George Mintsioulis

Efficacy of topical flurbiprofen and indomethacin in preventing pseudophakic cystoid macular edema

Abstract We evaluated two topical cyclo‐oxygenase inhibitors (COIs), 0.03% flurbiprofen and 1 % indomethacin, for their ability to prevent pseudophakic cystoid macular edema (CME). The study was a randomized, doublemasked, vehicle‐controlled, parallel group, clinical trial for six months at eight sites in Canada and two in Germany. The study population consisted of 681 patients who had extracapsular cataract extraction and posterior chamber lens implantation. Flurbiprofen, indomethacin, or the vehicle was instilled into the eye four times daily for two days preoperatively and three months postoperatively. Results were measured by angiographic and clinical CME at visit 5 (day 21–60) and visit 7 (day 121–240) and by contrast sensitivity and Snellen visual acuity at all five postoperative visits. At visit 5, the incidence of angiographic CME was comparable in the two COI treatment groups (16.8% flurbiprofen, 12.4% indomethacin) and was significantly lower than in the vehicle group (32.2%). The incidence of clinical CME was also significantly lower in the COI‐treated groups (10.7% flurbiprofen, 9.6% indomethacin) than in the vehicle group (21.9%). By visit 7, the incidence of angiographic CME had declined to between 4% and 8% and the incidence of clinical CME was less than 2% in all three groups. At visit 5, contrast sensitivity scores were significantly worse in vehicle‐treated patients with angiographic CME than in those without CME, and Snellen visual acuity was one line worse in patients with CME. Flurbiprofen‐treated patients achieved good Snellen visual acuity (better than 20/40) sooner than vehicle‐treated patients. The results suggest that angiographic evidence of CME is related to a clinically relevant decrease in visual function and that treatment with flurbiprofen or indomethacin reduces the incidence and severity of CME and the associated visual dysfunction in the early postoperative period.

Intraocular pressure decrease after phacoemulsification in patients with pseudoexfoliation syndrome.

Purpose: To determine the intraocular pressure (IOP) response to phacoemulsification cataract extraction with posterior chamber intraocular lens (PC IOL) implantation in patients with pseudoexfoliation syndrome. Setting: Eye clinics at the University of Ottawa Eye Institute, Ottawa, Ontario, Canada. Methods: A retrospective cohort study design assigned patients to 1 of 3 subgroups: pseudoexfoliation syndrome (PEX) (n = 21), primary open‐angle glaucoma (POAG) control (n = 23), and cataract control (n = 23). Inclusion criteria consisted of age older than 50 years, open angle by gonioscopy, and a cataract requiring phacoemulsification. The IOP response was determined at intervals up to 18 months. Results: Postoperative IOP changes from baseline in the PEX group were –1.81, –4.52, and –2.31 mm Hg at 3, 6, and 12 months, respectively. The changes in the POAG control group were –2.22, –2.32, and –1.88 mm Hg, respectively, and in the cataract control group, –2.49, +0.45, and +0.28 mm Hg. Patients in the PEX group had a reduction in IOP from baseline at all postoperative measurements. That reduction was significantly greater than in the POAG and cataract control groups at 6 months (P = .012 and P = .002, respectively) and 12 months (P = .001 and P = .050, respectively). Conclusions: Patients with pseudoexfoliation syndrome had a postoperative IOP reduction from baseline at all measurements and a significantly greater reduction than patients in the POAG and cataract control groups at 6 and 12 months. Phacoemulsification cataract surgery with PC IOL implantation may be effective in managing patients with pseudoexfoliation syndrome who have elevated IOP and visually significant cataract but no advanced optic nerve damage.

Intraocular pressure following phacoemulsification in patients with and without exfoliation syndrome: a 2 year prospective study

Aim: To determine the long term intraocular pressure (IOP) response to phacoemulsification in patients with and without exfoliation syndrome (XFS). Methods: Prospective, multicentre, cohort study with the following inclusion criteria: age over 50 years, open iridocorneal angle, and cataract. Two groups were enrolled: those with XFS and those without. The main outcome was mean IOP reduction 2 years after phacoemulsification cataract extraction (PCE). Univariate and multivariate analyses were performed. Results: 183 patients were enrolled, 71 with and 112 without XFS. There were 29 patients with glaucoma in both groups. Mean baseline IOP was higher in XFS compared to control eyes (17.60 (SD 3.23) mm Hg v 16.08 (3.18) mm Hg, p = 0.002). Overall IOP reduction was significantly greater in the XFS group at the 2 year time point (−1.85 mm Hg v −0.62 mm Hg in the controls (p = 0.0037)). Multivariate analysis demonstrated that the IOP lowering effect in the XFS group may be related to irrigation volume at the time of surgery. In the subgroup analyses IOP lowering was significantly greater in the XFS and XFG patients than in controls without glaucoma, and POAG controls, respectively. The percentage of patients with a postoperative IOP spike was similar and relatively high in both XFS and control groups (34% v 25%; p = 0.54). Conclusion: IOP decreases more in patients with XFS following PCE compared to control eyes without XFS. This effect is more pronounced in glaucoma patients and persists for at least 2 years.

Laser vision correction for low hyperopia. An 18-month assessment of safety and efficacy.

OBJECTIVE This study aimed to assess the efficacy and safety of hyperopic photorefractive keratectomy (PRK) and to evaluate the effect of degree of hyperopia, two epithelial removal methods, and various postoperative patient management techniques on clinical outcomes. DESIGN Prospective, nonrandomized, open-label clinical trial. PARTICIPANTS A total of 38 patients with mean follow-up of 13.9 months (n = 65 eyes with hyperopia from +1.00 diopter [D] to +4.00 D) participated. INTERVENTION Hyperopic PRK with the VISX STAR Excimer Laser System was performed. MAIN OUTCOME MEASURES Spherical equivalent (SE) including vector analysis of SE; uncorrected visual acuity (UCVA); best-spectacle corrected visual acuity (BSCVA); low-, medium- and high-contrast visual acuities; topography; keratometry; pachymetry; and intraocular pressure, haze, and all other potential complications were measured. RESULTS A total of 80% of eyes were within +/- 0.5 D and all but 1 eye (98%) were within +/- 1.0 D of intended manifest SE at 1 year. There was no induced astigmatism at 1 year. At 12 months, 72% of eyes had UCVA of 20/25 or better and 70% had achieved preoperative BSCVA, with no eye seeing worse than 20/25. These results remained constant at 18 months. There was a tendency toward regression between months 1 and 6 with stabilization of SEs between months 6 and 12. Thereafter, up to 18 months, there was some regression with a mean of +0.31 D, but the number of patients was small. There was one mild decentration and very slight decreases in mean intraocular pressure and central corneal thickness. One patient had grade 1.0 haze develop in both eyes at 12 and 18 months; all other patients experienced trace or no haze. There were no significant complications. CONCLUSIONS The results of this study support the hypothesis that laser vision correction is safe and effective for treating low hyperopia. The predictability of the hyperopic laser vision correction procedure used in this study was very good. Other than the slower recovery of BSCVA and UCVA seen with this procedure, as compared with myopic PRK, there were no significant complications. The trend toward some later regression needs to be further evaluated in a larger number of patients. Overall, patients were very pleased with the treatment, even in the first 6 months.

Evaluation of current techniques of corneal epithelial removal in hyperopic photorefractive keratectomy

Purpose: To determine the efficacy of 3 current methods used to remove corneal epithelium prior to photorefractive correction of hyperopia and to compare clinical data in patients who had rotary brush or blunt scrape epithelial removal in the treatment of hyperopic photorefractive keratectomy (PRK). Setting: University of Ottawa Eye Institute, Ottawa General Hospital, Ottawa, Ontario, Canada. Methods: The epithelium from human eye‐bank eyes was removed using a Paton spatula, 15% alcohol, and the Amoils rotating plastic brush. The effects were examined by scanning and transmission electron microscopy. Twelve month postoperative data were obtained on 25 eyes with refractions of +1.00 to +4.00 diopters (D) that had been treated for hyperopia with the VISX Star excimer laser, using blunt scrape or the rotary brush to remove the corneal epithelium. Results: All 3 methods effectively removed corneal epithelium. The Paton spatula, however, left small nicks in Bowman’s layer. Both the rotating brush and alcohol debridement left Bowman’s layer intact. Alcohol treatment required follow‐up epithelial debris removal, while brushing left minimal amounts of debris. There was a strong trend toward rapid epithelial healing in the brushed corneas compared with the scraped ones, but this was not statistically significant. Clinically, at 12 months postoperatively, brushed corneas showed a trend toward more superior outcomes than scraped corneas in actual refractive outcome, uncorrected visual acuity (UCVA), lines of UCVA gained, and predictability of the desired outcomes. However, only the outcome in UCVA of 20/40 or better and the decreased incidence of haze in the brushed corneas over scraped ones were statistically significant. Conclusions: Both alcohol and the rotating brush provide a quick, effective means of removing the corneal epithelium with minimal risk of damage to Bowman’s layer. In our experience, the brush technique was as effective as and possibly superior to the blunt scrape for epithelial removal in hyperopic PRK.

Changes in measured intraocular pressure after hyperopic photorefractive keratectomy.

Purpose: To investigate the effect of hyperopic photorefractive keratectomy (PRK) on intraocular pressure (IOP) measurements. Setting: University of Ottawa Eye Institute, Ottawa Hospital, Ottawa, Canada. Methods: In this retrospective cohort study, IOP and central corneal thickness (CCT) were measured preoperatively and at 1, 2, 3, 6, 12, 18, and 24 months in 191 eyes that had hyperopic PRK with the VISX Star excimer laser. All corrections applied were between +1.00 and +6.50 diopters (D) of sphere and less than 3.75 D of cylinder. Results: At all postoperative examinations, the mean IOP in the hyperopic PRK group was 1.0 to 1.8 mm Hg lower than the preoperative IOP (P < .001). A large range of IOP changes was found across the population; eg, at 6 months, 49% of the eyes had a change in IOP from baseline of at least ±3 mm Hg. A mean reduction of 19 &mgr;m of CCT was found with pachymetry after surgery (P < .001). The change in IOP readings postoperatively was not correlated with age, sex, keratometric readings, or applied correction. Changes in IOP were strongly correlated with preoperative IOP at all time points and with preoperative CCT at 18 and 24 months (P < .001). After hyperopic PRK, the measured IOP was more likely to increase in patients with preoperative IOPs less than 14.5 mm Hg and more likely to decrease in patients with preoperative IOPs above 14.5 mm Hg. Conclusion: Changes in IOP after hyperopic PRK were similar to changes after myopic PRK, despite only minimal changes in the CCT. This suggests that hyperopic PRK results in biomechanical effects that modify the elastic properties of the cornea beyond the changes in rigidity expected from central corneal thinning. There was a strong negative correlation between the measured preoperative IOP and the change in IOP postoperatively that was likely the result of regression of the mean effect.

Excimer laser photorefractive keratectomy for low hyperopia: Safety and efficacy

Purpose: To assess the safety and efficacy of photorefractive keratectomy (PRK) to correct low hyperopia. Setting: University of Ottawa Eye Institute, Ottawa General Hospital, Ontario, Canada. Methods: Twenty‐five eyes with refractions of +1.00 to +4.00 diopters (D) and cylinder of 1.00 D or less were treated for hyperopia with the VISX Star excimer laser system using a refined ablation architecture. Thorough visual assessments were performed preoperatively (baseline) and 1, 3, and 6 months postoperatively. Complications were recorded and the level of patient satisfaction was noted. Results: Mean spherical equivalent at 6 months was +0.27 D ± 0.55 (SD), which was an 89% reduction over baseline. Eighty‐four percent of patients gained two to seven lines of near uncorrected visual acuity (UCVA) and 1 patient (4%) lost more than one line. Eight percent achieved 20/25 or better UCVA. Approximately half realized their preoperative distance best corrected visual acuity (BCVA) by 1 month. By the end of the study, all patients had improved, achieved, or were within one line of their baseline distance BCVA. There were some slight reductions in lower contrast acuity at 6 months, although dim lighting conditions did not further reduce these acuities. Most patients had no clinically meaningful change in cylinder. The most common complications included early, transient corneal surface irregularities and visual symptoms and trace haze (grade ≤0.5) in 14 of 23 patients at 6 months. All but 1 patient expressed a high degree of satisfaction. Conclusions: These results support the hypothesis that PRK shows great promise as a safe and effective treatment for low hyperopia. There were no significant complications and no decentered ablations. The slight regression occurred with or without the presence of trace haze. Overall, refractive stability was encouraging, although longer follow‐up is needed.

Phototherapeutic keratectomy versus mechanical epithelial removal followed by corneal collagen crosslinking for keratoconus

OBJECTIVE To compare the visual outcomes of patients with keratoconus treated with either phototherapeutic keratectomy (PTK) or mechanical epithelial removal prior to corneal collagen crosslinking (CXL). DESIGN Comparative study. PARTICIPANTS The records of 34 patients (34 eyes) who had PTK (17 eyes) or mechanical (17 eyes) epithelial removal prior to CXL for keratoconus were reviewed retrospectively. METHODS CXL was performed by 1 of 3 surgeons (G.M., W.B.J., or K.B.). Of the eyes, 17 had undergone mechanical epithelial removal prior to CXL and were consecutively selected, after matching with the 17 eyes in the PTK group, for the variables of procedure date, average keratometry, and pachymetry. All eyes had central cones. Manifest refraction spherical equivalent, sphere, cylinder, best-corrected distance visual acuity, and pachymetry were measured and compared preoperatively and in follow-up. RESULTS The mean change between the pre- and postoperative manifest refraction spherical equivalent for the PTK and mechanical groups was 1.68 ± 0.80 and 0.26 ± 0.90, respectively (p < 0.05). The mean change between pre- and postoperative cylinder for the PTK and mechanical groups was 0.53 ± 0.28 and 0 ± 0.18, respectively (p < 0.05). The mean number of lines of improvement in the PTK and mechanical groups were 0.33 ± 0.82 and -0.58 ± 0.45 lines, respectively (p > 0.05). CONCLUSIONS Early results suggest that CXL with laser epithelial removal is superior to CXL with mechanical epithelial removal because it reduces refractive error in qualified patients. Although not statistically significant, there was also a trend for PTK CXL patients to have better visual outcomes.

Scheie's syndrome. An ultrastructural analysis of the cornea.

The histopathology of a corneal graft specimen obtained from a patient with Scheies syndrome (systemic mucopolysaccharidosis, type IS) is described with particular emphasis on the ultrastructural findings. Numerous vacuoles containing fibrillogranular material were found in the corneal epithelial cells, the keratocytes, and the endothelial cells. The basement membrane of the epithelium contained frequent breaks and peg-like undulations, and Bowmans layer was markedly attenuated. Fibrous long-spacing (FLS) collagen featured prominently in the stroma. Descemets membrane was normal. The findings of a markedly attenuated Bowmans layer and FLS collagen may be abnormalities specific to Scheies syndrome resulting from the altered glycosaminoglycan composition of the extracellular matrix.

Aspheric Wavefront-guided LASIK to Treat Hyperopic Presbyopia: 12-Month Results With the VISX Platform

PURPOSE To evaluate an aspheric ablation profile to improve near vision in presbyopic patients with hyperopia and to outline the key factors of success. METHODS A prospective, nonrandomized, clinical trial of 66 eyes of 33 hyperopic patients who underwent customized bilateral refractive surgery, which included an aspheric presbyopia treatment shape and wavefront-driven hyperopic treatment, was studied. Surgeries were performed using the VISX STAR S4 or STAR S4 IR excimer laser system (Abbott Medical Optics). Mean preoperative refractive error was +1.77 ± 0.56 diopters (D) sphere (range: 0.75 to 3.50 D) with 0.41 ± 0.34 D cylinder (range: 0.00 to 1.50 D). All patients received full distance refractive correction. No patients received monovision or were intentionally left with residual myopia. Patient satisfaction results were evaluated using a questionnaire with a 5-point scale. RESULTS Sixty eyes completed 6-month and 50 eyes completed 12-month postoperative follow-up. At 6 months, mean corrected distance visual acuity (CDVA) was 20/20±1 line (range: 20/25 to 20/10). Mean gain in distance-corrected near visual acuity (DCNVA) was 2.7 ± 1.7 lines with a maximum of 6 lines of near. Spectacle dependence for tasks, such as reading and computer use, was reduced. At 12 months, 100% of patients had achieved binocular simultaneous uncorrected vision of 20/25 or better and J3. Refraction was stable over 12 months. Contrast sensitivity reduction was clinically insignificant (1 step or 0.15 logCS). Negative spherical aberration highly correlated with postoperative improvement of DCNVA. Patients who had a larger amount of preoperative hyperopia or a greater decrease of preoperative DCNVA were more likely to have overall satisfaction. CONCLUSIONS The aspheric ablation designed to expand near functional vision was effective and stable over 12 months. The wavefront-customized hyperopic treatment significantly reduced spectacle dependence.