David J. Spalton

Intravitreal triamcinolone for uveitic cystoid macular edema: an optical coherence tomography study

PURPOSE To investigate the use of intravitreal injection of triamcinolone acetonide (TA) for the treatment of refractory uveitic cystoid macular edema (CME). DESIGN Prospective, nonrandomized, self-controlled comparative trial. PARTICIPANTS Six patients with chronic CME resistant to treatment with systemic steroids, orbital floor steroids, and cyclosporine A. Three patients were followed for more than 1 year, and the other three for between 3 and 9 months. INTERVENTION Injection of 2 mg of TA into the vitreous cavity. TESTING Optical coherence tomography scanning of the fovea before and after injection and logarithmic minimal angle of resolution visual acuity. MAIN OUTCOME MEASURES Visual acuity, retinal thickness, cystoid space height, and intraocular pressure. RESULTS There was complete anatomic resolution of CME in five of the six cases within 1 week after injection. Cystoid spaces began to return between 6 weeks and 3 months after injection. Two patients with longer term follow-up responded to further orbital floor steroid injection and had no CME 1 year later. One patient had raised intraocular pressure develop, requiring a trabeculectomy. Mean improvement in visual acuity after 12 months was 0.27 (range, 0.14-0.42). CONCLUSIONS Complete anatomic and, to some extent, functional recovery can be induced by intravitreal TA despite long-term refractory inflammatory CME. Optical coherence tomography aids in the management of these cases.

Relationship between intraocular lens biomaterials and posterior capsule opacification

Purpose: To determine whether posterior capsule opacification (PCO) is influenced by intraocular lens (IOL) material. Setting: A British teaching hospital eye department. Methods: Ninety eyes were prospectively randomized to receive a poly(methyl methacrylate) (PMMA), silicone, or AcrySof® IOL. All lenses had 6,0 mm optics and PMMA haptics. A standardized surgical protocol was performed by a single surgeon using an extracapsular technique with capsulorhexis. Patients having surgical complications were excluded, and all patients had standardized medication and follow‐up. Posterior capsule opacification was assessed by a digital retroillumination camera using a dedicated software program based on the analysis of texture in the image and calculated as the percentage area of opacified capsule. Data were analyzed 2 years postoperatively. Results: There was a significant difference in percentage of PCO at 2 years among the three lens types (P < .0001). The AcrySof lenses were associated with less PCO (median 11.75%) than PMMA (43.65%) and silicone (33.50%) lenses (P < .001 and P = .025, respectively). The difference between PMMA and silicone lenses was not statistically significant. Conclusion: Intraocular lenses made from AcrySof were associated with a significantly reduced degree of PCO.

The effect of polymethylmethacrylate, silicone, and polyacrylic intraocular lenses on posterior capsular opacification 3 years after cataract surgery

OBJECTIVE To compare the visual outcome, neodymium:YAG (Nd:YAG) capsulotomy rates, and percentage of posterior capsular opacification (PCO) seen with polymethylmethacrylate (PMMA), silicone, and polyacrylic intraocular lens implants 3 years after surgery. DESIGN Randomized, prospective trial. PARTICIPANTS Ninety eyes of 81 patients were examined at a British teaching hospital. INTERVENTION Ninety eyes were prospectively randomized to receive a PMMA, silicone, or polyacrylic (AcrySof, Alcon, Fort Worth, TX) implant. All lenses had 6-mm disc optics with PMMA haptics. A standardized surgical protocol was performed by a single surgeon using an extracapsular technique with capsulorhexis; any surgical complications were excluded and all patients had standardized postoperative medication and follow-up. MAIN OUTCOME MEASURES Patients were seen at 6 months and 1, 2, and 3 years after surgery. At 3 years, logarithm of the minimum angle of resolution (LogMAR) visual acuity and Pelli-Robson contrast sensitivity were measured and YAG capsulotomy rates determined. Posterior capsular opacification was assessed objectively by digital retroillumination imaging using dedicated software and calculated as the percentage area of opacified capsule. RESULTS At 3 years, the overall follow-up rate was 71%: 19 patients were available for examination with polyacrylic lens implants, 22 with silicone, and 23 with PMMA. There was a significant difference in percentage PCO at 3 years among the lens types (P = 0.0001). Polyacrylic lenses were associated with less PCO (10%) than silicone (40%) and PMMA lenses (56%). The YAG capsulotomy rate was 0% for polyacrylic, 14% for silicone, and 26% for PMMA (P = 0.05). The visual acuity and contrast sensitivity were not significantly different among the three groups if patients with age-related macular degeneration and those requiring YAG capsulotomies are excluded. CONCLUSIONS Intraocular lenses made from polyacrylic are associated with a significantly reduced degree of PCO and lower YAG rates.

Comparison between optical coherence tomography and fundus fluorescein angiography for the detection of cystoid macular edema in patients with uveitis

PURPOSE To compare optical coherence tomography (OCT) with fundus fluorescein angiography (FFA) for the detection of cystoid macular edema (CME) in patients with uveitis. DESIGN Prospective comparative observational series. PARTICIPANTS One hundred twenty-one eyes of 58 patients with uveitis of varied causes (seven patients were studied twice). TESTING Patients with suspected CME underwent OCT scanning followed by FFA at the same visit. MAIN OUTCOME MEASURES Detection and distribution of macular edema. RESULTS One hundred eight eyes had similar results on both OCT and FFA in that 67 eyes had CME and 41 eyes had no CME. In 10 eyes subretinal fluid was detected on OCT but not FFA. Five of these eyes had CME on FFA but not OCT. Three other eyes had CME that was detected by FFA but not by OCT. Compared with FFA, the OCT sensitivity for detecting CME was 96% (including the eyes with subretinal fluid), and the OCT specificity was 100%. CONCLUSIONS OCT is as effective at detecting CME as is FFA but is superior in demonstrating axial distribution of fluid.

The effect of capsulorhexis size on posterior capsular opacification: one-year results of a randomized prospective trial

PURPOSE Posterior capsular opacification is the most common surgically related cause of reduced vision after cataract surgery. We studied the effect of capsulorhexis size on the pattern and severity of posterior capsular opacification. METHODS In this prospective study 75 patients underwent standardized phacoemulsification with capsulorhexis and in-the-bag placement of a 5.5-mm polymethylmethacrylate intraocular lens implant. The patients were randomly assigned to receive either a small capsulorhexis of 4.5 to 5 mm to lie completely on the intraocular lens optic or a large capsulorhexis of 6 to 7 mm to lie completely off the lens optic. Patients were examined at days 1, 14, 30, 90, and 180 and at year 1 with logMAR visual acuity assessment, Pelli-Robson contrast sensitivity testing, anterior chamber flare and cell measurement, and high-resolution digital retroillumination imaging of the posterior capsule. The pattern of posterior capsular opacification was determined, and the percentage area of posterior capsular opacification was calculated for each image with dedicated image analysis software. RESULTS Large capsulorhexes were associated with significantly more wrinkling of the posterior capsule and worse posterior capsular opacification than small capsulorhexes. At 1 year the average percentage area of posterior capsular opacification was 32.7% for small capsulorhexes (95% confidence interval, 19.8 to 45.6) and 66.2% for large capsulorhexes (95% confidence interval, 57.7 to 74.6) (P = .0001). The patients with large capsulorhexes had significantly poorer visual acuities and a trend toward worse contrast sensitivities. CONCLUSION This study demonstrated significantly greater wrinkling and opacification of the posterior capsule and worse visual acuity with large capsulorhexes than with small capsulorhexes. In cataract surgery with a polymethylmethacrylate intraocular lens, a small capsulorhexis with the edge completely on the surface of the implant is preferable to a large capsulorhexis in reducing posterior capsular opacification.

Cystoid macular edema after phacoemulsification: Relationship to blood-aqueous barrier damage and visual acuity

PURPOSE To ascertain the incidence of cystoid macular edema (CME) after phacoemulsification and its relationship to blood-aqueous barrier damage and visual acuity. SETTING A British teaching hospital. METHODS A prospective trial was performed to document the incidence of CME after routine phacoemulsification with continuous curvilinear capsulorhexis. LogMAR visual acuity and laser flare were measured using the KOWA FC 1000 laser cell-flare meter preoperatively and 1, 14, 30, and 60 days postoperatively. At day 60, a standardized fluorescein angiogram was performed and graded by masked observers. RESULTS The rate of angiographic CME on day 60 was 19%. Visual acuity at each visit was significantly worse in the CME group (P < .05). The flare and cell values at days 14, 30, and 60 were higher in the CME group at day 60; however, the difference was not statistically significance (P > .05). CONCLUSIONS The incidence of CME after routine phacoemulsification was 19%. Patients with CME at day 60 had significantly worse visual acuity than those who did not from the first postoperative day throughout the follow-up. There was a trend for patients who had CME at day 60 to have more postoperative inflammation.

Biocompatibility of poly(methyl methacrylate), silicone, and AcrySof intraocular lenses: Randomized comparison of the cellular reaction on the anterior lens surface

Purpose: To determine the foreign‐body response to three intraocular lens (IOL) biomaterials (poly[methyl methacrylate] {PMMA], silicone, and AcrySof) and use this as an indicator of their comparative biocompatibility postoperatively within the eye. Setting: A British teaching hospital eye department. Methods: Ninety eyes were prospectively randomized to receive a PMMA, silicone, or AcrySof IOL. All lenses had 6.0 mm optics with PMMA haptics. A standardized surgical protocol was performed by a single surgeon using an extracapsular technique with`capsulorhexis; eyes that experienced a surgical complication were excluded. All patients had standardized postoperative medication and follow‐up. Specular microscopy of the anterior IOL surface was carried out after pupil dilation on days 1, 7, 30, 90, 180, 360, and 720 to assess small cell and giant cell reactions. Results: All three IOL types produced a mild degree’ of nonspecific foreign‐body response, which resolved over the study period without detrimental effect. The silicone group had significantly higher small cell counts than the PMMA and AcrySof groups (P = .02); the AcrySof group had significantly lower giant cell counts than the other two groups (P = .003). Conclusion: The three IOL types were sufficiently biocompatibfe to function in normal eyes with age‐related cataracts. However, AcrySof IOLs were associated with lower giant cell counts than PMMA and silicone IOLs and might produce better results in eyes with pre‐existing blood‐aqueous barrier damage.

Lens epithelial cell regression on the posterior capsule with different intraocular lens materials

BACKGROUND/AIMS Posterior capsular opacification (PCO) is caused by proliferation and migration of lens epithelial cells (LECs) across the posterior capsule and is the commonest cause of reduced vision after cataract surgery. The influence of intraocular lens (IOL) material on the process of LEC migration was studied. METHODS 90 eyes underwent standardised extracapsular surgery, with capsulorhexis and “in the bag” IOL placement. They were randomised to receive a three piece 6 mm lens of PMMA, silicone, or polyacrylic (AcrySof, Alcon, Fort Worth, TX, USA). On days 7, 30, 90, 180, and years 1 and 2 high resolution digitised retroillumination images were taken of the posterior capsule. The presence of LECs was determined at 90 days and 2 years, and their progression or regression was established by serial examination of images. RESULTS LECs were seen in 93% of silicone and 97% of PMMA IOLs at 90 days, compared with 46% of polyacrylic (p<0.001). At year 2 LECs were present in all patients with silicone or PMMA lenses, whereas 62% of patients with polyacrylic IOLs had LECs (p<0.001). Of those patients with LECs at day 90 LEC regression occurred in 8% with silicone IOLs and 15% of PMMA cases, compared with 83% of patients with polyacrylic IOLs (p<0.0001). CONCLUSION The presence of LECs on the posterior capsule was considerably lower with polyacrylic than PMMA or silicone IOLs and LEC regression occurred more frequently. The lower incidence of LECs and the higher rate of regression may explain why PCO formation appears to be reduced with polyacrylic lenses. This has important clinical implications for the prevention of PCO.

Postoperative inflammatory response to phacoemulsification and extracapsular cataract surgery: Aqueous flare and cells

Purpose: To compare the postoperative blood‐aqueous barrier (BAB) breakdown induced by phacoemulsification with continuous curvilinear capsulorhexis (CCC) and by extracapsular cataract extraction (ECCE) with a linear capsulotomy. Setting: Cataract and Refractive Surgery Research Unit, Department of Ophthalmology, St. Thomas’ Hospital, London, United Kingdom. Methods: Anterior chamber flare and cells were measured preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively in two parallel groups of 31 consecutive cataractous eyes. In Group 1, one surgeon performed ECCE with a linear capsulotomy; in Group 2, a second surgeon performed divide and conquer phacoemulsification with CCC. The preoperative, intraoperative, and postoperative medication regimen was the same in both groups. Results: Group 2 eyes had significantly lower anterior chamber flare and cell measurements in the first postoperative month than Group 1 eyes (.01 < P < .00001). Conclusions: Phacoemulsification with CCC induced a less severe BAB breakdown than ECCE with a linear capsulotomy. Phacoemulsification with CCC may be preferable in high‐risk eyes such as those with glaucoma, diabetes, or uveitis, which are prone to complications resulting from postoperative BAB breakdown.

Measurement of aqueous cells and flare in normal eyes.

(abstractThe Kowa laser cell flare meter has been recently introduced to quantify the assessment of aqueous cells and flare in vivo by measurement of light scattering from a low power HeNe beam. Computer analysis of this scattered light can distinguish cells (expressed as cell count) from protein (expressed as photon count/ms), and in-vitro work with albumin solutions has shown that the photon count/ms is linearly related to protein concentration. This study of 106 normal eyes (53 subjects) assesses the accuracy and sensitivity of the instrument and the factors affecting the interpretation of its results. Using in-vitro solutions of human albumin we found a highly significant linear correlation (r = 1, p = 0.0001) between photon count and protein concentration. The results show that the instrument has a photon count/ms reproducibility of 8.26% and that there is a within-subject variability in photon count/ms (aqueous flare) of 12.2% in normal eyes. No significant difference in photon count/ms (aqueous flare) was found to exist between right and left eyes (p greater than 0.4), between sexes (p greater than 0.5), or between irides of different colour (p greater than 0.8). There was also no statistically significant variation in photon counts/ms with time of day over the period of measurement (1000-1900 h) (p = 0.4). There was, however, an increase in photon count/ms with age (r = 0.57, p less than 0.001) and a decrease with pupillary dilatation at both 30 and 60 minutes after instillation of tropicamide 1% (p less than 0.05). An occasional cell was found in only 10.4% of normal eyes, and there was no significant increase in the cell counts on mydriasis (p>0.05). These findings indicate that the Kowa laser flare meter is an accurate and sensitive instrument with potential application in the investigation of blood-aqueous barrier.