Comprehensive Eye ExaminationCheck Yearly, See Clearly
Comprehensive eye and vision exam
A regular eye examination is an important preventive measure to protect our vision as many of the sight-threatening eye diseases have no obvious symptoms. Only by early diagnosis, timely referral and appropriate treatment, our vision can be saved.
A comprehensive eye exam includes:
We will ask about your visual problems, the history of the visual problem such as past investigations and treatment that had been received. We will also ask about your medical, drug and family history to gather information on how these factors are related to your presenting complaint.
These include evaluation of color vision, depth perception, eye muscles movement, pupil response and visual acuity. This fundamental information provides us with how good your eyes are functioning and coordinating with each other. Further investigation will then focus on the weaker part of your visual system.
Refraction or subjective refraction determines the lens power that you need to correct your shortsightedness, farsightedness and astigmatism. Starting with a quick Auto-refraction, a preliminary refractive status of your eyes is measured. We will then refine the refraction by adding lenses in front of your eyes and base on your responses, the subjective refraction is determined.
Occasionally we will use eye drop on young children or adults who are suspected to have over-active focusing power to check the baseline refraction when the muscles are relaxed i.e. cycloplegic refraction. Cycloplegic refraction is also useful in toddler when a subjective response is not always reliable.
Eye Health Evaluation
Our eyeball is basically divided into 2 segments: the anterior segment which corresponds to the front 1/3 of the eye that includes the cornea, iris, ciliary body and the crystalline lens. The posterior segment, the back 2/3 of the eye, includes vitreous humor, retina, choroid and optic nerve.
To evaluate the anterior segment, we will use a slit lamp to specifically focus on a particular structure to see if there is abnormal change. Conditions such as dry eyes, corneal opacity and cataract etc. can be investigated using this technique. Slit lamp can also be used in evaluating external eye structures like eye lid and eye lashes.
To evaluate the back of the eye, the posterior segment, we will first dilate the pupils with eye drop. Pupil acts as a curtain to limit the amount of light entering the eye. An enlarged or dilated pupil allows more light to enter the eye as well as providing a larger view of the retina. It also allows a full view of the crystalline lens. In this way, both the central and peripheral retina can be examined and any lens changes can be seen. Retinal diseases or conditions like age-related macular degeneration (AMD), retinal degeneration (holes, breaks or tears etc.), diabetic retinopathy, retinal vein/artery occlusion, posterior vitreous detachment, floaters and optic nerve atrophy will be investigated. Examination on the optic nerve head also provides us with important information about potential glaucoma, inflammation of the optic nerve or even potential tumour at the back of the eyeball. Therefore a dilated eye examination is an essential part of an eye examination. You are recommended to prepare a sunglasses to protect your eyes from direct sunlight after the exam and not to drive as dilated pupils will cause blurry vision at both distance and near visions for several hours.
Eye pressure measurement
Intraocular pressure (IOP) measurement or tonometry is an evaluation of the pressure inside the eye. An IOP of 10-21 mmHg is generally considered as normal. Too high the pressure may cause glaucoma – a disease with progressive loss in the visual field and eventually lead to blindness. Checking the IOP is the first line screening for glaucoma. It can be done easily by a non-invasive method called non-contact air puff test.
Depends on the individual result, additional test may be needed to further investigate the condition of the eye. For example, a visual field screening test will be suggested if there is family history of glaucoma, or the IOP reading is on the high side.