4ustralian Journal 01‘ Ophthn lmolo~v . ( 1980), 8, pp. 189-301

THE PREVALENCE OF CORNEAL DISEASE AND CATARACTS IN AUSTRALIAN ABORIGINES IN NORTHWESTERN AUSTRALIA

Hugh R. Taylor, M.D., F.R.A.C.O., F.R.A.C.S.. The Wilmer Opbtbalmo/og;ca/ Institute, Johns Hopkins Hospital, Ba/timore, Maryland

Summary Fifty percent of the Aborigines over the age of 30, in two settlements, were examined and the presence of anterior ocular disease was recorded. A group of urban Europeans were also examined. All of the 82 Aborigines showed signs of trachoma, eight were bilaterally blind and 15 had monocular blindness. Corneal opacities were found in 60% of Aborigines, pterygium in 44%, cataract in 32%, climatic droplet keratopathy in 18% and pseudo-exfoliation of the lens in 11 %. Only 4% of Europeans had corneal scarring and 4% had pterygium, 10% of Europeans had cataracts. Trachaoma, climatic droplet keratopathy and pseudoexfoliation were not seen in Europeans. It is postulated that much of the anterior segment disease seen in Australian Aborigines is due to environmental factors.

INTRODUCTION Corneal disease and cataract are responsible for most of the blindness found in the Australian Aborigine and also in a number of other non-industrialized groups.1 2 3 4 5

As a precise epidemiological survey of these diseases as they occur in Australian Aborigines had not been undertaken previously, this study was initiated to ‘define the prevalence of anterior segment disease, to document the age of its onset and the presence of any sexual differences, and to investigate a number of personal and environ- mental factors that may play a causative role. It was conducted during routine field work carried out by the National Trachoma and Eye Health Programme (NTEHP).

A group of Europeans was also studied so that a comparison could be made of the prevalence of anterior segment disorders in these two groups.

The Europeans were not studied as a “control” group but were examined to asses the distribution of anterior segment in urban European Australians. This data had not been available previously and is used for general comparison d y .

Methodr 1. Aborigines

Fifty percent of the Aborigines over the age of 30 years were examined in two communities in Western Australia: Warburton Range and Jigalong. These communities were chosen because both had relatively large populati’ons of full-blood Aborigines and they were considered to be representative of the many settlements in Central and Northwestern Australia.

At Warburton every second person in each age and sex group presenting to the N.T.E.H.P.

*Formerly Assistant Director, National Trachoma and Eye Health Programme Present appointment: Co-director, International Center for Epidemiologic and Preventive Ophthalmology Reprint requests: Dr Hugh R. Taylor, The Wilmer Institute, Johns Hopkins Hospital, Baltimore, MD 21205.

THE P R E V A L E N C E 01. C ’ O R N E A L D I S E A S E ANTI CATARACTS I N A U S T R A L I A N AROKIGINES 989

Figure I: Grade 2 climatic droplet keratopathy. Fine droplets lying at the level of Bowman’s membrane in the area of interpalpebral fissure extend over the central cornea. Their presence is shown by the blurring of the underlying iris details and of the phpillary margin.

Figifre 2: Grade 3 climatic dro let keratopathy with a dense accumulation of droprets and reduction of visual acuity. Clear areas or lacunae are seen centrally.

examinations was included for study. At Jigalong, at the conclusion of routine field examinations a list of people in each age and sex group was drawn up and half of these were randomly selected for inclusion in this study.

In both centers it was estimated that over 9570 of the community had been seen during the N.T.E.H.P. examinations so that 82 Aborigines of a total 167 available for inclusion in this study were examined. 2. Europeans

One hundred and seventeen Australian European adults were examined as part of an ocular screening program for the National Hypertensive Survey. These patients had been identified in 1973 as having mild asymptomatic hypertension (diastolic blood pressure of 95-105mm Hg). They had been entered into a coded control trial conducted at the Austin Hospital, Melbourne. Of the total group of 576 so selected, one-third of the patients were treated with a placebo, one-third with a diuretic alone (chlorthiazide), and one-third with a beta blocking agent (pindolol) and a diuretic (chlorthiazide). From the total group, 117 patients were selected for screening so that equal age and sex mawhed subgroups of each treatment group were created. Each patient had received antihypertensive treatment for at least two years, and apart from hypertension was otherwise well and on no other medical treatment. The patients were divided into three age groups: 33-44 years, 45-54 years, and 55-64 years.

Detailed analysis of the three treatment subgroups failed to show any difference in the tear function tests or ocular pathology, and the results of the three treatment subgroups have been combined! The group of 117 mildly hypertensive Europeans is thought to be representative of Europeans in this age group with regard to ocular pathology.

Figure 3 (left): Grade 4 climatic droplet keratopathy with extensive find droplets covering the exposed cornea. Larger golden yellow droplets are seen immediately above this band overlying the pupil (arrow). This eye also has extensive trachomatous pannus and Herbert’s pits, nuclear sclerosis, pseudoexfoliation and a small pterygium which is not

’ well-shown.

290 AUSTRALIAN J O U R N A L OF OPHTHALMOLOGY

3. Examination Detailed histories covering personal,

environmental and general features were taken for the Aborigines as previously described.3

Visual acuity was measured by the Snellen or E chart and recorded for each person. The presence and severity of signs of trachoma were graded according to the protocol of the N.T.E.H.P.3 The severity of cicatrization attributable to Trachoma was determined by using the Trachoma Scarring Index.3 Each person was examined with a slit- lamp, and dilated fundal examination was performed.

Any abnormality of the cornea was described and recorded. An attempt was made to define the cause of each abnormal finding. Pathology was coded according to the international classification of disease using the 5-digit code.7

Corneal opacities were graded according to severity, using grades 1, 2 and 3 to correspond to mild, moderate and severe opacities. The extend of pterygia was recorded in millimeters.

The grading of clunatic droplet keratopathy was: 1 - peripheral changes present, 2 - changes across the pupillary axis, 3 - changes leading to a decrease in visual acuity, 4 - the presence of nodules (Figures 1-3).8

The severity of lens opacities was graded according to the degree of reduction of visual acuity . attributable to those opacities: grade 1, visual acuity correctable to 6/6; grade 2, visual acuity correctable to better than 6/60 but less than 61’6; grade 3, visual acuity correctable to 6/60 or less.

The data were coded on specially prepared clinical sheets and transferred to computer tape. The computer analysis was conducted on the Unix time-sharing PDP 1145 computer at the Johns Hopkins Hospital. The test of statistical significance used throughout was the chi-square test.

Results An obvious difference in the frequency and occurrence of all forms of corneal disease and cataracts in the two groups is readily apparent (Table 1).

Every Aborigine showed some signs of

Figure 4: Caruncular hypertroph and arcus senilis seen in a middle-aged aborigina? male. Both these changes are found commonly in older Aborigines.

trachoma, whereas no signs of trachoma were found in any Europeans.

Two of the 82 Aborigines had each lost an eye following trauma. In one person the eye was phthisical and in the other it had been enucleated. Eight Aborigines had binocular blindness (visual acuity of 6/60 or less), and a further 15 had monocular blindness. One case of traumatic optic atrophy was seen. Of the 11 Aborigines over the age of 60 with monocular blindness, five had visual acuity reduced to 6/24 or less in the fellow eye. None of the 15 aboriginal females over the age of 60 had acuity of 6/6 bilaterally, and only four of the 18 males in this age group could see 6/6 with each eye. There were no cases of binocular or monocular blindness in the Europeans.

Two interesting findings were noted to be common in Aborigines, especially in the elderly. The caruncles often appeared hyperplastic, hyperpigmented and keratinized, although no cause for this has been found and no symptoms appeared to result from it (Figure 4). Normally in Aborigines the iris is a dark and velvety brown, the pigmentation extending uniformly to the pupillary margin and obliterating details of iris vasculature. Often in elderly Aborigines there is a patchy atrophy of the iris which shows as grey-white areas between the pupillary margin and the collarette.

As mentioned, every Aborigine showed signs of trachoma, whereas none was seen in the Europeans. In terms of the Trachoma Scarring

THE PREVALENCE OF CORNEAL DISEASE A N D CATARACTS IN AUSTRALIAN ABORIGINES 29 I

Index, females as a group had more severe trachoma than males (P = 0.0 15) (Table 2) . Severe trachoma was seen more commonly in the elderly than the young (P ( 0.01).

I . Corneal Scarring Overall, 49 (or 60%) of the 82 Aborigines had

corneal opacities other than trachomatous pinnus (Table 1). No definite tendency was found for corneal opacities to occur more often in a particular age or sex group of Aborigines. Only 5 (or 4%) of the 117 Europeans had corneal opacities: they were more common in males.

The. types and causes of the corneal opacities found are shown in Tables 3 and 4. Because of the small numbers involved, these data for Europeans have been consolidated and are not given for each age and sex group. In the aborigines, 29 of the cases of opacity were either peripheral or minor:

and there were 2 adherent leukomata (Figure 8). It was impossible to determine the cause of the

opacity in eight people. In the remainder, infection was considered the cause in 18; five of these were considered to be due to phlyctenular disease. Twenty-three cases were due to trauma. One

TABLE 2 Severity of trachoma as determined by the Scarring Index ' and also the presence of trichiasis in 82

Aborigines, given by age and sex.

Age 30-44 45-59 2 60 Sex M F M F M F

Trachoma Scarring Index

Mild 12 9 7 2 7 3 Severe 5 4 4 6 11' 12

Trichiasis I 0 0 0 3* I Number Examined 17 13 11 8 18 15

however, 9 were dense central opacities (Figures 5 and 6), a further 9 were vascularized (Figure 7),

* Two elderly ma,es had ..end-stage trachoma,. causing blindness.

TABLE 1 The occurrence of anterior segment pathology in 82 Aborigines and

I17 Europeans presented by age and sex

Aborigines Europeans

Age Group (yrs) 30-44 45-59 2 60 35-44 45-54 55-65 Sex M F M F M F M F M F M F

Number Examined 17 Number Without 4

Pathology (Trachoma Excluded)*

End-stage Trachoma -

Non-trachomatous 13 Corneal Scarring

Keratopathy Climatic Droplet 1

Pterygium 4 Senile Cataract 1 Traumatic Cataract Lens Subluxation Pseudoexfoliation -

Enucleation-Phthisis -

Monocular Blindness 1 Binocular Blindness -

Optic Atrophy -

13 I I 8 18 15 21 13 22 21 22 18 6 - - I 1 21 13 20 19 14 1 1

~~

* Every Aborigine showed signs of trachomd.

291 AUSTRALIAN JOURNAL OF OPHTHALMOLOGY

Figure 5: Extensive corneal scarring and ectasia of unknown cause in an elderly aboriginal female.

Fir. fo lowing 7:

Figure 6: An extensively scarred cornea with elevated secondary olden droplet formation (shown by heightened &ht reflexes.) These nodules occur as a secondary phenomenon to the underlying ocular patholog and should be differentiated from climatic droplet %eratopathy which occurs as a primary phenomenon.

-~ - ~~- - Extensive vascularized corneal opacities

blunt trauma in an elderly aboriginal male. Figure 8 A superior adherent leukoma from a previous perforating corneal ulcer in an elderly aboriginal female

TABLE 3 Details of type of corneal scarring (excluding trachomatous pannus) found in

82 Aborigines and 117 Europeans

Aborigines Europeans

Age 30-44 45-59 2 60 All Ages Sex Male Female Male Female Male ,Female Male Female

Minor or Peripheral 6 4 5 7 4 3 4 1 ~ - - Central 4 1 - 2 2

4 Vascularized 2 2 Leukoma Adherens - - - - - Total 12 6 6 8 6 I 1 4 1 Number Examined 17 13 11 8 18 15 65 52

~ - - 1 -

- 1 - -

THE PREVALENCE OF CORNEAL DISEASE A N D CATARACTS IN AUSTRALIAN ABORIGINES 293

TABLE 4

Causes of corneal scarring (excluding trachomatous pannus) in 82 Aborigines and 117 Europeans

Aborigines Europeans

Age 30-44 45-59 2 60 All Ages Sex Male Female Male Female Male Female Total

Infection Trauma Blunt Sharp Foreign Body Burn Unknown Total with Corneal

Scarring No. examined

13 17

4

-

2

13 6 6 11

8 8

6 10 49 5 18 15 82 117

TABLE 5

Laterality and size of pterygium by sex and age in 82 Aborigines and 117 Europeans

Aborigines Europeans

Age 30-44 45-59 2 60 35-44 45-54 55-65 Sex M F M F M F M F M F M F

Bilateral 4 2 5 4 7 3 - - - - - 2 Unilateral - 1 3 - 2 5 - - I - I 1 Size of Pterygium (mm)

I 2 3 4 1 4 7 - - 1 - 1 2 2 2 - 2 1 3 - - - - - - 1

- - , - 2 1 - - - - 3 4 - 2 - I l - - - -

- - -

- - -

Total with Pterygium 4 3 8 4 9 8 0 0 1 0 1 3 Number Examined 17 13 1 1 8 18 15 21 11 22 21 22 18

elderly female who had had bums to the lid of one eye had symblepharon, associated with a vascularized corneal scar. While the seventy of corneal scamng was related to the seventy of cicatrization caused by trachoma (Trachoma Scamng Index) this association was not statistically significant (P = 0.15). The opacities found in the Europeans were all minor or peripheral. Four were from foreign bodies and one from marginal kera tit is. 2. Pteiygium and Climatic Droplet Keratopathy

Thirty-six (44%) of the Aborigines had pterygium (Figure 9). The lesions were equally

common in males and females, although they tended to occur in older age groups (P = 0.03). Five (4%) of Europeans had pterygium, and again it occurred more frequently in the older people (Table 1).

In 25 of the 36 Aborigines with pterygium the pterygium occurred bilaterally (Table 5). Bilateral pterygia were found in two of the five Europeans affected. In the Aborigines the pterygia were larger than in the Europeans. Larger pterygia were also seen more commonly in the older age groups.

Thirteen aboriginal males and two aboriginal females had climatic droplet keratopathy, and it

994 AUSTRALIAN JOURNAL OF OPHTHALMOLOGY

TABLE 6 Distribution and severity of climatic droplet

keratopathy in 82 Aborigines

Age 30-44 45-49 2 60 Sex M F M F M F

Climatic Droplet Keratopathy Grade: I - - 2 - 3 1

1 1 1 - 3 1 4 - I11 - - - - - -

Total with Keratopathy I 0 5 I 7 1 No. examined 17 13 I 1 8 18 15

was more common in the older age groups. The sex difference was significant (P = 0.008). No Europeans had clunatic droplet keratopathy (Table 1).

No clear trend for increasing severity of climatic droplet keratopathy with increasing age was apparent (Table 6). Thirteen of the 15 Aborigines with climatic droplet keratopathy had the condition bilaterally. One of the two with unilateral disease had had the fellow eye enucleated .

Among the 82 Aborigines, 23 men had worked as stockmen. Six of these stated they had worked for less than 20 years (range 1-15, mean 8.8 k 4.9). None of these men had climatic droplet keratopathy. Fourteen stated they had worked for 20 years or more (range 20-30, mean 27.6 2 3.6). Eleven (65%) of those men who had worked as

TABLE 7 The occurrence of climatic droplet Keratopathy and

pterygium alone or together in 82 Aborigines

Climatic Droplet

Age Keratopathy (Years) Sex Alone

30-44 Male 0 Female 0

45-59 Male I Female 0

2 6 0 Male 5 Female 1

Pterygium Both Alone Together

3 1 3 0 4 4 3 1 7 2 8 0

Total 7 28 8

Figure 9: A large Reshy nasal pterygium extending 4mm onto the cornea of a middle-aged aboriginal male.

stockmen for more than 20 years had clunatic droplet keratopathy. The only people with climatic droplet keratopathy who had not worked as stockmen were the two women; one aged 61 had worked for 10 years in a laundry. The other, aged 51, had done housework for 15 years.

Eight people had both climatic droplet keratopathy and pterygia (Table 7). All had bilateral keratopathy and six of the eight had bilateral pterygia. This finding was more common in younger people. There was not a significant correlation of these diseases occurring together when analyzed by the number of people with either condition. However, when eyes having these conditions were analyzed, a trend for climatic droplet keratopathy and pterygia to occur together was seen (P = 0.14) (Table 8).

TABLE 8 The occurrence of pterygium and climatic droplet

keratopathy in 82 Aborigines

Pterygium Present Absent Total

Climatic Present 8( 14)" 7( 14) 15(28) Droplet Keratopathy

Absent 28(47) 39(87) 67( 134)

Total 36(61) 46(101) 82(162) xz test people p = 0.42 xz test eyes p = 0.14

* Figures in bracket5 refer to the number of eyes. Two eyes had been enucleated or were phthisical.

THE PREVALENCE OF C O R N E A L DISEASE A N D CATARACTS I N AUSTRALIAN ABORIGINES 295

Figure 10: A mature cataract in an elderly aboriginal female whose vision was reduced to light perception.

3. Cataract and Pseudoexfoliation Twenty-five (3ocTo) of Aborigines had lens

opacities, whereas only in 12 (10%) of Europeans were lens opacities seen (Table 1). In both races lens opacities were seen equally in both sexes and were significantly more common in those over the age of 60 (P < 0.001).

The type and severity of the lens opacities found are shown in Table 9. None of those found in Europeans reduced correctable acuity to less than 6/6. Eighteen Aborigines had vision reduced by

cataract to less than 6/6, but better than 6/60. A further seven Aborigines had visual acuity of 6/60 or less, the loss of vision being attributable to the cataract (Figure 10). AU the cataracts occurring in Europeans were

bilateral. The aboriginal male aged between 3045 with co@ical opacities had these unilaterally. The three traumatic cataracts were unilateral, although two occumng in elderly males were associated with nuclehr sclerosis in the fellow eye. One elderly female had nuclear sclerosis in one eye, the other lens being clear. Another two elderly females had nuclear sclerosis in one eye with dense scamng of the fellow cornea, so that assessment of the other lens could not be made. One elderly male had a mature cataract in one eye, and the fellow eye had been enucleated. Three Aborigines had mature lens opacities. In two cases they were unilateral, with the fellow eye being phthisical in one and having nuclear sclerosis in the other. The third had bilateral mature lens opacities; one of the lenses was subluxed. Two people had hypermature cataracts in one eye and nuclear sclerosis in the other. In all other cases the cataracts found in Aborigines were bilateral and of the same type.

Four subluxed lenses were found in three aboriginal males and one aboriginal female. Three

TABLE 9 Type and severity of cataracts in 82 Aborigines and 117 Europeans

Aborigines Europeans ~ . ~~ -

Age Group (yrs) 30-44 45-59 2 60 35-44 45-54 55-65 Sex M F M F M F M F M F M F

Cataract Type/Severity Cortical 1 1

2 - 3 -

Nuclear I - Sclerosis 2 -

3 - Mature 3 - Hypermature 3 -

Traumatic 1 - 2 - 3 -

Total with Cataract 1 0 3 0 1 1 9 0 0 0 2 5 5 No. Examined 17 13 1 1 8 18 15 21 13 22 21 22 18

+ Blunt trauma * Sharp trauma

296 AUSTRALIAN JOURNAL OF OPHTHALMOLOGY

of these wex mature cataracts and the subluxation was thought to be spontaneous. The fourth was a traumatic cataract and the subluxation was presumed to be from trauma.

Pseudoexfoliation was found in nine Aborigines (Table 1 and Figure 11). Eight had lens opacities; one was cortical, five nuclear, two mature. Both of the mature cataracts were subluxed. Eight of the nine Aborigines with pseudoexfobation were over the age of 60. None of these people had associated glaucoma.

4. Demographv oJ A+origines examined All the Aborigines examined were of full

aboriginal blood. Comparison of each of the age and sex groups showed that there was not a difference in tribal representation or of the site of residence between these different groups.

The number of Aborigines who had worked (in the European sense) declined with increasing age, although the type of occupation was similar for members within each sex (Table 10). A marked difference in the occupations recorded for the two sexes were found, as would be expected. Apart from the finding of climatic droplet keratopathy in stockmen occupation was not significantly associated with the presence of anterior segment disease.

Many more of the younger Aborigines considered themselves to be drinkers (Table 11). Heavy drinkers were more common in the males than in the females. Ten of 17 young males

TABLE 10 The Types of Occupation Undertaken by

82 Aborigines Shown by Age and Sex

Age Group 30-44 45-59 2 60 Sex M F M F M F ~

Occupation None Stockman Stationhand Laborer Housework Welfare Mining Storekeeper

2 6 - 3 9 1 3 9 - 8 - 6 - 2 - - - 3 - 4 - 2 - - -

- 6 - 3 - 2 - 2 ' - -

- 1 - - -

- 1 - - - -

- -

-

Total 17 13 1 1 8 18 15

Figure f f I Pseudoexfoliation occurring in an elderly Aborigine with a heavy deposition of pseudo- exfoliation material on the pupillary margin. Peripapillary iris atrophy is also present. This atrophy is not uncommon in elderly Aborigines and the loss of iris pigment around the pupil exposes the underlying gre iris stroma. These two conditions occur indepeniently .

considered themselves to be, or to have been, heavy drinkers, and only one was a non-drinker. Alcohol use was not associated with a higher prevalence of anterior segment disease.

No difference in the reported occurrence of previous ocular trauma was seen between each age and sex group.

TABLE 11

Alcohol Consumption for 82 Aborigines Shown by Age and Sex

Age group 30-44 45-59 2 60 Sex M F M F M F

Alcohol consumption

Nil 1 7 2 5 1 2 1 3 Mild 6 6 3 1 3 1 Heavy 10 0 6 2 3 I

Total 17 13 I 1 8 18 15

DISCUSSION 1. Validity of Samples

The samphg technique used was intended to include 50% of the Aborigines over the age of 30 years in two communities. 98% of those chosen for study were examined. The group was thought to be truly representative of the aboriginal

THE PREVALENCE OF CORNEAL DISEASE A N D CATARACTS I N AUSTRALIAN ABORIGINES 297

population. The Europeans examined came from a selected group of patients in that they had attended a hypertensive screening programme and had been found to be mildly hypertensive. They had then been enrolled in a prospective trial and had remained in the study for two, and in some cases nearly three years. From this cohort the present study group was randomly selected. For these reasons, the Europeans studied are not representative of the general population, but there is no reason to suppose that these attributes would affect ' their ocular status. They are, therefore, considered to represent the ocular pathology that would be found in the general European population.

Some difficulty in comparing the results of these two groups arises as different age groupings were used. The age grouping in the Europeans had been predetermined by the study in which they were enrolled. It had been hoped to use similar groups with the Aborigines. However, as a clustering of ages was noted in the Aborigines and it was frequently impossible to learn the exact age of elderly Aborigines, an alternative age grouping had to be used. The age of 60 has particular importance for older Aborigines, because this is the age at which a person becomes eligible to receive a government old-age pension. As the eligibility to receive a pension is investigated by government agencies, the receipt of an elderly pension is reasonable indication that the recipient is aged 60 years or more. The aboriginal group also included those over the age of 65, whereas no Europeans over this age were included. This inclusion of an older group of Aborigines will result in a bias of age related conditions when the oldest group of each race are compared. 2. Generul Compurisons

Aborigines differed markedly from Europeans in most of the ocular parameters. Every Aborigine showed signs of trachoma whereas none of the Europeans did. Eight Aborigines had bilateral blindness and 15 had monocular blindness, whereas none of the Europeans were blind. Two Aborigines had lost an eye following trauma. Sixty percent of the Aborigines had corneal opacities not directly attributable to trachoma, whereas only 4% of Europeans had corneal opacities. (In a group of

'98

older Europeans in the U.S.A. Leibowitz, et al, found that 12% of males and 7% of females had corneal opacities).* Forty-four percent of Aborigines had pterygium, as compared with only 4% of Europeans. Thirty-two percent of Aborigines had cataract, as compared with 10% of Europeans. Pseudoexfoliation was found in 11% of Aborigines and in none of the Europeans.

The environment in which the Aborigines lived is much harsher than that in which the European group lived (Table 12).10 11 12 13 For each age and sex group of Aborigines the distribution of meteorological parameters was similar. However, as many of the parameters were not uniformly distributed, the range and median values have been presented in Table 12. The data given for the Europeans are those for Melbourne. Without exception, the Aborigines lived in areas with a longer daily exposure to sun, higher global radiation, ultraviolet radiation, temperature and evaporation rates, lower humidity and lower rainfall. Most Europeans spend most of the day

TABLE 12

Environmental Variables for Aborigines and Europeans

Aborigines Europeans Range Median

Latitude (degree) 21-31 Longitude (degree) 119- 128 Median Annual

Rainfall (mm) 168-912 Average Daily Hours

of Sunshine 7.5-9.5 Average Daily Global

Radiation (mWh cm-2)

Annual 550-650 Mean Daily Maximum

Temperature ("C)

Annual 25.3-35.3

January 400-600 Annual 1,400-4.000

Humidity (a) Januar 24-44 Annua? 30-56

Daily Total Global Erythema1 Dose of UV Radiation January 3,500-4.500 Annual 2,000-3,000

January 750-850

January 33.6-40.8

Evaporation (mm)

Mean Daily Relative

26 125

234

9.5

850 600

38.2 30.7

600 4,000

29 33

4,000 2,500

37 145

734

6.0

650 400

26.0 19.5

165 1,000

61 73

3,000 1.000

AUSTRALIAN JOURNAL OF OPHTHALMOLOGY

protected from the environment while Aborigines usually live unprotected from their harsher environment.

Attention has been drawn to the serious problems alcohol is causing in rural fringe- d w e h g Aborigines.14 While the techniques and definitions used in the present study in more remote settlements are not as precise as those used by Kamien, the findings in this study are in remarkable agreement with his. Table 13 compares the findings of the alcohol consumption of aboriginal males and females of all ages obtained in this study with those obtained by Kamien.14 Kamien’s definition of heavy usage was the consumption of more than 80 G. of alcohol three or more times a week. The only area of disparity between the two studies is the higher number of males who claimed to be nondrinkers that were found in the present study. The difference may be explained by the differences between those living in fringe camps and settlements.

No attempt was made to document the alcohol consumption of the Europeans, although it has been shown by Reynolds, et al, that their intake is less than the Aborigines (Table 13).15

2, Specific Comparisons Although corneal opacities were infrequently

seen and were of a trivial nature in Europeans, they were a frequent problem in Aborigines. Twenty, or 24%, of Aborigines had severe corneal

TABLE 13

Comparison of the alcohol consumption of aboriginal males and females determined by this study and that found in Aborigines by Kamien (1975) and in Europeans by Reynolds, et al(1976),15

shown as a percentage of each group.

Male Female Abor- Euro- Abor- Euro- igines peans igines peans

Alcohol Con- Tay- Kam- Rey- Tay- Kam- Rey- sumDtion lor ien nolds lor ien nolds None 32.6 0.7 13.3 69.4 71.0 47.3 Mild 26.1 46.1 71.0 22.2 25.9 50.0 Heavy 41.3 53.2 15.7 8.3 3.1 2.7

scarring in the form of central or vascular scars or leukomata adherens. This type of corneal scarring is frequently attributed to trachoma.16 A further two people were blinded by trachoma. Unless there was irrefutable evidence that corneal scarring was due to trachoma (i.e., gross scarring of the superior tarsal conjunctiva and trichiasis), we did not assume that trachoma was the cause of the corneal scarring. However, 13 of the 20 Aborigines with severe corneal scarring had severe trachomatous change, whereas 13 of 29 with minimal or minor scamng also had severe trachoma. Although this difference was not statistically significant (Xz, p = 0.15), it should be remembered that even with relatively minor conjunctival scarring and distortion of the tarsal plate, the effective protective role of the conjunctiva is reduced, so that minor ocular trauma or infection is more likely to progress to significant structural damage and resultant corneal ~carring.~718 In a larger series the severity of trachoma scarring was significantly related to “non-trachomatous” corneal scarring19

The high incidence of ocular trauma is noteworthy. In 22 of the 49 corneal opacities, trauma was considered to be the initiating factor. Often this was “minor” ocular trauma which went unattended and led to “major” sequelae. Two eyes were also lost as a result of trauma. Three traumatic cataracts were seen, and there was one case of traumatic optic atrophy. The much higher prevalence of pterygium and cataract in Aborigines is also noteworthy, as is the finding of climatic droplet keratopathy.

Climatic droplet keratopathy is shown to be clearly related to occupation, as was reported by McGuinness, et a1.20 There is a strong correlation with having worked as a stockman for more than 20 years and the appearance of climatic droplet keratopathy. The high prevalence of pseudoexfoliation of the lens in Aborigines and the infrequent association of glaucoma has been reported previously.21 Our earlier report, however, dealt mainly with members of the Pitjantatjara tribe living in South Australia and the southern part of the Northern Temtory, whereas in the present study members of two different tribal groups in Western Australia were examined. No

THE PREVALENCE OF CORNEAL DISEASE A N D CATARACTS IN AUSTRALIAN ABORIGINES ‘99

evidence was found to suggest a “tribal” distribution. 3 . Comparison With Other Reports

The high incidence of trachoma in Australian Aborigines has been reported pre- viously.12 18 22 23 24 25 A high prevalence of corneal opacities had been suggested by earlier reports dealing with sporadic cases.2627 It is worth noting that a high prevalence of corneal disease has persisted over the 30 years from the Schneider report to the present study, and that corneal opacities are still seen often in the young Aborigines. The aetiological factors are also similar to those reported 30 years ago. However, in this study scarring attributed to phlyctenular disease was noted in 6% of people, whereas Mann had considered phlyctenular disease to be rare.28 The reason for this difference is not known. Phlyctenular keratitis is also seen commonly in Eskimos and has been attributed to tuberculosis,29 30 which is common in both Aborigines and Eskimos.

Although clunatic droplet keratopathy was not mentioned by Mann, its presence in Aborigines has been noted by McGuinness, et a1,20 and Taylor, et a1.21 The present study is the first to present the prevalence for this condition in Australian Aborigines.

Mann also considered cataracts an infrequent finding in Australian Aborigines.31 The findings present here would indicate that not only are cataracts (especially nuclear sclerosis) found frequently in Aborigines, but they also occur more often and at a younger age than in Europeans.

The difference in the frequency of finding climatic droplet keratopathy, pseudoexfoliation, and cataracts as between the studies conducted by Mann and the present study is probably related to the use of careful slit-lamp examination. Professor Mann did not have the use of slit-lamp facilities, although (once recognized) the changes of clunatic droplet keratopathy are fairly easily seen with magnifying loupes, as indeed is gross pseudoexfoliation.

The prevalence of corneal scarring, pterygium, and cataracts found in Australian Aborigines are much higher than that reported in Papua and New Guinea,32 33 Solomon Islanders,% Eskimos,m and

300

Xavante Indians.35 An increase in corneal disease with increasing age, as is seen in Eskim0s,2~ was not found in our study. Another marked difference between the Eskunos and the Aborigines, of course, is the absence of trachoma among Eslumos, as noted previously by Mann.36

Eskimos are an interesting group to compare with Australian Aborigines as both groups have been long isolated, nomadic and non- industrialized. Both are now experiencing cultural invasion and disruption of traditional lifestyles. The health of the Eskimos has been better documented than it has for most other similar groups.

Ocular trauma was a much more significant cause of corneal scarring in the Aborigines than has been reported for Eskimos,29 although the importance of ocular trauma among Canadian Indians30 is similar to our findings. The reduced prevalence among Eskimos may be related to the absence of trees and sticks in the Arctic. Although both groups are at risk from unattended minor ocular trauma of any cause, Wyatt considered that much of the ocular trauma in Eskimos was related to the overuse of alcohol, which may well be the case in the Aborigines. Bettman also considered that most of the severe ocular trauma seen in the American Indians was alcohol-related.37

The absence of congenital cataract in Aborigines contrasts with the findings in Eskimos29 and follows the findings of Mann. There is some similarity in the overall picture of eye disease to that found by Freedman in the Nama people in Southwest Africa.5 38 Although only two of the 680 people he examined had trachoma, he found climatic droplet keratopathy and cataracts occurred frequently. He also reported several cases of phthisis.

Overall, this study differs from previous reports of ocular disease in Australian Aborigines because it was an epidemiological survey based on a representative study group drawn from the adult population, and it employed careful history-taking and slit-lamp examination. The findings for anterior-segment disease contrast strongly with those seen in a group of urban Europeans.

The author thanks members of the National Trachoma and Eye Health Program for their

AUSTRALIAN JOURNAL OF OPHTHALMOLOGY

support and is indebted to all members of the communities that were visited for their cooperation. Assistance was also received from Professor F. C. Hollows and Professor G. W. Crock.

The National Trachoma and Eye Health Programme is sponsored by the Royal Australian College of Ophthalmologists and funded by the Commonwealth Department of Health under the provision of the National Health Insurance Act. The author also received support from the Felton Bequest, the Potter Foundation and the University of Melbourne (Hugh Noel Puckle Fellowship and the Sir Thomas Naghten Fitzgerald Scholarship). References

I . Mann, I . : Ophthalmic survey of the Kimberley division of Western Australia. William H. Wyatt, Government Printer, Perth, 1954.

2. Mann, 1.: Ophthalmic survey of the Eastern Goldfields Area of Western Australia. William H. Wyatt, Government Printer, Perth, 1954.

3. Taylor, H. R.: The causes and distribution of blindness in Australian Aborigines, Med. J. Aust. (submitted).

4. Chakrabarti, J., Garg, A. C. and Siddhu, C. M. S.: Prevalence and pattern of blindness in the field practice area of a rural health training center. Ind. J. Ophthalmol., 1974, 22:4.

5 . Freedman, J.: Survey of ocular disease among the Nama people of South West Africa. Br. J. Ophthalmol., 1973, 57:681.

6. Louis, W. J . and Taylor, H. R.: The ocular effects of beta blocker therap in mild h pertension (in preparation).

7. International rounci l of 6Vphthalmology: Classification of disorders of the eye. Fie d Trial Edition, 1975.

8. Johnson, G. J., Ghosh, M.: Labrador keratopathy: Clinical and pathological findings. Can. J. Ophthalmol., 1975, 10: 119.

9. Leibowitz, H. W., Kini, M. M., Nickerson, R. S., Pool, J., Colton, T.. Ganley, J. P. and Dawber, T. R.: The Framin ham eye stud Corneal abnormalities. Arch. Ophthafmol. Suppl., lq79 (in press).

10. Department of Science, Bureau of Meteorology: Global radiation, climatic atlas of Australia, map set 2. Australian Government Publishing Service, Canberra, 1975.

1 1 . Department of Science, Bureau of Meteorology: Evaporation, climatic atlas of Australia, map set 3. Australian Government Publishing Service, Canberra, 1975.

12. Department of Science and Consumer Atfairs, Bureau of Meteorology: Climatic averages Australia. Australian Government Publishing Service, Canberra, 1975.

13. Paltridge, G. W. and Barton, I . J.: Erythema1 ultraviolet radiation distribution over Australia ~ the calculations, detailed results and input data including fre uenc analysis of observed Australian cloud cover. &SIR8 Division of Atmospheric Physics Technical Paper, 1979 (in press).

14. Kamien, M.: Aborigines and alcohol: Intake, effects and social implications in a rural community in Western New South Wales. Med. J. Aust.. 1975, 1:291.

15. Reynolds, I. , Harnas, J . , Gallagher, H. and Bryden, D.: Drinking and drug-taking patterns of 8,516 adults in Sydney. Med. J. Aust., 1976, 2:782.

16. Hosni, F. A,: Clinical aspects of corneal trachoma. Br. J. Ophthalmol., 1978, 62: 159.

17. Dawson, C. R., Daghfous, T., Messadi, M., Hoshiwara, I. and Schachter, J.: Severe endemic trachoma in Tunisia. Br. J. Ophthalmol., 1976, 60:245.

18. Hollows, F. C.: The national trachoma and eye health program. Aust. J. Ophthalmol., 1977, 5:151.

19. Taylor, H. R.. Vision of Australian Aborigines. M.D. Thesis submitted to University of Melbourne, 1978.

20. McGuinness, R., Hollows, F. C., Tibbs, J . and Campbell, D.: Labrador keratopathy in Australia. Med. J . Aust., 1972, 2: 1249.

2 I . Tafylor, H. R., Hollows, F. C. and Moran, D. M.: Pseudo- ex oliation of the lens in Australian Aborigines. Br. J. Ophthalmol., 1977, 61:473.

22. Mann, 1.: Ophthalmic survey of the South-West portion of Western Australia. William H. Wyatt, Government Printer, Perth, 1956.

23. Mann, I.: Report of ophthalmic findings in Warburton Ran e natives of Central Australia. Med. J. Aust., 1957, 2:618.

24. Moore, M. C., Howarth, W. H., Wilson, K . J., Derrington, A. W. and Surman, P. G.: Clinical and laboratory assessment of trachoma in South Australia. Med. J . Aust., 1965, 2:441.

25. Taylor, H. R.: Blindness in Australian Aborigines. Aust. J. 0 hthalmol , 1977, 5: 155.

26. Blacg, E. C. and Cleland, J. B.: Pathological lesions in Australian Aborigines, in Central Australia (Granites) and Flinders Range. J. Trop. Med. Hy iene, 1938,41:69.

27. Schneider, M.: A sociological study o!the Abori ines in the Northern Territory and their eye diseases. h e d . J. Aust., 1946, 1:99.

28. Mann, 1.: Geogra hic ophthalmology: A report on a recent survey o r Australian Aborigines. Am. J. Ophthalmol., 1968, 66: 1020.

29. Wyatt, H. T.: Abnormalities of cornea, lens and retina: Survey findings. Can. J. Ophthalmol., 1973, 8:291.

30. Cass, E.: Ocular conditions amon st the Canadian Western Arctic Eskimo. Excerpta d e d . Int. Congress Series, No. 146, Proceedings of XX Int. Congress of Ophthal., 1966, p 1041.

3 I . Mann, 1.: Culture, race, climate and eye disease. Charles C. Thomas, Springfield, Ill. , 1966, p 464.

32. Vines, A. P.: An epidemiological sample survey of the Highlands, Mainland and Island Regions of the Territory of Papua and New Guinea, Dept. Public Health, Govt. Printer, Port Moresb

33. Mann, I . and Loschdorfer, J.: 0 htkdmic survey of the Territories of Papua and New 8uinea . W. S. Nicholas, Government Printer, Port Moresby, 1955.

34. Verlee, D. L.: 0 hthalmic survey in the Solomon Islands. Am. J. OpEthalmol., 1968, 66:304.

35. Neel, J. V., Salzano, F. M., Junqueria, P. C., Keiter, F. and Maybury-Lewis, D.: Studies on the Xavante Indians of the Brazilian Mato Grosso. Am. J . Hum. Genet., 1964, 16:52.

36. Mann, I.: Eye disease in the Eskimo and in the Australian Aborigines: A brief comparison. Acta Ophthalmol., (Kbh), 1972, 501543.

: Eye disease among American Indians of I . Overall analysis. Arch. Ophthalmol.,

1972, 88:263. 38. Freedman, J.: Nama keratopathy, Br. J. Ophthalmol.,

1973, 57:688.

1967, p 422.

THE PREVALENCE OF CORNEAL DISEASE A N D CATARACTS IN AUSTRALIAN ABORIGINES 30 1