Zyoptix wavefront-guided versus standard photorefractive keratectomy (PRK) in low and moderate myopia: randomized controlled 6-month study.

PURPOSE: To evaluate the refractive and aberrometric outcome of wavefront-guided photorefractive keratectomy (PRK) compared to standard PRK in myopic patients. METHODS: Fifty-six eyes of 56 patients were included in the study and were randomly divided into two groups. The study group consisted of 28 eyes with a mean spherical equivalent (SE) of -2.25+/-0.76 diopters (D) (range: -1.5 to -3.5 D) treated with wavefront-guided PRK using the Zywave ablation profile and the Bausch & Lomb Technolas 217z excimer laser (Zyoptix system) and the control group included 28 eyes with a SE of -2.35+/-1.01 D (range: -1.5 to -3.5 D) treated with standard PRK (PlanoScan ablation) using the same laser. A Zywave aberrometer was used to analyze and calculate the root-mean-square (RMS) of total high order aberrations (HOA) and Zernike coefficients of third and fourth order before and after (over a 6-month follow-up period) surgery in both groups. Preoperative and postoperative SE, un-corrected visual acuity (UCVA), and best-corrected visual acuity (BCVA) were evaluated in all cases. RESULTS: There was a high correlation between achieved and intended correction. The differences between the two treatment groups were not statistically significant for UCVA, BCVA, or SE cycloplegic refraction . Postoperatively the RMS value of high order aberrations was raised in both groups. At 6-month control, on average it increased by a factor of 1.17 in the Zyoptix PRK group and 1.54 in the PlanoScan PRK group (p=0.22). In the Zyoptix group there was a decrease of coma aberration, while in the PlanoScan group this third order aberration increased. The difference between postoperative and preoperative values between the two groups was statistically significant for coma aberration (p=0.013). No statistically significant difference was observed for spherical-like aberration between the two groups. In the study group eyes with a low amount of preoperative aberrations (HOA RMS lower than the median value; <0.28 microm) showed an increase of HOA RMS while eyes with RMS higher than 0.28 microm showed a decrease (p<0.05). CONCLUSIONS: Zyoptix wavefront-guided PRK is as safe and efficacious for the correction of myopia and myopic astigmatism as PlanoScan PRK. Moreover this technique induces a smaller increase of third order coma aberration compared to standard PRK. The use of Zyoptix wavefront-guided PRK is particularly indicated in eyes with higher preoperative RMS values.

Morphological evaluation of Schnyder's central crystalline dystrophy by confocal microscopy before and after phototherapeutic keratectomy.

A 29-year-old man with Schnyder's central crystalline dystrophy was treated with phototherapeutic keratectomy (PTK) in his right eye. Ocular examination revealed abnormal deposits of cholesterol and lipid within the corneal stroma (appearing as crystalline spindle-shaped deposits), high myopia, phakic anterior chamber intraocular lens implantation, and myopic macular degeneration in both eyes. Phototherapeutic keratectomy ablation to a central zone of 7.0 mm and a depth of 96 microm was performed with an Aesculap Meditec MEL-70 excimer laser. Confocal microscopy performed before PTK showed multiple deposits of large, brightly reflective crystalline material extending from the anterior to the mid stroma. The Z-scan curves revealed that the highest density of crystalline deposits was located within the first 140 microm of corneal depth. Six months after PTK, confocal microscopy showed a markedly decreased density of corneal crystalline deposits in the anterior stroma.

In vivo confocal microscopy of patients with amiodarone-induced keratopathy.

PURPOSE: To describe the corneal findings in patients with amiodarone-induced keratopathy by means of in vivo confocal microscopy. METHODS: Twenty-two eyes of 11 patients (eight men and three women) receiving amiodarone therapy and 20 eyes of 10 healthy sex-and age-matched control subjects were selected for confocal microscopic examination. The patients were examined by use of a scanning slit corneal confocal microscope (Confoscan 2.0). Five complete scans of the entire cornea were performed for each eye with a total examination time of less than 5 minutes. RESULTS: All patients receiving amiodarone showed the presence of high reflective, bright intracellular inclusions in the epithelial layers. These findings were more evident within the basal cell layers. In the eyes with advanced keratopathy (stages 2 and 3), bright microdots were detectable within the anterior and posterior stroma and on the endothelial cell layer. In the anterior stroma, the keratocyte density in the treated group was reduced compared with values of the control group (p < 0.001), and a markedly irregular aspect of the stromal nerve fibers was found. The main characteristic of this nerve irregularity was represented by the clew-shaped appearance of the nerve trunks. CONCLUSION: Detailed examination of corneal structure by confocal microscopy shows that amiodarone keratopathy in long-term treated patients presents some findings that are consistent with higher toxicity than was expected and that involve the deep corneal layers.

Effect of photorefractive keratectomy for myopia on measurement of retinal nerve fiber layer thickness using optical coherence tomography.

PURPOSE: To evaluate the effect of excimer laser photorefractive keratectomy (PRK) on nerve fiber layer thickness measurements by optical coherence tomography in myopic eyes. METHODS: Twenty-two patients who had PRK for myopia underwent nerve fiber layer measurement by optical coherence tomography in both eyes before and 6 months after surgery in the first operated eye and before surgery in the fellow (control) eye, 6 months after the first PRK. Optical coherence tomography was performed with a Humphrey Optical Coherence Tomography Scanner. Each eye was scanned at the nerve head program radius of 1.5. For each of the optical coherence tomography parameters (average for each quadrant, superior, inferior, temporal, nasal; average for each clock hour; average over the entire cylindrical section), descriptive statistics were calculated. The difference between the observed change from the first to the second examination was calculated between the treated and the control eye. Individual mean differences were tested with Student's t-test. Hotelling's T-squared generalized means test was used to determine whether the set of mean differences was equal to zero. RESULTS: The average preoperative refractive error was -3.90+/-1.50 D in treated eyes and -3.89+/-1.50 D in control eyes (P = .81, Student's t-test). Mean achieved refractive correction was 3.70+/-1.70 D, corresponding to 48.1+/-22.1 microm of corneal ablation. No statistically significant difference was found in any measurement in the treated eye compared with the untreated control eye. CONCLUSIONS: At 6 months postoperatively, photorefractive keratectomy for moderate myopia that resulted in clear corneas did not affect nerve fiber layer thickness measurements, as obtained by optical coherence tomography.

Delayed post-operative use of 5-fluorouracil as an adjunct in medically uncontrolled open angle glaucoma.

PURPOSE: The current study was performed to evaluate the efficacy and safety of late post-operative use of subconjunctival 5-fluorouracil (5-FU) with ocular massage (OM) after trabeculectomy with or without intraoperative mitomycin C (MMC) in patients with medically uncontrolled primary open angle glaucoma (POAG). METHODS: Initial trabeculectomy was performed in 60 eyes of 60 consecutive patients with medically uncontrolled POAG. Thirty eyes (group 1) were randomly assigned to intraoperative MMC (0.2 mg/ml for 3 min) and 30 (group 2) were randomised to standard trabeculectomy. During the first 3 months post-operatively OM and subconjunctival injections of 5-FU (5 mg in 0.5 ml of balanced salt solution) were performed in both groups every time the clinical evaluation suggested imminent bleb failure. Suture lysis was not performed in any patient. RESULTS: Follow-up ranged from 14 to 53 months (mean 30.17, SD 9.23) in trabeculectomy + MMC treated eyes and from 6 to 54 months (mean 27.37, SD 10.83) in trabeculectomy treated eyes. During the first 3 months of follow-up OM and subconjunctival injections of 5-FU were performed in 14 cases in group 1 and in 18 cases in group 2 (p = NS). A positive response to OM was obtained in 14 of 14 eyes and in 14 of 18 eyes in group 1 and in group 2, respectively (p = 0.042). The difference in post-operative mean IOP between the two groups was statistically significant at each time interval studied (p < 0.001). Success (complete or qualified) was achieved in 50 of 60 eyes (83.33%): 28 (93.3%) in the trabeculectomy + MMC treated group and 22 (73.3%) in the trabeculectomy treated group (p = 0.039). Among the complications seen, the incidence of bleb fibrosis was higher in group 2 (p = 0.0026). By means of post-operative treatment four nonrandomised subgroups were identified: intraoperative MMC + post-operative 5-FU, intraoperative MMC + no post-operative 5-FU, no intraoperative MMC + post-operative 5-FU, no intraoperative MMC + no post-operative 5-FU. The eyes treated with intraoperative MMC and post-operative 5-FU had a better long-term (48 months) cumulative probability of success (100%); treatment with intraoperative MMC or post-operative 5-FU alone was followed by a success rate of 87.1% and 72.2%, respectively. The cumulative probability of success after only trabeculectomy was 56% (p < 0.05). One case of hypotony maculopathy was found in the subgroup treated only with intraoperative MMC. CONCLUSIONS: This study confirms the effectiveness and relative safety of delayed post-operative 5-FU treatment in patients with clinical evidence of bleb failure. Only when OM had caused a lowering of IOP were late subconjunctival injections of 5-FU followed by good control of IOP. The use of intraoperative MMC may ensure a greater IOP decrease after OM.

Echobiometry of the ocular layers at the posterior pole.

The thickness of the retina, choroid and sclera in relation to macular oedema (ME) can be measured using A scan echography. Ninety diabetic patients (180 eyes) divided into two groups with and without ME, respectively, were studied compared to a third group of 73 healthy controls (146 eyes). Statistical analysis of results showed good specificity (80%) and reasonable sensitivity (70%) of the echographic method in showing the presence of ME confirmed by fluorescein angiography.

Effects of brimonidine 0.2% on blue-yellow perimetry of glaucomatous patients.

A cross-over double-blind study was performed to evaluate the effect of acute administration of brimonidine on the blue-yellow perimetry. Thirty patients with primary open-angle glaucoma were admitted. After brimonidine administration, IOP and pupil diameter showed a significant reduction (p < 0.01) without modification in systolic and diastolic blood pressure. Blue-on-yellow perimetry showed a significant reduction in CPSD from 3.81 +/- 1.60 to 2.71 +/- 1.92 (p < 0.05). This result suggests that brimonidine improves ocular perfusion via a reduction of IOP.

Long-term results of Krupin-Denver valve implants in filtering surgery for neovascular glaucoma.

The long-term results obtained with the Krupin eye short valve shut in 28 eyes with neovascular glaucoma were retrospectively analyzed by means of Kaplan-Meier survival curve. The preoperative intraocular pressures (IOPs) ranged from 28 to 62 mm Hg (mean, 36.8 +/- 5.8 mm Hg). Success was considered an IOP of less than 22 mm Hg and greater than 5 mm Hg without medication (complete success) or with medication (qualified success) without additional glaucoma filtering surgery or devastating complications. Postoperative success was obtained in 10 out of 28 eyes after a mean follow-up period of 58.4 +/- 23.02 months (range, 10-108 months). The 3- and 6-year life table success rates were 66 and 34%, respectively. Early complications were: shallow or flat anterior chamber (15 patients, 53.6%), hypotony (16 patients, 57.1%), hypertony (7 patients, 25%), serous choroidal effusion (7 patients, 25%), fibrinous uveitis (5 patients, 17.9%), blockage of the intracameral portion of the tube by fibrin (5 patients, 17.9%), choroidal hemorrhage (2 patients, 7.1%). Late complications were: external conjunctival bleb failure (12 patients, 42.9%), blockage of the intracameral portion of the tube by fibrovascular tissue (5 patients, 17.9%), cataract (2 patients, 7.1%), bullous keratopathy (2 patients, 7.1%), external erosion of the Silastic valve (2 patients, 7.1%), phthisis bulbi (2 patients, 7.1%). Mortality during long-term follow-up was high in our series. The complications of an underlying diabetes mellitus were the most common cause of death (15 out of 22 patients). The high mortality of patients subjected to valve implantation makes it difficult to interpret the results of long-term studies. However, the valve implant is still today an alternative surgical procedure for controlling IOP in eyes with neovascular glaucoma that have visual potential.