[Magnification in ophthalmoscopy. I. Theory of magnification in direct ophthalmoscopy].
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A hand-held indirect lens and an operating microscope can provide a view of the fundus similar to that provided by the usual binocular indirect ophthalmoscope headpiece. The only modification required is that the working distance must be increased to allow the microscope to be focused on the aerial image created by the hand-held lens. This technique provides a cost-effective means of retinal examination in preparation for intraocular lens implantation. Also, the view of the fundus it provides when complications such as choroidal hemorrhage or lens nucleus dislocation occur, facilitates appropriate management. It also can be used during posterior segment procedures such as foreign body removal, posterior vitrectomy, and retinal detachment repair. The advantages of this method include the possibility of using the microscope's zoom capability to provide greater magnification, and beam splitters for video or still-camera documentation of the findings during examination under anesthesia.
BACKGROUND: The purpose of this study was to estimate if and to what extent scanning laser ophthalmoscopy can help in the early diagnosis and follow-up management of the vitreoretinal interface syndrome, which includes disorders such as cellophane maculopathy, pseudomacular hole, macular pucker, and macular hole. METHODS: The 35 fellow eyes of 35 patients with vitreoretinal interface syndromes in the first eye underwent scanning laser ophthalmoscopy microperimetry and argon, helium-neon, and infrared scanning laser ophthalmoscopy. Fellow eyes were defined as clinically positive or negative for vitreoretinal interface syndrome. Fellow eyes then were classified based on scanning laser ophthalmoscopy techniques. Patients were observed for an average of 18 months (range, 10-26 months). RESULTS: Thirty-two of the 35 fellow eyes were classified as clinically negative, and three of the 35 were classified as clinically positive. Fifteen of the 32 clinically negative fellow eyes were redefined as positive on scanning laser ophthalmoscopy. None of the clinically positive eyes proved to be negative on scanning laser ophthalmoscopy. During the average follow-up period (18 months), the condition of five of 18 fellow eyes that were positive on scanning laser ophthalmoscopy worsened. None of the 17 eyes that were negative on scanning laser ophthalmoscopy worsened. CONCLUSION: Scanning laser ophthalmoscopy can produce beautifully clear images of structures that are otherwise difficult to see and document, such as posterior hyaloid and the inner retinal layers. Despite a relatively limited number of cases and the short duration of the follow-up period, the present study suggests that scanning laser ophthalmoscopy has good sensitivity and specificity for the early diagnosis of vitreoretinal interface syndromes.
PURPOSE: To evaluate single-field digital monochromatic nonmydriatic fundus photography as an adjunct in the screening of diabetic retinopathy. DESIGN: Prospective, comparative, observational case series. METHODS: Patients with type I and type II diabetes mellitus (n = 197) were sequentially evaluated by three different techniques: single-field digital monochromatic nonmydriatic photography; dilated ophthalmoscopy by an ophthalmologist; and seven Early Treatment Diabetic Retinopathy Study (ETDRS) standardized 35-mm color stereoscopic mydriatic images. The seven stereoscopic color photographs served as the reference standard and were compared with either ophthalmoscopy or a single digital photograph transmitted electronically to a reading site. Levels of agreement were determined by kappa analyses. The sensitivity and specificity of the three methods were compared based on a threshold for referral to further ophthalmologic evaluation (ETDRS level > or =35). RESULTS: There was highly significant agreement (kappa = 0.97, P =.0001) between the degree of retinopathy detected by a single nonmydriatic monochromatic digital photograph and that seen in seven standard 35-mm color stereoscopic mydriatic fields. The sensitivity of digital photography compared with color photography was 78%, with a specificity of 86%. Agreement was poor (kappa = 0.40, P =.0001) between mydriatic ophthalmoscopy and the seven-field standard 35-mm color photographs. Sensitivity of ophthalmoscopy compared with color photography was 34%, with a specificity of 100%. CONCLUSION: A single nonmydriatic monochromatic wide-field digital photograph of the disk and macula was more sensitive for diabetic retinopathy screening than mydriatic ophthalmoscopy, the currently accepted screening method. When adjudicated by standard seven-field color photographs, the higher sensitivity of digital photography primarily reflected the reduced sensitivity of ophthalmoscopy in detecting early retinopathy.
PURPOSE: To compare disc measurements obtained by indirect ophthalmoscopy, the Heidelberg Retina Tomograph (HRT), stereoscopic slide viewing (SSV) of color transparencies, and the Topcon ImageNet System (ImageNet). DESIGN: Population-based cross-sectional study. METHODS: From the Rotterdam Study, 324 subjects (567 eyes) were nonselectively included. All underwent a full ophthalmologic examination in mydriasis. Vertical cup/disc ratios (VCDRs) were compared between all four methods and disc area (mm(2)), neural rim area (mm(2)), cup area (mm(2)), and cup volume (mm(3)) between HRT and ImageNet. RESULTS: Mean VCDR for ophthalmoscopy was 0.25 (standard error [SE], 0.007), for HRT 0.42 (SE, 0.008), for SSV 0.39 (SE, 0.010), and for ImageNet 0.50 (SE, 0.006). The correlation for VCDR between ophthalmoscopy, the two devices, and SSV was 0.42, respectively 0.57; between ImageNet and HRT 0.75. The 97.5th percentiles of the VCDR for ophthalmoscopy, HRT, SSV, and ImageNet were 0.80, 0.73, 0.80, and 0.73, respectively; the 99.5th percentiles thus were 0.90, 0.79, 0.86, and 0.79. The mean disc area, rim area, cup area, and cup volume were 2.08, 1.63, 0.45 mm(2) and 0.09 mm(3) for HRT, and 2.39, 1.77, 0.61 mm(2) and 0.16 mm(3) for ImageNet, respectively. The corresponding correlations for these four parameters were 0.67, 0.42, 0.81, and 0.82. CONCLUSIONS: Different techniques lead to considerable differences in disc morphometric values. ImageNet produced higher mean values compared with HRT and ophthalmoscopy. Ophthalmoscopy showed the lowest correlations and SSV the highest ones with the two semiautomated devices. Between ImageNet and HRT the correlation for all parameters was high except for the neural rim area.
AIMS: To identify whether after performing retinal photography, direct ophthalmoscopy can improve the yield of screening for the detection of sight-threatening diabetic eye disease (STDED). METHODS: Patients (n = 408) who had previously received both dilated direct ophthalmoscopy by a diabetologist and retinal photography graded by a diabetologist within 3 months of each other were included. The results of the other screening modality were not available to the grader/screener. The first 308 patients were consecutive attendees at the clinic who fulfilled the study criteria and 100 were selected because they were identified as having potential STDED by either one of these modalities. An ophthalmologist using slit lamp biomicroscopy then examined patients identified with potential STDED. RESULTS: In 357 (88%) patients there was agreement between the two modalities about whether referral to an ophthalmologist was required (kappa 0.62). Retinal photography identified 38 patients for referral to ophthalmology which ophthalmoscopy missed. Of these, the ophthalmologist agreed that STDED was present in 32 (84%) and four patients required early laser. Ophthalmoscopy identified 13 patients for referral who were not identified by photography. Of these, the ophthalmologist agreed with the diabetologist that STDED was present in seven (54%) and one patient required early laser. CONCLUSION: Ophthalmoscopy may identify the occasional patient with diabetes who has STDED which is missed by retinal photography. For a systematic retinal screening programme, adding ophthalmoscopy to retinal photography will increase false-positive referrals and is likely to detect only a few extra patients requiring laser.
OBJECTIVE: To determine whether non-mydriatic Polaroid retinal photography was comparable to ophthalmoscopy with mydriasis in routine clinic screening for early, treatable diabetic retinopathy. DESIGN: Prospective study of ophthalmoscopic findings according to retinal camera screening and ophthalmoscopy and outcome of referral to ophthalmologist. SETTING: Outpatient diabetic clinics of three teaching hospitals and three district general hospitals. PATIENTS: 2159 Adults selected randomly from the diabetic clinics, excluding only those registered as blind or those in wheelchairs and unable to enter the screening vehicle. MAIN OUTCOME MEASURES: Numbers of patients and eyes correctly identified by each technique as requiring referral with potentially treatable retinopathy (new vessel formation and maculopathy) and congruence in numbers of microaneurysms, haemorrhages, and exudates reported. RESULTS: Camera screening missed two cases of new vessel formation and did not identify a further 12 but indicated a need for referral. Ophthalmoscopy missed five cases of new vessel formation and indicated a need for referral in another four for other reasons. Maculopathy was reported in 147 eyes with camera screening alone and 95 eyes by ophthalmoscopy only (chi 2 = 11.2; p less than 0.001), in 66 and 29 of which respectively maculopathy was subsequently confirmed. Overall, 38 eyes received laser treatment for maculopathy after detection by camera screening compared with 17 after ophthalmoscopic detection (chi 2 = 8.0; p less than 0.01). Camera screening underestimated numbers of microaneurysms (chi 2 = 12.9; p less than 0.001) and haemorrhages (chi 2 = 7.4; p less than 0.01) and ophthalmoscopy underestimated hard exudates (chi 2 = 48.2; p less than 0.001). CONCLUSIONS: Non-mydriatic Polaroid retinal photography is at least as good as ophthalmoscopy with mydriasis in routine diabetic clinics in identifying new vessel formation and absence of retinopathy and is significantly better in detecting exudative maculopathy.
This is a prospective study to compare the effectiveness of non-mydriatic photography with that of direct ophthalmoscopy in screening for diabetic retinopathy in 153 patients attending a hospital clinic in Hong Kong. Retinal photography under physiological mydriasis and direct ophthalmoscopy of patients with dilated pupils were compared with the ophthalmologists' examination results as a reference standard. The prevalence of diabetic retinopathy in this sample population was 15%. The sensitivity of detecting diabetic retinopathy by retinal photography was higher than that of direct ophthalmoscopy (64% versus 41%; 95% confidence interval of difference, 1.2%- 44.3%). Of five patients who had serious retinopathy, retinal photography failed to detect the disease in two; direct ophthalmoscopy failed to detect the disease in all five patients. Specificities of retinal photography and direct ophthalmoscopy were 90% (95% confidence interval, 84%-96%) and 93% (95% confidence interval, 88%-97%), respectively. We conclude that retinal photography is significantly more effective than direct ophthalmoscopy in detecting diabetic retinopathy. In addition, the non-mydriatic camera is easy to use and is the preferred method of screening.
In order to assess the relative ability of general practitioners (GPs) to detect diabetic retinopathy (DR), especially sight-threatening diabetic retinopathy (STDR) by direct ophthalmoscopy or by examining, on a separate occasion, retinal images as 35 mm colour transparencies, a South and Mid Wales primary care-based study was performed in four general practices (six GPs). The participating GPs were provided with standardized training and equipment. Both methods were compared to the 'reference' grade of DR provided by the Diabetic Retinopathy Reading Centre (London), based on the same retinal images. Ophthalmoscopy and retinal photography (Canon CR4 45NM) with mydriasis were all practice based. The clinical assessments were based on a protocol developed for screening for DR in Europe. A total of 996 people with diabetes were identified, representing a prevalence of known diabetes of 2.1%. After exclusions on medical grounds, 897 patients were available for screening, of whom 605 (68%) were photographed. Based on the retinal images, the reference centre identified DR in 43% and STDR in 14.4%. In total, 597 valid comparisons between GPs and the reference centre were obtained; of these, 462 (77%) were high quality photographs which were used in subsequent analysis. The sensitivity for detecting any DR increased from 62.6% (95% CI 55.9-69.4) with ophthalmoscopy to 79.2% (95% CI 73.6-84.9) using retinal photographs, specificity remaining essentially unchanged at 75.0 (95% CI 69.5-80.5) and 73.5% (95% CI 68.0-79.1) with the positive predictive value (PPV) increasing from 67.2 (95% CI 60.4-74.0) to 71.0% (95% CI 65.0-77.0), respectively. The detection of STDR sensitivity increased from 65.7 (95% CI 54.4-77.1) with ophthalmoscopy alone to 87.3% (95% CI 79.4-95.2) based on retinal photographs with specificity falling from 93.8 (95% CI 91.4-96.3) to 84.8% (95% CI 81.2-88.5) and PPV from 65.7 (95% CI 54.4-77.1) to 51.2% (95% CI 42.1-60.3), respectively. We conclude that the use of standardized 35 mm colour transparency retinal photographs for screening by trained GPs in a primary care setting achieves an acceptable detection rate (>87%) for STDR, contrasting with ophthalmoscopy alone (66%), which was below the proposed UK standard of 80%.
Diabetic retinopathy was assessed in a population-based study of 2708 diabetic persons in southern Wisconsin. The retinopathy levels as determined by ophthalmoscopy and by the grading of stereoscopic fundus photographs were compared in the eyes of 1949 persons. Ophthalmoscopy was performed by an ophthalmologist and a specially trained optometrist and ophthalmic technician. Consultation among the three examiners was permitted. There was exact agreement between ophthalmoscopy and grading for detecting retinopathy (none, nonproliferative, proliferative) 85.7% of the time. The kappa statistic, which corrects for chance agreement, was 0.749. There were no significant differences among the three ophthalmoscopists. Ophthalmoscopy was more likely to disagree with fundus photography grading in eyes with less severe forms of retinopathy and in patients examined early in the study. Other factors found to influence the degree of agreement were age, visual acuity, and duration of diabetes. It is concluded that with proper training ophthalmoscopy can be an acceptable alternative to fundus photography in certain situations.
PURPOSE: To compare fundus photography with ophthalmoscopy in the detection of diabetic retinopathy. METHODS: Ophthalmoscopy and fundus photographs with a nonmydriatic camera, both performed through dilated pupils, were compared to diagnose retinopathy in a cohort of 410 Oklahoma Indians with noninsulin-dependent diabetes mellitus. A total of 795 eyes were examined using both methods. The mean age of participants was 60.3 years, with a mean duration of diabetes of 17.3 years. RESULTS: An overall agreement of 86.3% with a kappa statistic kappa of 0.74 was found between ophthalmoscopy and fundus photography with a nonmydriatic camera. For the diagnosis of proliferative diabetic retinopathy, kappa = 0.84 with an agreement of 98.1%. With a total of 61 cases of proliferative retinopathy diagnosed by either method in our study, ophthalmoscopy alone detected 88.5% and fundus photography, 78.7%. When compared on a lesion-by-lesion basis, agreement between the two diagnostic methods was highest for nonproliferative retinopathy, as well as fibrous proliferation. CONCLUSION: The fundus photography with a nonmydriatic camera, performed with mydriasis, is comparable to ophthalmoscopy for the detection of retinopathy. It may prove to be a suitable, cost-effective method for routine screening in diabetes clinics, provided ophthalmologic referral is ensured for those with a diagnosis of any form of retinopathy, questionable retinopathy, nondiabetic retinopathy, those with poor quality photographs, as well as those with acute changes in visual acuity.
OBJECTIVE: To evaluate different methods for community based screening for sight threatening diabetic eye disease. DESIGN: Prospective study. SETTING: Mobile screening unit visiting inner city community clinics; hospital assessment clinic (tertiary centre). SUBJECTS: 395 diabetic patients registered with four general practices in an inner city location. INTERVENTIONS: Community based photography with mydriasis and direct ophthalmoscopy through dilated pupils by an experienced ophthalmologist, both compared with reference standard of slit lamp biomicroscopy by a consultant specialist in medical retinal disease. MAIN OUTCOME MEASURES: Sensitivity and specificity of screening method and prevalence of sight threatening diabetic eye disease (moderate preproliferative retinopathy, circinate maculopathy, exudate within 1 disc diameter of fixation, other diabetes related eye disease). RESULTS: 358 subjects underwent photography, 326 attended hospital clinic for ophthalmoscopy, and six were ungradable on photographs and biomicroscopy, leaving 320 for analysis. Of these 295 (91%) attended clinic within four months of photography. Sensitivity of detection of eye disease by photography was 89% (95% confidence interval 80% to 98%), significantly better than for direct ophthalmoscopy (65% (51% to 79%)). Analysis of patients with false negative results indicated possible improvement of photographic sensitivity to 93% by addition of stereoscopic macular pair photographs. Specificity of detection of sight threatening eye disease was 86% (82% to 90%) for photography and 97% (95% to 99%) for direct ophthalmoscopy. CONCLUSIONS: Since high sensitivity is essential for an effective screening programme, a photographic method should be considered as preferred option in national, community based screening programmes. Even in the hands of an experienced ophthalmologist, direct ophthalmoscopy is limited by weaknesses inherent to the instrument.
UNLABELLED: Our objective was to assess junior house officer (JHO) practice of visual acuity testing and ophthalmoscopy in clerking patients. DESIGN: Cross-sectional questionnaire-based study using a standardised structured interview technique. SETTING: A Scottish university teaching hospital employing 65 JHOs. PARTICIPANTS: All medical and surgical JHOs from this hospital were interviewed over a three month period. MAIN OUTCOME MEASURES: Questionnaire-based data on the subjective responses studying current practice of visual acuity testing, and direct ophthalmoscopy with and without topical mydriatics. RESULTS: 18.5% and 4.6% of participants perform daily ophthalmoscopy and visual acuity testing respectively. Most do not routinely use the Snellen chart (80.0%) or topical mydriatics during ophthalmoscopy (75.4%). JHOs claimed these were not easily available in the wards. CONCLUSIONS: The majority of JHOs fail to test visual acuity or perform ophthalmoscopy in clerking patients. This study highlights the poor availability of Snellen charts, functioning ophthalmoscopes, and topical mydriatics in the wards. This warrants further investigation.
Ophthalmoscopy is an essential part of a complete clinical examination of a patient. However specific formal instruction in fundoscopy is rarely given to medical students. We decided to determine the value of explicit teaching of ophthalmoscopy and devised and validated a rating scale for assessing performance which was used to evaluate 29 first year clinical medical student volunteers at St. Bartholomew's Hospital Medical College, before and after formal instruction in fundoscopy. The competence of this group at ophthalmoscopy was then compared to the rest of their year (109 medical students) during the objective structured clinical end-of-year examination. Students formally instructed in ophthalmoscopy showed an improved score after instruction (from 53% to 77%). They also performed better at fundoscopy than the rest of their year (mean average score 64%), when tested 2 months later, suggesting persistence of the training effect. However as a group they performed no better than their peers at clinical skills other than ophthalmoscopy. We suggest that as fundoscopy is such an important clinical skill, medical students should be given specific teaching, preferably in their ophthalmology firm attachment, as we have shown that it results in a persistent improvement in performance.
Beside dyslipoproteinemia, one of the key risk factors for the onset of brain atherosclerosis, as well as ischemic brain disease (IBD) is arterial hypertension. Significant number of patients is not aware of their hypertension, and a paradoxical blood pressure decrease can occur at the onset of IBD, due to the failure of autoregulation mechanisms. Likewise, valid anamnestic data can not frequently be obtained due to difficulties in communication with patients. Regarding these facts, our hypothesis was that ophthalmoscopy in patients with IBD had the greatest sensitivity in the diagnosis of hypertensive disease, its duration and severity. For that reason, the purpose of this study was to determine the significance of ocular fundus examination in those patients with IBD who were not aware of their hypertension, or the high blood pressure was not registered at the admission. Study comprised 140 IBD patients selected upon the following criteria: ophthalmoscopy was performed by the same ophthalmologist, and IBD was diagnosed according to clinical criteria and by brain computerized tomography. Results of the study demonstrated that 26 (18.6%) patients, although not aware of having hypertensive disease, had grade I hypertonic fundus, 14 (10%) had grade II, and 8 (5.5%) had grade III hypertonic fundus, which indicated the high sensitivity of ophthalmoscopy in the diagnosis of hypertensive disease, as well as its duration and severity. This is particularly important in patients with negative history of hypertension, and also suggests the significance of routine ophthalmoscopy in normotensive patients.
The Welsh Community Diabetic Retinopathy Study was designed to assess the effectiveness of the Field Guide Book for screening for diabetic retinopathy in Europe. A community-based sample (prevalence 2%) of diabetic patients was recruited from four general practices. Standardised training and equipment were provided. All patients were invited to attend practice-based screening sessions on two occasions over 3 years (phases 1 and 2). After mydriasis, clinical ophthalmoscopy was performed by a study optometrist and general practitioners (GPs). 2 x 45 field 35 mm retinal slides were obtained according to EURODIAB protocol. Anonymised slides were assessed by GPs, diabetologists and the optometrist. All the findings were graded externally (reference standard). In phase 2 community optometrists also performed ophthalmoscopy and assessed photographs. For detecting sight threatening diabetic retinopathy using ophthalmoscopy, GPs achieved a sensitivity of 65.7%, specificity 93.8% and positive predictive value (PPV) 65.7%. Community optometrists achieved a sensitivity of 82.2% with a PPV of 50.7%; the study optometrist 79.2 and 55.9%, respectively. The use of 35 mm slides improved sensitivity for the detection of sight threatening retinopathy to 87.3, 91.1 and 97.2% for GPs, community optometrists and the study optometrist, respectively. PPV fell to 51.2% for GPs, 40.6% for community optometrists, but increased to 58.8% for the study optometrist. Diabetologists achieved a sensitivity of 88.7% and a PPV of 65.6%. It is concluded that the European field guide is an effective tool for screening for retinopathy in clinical practice.
A panel of two physicians and two ophthalmologists examined 25 patients with untreated essential hypertension by direct ophthalmoscopy and assessment of fundal photographs; daytime ambulatory sphygmomanometric blood pressure monitoring, estimation of left ventricular mass by electrocardiography and two-dimensional echocardiography, and measurement of urinary microalbumin excretion were also carried out. No relation was found between blood pressure determined by clinic or ambulatory sphygmomanometry and retinopathy. The retinal features sought on fundal photographs were the percentages of arteriovenous crossings with venule nipping, venule deviation, or attenuation of venular light reflex. The ratio of arteriolar to venular diameter was measured. Only focal narrowing of arterioles was associated with higher blood pressure. There was no independent relation between retinal features and age, measures of left ventricular mass, or urinary microalbumin excretion. Assessment of arteriovenous crossing abnormalities by direct ophthalmoscopy was subject to wide variability among the panel members. Direct ophthalmoscopy was not clinically useful in the assessment of mild to moderate hypertension, whereas urinary microalbumin excretion correlated strongly with clinic blood pressure.