Session Title: AMD II
Session Date/Time: Friday 18/09/2015 | 14:30-16:00
Paper Time: 15:10
First Author: : S.Mazumdar INDIA
Co Author(s): : S. Sil
PURPOSE:AMD is an important cause of legal and irreversible blindness in eastern part of India and largely prevalent among people with age more than 50 years. Drusens are the hallmark of the condition. The most dreaded complication of AMD is choroidal neo-vascularisation (CNV). Though multiple risk factors are associated, sufficient epidemiological data of AMD in India is still unavailable. Etiologies are largely unknown. There may be some preventive measures that restrict the disease progression.
Aim of this study was to detect the different epidemiological parameters associated with AMD development in eastern India to find out the causal and risk factors.
This was a retrospective cohort study of 460 eyes of 250 patients done over 2 years in a tertiary care eye hospital in Eastern India. The different risk factors evaluated were divided into two groups. The Group I had non modifiable factors. Group II contained modifiable factors.
In group I, the non-modifiable factors assessed were (i) age, (ii) gender, (iii) socioeconomic status. The socioeconomic status was categorized into poor (monthly income less than 75 Euro); moderate (monthly income 75-151 Euro) and good (monthly income more than 151 Euro. In group II, the modifiable factors assessed were (i) associated cataract, (ii) cup disk ratio (CDR), (iii) tobacco addiction (iv) antioxidant intake habit and (v) systemic disease association (diabetes, hypertension and dyslipidemia). Tobacco addiction was subdivided into smoking and chewing. Regular antioxidant intake was assessed by simple questions of ingestion of nutrient rich foods and broadly classified as positive (yes) or negative (no) intake. Different types of AMD were classified. Based on previous age related eye disease study (AREDS), dry AMD subdivided into early (small hard drusens: less than 0.5 vein width/63µ; in one or both eyes), intermediate (medium hard drusens: 63-125 µ; in one or both eyes) and late (advanced: hard drusens with breached photoreceptors, detected on OCT). Associated geographic atrophy was also observed. Wet AMD (large soft drusens) and CNV assessed separately. Color digital fundus photographs and spectral domain OCT were done. The different epidemiological indices measured were relative risk (RR), attributable risk (AR) and incidence rate.
Mean age detected for AMD was 66.5 (range 30-90) years. In group I, AMD was found more at ages more than 60 years (AR = 71%) and it was most prevalent at 7th decade (33%; 84/250 patients). Male: Female was 141:109. More than 55% (138/250 patients) had a medium socioeconomic status. In group II, cataract was detected in 53% (245/460 eyes; RR = 1.14). A CDR ≤ 0.6 was present in 94% (432/460 eyes). Intake of diet deficient in antioxidant found in 62% (155/250 patients; RR = 1.63; AR = 39%). Positive tobacco intake detected in 53% (133/250 patients; RR = 1.13). Hypertension showed a significant presence in 46% (115/250 patients; RR=0.85). Different types of AMD detected were dry in 76% (349/460 eyes) and wet in 11.5% (53/460 eyes). Also Choroidal neovascularisation (CNV) was detected in 12.5% (58/460 eyes). Incidence of CNV calculated was 126/1000 AMD.
The current study showed male preponderance with the most affected age group being 7th decade. So, higher age carries more risk. Population with moderate quality of life were mostly affected which indicated that socioeconomic status has no direct influence. Among the modifiable risk factors tobacco intake was found positively associated with development of the disease. Similarly deficient antioxidant intake (through food) was detected as a positive association. Ocular association like cataract was found again positively associated with AMD. Different systemic diseases didn’t show significant risk association except hypertension which may had a causal relation with the development of AMD. The incidence of CNV detected was also very high. Thus majority of the risk factors found were modifiable. So prevention is possible with lifestyle modification (increased antioxidant intake, decreased tobacco addiction) and treatment of associated diseases (cataract and hypertension). Also routine screening of patients with the above factors positive should be done. To conclude, AMD is endemic and multifactorial in Eastern India. Positive association was detected with higher age, deficient antioxidant intake, tobacco intake and cataract. As risk factors are mostly modifiable, both prevention and intervention can restrict the disease progression and improve quality of life.