Ocular diseases and blindness in elderly Thais.

The prevalence of ocular disease and blindness in 2,092 Thai subjects, aged 60 years and over, in 33 communities in the vicinity of Siriraj Hospital, Bangkok was studied. The subjects were examined by a team which consisted of 3-4 ophthalmologists, 6 nurses and a trainee health officer. The history, visual acuity and ocular tension were recorded. The anterior and posterior segments of the eye were assessed by using a portable slit lamp biomicroscope, and a direct and indirect ophthalmoscope. The examination revealed disease of the lens in 1656 cases (79.16%), cornea 852 cases (40.72%), lid 516 cases (24.67%), conjunctiva 462 cases (22.08%), retina 300 cases (14.34%), glaucoma 128 cases (6.12%) and of the optic nerve in 39 cases (1.86%) respectively. There were 66 cases of blindness (3.15%) and 743 cases of low vision (35.5%). The causes of blindness were cataract, glaucoma, late age-related maculopathy, optic atrophy and corneal opacity.

Lens thickness in early cataract.

The measurement of lens thickness by the 3M Digiecho III was carried out in 82 patients with early cataract (41 male, 41 female) from 1st January to 31 December 1988. There was the total of 100 eyes of 46 males and 54 females included in this study. The average lens thickness in patients with early cataract was 4.24 + 0.62 mm, ranging from 5.5 mm to 2.92 mm. It was also found that in comparison with the normal lens thickness it decreased with advanced age.

Normal intraocular pressure.

A study of the intraocular pressure on 1,000 apparently normal eyes, from 668 women (66.8%) and 332 men (33.2%) in whose ages ranged from 14 to 81 years (mean age = 50.16 years) revealed the mean intraocular pressure of 15.16 + 3.11 mmHg with the highest range at 21.38 mmHg. The maximum pressure among subjects in the 50-59 years age-group was 22.26 mmHg. In women the mean intraocular pressure was 15.04 + 3.07 mmHg, and in men 15.38 + 3.18 mmHg. The maximum intraocular pressure among women aged 40-49 years was 21.64 mmHg, while among men aged 50-59 years was 23.24 mmHg.

Effect of pupillary dilation on intraocular pressure.

A prospective study of the effect of papillary dilation on intraocular pressure was carried out in the Outpatient Section, Department of Ophthalmology, Siriraj Hospital. There were a total 100 cases, 43 male (43%), 57 female (57%) with a total of 200 eyes. Ages ranged from 15-81 years, mean 56.13 years. The mean of the intraocular pressure before papillary dilation was equal to = 15.42 + 2.87 mm Hg, while the mean of the intraocular pressure after papillary dilation was = 16.07 + 2.94 mm Hg. There was no change in the intraocular pressure in 48 eyes (24%). In the increased intraocular pressure group, a range of 2.0-3.9 mm Hg was found in 43 eyes (53.09) and a range of 2.0-3.9 mm Hg, in 14 eyes (29.17%). The change in intraocular pressure after papillary dilation was statistically significant (p < 0.001).

Malignant melanoma of the choroid.

Two cases of the malignant melanoma of the choroids were revealed from the in-patient section, Department of Ophthalmology, Siriraj Hospital, from 1978 to 1986. This is a rare disease and frequently found in the white patient rather than in the black. The first case was male and the second case was female. The age was 35 and 33 years respectively one of them came from the Northern province. The presenting symptom was the same (blurring of vision about 2 months). On the eye examination, found secondary retinal detachment from the underlying intraocular tumour both of them. Enucleation was done in both cases. The pathologic whole eye section was confirmed microscopically the malignant melanoma of the choroids with secondary retinal detachment.