A glaucoma survey was carried out in Malta and Gozo. Using non-contact pulseair tonometer, 2245 participants selected on a random basis, aged 40 years and above, were examined and 3.29% were found to have glaucoma. Among them 1.69% were newly detected glaucoma cases. The main risk factors were diabetes mellitus in the personal past history and glaucoma in the family history. Age was confirmed to be a risk factor, but arterial hypertension and myopia could not be proved as risk factors. About 4000 glaucoma cases were estimated to be present in Malta and Gozo at the time of the survey. Some other ocular conditions were also found in relatively high percentages: cataract -3.3%, myopic maculopathy -2.9% and diabetic retinopathy -1.5%.peer-reviewe

Agius Muscat, Hugo

Blagojevic, Milan

Cachia, John

Soler, Richard

English

OAR@UM

Maltese Medical Journal 20 Volume IV Issue I 1992 PREVALENCE STUDY OF GLAUCOMA IN MALTA AND GOZO DR. JOHN CACHIA, M.D., M.Sc. , P.M. O. II, Head of Community Care Services. DR. RICHARD SOLER, FR.C.S., Consultant Ophthalmologist and Head of Ophthalmic Department in St. Luke's Hospital. PROF DR. MILAN BLAGOjEVIC, M.D., DR.Sc., Consultant Ophthalmologist. DR. HUGO AGIUS MUSCAT, M.D., M.Sc., Health Services Information Unit. ABSTRACT A glaucoma survey was carried out in Malta and Gozo. Using non-contact pulseair tonometer, 2245 participants selected on a random basis, aged 40 years and above, were examined and 3.29% were found to have glaucoma. Among them 1.69% were newly de­tected glaucoma cases. The main risk factors were diabetes mellitus in the personal past history and glaucoma in the family history. Age was confirmed to be a risk factor, but arterial hyperten­sion and myopia could not be proved as risk factors. About 4000 glaucoma cases were estimated to be present in Malta and Gozo at the time of the survey. Some other ocular conditions were also found in relatively high percentages: cataract - 3.3%, myopic maculopathy - 2.9% and diabetic retinopathy - 1.5%. INTRODUCTION Glaucoma in many countries is one of the most prominent causes of visual impairment and even blindness. For this reason the early detection of glau­coma is very important for the preven­tion ofvisual invalidity. The screening of total populations cannot be realisti­cally achieved but the screening of selected groups represents an alterna­tive method for active and early detec­tion of glaucoma and can single out some risk factors, which may be im­portant for the onset of disease. In many countries glaucoma surveys were carried out and it was proved that the prevalence of glaucoma in populations is around 1 to 2% 1.2.3.4,5, 8 . Since the Maltese population has some inhererent 'risk factors' for glaucoma (eg. high prevalence of diabetes and arterial hypertension) and since the Maltese population is rapidly aging (29% are aged 35 - 60 years, and 13% are over 60 years), it was felt justified to undertake a survey to assess preva­lence. ORGANISATION AND METHODOLOGY Between 10th April and 17th June 1989, an EYE DISEASE SURVEY was car­ried out in Malta and Gozo. This sur­vey was organised by the Department of Health, Malta, with the cooperation of the World Health Organization (W.H.O.) and International Initiative Against Avoidable Disablement (I.M.P.A.C.T.). The objectives of the survey were as follows:­Maltese Medical Journal 21 Volume IV Issue I 1992 0.5 was taken as pathological. Other fundal changes like optic atrophy not 10 11 [~J13 14 15 ID7 18 19 20 21 ~3 24 25 mmHg. Orhaving glaucomatous origin; macular, less myopic or senile degeneration and dia- 1.31.5 [] 1.7 1.9 2.0 lTII2.3 2.4 2.5 2.7 2.8 [2]3.1 3.2 3.3 KiloPascal a) to estimate the prevalence of glaucoma in the population selected on a random sample basis" among those aged 40 years and above. b) to analyse the relation existing between the presence of primary glau­coma and 'risk factors', such as diabe­tes mellitus, arterial hypertension, myo­pia and familial predisposition for glau­coma. c) to evaluate the reliability and practicability of non-contact pulseair tonometer (PULSAIR - KEELER) in mass screening for glaucoma, and d) to design a contro] programme for glaucoma, incorporating active de­tection, prophylaxis and treatment. Before beginning, the survey the fol­lowing preparations had to be done:­a) a modified version of W.H.O./ P.B.L. Eye examination protocol was adapted for the objectives of the sur­vey. b) a computer data base to accept the data collected in the questionnaire was designed. c) a training course for the survey staff on the use of the non-contact tonometer. d) 3212 participants from Malta and 282 from Gozo, totalling 3494 participants, representing about 3% of the popUlation aged 40 years and above were selected at random from the elec­toral register. The examination of the partlclpants was performed in Malta between 10 April and 10 June, 1989 and in Gozo from] 2 to 17 June, 1989. It included:­a) Personal and family medical history of the main risk factors related to glaucoma, namely diabetes mellitus, glaucoma and arterial hypertension. b) Visual Activity: participants were invited to use either unaided eyes or if they had spectacles to wear them during the examination. Improvement vision using the pinhole tcchnique was also recorded. c) Fundoscopy. Cupping of over be tic retinopathy were also recorded. RESULTS AND DISCUSSION From 3494 selected persons, 64% re­sponded to the survey. Among the respondents there was no significant difference between males (46.9%) and females (53.1 %). The prevalence of females was more evident after the age of 70 years, reflecting national life ex­pectancy trends thus validating the rep­resentativeness of the surveyed sam­ple. As regards visual acuity, 52.4% of the participants did not need correcti ve spectacles, 39.2% had correct specta­cles and only 8.4% were deemed to need refractive correction on their visual acuity improved after using the pin­hole. Visual acuity was better than 6/60 in 97.4% but in 2.6% it was reduced to 3/ 60 or below and was interfering with normal activity. 0.16% of the partici­pants were blind (amaurotic). The following ocular pathology was also detected: Lens opacities prevent-GLAUCOMA SURVEY· MALTA 1989 DISTRIBUTION OF 10 P 4.289 EYES EYES I 500 450 400 350 300 250 200 150 100 68soL ~~ .I~ 5.8% 86.6% ing fundal view (3.3%), myopic macu]opathy (2.9%), diabetic retinopathy (1.5%), senile macular de­generation (0.4%), comeal opacities (0.4%), vitreous opacities (0.17%), optic atrophy (0.13%), and phthisis (0.13%). A. TONOMETRY The main objective of this survey was to detect increase in LO.P. as animpor­tant sign of glaucoma. It was therefore necessary to have practical and reli­able tonometry. The non-contact tonometer has the following advan­tages: no need for anaesthetic drops, no flourescein staining, no danger of infection and the measurement can be done quickly by appropriately trained paramedical staff 7.8. This tonometer was tested prior to the survey. In some cases dispersal of the readings from which mean lOP is cal­culated was noted to be 7mm Hg or above. It was concluded that the dis­persal of lOP measurements for four consecutive readings in the same eye Maltese Medical Journal 24 Volume IV Issue I 1992 should not be higher than 6mm Hg. As a result of this pilot study, in cases showing such high dispersal of lOP measurement, a fresh set of four meas­urements was performed during the survey, discarding the first result. The distribution of lOP taken in 4289 eyes is represented in graph l. 86.6% had lOP ranging from 12 - 22mm Hg with the highest peak situated at 16mm Hg. In 7.6%, lOP was above 22mm Hg. These eyes could not be consid­ered as normotensive and were referred for further investigations for glaucoma. Mean I.O.P. for the right eye was found to be 16.38mm Hg (SD +/- 3.60) and for the left eye 17.06mm Hg (SD +/­3.55). The difference of LO.P. between fel­low eyes in the same persons was from o - 5mm Hg in 90.9%, and from 0 ­6mm Hg in 95.1 %. All persons having a difference in mean l.O.P. between fellow eyes higher than 6mm Hg were also deemed to need further investiga­tion. B.THE RISK FACTORS The occurence of diabetes mellitus, arterial, hypertension, and glaucoma as risk factors was analysed in the past history ofthe participants, their parents and their siblings. It seems that a known family history is rather low for glaucoma (2.1 % only), higher for arte­rial hypertension (31.6%) and much higher for diabetes mellitus (44.1 %). (Table 1). In persons affected by glaucoma (74 persons), two major risks factors could be determined:­a) positive family history for glau­coma (15.5% versus 2.1% in general population) and b) positive personal history for dia­betes (24.4% versus 14% in general population) (Table 2). Aging was found to be a risk factor for glaucoma, diabetes and arterial hyper­tension (Table 3). Myopia was detected in 11.0% of all 2245 participants (Table 4) and in 10.8% of7 4 glaucomatous participants. On the other hand, glaucoma was found in 3.29% ofall 2245 participants and in 3.20% of 249 myopic participants. In this study there was no evidence that myopia represented a major risk factor for glaucoma. Meanwhile, due to low scleral rigidity and late appearance of disc cupping, there is a risk of over­looking the diagnosis of glaucoma es­pecially in high myopia. High myopia cases should be accurately investigated for glaucoma. (Table 4) C. PREVALENCE OF GLAUCOMA The main objective of this survey was to estimate the prevalance ofglaucoma. Glaucoma cases were defined as par­ticipants whose l.O.P. was over 25mm Hg, measured with pulse-air and con­firmed by applantation tonometer. The diagnosis of low tension glaucoma was Glaucomatous persons (74 cases). GENERAL POPULATION PARTICIPANTS HIST. OF FAMILY GLAUCOMA DIABETES MELLITUS ARTERIAL HYPERTENSION 2% 14% 23ck 2.1% 44.1% 31.6% Table 2 History of Glaucoma, Diabetes Mellitus and Arterial Hypertension IN PARTICIPANTS IN PARENTS AND SIBS GLAUCOMA 45 (2%) 49 (2.1%) DIAB ETES MELLITUS 316 (14%) 991 (44.1%) ARTERIAL HYPERTENSION 519 (23%) 710(31.6%) Table 1 Risk factors in the history of general population (2,245 persons) versus GLAUCOMATOUS PERSONS PARTICIPANTS HIST. OF FAMILY 100% 24.4% 28.8% 15.5% 42.2% 17.7% Positive past history in different age groups of the participants AGE OF PARTICIPANTS GLAUCOMA % 40 - 49 years 0.4 50 - 59 years 0.8 60 - 69 years 2.7 70 - 79 years 5.6 Over 80 years 7.7 All ages 2.0 Table 3 Myopia and Glaucoma Disease Myopia Glaucoma Table 4 In 2245 participants 11.0% 3.29% DIABETES ARTERIAL HYPERTENSION % 'k 3.7 15.5 11.6 25.3 20.5 27.8 27.2 25.6 28.8 28.8 14.1 23.1 In 74 glaucomatous In 249 myopic participants participants 10.8% 3.20% --------------------------------I Maltese Medical Journal 25 Volume IV Issue I 1992 confirmed by the appearance of optic disc (cupping) and visual field defects. We could record thirty six (1.60%) persons who were known and were already being treated for glaucoma and thirty eight (1.69%) new glaucoma cases were diagnosed and started on treatment. This means that for every case already known and treat~d for glaucoma, there was another new case of glaucoma which was not known prior to the survey. The prevalence of glaucoma in this survey was therefore at 3.29%. TwentytwopersonsorO.97% were classified as suspicious cases re­quiring close follow up (Table 5). Ex­trapolation of this data to the whole population would imply that the number of persons affected by glaucoma in the population aged 40 years and above in Maltese Islands should be about 4000. CONCLUSIONS 1. Glaucoma represents an important public health problem in the Maltese Islands. A prevalence rate of 3.29% is definitely higher than experience in most countries where prevalence rates of 1 to 2% were detected. 7.6% of the population had LO.P. between 23 and 25mm Hg. and these eyes require fol­low-up. 2. The non-contact tonometer was found to have many advantages, pro­vided that the dispersal of the four readings for the determination of the mean LO.P. and did not exceed 6mm Hg. 3. The most important risk factors were found to be a personal history of diabetes meIlitus combined with a he­reditary predisposition to glaucoma defined as the presence of glaucoma in parents or siblings. 4. Arterial hypertenson and myopia were not proved to be risk factors for glaucoma in this study. 5. This survey has shown that for every case already known and treated for glaucoma, there was another case of glaucoma which was previously un­known and was detected as a result of the glaucoma survey. The manage­ment ofglaucoma from the public health aspect should include the active detec­tion of glaucoma, medical treatment, operative procedures and organizedfol­low-up. Medical treatment is expen­sive and provision of free medication for glaucoma should be considered. 6. There were other ocular conditions detected in relatively high prevalence: cataract preventing fundal view was present in 3.3%, myopic maculopathy in 2.9% and diabetic retinopathy in 1.5% of the surveyed population. REFERENCES J 	 Goldmann H: Docum Ophth 1959; 13:382-386 2. 	 Leydhecker W: Docum Ophth 1959: 13:359-379 3. 	 Leydhecker W: Glaucom, Springer, Berlin 1960 4. 	 Meuller M: Kl Mbl Augenheilk 1954; 1:67-72 5. 	 Cvetkovic D, Blagojevic' M et al:Acta Ophthal Yugoslavica 1971; 8:46-51 6. 	 D'Ambrosio C, Ilari M et al:Bull oculist 1989; 68:661-667 7. 	 Fisher JH, Watson PG and Speath G: Eye 1988; 2:238-242 8. 	 Veron A S: Br J Ophth 1989; 73:247-249 Glaucoma Prevalence Participants Malta 2076 Gozo 169 Total Number 2245 Prevalence of Glaucoma Suspicious Glaucoma 20 2 22 I 0.97~ Old New Total Cases Cases 33 33 66 3 5 8 36 38 74 1.60% 1.69% 3.29% ~==~-----------------------Table 5 The copyright of this article belongs to the Editorial Board of the Malta Medical Journal. The Malta Medical Journal’s rights in respect of this work are as defined by the Copyright Act (Chapter 415) of the Laws of Malta or as modified by any successive legislation. Users may access this full-text article and can make use of the information contained in accordance with the Copyright Act provided that the author must be properly acknowledged.  Further distribution or reproduction in any format is prohibited without the prior permission of the copyright holder. This article has been reproduced with the authorization of the editor of the Malta Medical Journal (Ref. No 000001)  

Blagojevic' M et al:Acta Ophthal Yugoslavica

Docum Ophth

H: Docum Ophth

Ilari M et al:Bull oculist

Kl Mbl Augenheilk

Prevalance study of glaucoma in Malta and Gozo

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Prevalance study of glaucoma in Malta and Gozo

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