES: The number of studies judged to be of adequate quality to evaluate zonules was noted, and the number of cases in which zonular defects were found was recorded. The number of cases in which surgery was subsequently performed was noted, and postoperative results were obtained. RESULTS: Fifty-nine charts and 60 UBM studies were reviewed. Forty-nine studies were judged to be adequate for imaging zonules. Most poor-quality studies were in the early years of the study. Further analysis was carried out on the reliable studies. Occult zonular defects were identified in 21 of 49 patients (42.9%). Thirty-one patients went on to have cataract, filtering, and/or vitreoretinal surgery. One surgeon (ACS) performed 25 of the surgical cases, for which a summary is provided. Referring surgeons found the information helpful in surgical planning and anticipating complications in reliable study cases. CONCLUSIONS: UBM is an effective method for identifying occult zonular damage in patients with anterior segment trauma. There is a significant learning curve in the examination technique. The ability to diagnose zonular rupture preoperatively is of significant benefit to the surgeon and might reduce the chance of intraoperative complications.