The amplitude of accommodation
decreases steadily with the age. This occurs mainly due to sclerosis of the
lens fibres and changes in the lens
capsule which reduces the spontaneous steepening of lens surface when cilliary muscle contract. Also the cilliary muscle itself may become less
efficient with advancing age i.e. after 40 years. The eye is
capable of 14 D (dioptres) accommodation in infancy
which declines to 4 D by the age of 45 years and 1 D by the age of 60 years1.
To focus at a reading object at 25 cm eye must accommodate by 4 D keeping one
third of the available accommodation in reserve. A person will begin to
experience difficulty for near vision at 25 cm when his accommodation decays to
6 D which usually occurs between the age of 40 and 45 years. This discomfort
for near vision is experienced due to reduced amplitude of accommodation and
the person is said to be presbyopic and is prescribed
convex lenses to aid the near vision which is called presbyopic correction and this age
related inadequacy of accommodation is called presbyopia1. Presbyopia
literally means old eye. It is most common ocular affliction in the world and
no individual appears exempt, although high myopes who remove their spectacles
may have their far point close enough to the eye to function satisfactorily2.
In premature presby-opia, accommodative ability
becomes insufficient for the patient's usual near vision tasks at an earlier
age than expected, due to environmental, nutritional, disease related, or
drug-induced causes.3,4 Although age is the
major risk factor for development of presbyopia, but the condition may occur
prematurely as the result of factors such as trauma, systemic disease, cardiovascular
disease, or a drug side effect5. There is earlier onset of
presbyopia in females due to short stature, or menopause6.
Persons involved in occupations with near vision demands may also develop
premature presbyopia7. Hypermetropia where there is additional
accommodative demand (if uncorrected) also leads to early presbyopia8.
Ocular disease or trauma, removal or damage to lens, zonules, or ciliary muscle, laser photocoagulation of retina
systemic disease like diabetes mellitus where changes in lens leads to change
in refractive state of the eye, multiple sclerosis associated with impaired
innervations, cardio vascular accidents leading to impaired accommodative
innervations, vascular insufficiency, myasthenia may all lead to early onset of
presbyopia7. Decreased accommodation is a side effect of both non
prescription of appropriate spectacles and drugs such as chlorpromazine, hydrochlorothiazide,
anti anxiety agents, anti depressants, antipsychotics, antispasmodics, anti
histamines and diuretics. Alcohol intake is also reported to
be associated with early presbyopia7. Geographic factors as
proximity to the equator (higher average ambient temperatures, greater exposure
to ultraviolet radiation) have also been reported to be a cause of early
presbyopia9.
MATERIAL
AND METHODS
Patients were selected from
outpatient department through non probability consecutive sampling technique and
included 246 patients.
It was a hospital based
descriptive cross sectional study. Sample size was calculated by WHO formula
given by L Lemesho and SK Lawanga10 keeping confidence interval 95%,
Absolute precision 0.03%, Population size 1000 and
prevalence P 35.1% (Tobbacco users with
early presbyopia).11
Patients with complains of
decreased near vision (N/12-N10 on near vision chart)
were included in the study. Majority of them were those who complained of
inability to see the font of cell phone and cell phone cards. Majority of the
patients were emmetrope. Patients having ocular
pathologies that could affect the clarity of medias
like corneal opacities cataract, uveitis, vitritis and retinal detachment were
excluded from the study.
A detailed history of the
patients was taken regarding their occupation tobacco use, any refractive error
and glaucoma. In addition to ocular history, history regarding hypertension,
diabetes mellitus gastritis and heart burn was also taken. Blood CP,
Urine D/R, Random and fasting blood sugar were also done as and when required. Patients
were examined thoroughly in the OPD Slit lamp examination applanation tonometery
and direct and indirect fundoscopy and tonometery was done as and when
required. Patients were refracted and appropriate glasses prescribed. Data was
recorded and analyzed on SPSS programme version 14.
No: of patients between 31 33 years
= 45 (18.29%)
No: of patients between 34 36 years
= 126 (51.21%
No: of patients between 37 39 years
= 75 (30.48%)
Fig. 1: Age Distribution
RESULTS
Our study included 246
patients over a period of 1.8 years. Female patients were 60% (148 and male
patients were 40% (98). Mean age of the patients was 35.6 ± 4.01 years. Tobacco
users who presented with early presbyopia were 88 (35.7%). 18 (7.31%). 16 (6.50%) patients were diabetic among
the early presbyops. 10 (4.06%)
had both diabetes and hypertention. Computer operators with early presbyopia were
15 (6.09%). Presentation of patients with refractive errors as 14 (5.69%). Here
12 patients had hypermetropia and 2 patients had hypermetropic astigmatism. Less prevalent factors
associated with early presbyopia were smoking 7 (2.85%) patients, glaucoma 5
(2.03%), anaemia 5 (2.03%),
thyroid disease 4 (1.6%), history of use of hair dyes 4 (1.6%), osteoarthritis
2 (0.81%) and allergic disorders 2 (0.81%). Patients who presented with no
specific cause were 4 (1.62%) (Table 1).
DISCUSSION
Although age is the major risk factor for development of
presbyopia, but the condition may occur prematurely i.e. before 40 years of age
the prevalence of presbyopia is higher in societies in which large proportions
of the population survive into old age. Because presbyopia is age related, its
prevalence is directly related to theproportion of
older persons in the population. Although it is difficult to
estimate the incidence of aged 42 to 44 years1. Early
diagnosis and intervention in systemic diseases identified in the process of
caring for the presbyopic patient has public
health ramifications. Unmanaged presbyopia can result in significant visual
disability, depending on factors such as the individual patient's amplitude of
accommodation, refractive error, and nature of the near vision tasks. Given the
variety of spectacle and contact lens management options available, most
patients do not experience significant disability due to presbyopia. Our
study reported a female preponderance as there were 60% female patients and 40%
male patients but O Bernice and et al reported that males had higher degrees of early presbyopic errors than
females which is contrary to our study.14 Our study had a female
preponderance perhaps due to the fact that females bear more stresses in our
society as compared to males including multiparity which was
commonly reported in our study, child raising, anaemia
and other household stresses. Weale RA has also
reported a female preponderance in his study16.
Our study reported that major factorassociated with early presbyopia was tobacco use 88
(35.7%) patients more common among male patients, followed by gastritis 52
(21.1%) patients more common among female patients. A Population Based
Assessment of presbyopia was conducted in the State of Andhra Pradesh, South
India known as The Andhra Pradesh Eye Disease Study'. According to this study 35.1% of subjects aged 35 years had presbyopia and
they were tobacco users. These findings are quite close to our study12.
Tobacco use and gastritis are usually associated with stressful living
conditions so early presbyopia could be a psychosomatic disorder. It should be kept in mind that Spencer Eye Hospital is
located in an old town Lyariand illiteracy,
ignorance and poverty prevails here. People usually live a stressful life
style; they are addicted and habituated to different forms of tobacco. However
no association between early presbyopia and gastritis has been reported in
literature previously. Among the early presbyopes 18
(7.31%) patients had associated hypertension and 16 (6.50%) patients had
diabetes. Those who presented with diabetes and hypertension both were 10
(4.06%). The medical history is important in the diagnosis
of premature presbyopia, particularly diabetes mellitus (lens,
refractive effects); multi plesclerosis (impaired innervation);
cardiovascular accidents (impaired accommodative innervation) vascular
insufficiency; myasthenia gravis anemia; influenza; measles5,7. In our study commonly found
medical problems were diabetes mellitus, hyperten-sion and anaemia.
Early presbyopes who presented with associated headache
and refractive errors were 14 (5.69%) and with glaucoma were 5 (2.03%). Jain and
et al and pointer have reported that in hypermetropia where there is additional
accommodative demand (if uncorrected) also leads to early presbyopia. Here latent
hypermetropia should be considered as important
feature. In addition ocular disease as glaucoma or trauma, removal or damage to
lens, zonules, or ciliary muscle, laser photocoagulation of retina may
also lead to early presbyopia.7,8,13,16 In our study 4 (1.62%)
patients has early presbyopia associated with the use of hair dye. Jain and et al reported in their study that
35.75% patients entered presbyopia at or before the age of 38
years. Environmental conditions including high average temperature, much
ultraviolet radiation, chronic deficiency of essential amino acids, and
exposure to toxic factors, particularly hair dye, may play a significant role
in precipitating the early onset of presbyopia7. Our study reported
15 (6.09%) computer operators had early prebyopia.
Computer operators are usually engaged in prolong near work. A hospital based
prospective study conducted in Nigeria revealed that 15.5% of the patients had presbyopia
before age 40 years and majority of them were engaged in prolong near work.
Thus increased visual tasks are a major contributory factor towards onset of
presbyopia before 35 years of age14-16; although age is a major risk
factor for the development of presbyopia. Several studies have reported that
presbyopia occurs earlier among people who are exposed to high ambient
temperature and ultraviolet radiation9. This phenomenon could have
been implicated in our study as quite a number of patients presented from
coastal areas of Makran and Balochistan where temperatures are at
extremes during summers and exposure to ultraviolet radiations is more near
coastal areas. Our study reported 5 (2.03%) patients with anaemia.
Anaemia and poor nutritional status are also
associated with early onset of presbyopia. Gary L has also reported an association
between poor nutrition and early onset of prebyopia15. Less prevalent factors associated with early
presbyopia were smoking 7 (2.84%) patients. Glaucoma 5 (2.03%), anaemia 5 (2.03%),
thyroid disease 4 (1.6%), hair dyes 4 (1.6%), osteoarthritis 2 (0.81%) and
allergic disorders 2 (0.81%). Patients who presented with no specific cause
were 4(1.62%).
CONCLUSION
Early presbyopia is not uncommon in a society with associated
psychosomatic disorder. People have habit of nicotine and tobacco abuse. Associated
gastritis, hypertension and headache are further indicators of early presbyopia
being a psychosomatic disorder. Although other factors
like systemic diseases, nutritional deficiencies and environmental factors also
cause early onset of presbyopia to some extent.
N.B this study was conducted
in a hospital located in an area with low socioeconomic strata perhaps the
findings may differ depending on the locality.
Authors Affiliation
Dr. Uzma
Fasih
Associate Professor
Eye Dept. (Unit 2)
Karachi Medical and Dental College
Abbasi Shaheed
Hospital, Karachi
Spencer Eye Hospital, Karachi
Dr. M. Rais
Senior Registrar
Eye Dept. (Unit 2)
Karachi Medical and Dental College
Abbasi Shaheed
Hospital, Karachi
Spencer Eye Hospital, Karachi
Dr. Atiya Rahman
Assistant Professor
Eye Dept. (Unit 2)
Karachi Medical and Dental College
Abbasi Shaheed
Hospital, Karachi
Spencer Eye Hospital, Karachi
Dr. Arshad
Shaikh
Professor and Head of Eye
Department
Eye Dept. Karachi Medical and
Dental College
Spencer Eye Hospital, (Unit 2)
Karachi Medical and Dental College,
Abbasi Shaheed Hospital, Karachi
Dr. M. S. Fahmi
Professor and Incharge
Spencer Eye Hospital (Unit 2)
Karachi Medical and Dental
College, Karachi
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