Scanning Electron Microscopy Evaluation of an EX-PRESS Mini Glaucoma Shunt After Explantation.

We report a case of an explanted stainless steel miniature glaucoma drainage device (EX-PRESS) implanted under a scleral flap for pseudoexfoliation open-angle glaucoma surgical treatment. The glaucoma shunt was implanted in a 75-year-old white man with medically refractive glaucoma. Cataract surgery was performed simultaneously. After 2 years, the shunt extruded through the scleral flap and the conjunctiva and it was, therefore, explanted. Scanning electron microscopy images of the EX-PRESS mini glaucoma shunt were acquired to verify the patency of the device lumen and the presence of fibrosis or cellular adhesion on the device. Energy dispersive spectroscopy for chemical surface characterization of the EX-PRESS shunt was performed. Scanning electron microscopy-acquired images showed minimal extracellular material proliferation on the lumen device. The energy dispersive spectroscopy analysis revealed a high peak of carbon suggesting the organic nature of the residuals found on the shunt lumen. The surface showed few superficial pits, likely due to an initial corrosion process.

Unilateral Optic Neuritis: A Rare Complication after Measles-Mumps-Rubella Vaccination in a 30-Year-Old Woman.

Purpose. To report a case of unilateral optic neuritis following Measles-Mumps-Rubella (MMR) vaccination. Methods. A 30-year-old female developed unilateral optic neuritis five days after a Measles-Mumps-Rubella (MMR) booster vaccination. The patient displayed unilateral involvement, with severe visual loss. However, visual acuity improved significantly after four days of intravenous steroid therapy with 500 mg/day of methylprednisolone. Conclusions. Optic neuritis is one of the rare complications associated with the mumps, measles, and rubella vaccine. It may be a toxic reaction to the nonviral component of the vaccine, but the exact etiology is unknown. Postvaccination neuritis is generally bilateral and usually affects children. In adults, unilateral optic neuritis is usually correlated with multiple sclerosis (MS).

GDx-VCC performance in discriminating normal from glaucomatous eyes with early visual field loss.

BACKGROUND: To evaluate the ability of scanning laser polarimetry with variable corneal compensation (GDx-VCC) in separating healthy from glaucomatous patients with early visual field (VF) loss. METHODS: Sixty-two healthy and 48 glaucomatous age-matched patients with early glaucoma [mean deviation (MD): -1.74dB +/-1.69] underwent complete ophthalmological evaluation, automated achromatic perimetry (AAP) and retinal nerve fiber layer (RNFL) measurement with GDx-VCC. One randomly selected eye from each subject was considered. Glaucomatous VF defects had either Glaucoma Hemifield Test (GHT) outside normal limits or pattern standard deviation (PSD) outside 95% confidence limits. Mean (+/-SD) MD, PSD and GDx-VCC parameters in the two groups were compared by t-test. For each GDx-VCC parameter, area under receiver operating characteristics (AUROC) curve and sensitivity at predetermined specificity > or =80% and > or =95% were calculated. Moreover, the parameter with largest AUROC was evaluated by likelihood ratios (LRs). RESULTS: Mean values for MD, PSD and ten of 14 GDx-VCC parameters were significantly different between the two groups (P<0.001). The three parameters with largest AUROCs were the nerve fiber indicator (NFI) (0.870), superior average (0.817) and normalized superior area (0.816) (P=0.08 for differences between AUROCs). NFI displayed sensitivity values of 80.2% and 60.4% for specificity > or =80% and > or =95%, respectively. At NFI cutoff value of 30, positive LR was 34.9 (95% CI: 4.9-247.6) and negative LR was 0.45 (95% CI: 0.32-0.61). Interval LRs showed large effect on post-test probability for NFI values < or =18 or > or =31. CONCLUSIONS: In our sample of eyes with early VF loss, GDx-VCC showed moderate-to-good discriminating ability. Among the best performing parameters, NFI had the largest AUROC, but several glaucomatous eyes (21, 43.8%) had NFI <30. This suggests that algorithm for NFI calculation requires some refinement when eyes with early VF loss are evaluated.

Scanning laser polarimetry of nerve fiber layer thickness in normal eyes after cataract phacoemulsification and foldable intraocular lens implantation.

PURPOSE: To assess the effect of cataract phacoemulsification and intraocular lens (IOL) implantation on retinal nerve fiber layer (RNFL) thickness using scanning laser polarimetry (SLP). SETTING: Eye Clinic, Trieste University, Italy. METHODS: Forty-eight eyes were evaluated prospectively the day before and 30 days after cataract phacoemulsification and foldable IOL implantation. In each eye, lens opacity grading according to the Lens Opacities Classification System III (LOCS III), and axial length (AL) measurements were performed. Retinal nerve fiber layer thickness was quantified at baseline by means of SLP and anterior segment birefringence compensation was evaluated acquiring macular retardation map (MRM). Acrylic and silicone IOLs were implanted randomly. After surgery, RNFL thickness was reevaluated, and MRM was reacquired. Macular retardation map pattern variations regarding baseline profile were classified into 3 groups: no variation, bow-tie profile enhancement, or attenuation. Distribution of IOL power, AL, and cataract type in the 3 groups was assessed, as were presurgery and postsurgery SLP parameters with mean values (+/-SD) compared by paired t test. RESULTS: Twenty-two eyes (Group 1, 45.8%) showed no MRM variation, 14 (Group 2, 29.2%) an enhancement, and 12 (Group 3, 25%) an attenuation. In Group 1, no significant RNFL thickness variation occurred. In Group 2, variation 10% to 15% was measured, whereas thickening a 8% to 15% thinning appeared in Group 3. Variations occurred irrespective of IOL material, AL, or cataract type. CONCLUSIONS: Cataract surgery with IOL implantation was associated with an MRM profile change and RNFL thickness variations in 54.2% of eyes. Variations are probably related to opacified lens removal. A new baseline SLP reading is mandatory after cataract surgery.

Lens epithelial cell reaction after implantation of different intraocular lens materials: two-year results of a randomized prospective trial.

PURPOSE: To determine the influence of intraocular lens (IOL) material on anterior capsular opacification and membrane growth over the anterior IOL surface in patients who have undergone standardized small-incision cataract surgery and foldable IOL implantation in the capsular bag. DESIGN: Randomized controlled trial. PARTICIPANTS: Eighty-eight cataract patients (88 eyes). METHODS: Patients were randomly assigned to receive one of four different foldable IOLs after phacoemulsification: Storz Hydroview H60M, Corneal ACR6D, AMO SI40NB, and Alcon AcrySof MA60BM. Examinations on days 7, 30, 90, 180, 360, and 720 after surgery included ophthalmologic examination, slit-lamp biomicroscopy, and photography using red reflex and focal illumination of the anterior IOL surface. MAIN OUTCOME MEASURES: Best-corrected visual acuity was measured at each examination. In addition, the anterior capsule opacification and the membrane growth on the anterior IOL surface were graded according to a subjective method by the same researcher. RESULTS: The fibrosis of the anterior capsule was more frequently observed in the group using Corneal ACR6D and AMO SI40NB. The Hydroview and ACR6D groups showed a higher percentage of cases with membrane growth from the rhexis edge on the anterior IOL surface. AcrySof showed the lowest presence of fibrosis of the anterior capsule, and no membrane growth was noted. CONCLUSIONS: Anterior capsule opacification is an index of IOL biocompatibility. The natural location of lens epithelial cells (LECs) precludes the possibility of the IOL's design influencing the anterior capsule behavior. The local response of LECs varies according to the IOL studied. This may be related to the chemical and physical properties of the materials used in the different IOLs.

Retinal detachment after cataract extraction and refractive lens exchange in highly myopic patients.

PURPOSE: To assess the refractive effects and incidence of postoperative complications in patients with high myopia after cataract extraction. SETTING: University Eye Clinic, Trieste, Italy. METHODS: This noncomparative retrospective study comprised all eyes (N = 388) having cataract extraction and implantation of an intraocular lens with a power less than 11.0 diopters (D) between 1986 and 1999. The preoperative and postoperative refractions; preoperative, postoperative, and final best corrected visual acuity (BCVA); and postoperative complications were analyzed. The mean follow-up was 47.16 months +/- 32.83 (SD) (range 8 to 146 months). RESULTS: Phacoemulsification was performed in 237 eyes, extracapsular cataract extraction in 147 eyes, and intracapsular cataract extraction in 4 eyes. The mean preoperative BCVA was 0.20 +/- 0.21 and the mean postoperative BCVA, 0.58 +/- 0.32. At the final evaluation, the mean BCVA was 0.50 +/- 0.33. The mean refraction was -15.95 +/- 5.86 D preoperatively and -2.00 +/- 1.62 D postoperatively. One eye (0.26%) developed a retinal detachment postoperatively. Of the 127 eyes (32.73%) having a neodymium:YAG laser capsulotomy for posterior capsule opacification, 1 had a macular retinal hole. Posterior detachment of the vitreous occurred in 78.6% of cases. Peripheral retinal photocoagulation was required in 8 cases postoperatively. CONCLUSION: Refractive lens exchange led to good functional results and a low incidence of postoperative complications and can thus be regarded as a viable technique to correct high myopia associated with cataract. However, further study is required before it can be routinely recommended for the correction of high myopia in eyes with a transparent crystalline lens.

Correlation between the retinal nerve fiber layer thickness and the pattern electroretinogram amplitude.

OBJECTIVE: To establish a correlation between the retinal nerve fiber layer (RNFL) thickness measured by a scanning laser polarimeter (GDx) and the pattern electroretinogram (p-ERG) amplitudes in a heterogeneous population sample composed of normal subjects, ocular hypertensive and glaucomatous patients. METHODS: 112 subjects were considered: 40 glaucomatous patients, 39 ocular hypertensive and 33 normal subjects. All were examined with the GDx, and the RNFL thickness was measured. A transient p-ERG was then recorded. RESULTS: A statistically significant correlation was observed between the RNFL thickness and the p-ERG amplitudes (p < 0.001) by means of linear regression analysis. CONCLUSION: We observed a strict correlation between the measurements of the RNFL thickness obtained with the GDx and the amplitude of the p-ERG signal. These techniques represent additional objective tools to detect an early glaucomatous damage.