Hannu I. Alanko

OPTIC DISC HAEMORRHAGES PRECEDE RETINAL NERVE FIBRE LAYER DEFECTS IN OCULAR HYPERTENSION

Both small splinter haemorrhages of the optic disc and retinal nerve fibre layer (RNFL) defects have been reported to be the first signs of glaucomatous development before visual field defects. In this study their time‐ and location‐based relationship to each other was investigated by means of repeated optic disc stereophotography of 25 patients who showed a disc haemorrhage but no disc and field involvement in their ocular hypertensive eyes. During a mean follow‐up time of 6 years, 8 patients developed glaucomatous damage. Their sequential stereo‐photographs showed that disc haemorrhages preceded both development and progression of RNFL defects. Location of a defect was accurately predicted by the haemorrhage. In 4 patients the first visual field defects were detected with routine perimetry only 1 to 2 years after the RNFL defects had been observed. Three patients still show normal fields.

PREVALENCE OF EXFOLIATION SYNDROME IN FINLAND

Abstract. Three separate investigations are reported, covering a total of 795 patients from different parts of Finland, two of them consisting of inmates of old peoples 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 ≤69 years, 21.9% in age group 70–79 and 34.7% in age group ≥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.

Pars plana vitrectomy in the management of intraocular inflammation.

To evaluate the role of pars plana vitrectomy in the management of intraocular inflammation with dense vitreous opacification, vitrectomy was performed in 14 patients with chronic uveitis, 6 eyes with retinal periphlebitis, and in 8 cases of endophthalmitis. Visual acuity improved in 21 eyes, remained unchanged in 3, and deteriorated in 4 cases (follow‐up period 2 months to 3 years). Pre‐existing retinal damage such as cystoid macular oedema or degeneration restricted final visual acuity. In most eyes inflammation (aqueous flare and cells) diminished, except in hypotonic eyes with chronic iridocyclitis, which also gained little in vision. The results indicate that vitrectomy is valuable in the treatment of chronic uveitis with vitreous opacification due to cellular invasion and membrane formation, in periphlebitis with vitreous hemorrhages, and in endophthalmitis.

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

Abstract 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.

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.

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.

Lens autofluorescence in healthy individuals

Abstract. 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

Abstract. 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<0.0001) and with the neuroretinal rim area (r = 0.44; P<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

Abstract 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.

Demonstration of glaucomatous optic disc changes by electronic subtraction.

We describe a new method, the electronic subtraction, for objective, two‐dimensional detection, demonstration and recording of glaucomatous optic disc changes. Siemens subtraction unit M 707 A, based on a double videochain and originally developed for the study of roentgenograms, was used. The results show that this technique is useful in demonstrating the progressive damage of neural tissue of the disc and associated alterations in the course of the vessels. Further development of the electronic subtraction method for glaucomatous optic disc evaluation is discussed.