The multifocal pattern electroretinogram in glaucoma

AbstractBackground: The pattern ERG can be used to detect early glaucomatous change, because the response of cells in the inner retina from (typically) 20°–40° of area is reduced before perimetric abnormality is certain. The multifocal pattern electroretinogram (mfPERG) allows analysis of many local regions within this area. The aim of this study was to investigate whether in patients with presumed glaucoma the mfPERG permits diagnosis and discrimination from normals.Methods: Measurements on 25 age-related normal eyes were compared to those on 23 eyes with different stages of glaucoma. A RETIScan system was used to generate a stimulus pattern of 19 hexagons, each consisting of six triangles. The triangles pattern-reversed black to white at 75 Hz. Those 19 hexagons were grouped into three stimulus regions: a central field, a middle, and a peripheral ring. The complete array subtended 48° at the eye. The hexagons alternated between black and white, in a temporal pattern that followed a corrected binary m-sequence (length 512, 10 cycles with 39 s each). The amplitudes and latencies of positive responses at approximately 50 ms (P-50) and negative responses at approximately 95 ms (N-95) were analyzed.Results: In patients with glaucoma the P-50 and N-95 components of the mfPERG were significantly reduced for the central area and both outer rings compared to normal volunteers (p<0.001, Mann–Whitney-U). The most distinct reduction was observed for N-95 and the central ring. Changes in latencies were not conclusive. The reduction of the components increased with the stage of glaucoma. A predictive model for detecting early glaucomatous changes was designed based on P-50–N-95 with 88% sensitivity and 76% specificity.Conclusion: In glaucoma a marked reduction of components, especially centrally is observed in the mfPERG. This hints to an early involvement of central ganglion cells and may be useful for future functional tests

What would an 'ideal' glaucoma examination be like? - A conjoint analysis of patients' and physicians' preferences

PURPOSE To structurally determine patients' and physicians' preferences for glaucoma diagnostic methods in order to improve glaucoma patient care and improve patient compliance with follow-up visits. METHODS Forty-one patients with glaucoma and 32 ophthalmologists were included in this cross-sectional study. Profiles representing glaucoma examinations were created using conjoint analysis (CA). The following factors of a glaucoma examination method were evaluated: (1) examination comfort, (2) examination frequency, (3) follow-up examination necessary in case of suspicious result, (4) cost for the patient, (5) travel time to examination site, (6) sensitivity and (7) specificity of the examination method. RESULTS Preferences were highest in both groups for examination sensitivity, followed by cost and specificity for the patient group. For the physician group, specificity was second most important, followed by cost. Least important was travel time for the patients and follow-up examinations for the physicians. CONCLUSIONS Participants would rather pay more and travel longer to get a highly sensitive examination. This form of care is present in university eye hospitals. Consequently, it would be advisable to enhance capacities of these centers. Outpatient practices that offer glaucoma service should be fully equipped and should employ a glaucoma specialist

German claims data analysis to assess impact of different intraocular lenses on posterior capsule opacification and related healthcare costs

Aim: Cataract extraction is one of the most frequent surgeries in Germany. In most cases, the clouded natural lens is replaced by a hydrophobic or hydrophilic acrylic intraocular lens (IOL) implant. The most common long-term complication after cataract surgery is the development of a posterior capsule opacification (PCO). Although no precise real world data are available, published evidence suggests a lower risk for PCO development for hydrophobic acrylic IOLs compared to hydrophilic acrylic IOLs. Therefore, in the present study we assessed real world data on the impact of different IOL material types on the incidence of post-operative PCO treatment. Subject and methods: In this retrospective study, we included 3,025 patients who underwent cataract extraction and implantation of either an acrylic hydrophobic or hydrophilic IOL in 2010. We assessed clinical outcomes and direct costs in a 4-year follow-up period after cataract surgery from a statutory health insurance (SHI) perspective in Germany. Results: PCO that required capsulotomies occurred significantly (p < 0.0001) less frequent in patients who had received a hydrophobic IOL (31.57% of 2,078 patients) compared to the group with hydrophilic IOL implants (56.6% of 947 patients) and costs per patient for postoperative treatment in a 4-year follow-up were 50.03 € vs. 87.81 € (i.e. 75% higher in the latter group, p < 0.0001). Conclusion: Considering the high prevalence of cataract, the economic burden associated with adverse effects of cataract extraction is of great relevance for the German SHI. Hydrophobic lenses seem to be superior regarding both medical and economic results

Comparative Evaluation of Combined Navigated Laser Photocoagulation and Intravitreal Ranibizumab in the Treatment of Diabetic Macular Edema

Objective: To evaluate if a standardized combination therapy regimen, utilizing 3 monthly ranibizumab injections followed by navigated laser photocoagulation, reduces the number of total ranibizumab injections required for treatment of diabetic macular edema (DME). Research Design and Methods: A 12-month, prospective comparison of 66 patients with center-involving DME: 34 patients with combination therapy were compared to 32 patients treated with ranibizumab monotherapy. All patients initially received 3 monthly ranibizumab injections (loading phase) and additional injections pro re nata (PRN). Combination therapy patients additionally received navigated laser photocoagulation after the loading phase. Main outcome measures were mean number of injections after the loading phase and change in BCVA from baseline to month 12. Results: Navigated laser combination therapy and ranibizumab monotherapy similarly improved mean BCVA letter score (+8.41 vs. +6.31 letters, p=0.258). In the combination group significantly less injections were required after the 3 injection loading phase (0.88 +/- 1.23 vs. 3.88 +/- 2.32, p<=0.001). By month 12, 84% of patients in the monotherapy group had required additional ranibizumab injections as compared to 35% in the combination group (p<=0.001). Conclusions: Navigated laser combination therapy demonstrated significant visual gains in most patients. Retreatment rate and number of injections were significantly lower compared to ranibizumab monotherapy and compared to the results of conventional laser combination therapy previously reported in pivotal anti-VEGF studies

Age effect on retina and optic disc normal values

Purpose: To investigate retinal thickness and optic disc parameters by the Retinal Thickness Analyzer (RTA) glaucoma program in older normal subjects and to determine any age effect. Methods: Subjects over 40 years of age without any prior history of eye diseases were recruited. Only subjects completely normal on clinical ophthalmologic examination and on visual field testing by Humphrey Field Analyzer (HFA) using the SITA 24-2 program were included. A total of 74 eyes from 74 subjects with even age distribution over the decades were enrolled and underwent topographic measurements of the posterior pole and of the optic disc by RTA. The `glaucoma full' program in software version 4.11B was applied. Results: Mean patient age was 59.9 +/- 10.3 years with a range from 40 to 80 years. The only parameter intraocular pressure (IOP) correlated with was retinal posterior pole asymmetry (r=0.27, p=0.02). IOP itself increased significantly with age (r=0.341, p=0.003). Mean defect and pattern standard deviation of the HFA did not correlate with any of the retinal or optic disc measurements. Increasing age correlated significantly with some of the morphologic measurements of the RTA: decreasing perifoveal minimum thickness (r=-0.258, p=0.026), increased cup-to-disc area ratio (r=0.302, p=0.016) and increased cup area (r=0.338 p=0.007). Conclusions: An age effect exists for some of the retina and optic disc measurements obtained by the RTA. Copyright (C) 2005 S. Karger AG, Basel

Retinal pigment epithelium is protected against apoptosis by

PURPOSE. The degeneration of retinal pigment epithelial (RPE) cells is considered to be a crucial event in the pathophysiology of age-related macular degeneration (AMD). Cumulative oxidative damage has been implicated in the development of the changes seen in AMD. The present study was undertaken to evaluate the expression of the small heat shock protein ␣B-crystallin in the RPE in response to oxidative stress and to explore whether ␣B-crystallin expression confers an antiapoptotic cytoprotective effect on RPE cells. METHODS. Native human RPE cells from the macula and retinal periphery were analyzed by RT-PCR and Western blot analysis for expression of ␣B-crystallin. Monolayer cultures of human RPE cells were stressed by heat shock (42°C for 20 minutes) or oxidant-mediated injury (50 -300 M H 2 O 2 for 1 hour). Induction of ␣B-crystallin and the corresponding mRNA was assessed by Western and Northern blot analyses. To study the cytoprotective effect of ␣B-crystallin, human RPE cells were transfected with either a neomycin-selectable expression vector containing ␣B-crystallin cDNA or a control vector without ␣B-crystallin cDNA. Caspase-3 activity was determined by observing the cleavage of a colorimetric peptide substrate. Cell viability was quantified by combined propidium iodide and Hoechst 33342 staining. RESULTS. ␣B-crystallin is constitutively expressed in RPE under in vivo and in vitro conditions. Western blot analysis of freshly isolated RPE showed greater baseline expression levels in RPE derived from the macular area than in that from the more peripheral regions. Heat shock treatment and oxidative stress caused a significant increase in ␣B-crystallin mRNA and protein. Oxidant-mediated injury in RPE cells with baseline expression levels of ␣B-crystallin resulted in apoptotic cell death, as measured by caspase-3 activity, whereas RPE cells that had been stably transfected with ␣B-crystallin were more resistant to H 2 O 2 -induced cellular injury. CONCLUSIONS. ␣B-crystallin may function as a stress-inducible antiapoptotic protein in human RPE and is inducible by oxidative stress, a condition implicated in the pathogenesis of AMD. Overexpression of ␣B-crystallin may be an important mechanism for the RPE to prevent apoptotic cell death in response to cellular stress. (Invest Ophthalmol Vis Sci. 2002;43:3575-3582) A ge-related macular degeneration (AMD) is the leading cause of severe visual impairment in elderly individuals