Fast Automated Analysis and Classification of Color Pictures by Signature and Pattern Recognition Using a Color Scanner

A commercial color scanner with high resolution is used for picture processing. The scanner is modified and additional electronic instruments are connected to the built-in color computer. The operations are carried out in an on-line process, simultaneously with the scan of the picture a processed picture is recorded on a special scanner film. Because there is no storage of image datas short processing times are obtained. The image datas are handled in a color computer, a gradation processor, an operational amplifier and a comparator to realize various\u27 procedures of picture operations. The procedures are classified here in global, local and point operations. Global operations refer to the whole picture, these are for instance rectification, enlargement, density transformations. Local operations are mostly used for texture and pattern recognition and are related to the scanned picture element and its surrounding area. Point operations manipulate the information of a single picture element. The scanner generates three color signals from each picture element, which are handled in the color computer for color and signature recognition. Several operations may be carried out in the same scan. The processed picture is displayed on a b/w transparency or on a color film. A suitable display for thematic mapping is essential for a correct interpretation of the processed picture

Surgical treatment of diabetic retinopathy

Several complications of advanced diabetic retinopathy can be treated surgically. Vitrectomy can clear media opacities, relieve traction on the retina, and makes adequate laser treatment of the retina possible. Removal of premacular vitreous may also improve diabetic macular edema. Instrumentation, understanding of the pathophysiology, surgical skills as well as supplementary pharmacotherapy have improved surgical results. Indications and timing for surgery have considerably changed in the past decades and the threshold for surgery has been continuously lowered, as vitrectomy became safer. The primary disease of the retinal microvasculature with capillary occlusion and retinal ischemia is still the limiting factor, responsible for disappointing functional results in anatomically successfully operated eye

Predictive Factors in OCT Analysis for Visual Outcome in Exudative AMD

Background. Reliable predictive factors for therapy outcome may enable treating physicians to counsel their patients more efficiently concerning probability of improvement or time point of discontinuation of a certain therapy. Methods. This is a retrospective analysis of 87 patients with exudative age-related macular degeneration who received three monthly intravitreal ranibizumab injections. Visual acuity before initiation of intravitreal therapy and 4–6 weeks after last intravitreal injection was compared and related to the preoperative visualisation of continuity of the outer retinal layers as assessed by OCT: external limiting membrane (ELM), inner photoreceptor segments (IPS), junction between inner and outer segments (IS/OS), and outer photoreceptor segments (OPS). Results. Visual acuity increased in 40 of 87 (46.0%) patients, it remained stable in 25 (28.7%), and 22 (25.3%) patients had decreased visual acuity four to six weeks after triple intravitreal ranibizumab injections. No statistically significant predictive value could be demonstrated for grade of continuity of outer retinal layers concerning visual acuity development. Conclusions. In our series of AMD patients, grade of continuity of outer retinal layers was not a significant predictive value for visual acuity development after triple ranibizumab injections

Macular hole surgery: an analysis of risk factors for the anatomical outcome with special emphasis on the experience of the surgeon

Purpose: The aim of this study was to evaluate risk factors for the anatomical and functional outcomes of macular hole (MH) surgery with special emphasis on the experience of the surgeon. Methods: A total of 225 surgeries on idiopathic MHs (IMHs) performed by 6 surgeons with a mean follow-up period of 20.5 months were reviewed in this retrospective study. Outcome parameters focused on IMH closure, complications and visual acuity improvement. The results of MH surgeries performed by experienced surgeons were compared to those of surgeons in training. Results: The average MH size was 381 µm (standard deviation [SD]=168). Brilliant blue G (BBG) for internal limiting membrane (ILM) staining was used in 109 (48%) eyes and indocyanine green (ICG) in 116 (52%) eyes. As endotamponade, 20% SF6 was used in 38 (17%) cases, 16% C2F6 in 33 (15%) cases and 16% C3F8 in 154 (68%) cases. IMH closure was achieved in 194 eyes (86%). Mean preoperative visual acuity was 0.84 logarithm of the minimum angle of resolution (log MAR; SD=0.29, range: 0.3–1.5); surgery led to a mean improvement of 0.40 (SD=0.37) log MAR. Although the MH closure rate was the same using BBG or ICG for ILM peeling, visual acuity improvement was better in eyes peeled with BBG compared to eyes peeled with ICG (log MAR: BBG: 0.38 [95% CI: 0.32, 0.44] vs ICG: 0.48 [95% CI: 0.42, 0.54], P=0.029). Surgeons with previous experience in vitreoretinal surgery of ≥6 years achieved better visual outcomes compared to surgeons with 0–3 years of experience, regardless of the MH size, preoperative visual acuity, time to follow-up or dye used for ILM peeling (0–3 years [0.27, ∆log MAR] vs ≥6 years [0.43, ∆log MAR], P=0.009). Conclusion: Our results indicate that vitrectomy with ILM peeling performed by non-experienced surgeons is a safe procedure leading to good anatomical and functional results. Very experienced surgeons may achieve even better functional outcomes

The effects of midazolam on intraocular pressure in children during examination under sedation

Background: To obtain reliable and accurate measurements of the intraocular pressure (IOP) in children often requires sedation or anaesthesia. Therefore, we investigated the effects of oral midazolam on IOP in children. Methods: In a prospective study, IOP was measured in 72 eyes of 36 cooperative children without glaucoma requiring general anaesthesia (mean age 3.5±1.3 years, body weight ≤20 kg) by using a Perkins hand-held tonometer. Measurements of IOP were performed before, and 15 and 30 min after sedation with orally administered midazolam (1 mg/kg) given as preoperative medication, and 5 and 15 min after induction of general anaesthesia. The individual IOP courses were analysed. Results: In all of the cooperative children, IOP measurement was possible after sedation with midazolam. Mean IOP was 11.2±0.3 mmHg before sedation, 10.9±0.2 mmHg at 15 min, and 10.7±0.3 mmHg 30 min after administration of midazolam. This small decrease was not statistically significant, whilst the IOP decline at 5 and 15 min after induction of general anaesthesia was statistically significant (p<0.0001). Conclusion: Sedation with midazolam can be assumed to be an applicable, well-tolerated, safe method for IOP measurements in children

Characteristics of Bilateral Retinal Detachment

Introduction: Rhegmatogenous retinal detachment (RD) is still a sight-threatening and potentially blinding disease, especially if both eyes are affected. The purpose of this study is analysing the specific characteristics of bilateral rhegmatogenous RD. Methods: The files of all 5,791 consecutive eyes undergoing vitreoretinal surgery for uncomplicated RD in a single tertiary retinal centre between January 2005 and June 2021 were retrospectively reviewed. Results: A total of 300 patients (600 eyes) had bilateral retinal detachment. Interval between initial and subsequent RD surgery was 2.6 ± 2.8 (mean ± SD, median 1.5) years. Symptoms were reported by the patients for 20 ± 75 (median 5) days before presentation in the initial eye and 12 ± 32 (median 4) days in the subsequent eye. 220 patients were male (73%), and mean age at initial RD was 55 years. 183 (61%) of the initial RD eyes were phakic. In the initial eye, more patients had a detached macula, worse visual acuity, and more quadrants involved. Primary anatomic success rate was higher in the subsequent eye (90%) compared to the initial eye (83%). There was no difference in the reattachment rate of fellow eyes with primary failure in the first eye (91%) compared to those with primary success in the first eye (90%). There was a high symmetry between the eyes in terms of type of retinal break, number of breaks, and presumed localization of the causative retinal break. Conclusion: Patients with bilateral RD were more commonly male and younger than the group of all RD patients. The proportion of pseudophakia was not different. The majority of fellow eye RD occurred within 2 years after the RD in the first eye. Second eye RD was less advanced and had a better anatomical repair rate. Despite their experience in the first eye and despite typical symptoms, patients presented only after a mean of 12 days with RD in the second eye. RD in the initial and the subsequent eye showed a high symmetry. The anatomic result in the first eye is not a predictor for the anatomic result in the subsequent eye

Photostress Recovery Time as a Potential Predictive Biomarker for Age-Related Macular Degeneration

Abstract Purpose: The purpose of this study was to assess recovery time following photostress and its association with age-related macular degeneration (AMD) cross-sectionally and longitudinally in an elderly population-based cohort. Methods: We analyzed photostress recovery time (PRT) and AMD in >1800 AugUR study participants aged 70+ years. On color fundus images from baseline and 3-year follow-up, presence of AMD was graded manually (Three Continent AMD Consortium Severity Scale). Visual acuity (VA) was assessed via Early Treatment Diabetic Retinopathy Study (ETDRS) charts. After a 30-second bleaching of the macular region via direct ophthalmoscope, PRT was measured as the seconds to regain VA. Results: First, we analyzed 1208 AugUR participants cross-sectionally (288 with early AMD, and 78 with late AMD). Prolonged PRT was associated with early and late AMD versus no AMD (median PRT = 119.5, 198.0 versus 80.0 seconds, respectively; logistic regression odds ratio [OR] = 1.109–1.165 per 10 seconds, P values < 0.0001). Sensitivity analyses using alternative models or restricting to participants after cataract surgery revealed similar ORs. Second, the association was confirmed in an independent cross-sectional AugUR sample (n = 486). Third, in longitudinal analysis of 233 AugUR participants without AMD, prolonged PRT was associated with incident AMD ascertained 3 years later (follow-up time = 3.2 ± 0.2 years, OR = 1.112–1.162 per 10 seconds, P < 0.05). Overall, we demonstrate a significant association of prolonged PRT with AMD cross-sectionally and longitudinally in elderly individuals. Conclusions: Prolonged PRT might capture retinal function impairment after cell damage before early AMD is visible via color fundus imaging. Translational Relevance: Our results suggest PRT as quantitative predictive biomarker for incident AMD, making it potentially worthwhile also for clinical care