The application of teleophthalmology in examining patients with glaucoma: a pilot study.

PURPOSE: To test the feasibility of teleophthalmology applications in examining patients with glaucoma, test its use for training purposes in an ophthalmology residency program and as a consultation link between primary healthcare unit and university eye clinic, and to introduce a preliminary model for economic assessment of telemedicine application in ophthalmology. METHODS: A video slit-lamp, an automated perimeter, a nonmydriatic fundus camera and a videoconferencing system were installed in a healthcare center in a rural area. Twenty-nine patients with glaucoma were examined in the rural healthcare center instead of the university eye clinic. A control group consisted of 41 glaucoma patients examined at the eye clinic one year earlier. An ophthalmic resident examined the patients together with the local general practitioner. An interactive video consultation was created with the university glaucoma clinic using ISDN connections and special application software. RESULTS: Both patient groups were equally satisfied with the ophthalmic service. Nearly all patients in the telemedicine group (96%) wanted to have their next visit in their own healthcare center instead of the university clinic. The most important reasons were reduction in traveling (97%), costs (92%), and time (92%). The costs of the telemedicine and conventional visits were equal, but decreased traveling saved $55 per visit. However, the quality of the images obtained in the remote center was poorer than that of the images obtained at the university clinic. CONCLUSION: The results of this pilot study indicate that further research with a larger number of patients is warranted to evaluate both methods, technology, and economics of teleophthalmology.

Interobserver variation in the measurements of peripapillary atrophy in glaucoma.

PURPOSE: The purpose of this retrospective study is to compare the measurements of intrapapillary and peripapillary parameters between two observers and test the usefulness of measuring different types of crescents. METHODS: Optic disc photographs of 23 eyes of 23 patients with glaucoma and 23 age-matched normal eyes were measured in Oulu and in Erlangen using manual planimetric techniques. The authors measured the following magnification corrected intrapapillary and peripapillary areas: optic disc, neuroretinal rim, cup: disc area ratio, scleral ring, central (zone beta), and peripheral peripapillary atrophy (zone alpha). Twenty-one patients with glaucoma had a follow-up of 3.2 years (range, 1.1-4.7 years), and follow-up for 19 control eyes was 3.7 years (range, 2.5-5.9 years). The measurements were performed in a masked fashion for the diagnosis and temporal sequence of the photographs. RESULTS: Central peripapillary atrophy (zone beta) was statistically significantly largest in primary open-angle glaucoma in both centers (Oulu, P=0.003; Erlangen, P=0.004), whereas normal and exfoliative eyes did not differ significantly from each other. The results for peripheral peripapillary atrophy (zone alpha) and scleral ring were less consistent. Despite statistically significant interobserver correlations ranging from r=0.30 (scleral ring area; P=0.0472) to r=0.97 (optic disc area; P=0.0001), the means of all parameters, except for zone alpha and beta, differed statistically significantly between the two observers. CONCLUSIONS: The central peripapillary atrophy, or zone beta, is the most reproducible parameter when measuring peripapillary atrophy in glaucoma. Nonetheless, its measurement is of limited usefulness in the recognition of glaucoma or progression of glaucomatous nerve damage.

Neuroretinal rim area measurements by configuration and by pallor in ocular hypertension and glaucoma.

PURPOSE: The purpose of this study is to examine the differences between measurements of neuroretinal rim area of the optic disc defined by configuration and by pallor. METHODS: One hundred seventy-one patients were studied (59 with glaucoma, 96 ocular hypertensive patients, and 16 controls). The magnification-corrected neuroretinal rim area was measured from black-and-white stereoscopic paper prints. The central area of pallor was measured using computer-assisted image analysis techniques. The percentage of central area of pallor was converted into mm2, and an estimate of neuroretinal rim area defined by color was calculated. RESULTS: The correlation between the measurements of neuroretinal rim area by configuration and by pallor was statistically highly significant (r = 0.89, P less than 0.0001). No consistent differences between measurements were found in different diagnostic groups, or in different stages or types of glaucomatous optic disc abnormality. The correlation of changes of both measurements during a 9-year follow-up period also was statistically significant (r = 0.68, P less than 0.001). CONCLUSION: In clinical routine measurements of the neuroretinal rim area, using both configuration and pallor definition does not seem to add to the information.

Rate and pattern of neuroretinal rim area decrease in ocular hypertension and glaucoma.

The neuroretinal rim areas of 123 eyes (from five normal subjects, 75 patients with ocular hypertension, and 43 patients with glaucoma) were measured to determine the rate and pattern of rim area change during 5 to 15 years (mean, 10 years) of follow-up. Fifty-seven percent of the patients with ocular hypertension and 79% of those with glaucoma showed a statistically significant slope of rim area decrease, a high rate of loss being associated with a high initial rim area. Ninety percent of the variation of rim area loss was accounted for by variables other than the ones measured herein, however (age, disc area, initial rim area, and intraocular pressure). The yearly loss of rim area was 0.23% of the initial area in normal subjects, 0.47% and 2.75% in the patients with stable and deteriorating ocular hypertension, respectively, and 3.47% in the patients with deteriorating glaucoma. The pattern of rim area change was linear in 49% of the patients with a statistically significant rim area decrease, episodic in 22%, and curvilinear in 29%.

Neuroretinal rim area in low tension glaucoma: effect of nifedipine and acetazolamide compared to no treatment.

The purpose of this study was to measure the change of neuroretinal rim area in patients with low tension glaucoma on- and off-treatment. Thirty-two patients were followed up for a mean of 2.6 years. Ten patients received treatment with nifedipine, 11 patients with acetazolamide and 11 patients had no treatment. The total change of rim area and the yearly rate of rim area change did not differ statistically significantly between the three groups. Seven patients in each group suffered from cold hands and feet. The response to cold provocation visual field testing was positive in 25% of patients. Neither the history of cold hands and feet nor the cold provocation test result affected the rate of progression of optic disc abnormalities. Nifedipine and acetazolamide treatment seemed to show no advantage over no-treatment in our patients.

Lens autofluorescence in healthy individuals.

We measured blue-green autofluorescence (AF, 495 nm/520 nm) of the lens in 43 random eyes of 43 healthy volunteers aged 6-86 years, five in each decade, using an instrument designed by one of us (HN). The instrument generates an autofluorescence profile, which consists of anterior and posterior juxtacortical peaks and a central plateau. The height of the anterior peak was taken as a maximum autofluorescence value and the square root of the ratio between the posterior and the anterior peak was used as a lens transmission index. The coefficient of variation for the measurement technique was 3.9% for maximum autofluorescence and 2.9% for lens transmission index. Both the maximum autofluorescence and the transmission index were highly correlated with age. Statistically over 90% of the variation in maximum autofluorescence values and almost 70% of the variation in transmission could be attributed to age.

Retinal nerve fiber layer abnormalities and high-pass resolution perimetry.

The purpose of this study was to compare high-pass resolution perimetry (HRP) test results with clinical optic disc measurements and semi-quantitative retinal nerve fiber layer (RNFL) estimates. HRP reflects the separation of functional ganglion cells in the retina, and estimates a 'Functional Channel Fraction (FCF)' index that expresses the number of functional ganglion cells relative to average normal. FCF was statistically highly significantly correlated both with the overall and diffuse RNFL score (r = -0.63, P less than 0.0001) and with the neuroretinal rim area (r = 0.44; P less than 0.001). This suggests that HRP is a useful psychophysical test to assess optic nerve integrity in glaucoma.

Laser trabeculoplasty versus medication treatment as primary therapy for glaucoma.

The first-year results of a 5-year prospective randomized follow-up study on 39 glaucoma patients, of whom 19 patients received laser trabeculoplasty and 20 patients medication therapy as primary treatment of their newly detected open-angle glaucoma, are presented. The optic disc changes were recorded by measuring the magnification corrected neuroretinal rim area from stereoscopic optic disc photographs and the visual field changes with an automated perimeter. There were no statistically significant differences in success rate, intraocular pressure reduction, and optic disc or visual field changes between the two groups during the first year of follow-up. In half of the laser treated patients the intraocular pressure was below 22 mmHg without medication treatment. Many patients in the medication group required frequent modifications of their therapy. Laser trabeculoplasty has an important role as primary therapy in glaucoma.

Prevalence of exfoliation syndrome in Finland.

Three separate investigations are reported, covering a total of 795 patients from different parts of Finland, two of them consisting of inmates of old people's homes in two towns (N = 205 and 262) and one a randomly selected population from a rural commune (N = 328). They show the mean prevalence of exfoliation syndrome (PS) to be 14.2% in age group 60 less than or equal to 69 years, 21.9% in age group 70-79 and 34.7% in age group greater than or equal to 80. The prevalence increases statistically significantly with age. The mean prevalence of PS in all three groups was 22.4%. No isolate-like accumulation of PS could be demonstrated. The figures seem representative of the hole country.

A controlled five-year follow-up study of laser trabeculoplasty as primary therapy for open-angle glaucoma.

We followed up 32 eyes of 32 patients with early glaucoma (22 with capsular glaucoma and ten with simple glaucoma) who received laser trabeculoplasty as a primary therapy. These eyes were compared with a matched control group of 32 eyes treated with medication initially. The success rate (intraocular pressure below 22 mm Hg with laser alone or medication alone) at five years was 50% (16 of 32 eyes) in the laser-treated group and 22% (seven of 32 eyes) in the control group (P less than .02). The control group required more modifications of their therapy to control intraocular pressure. The neuroretinal rim area in the control eyes decreased 2.5 times as much as in the laser group (P = .017). Changes in the Friedmann visual fields did not differ significantly between the two groups.

Characteristics of corneal endothelial cells in Fuchs' heterochromic cyclitis.

We studied the corneal endothelial cells in 14 patients (6 men and 8 women, ranging in age from 15 to 70 years) with unilateral Fuchs' heterochromic cyclitis (FHC) by means of specular microscopy. The healthy fellow eyes of the patients served as control material. Two affected eyes had undergone an intracapsular cataract extraction before specular microscopy. In one patient, the cyclitic eye also had glaucoma. Changes of the endothelium characterized by intra- and intercellular dark bodies, larger dark defects spanning several endothelial cells and bright irregular patchy areas crossing cell borders on the specular reflex were found in all eyes with FHC. Individual cell analysis did not reveal any significant differences in the endothelial cell density, cell area, coefficient of variation for cell area, cell perimeter, cell shape and in the number of endothelial cell apices between unoperated cyclitic and healthy fellow eyes. The mean cell density was 4.9% lower in the unoperated eyes with FHC than in the control eyes. A significant negative correlation was observed between the patients' age and the cell density both in the healthy and the cyclitic eyes. On the other hand, the correlation between follow-up period and cell density was not statistically significant in the cyclitic eyes. Although FHC does not seem to accelerate significantly the age-related cell density reduction, the magnitude of the cell loss found in the two operated eyes (45.5% and 49.8%) and in the eye with glaucoma (45.2%) may indicate altered tolerance against endothelial traumas in this disease.

Dislocated intraocular lens after biodegradation of fixation loops. A case report.

A boy aged 3 years had a Worst Medallion intraocular lens with loops made of nylon 6 implanted in his right eye after aspiration of traumatic cataract. Post-operatively, the eye was irritated and showed increased tendency to secondary membrane formation. The patient was lost to follow-up 3 months post-operatively. He returned 5 years later because of 4 days of pain and redness in his right eye. On examination, the optic part of the intraocular lens was seen to lie free in the anterior chamber. The loops were broken near their insertions in the lens body. The distal ends of the broken loops could not be detected in the pupillary region. No traces of the iris fixation suture were to be seen. The lens was removed and subjected to scanning electron microscopy which revealed extensive biodegradative changes in the 3 loop stumps, the 4th being totally dissolved. The young age of the patient and the chronic inflammation may have had an accelerating effect on the nylon degradation. We conclude that children with eyes implanted with nylon-loop lenses should stay under regular ophthalmological control.

Clinical electro-oculography.

Electro-oculography (EOG), a retinal function test, indirectly records slow, light-induced changes in the potential difference between the anterior and posterior poles of the eye. EOG is a valuable clinical tool in diagnosis of tapetoretinal degenerations, vitelliform foveal dystrophy including the carriers of this disease, retinal intoxications and in differential diagnosis of choroidal malignant melanomas. EOG is not an alternative to electroretinography but yields additional information on the function of the retinal pigment epithelium. The main drawback of the present technique is the high inter- and intraindividual variability of the results.

Effects of topical timolol on corneal endothelial cell morphology in vivo.

To determine the effect of topical timolol on corneal endothelial cell morphology in a randomized, controlled, double-masked study of 40 healthy human eyes, we photographed the central corneal endothelium with a contact specular microscope before and after two weeks of treatment with placebo (20 eyes), with 0.5% timolol with 0.01% benzalkonium chloride (ten eyes), or with 0.5% timolol without benzalkonium chloride (ten eyes). From the specular photomicrographs, we analyzed five morphologic cell characteristics by means of electronic digitizer and microcomputer--cell density, mean cell area, the coefficient of variation for cell area, mean cell perimeter and a new feature quantifying cell shape. Statistical analysis of the data showed that two weeks of exposure to topical timolol or its preservative had no significant effect on corneal endothelial cell morphology in young, healthy eyes in vivo.

Vascular effects of timolol and pilocarpine in the iris. A simultaneous bilateral fluorescein angiographic study.

Simultaneous bilateral fluorescein angiography of the iris vessels (SIFA) was performed on 2 groups of patients. One group comprised previously untreated patients with elevated intraocular pressure who underwent a SIFA both before and after a 3 days' timolol treatment in one eye and pilocarpine treatment in the other eye. The other group consisted of glaucomatous patients treated with timolol for 4 to 24 (mean 11) months before the angiography. Short- or long-term use of timolol neither caused, increased nor decreased leak of the dye from the iris vessels, either at the pupillary border, or in other areas of the iris. Dynamics of the blood flow also remained unaffected. Short-term use of pilocarpine increased extrapupillary focal leakage in one eye.

Microcomputer analysis for corneal endothelial cell morphology.

A method for individual endothelial cell analysis using modern microcomputer hardware and the program package "ENDO", developed specially for this purpose, is described. To determine the areas and perimeters of individual cells the coordinates of cell apices are recorded directly from specular photomicrographs with a manual digitizer. To digitize 100 cells with this method takes an average of 16 min. A new parameter for cell shape, called hexadev and derived from cell areas and perimeters, is introduced. The shapes of the individual cells are compared with the shape of an equilateral hexagon and the deviations from this reference shape are expressed in percentage. In addition, the program calculates 6 other morphological parameters for the cell sample analyzed. Accuracy and repeatability of the method are presented, Current status of individual cell analysis and previous attempts to describe cell shape are discussed.

Effect of retinal nerve fibre loss on the optic nerve head configuration in early glaucoma.

Twenty-nine ocular hypertensive patients with an optic disc haemorrhage, normal optic discs and normal visual fields were followed in this partly retrospective study by means of sequential optic disc stereophotographs and retinal nerve fibre layer (RNFL) photographs for a period of up to 14 years (mean 5.2). During this time early structural glaucoma damage developed in 11 patients (12 eyes). RNFL photographs revealed a nerve fibre loss in 10 of the 12 cases (83%). However, even accurate cup to disc ratio measurements from disc stereophotographs enlarged 20 times showed a measurable increase of horizontal and vertical cup to disc ratios in only 33% and 42% of the pathological cases, respectively. This result indicates that haemorrhage-associated RNFL defects precede measurable changes of the optic disc configuration. Therefore, RNFL photography seems to be a useful and sensitive examination method for the detection of the earliest organic damage in glaucoma.

Pseudoinflammatory fundus dystrophy with autosomal recessive inheritance.

A family in southwest Finland with bilateral hemorrhagic degeneration of the retina and choroid was followed up for more than 16 years. The maculas showed subretinal hemorrhages, glial cicatrization of the outer retinal layers, and profound choroidal atrophy, particularly in the advanced stages of the disease. Fluorescein angiography demonstrated leakage through the pigment layer in the retinal tissue. The age of onset varied from the second to the fourth decade. The clinical pattern was similar to Sorsby's pseudoinflammatory dominant fundus dystrophy, except that the disorder appeared earlier in this Finnish family, the members of which show secondary dyschromatopsia, many deep hyaloid bodies in the retina, disturbed dark adaptation (1 to 4 log units), subnormal light-peak/dark-trough ratios, progressive myopia, and a mode of inheritance which is probably autosomal recessive. The affected parents are consanguineous in many ways and each of their eight children is affected.

Sensitivity of the electronic subtraction method in evaluation of simulated optic disc changes.

Electronic subtraction method can be used in evaluation of glaucomatous optic disc changes from sequential fundus photographs. To determine the resolving power of the subtraction method, minute changes in the diameter of the model optic cup of known dimensions were simulated by changing the magnification, i.e. the refraction, of an artificial test eye. The results show that with an overall magnification of 40 times a two-dimensional change of 25 micrometer or more in the optic disc can be detected with the electronic subtraction in optimal conditions. A larger magnification could improve the sensitivity, but at present it is restricted by unlinearity in the imaging system.

Changes in optic disc drusen. Demonstration by stereophotographs and electronic subtraction.

As a part of more comprehensive examination of 180 patients with optic disc drusen, fundus photographs of 159 cases were evaluated. There were 70 patients whose optic discs were photographed two or more times during the years from 1967 to 1981. Four patients were selected to present the changes which can take place in optic discs with drusen and the alterations are demonstrated by autofluorescence pictures, stereophotographs, and electronic subtraction method.