Primary Care and Refraction PDF

PRIMARY CARE AND REFRACTION ❖ COMPREHENSIVE VISION EXAMINATION -The primary care exam sequence can be grouped into four general areas: CASE HISTORY REFRACTIVE STATUS BINOCULAR AND ACCOMMODATIVE STATUS OCULAR HEALTH 1. CASE HISTORY Definition: -patient’s own account of information about...

PRIMARY CARE AND REFRACTION ❖ COMPREHENSIVE VISION EXAMINATION -The primary care exam sequence can be grouped into four general areas: CASE HISTORY REFRACTIVE STATUS BINOCULAR AND ACCOMMODATIVE STATUS OCULAR HEALTH 1. CASE HISTORY Definition: -patient’s own account of information about his visual problems. -detailed record of the background of a person/patient under study or treatment. Role and significance: -determine which specific tests or procedures should be performed during the examination and after interpretation and analysis.ultimately lead to a definitive diagnosis and management plan. -allows good rapport between the optometrist and the patient. Make sense of the patient’s story and physical findings and begin to generate differential diagnosis appropriate to the level of training. ★ FOUR BASIC COMPONENTS OF CASE HISTORY A. Defined database ★ History Patient profile Age Gender Occupation Address education Chief complaint Visual ocular history General health history Medication usage Allergies to medications Family eye and medical histories Occupational visual requirements Recreational visual requirements ★ Preliminary examination ★ Refractive examination ★ Binocular vision examination B. Complete problem list C. Initial treatment plan D. Progress notes ★ CHIEF COMPLAINT -stimulus which primarily drives the patient to seek ocular assistance. -explanation given by the patient as to why he is seeking visual care. -primary reason the patient is seeking consultation. ★ Ocular complaints or asthenopia: -uncomfortable,painful and irritable vision -used to designate a group of symptoms arising from any form of functional eyestrain. ★ Source of ocular complains: 1. Accommodative- as in hyperopia,astigmatism and presbyopia(due to uncorrected refractive error) 2. Motor- including excessive lateral phorias,cyclophorias and vertical imbalances and deficiencies of the fusional reserves.(due to muscular deficiency) 3. Integrative- involving lowered ability to fuse,aniseikonic involvements and distortion problems. It may be likely that these are related to the above in that the attempts to overcome the problems involve accommodation and convergence. ★ CHIEF COMPLAINT OR CONCERN -representative behavioral signs and symptoms related to visual efficiency deficits Accommodative deficiencies: blur or fluctuating vision at near point. eyes hurt,burn or tired when reading. asthenopia,headaches or ocular fatigue with near work. excessive rubbing ,blinking or tearing of eyes. intermittent blur of distance vision after near point activities. Vergence deficiencies: Asthenopia Intermittent diplopia Closing or covering one eye Difficulty aligning column of numbers Letter or words appear to jump ,float or move around Asthenopia,headaches or ocular fatigue with near work. Ocular motility deficiencies: Excessive head movement when reading Frequent loss of place when reading Omission of words or skipping of lines when reading. Use of a finger or marker when reading Lack of comprehension when reading ❖ PRELIMINARY TESTS 1. INTERPUPILLARY DISTANCE -distance between the centers of the entrance pupils of eye.also referred to as interocular distance(IPD) and pupillary distance(PD) -normally a distance PD (viewing distance at infinity) and a near distance PD(viewing distance at the px near working distance)are taken.  -Pupillary distances are recorded in millimeters with the distance PD,the larger of two numbers written first. (ex. 64/61) ★ Methods of taking the PD: A. ANATOMICAL METHOD(far and near) -the patient’s fication is the examiner’s eye for distance PD and examiner’s nose for near PD. B. CATOPTRIC METHOD -the patients ask to fixate at the bulb and place the mm rule aligning the zero mark of the rule with the image formed by the exposed bulb or penlight(reflection ng light sa pupil) If the PD for near is below 60 mm. Add 2 mm to represent the PD for far; 60-64 mm add 3 mm; if 65mm above add 4mm to make PD for far. Ex. NPD=60 mm+ 3mm+63mm —63/60 ★ Factors to be considered to insure accuracy in taking the PD Line of sight of the patient should be parallel to each other. Line of sight of the examiner should intersect the measuring rule from identical angles for both readings. ★ Factors to be observed when taking PD The examiner must not move his head when taking the examination. The illumination should not be of such intensity that will distort the fixation of the patient. The measurements are accurate only when the PD of both the examiner and the patient are approximately the same. While asymmetry exist,it is well to note the distance from the center of the nose to the center of pupil, the PD in his case shall be written as in the ff: PD= OD =32mm OS=31mm OU=63 mm If faulty binocular fixation(strabismus) is peasant, itis necessary to take the reading of each eye separately while the other eye is occluded. Where the two pupils are unequal size,the centers of the pupil must be used.(ANISOCORIA) ➔ Various devices such as pupillometers,centrometers and the like have been developed to improve the accuracy of those measurements. ★ Significance of taking PD: ➔ To place the optical centers(OC) of spectacle lenses accurately relative to the eyes,either to avoid unwanted prisms or to produce desired prism. ➔ The near point PD is needed for proper placement of bifocal in the finished lenses.  2. NEAR POINT OF CONVERGENCE -it is the point of intersection of the lines of sight of the eyes when maximum convergence is utilized. -The near point of convergence distance is the distance from the NPC to the midpoint of the line connecting the center rotation of the eyes. ★ Clinical use: -The NPC is a measurement of the maximum convergence ability of the patient. Patients who have reduced NPC distances may have visual and ocular discomfort when performing near point vision. TARGET: White headed pin upon a rod Raf rule Narrow edge of a white plastic rule Tip of Pencil Prince rule Pointer Florist pin Small penlight ★ Clinical implications -Patients with a remote NPC may express symptoms such as diplopia ,frontal headaches,decreased reading comprehension,asthenopia and occasional fatigue when undertaking near tasks.all these are amenable to treatment by vision training or prism prescription. ★ Clinical interpretation: -the NPC is expected to be 6-10cm. -closer than 5 cm is considered by some practitioners to be suggestive of convergence excess. 3. AMPLITUDE OF CONVERGENCE -dioptric value of the near point of convergence. -in order to determine the amplitude of convergence,the NPC must be specified in terms of the line joining the centers of rotation of the two eyes. -the Amplitude of Convergence is equal to the reciprocal (in meters)of the Near point of convergence multiplied by the patients PD in centimeters. AC: reciprocal(in meters) of NPC x PD in cm. Example: for a NPC of 7 cm,measured from the spectacle plane and a pd of 60 mm,the amplitude of convergence would be: 1 (6)-100(6)= 60 0.10 10 Conversion to meter: 10cm=1M =10M=0.10 —--1 100 cm 100 0.10  4. SIZE OF THE PUPIL: STATIC PUPIL EVALUATION:measurement of the pupil size under contents stimulus. DYNAMIC PUPIL EVALUATION:measurement of changes in the pupil size with changes in stimulus condition either light or accommodation. ★ Clinical use: -careful evaluation of the size of the pupil and mobility of the pupil provides the examiner information about the integrity and function of the : IRIS OPTIC NERVE POSTERIOR VISUAL PATHWAYS THIRD AND SYMPATHETIC NERVES TO THE EYES. ★ Clinical interpretation: -the pupils are normally equal in size and vary from 2 to 4 mm, in diameter in bright light, and from 4 to 8 mm in the dark. -pupils with 0.5mm difference in size in the light or dark or appear to be abnormally constricted or dilated,may indicate the presence of neurologic disease. 3-4 =normal size of the pupil 2 mm=constricted =myosis (hyperopia,astigmatism,presbyopia) 5mm=dilated=mydriasis myopia(Mydriasis refers to dilated pupils that do not change in response to changes in light levels.) ➔ ANISOCORIA-unequal size of pupil;normal in some individuals 5. FIXATION TEST/CORNEAL REFLEX TEST -the corneal reflex test is a convenient test for determining the presence of strabismus at near.(Strabismus (eye misalignment) is a condition in which one eye is turned in a direction that's different from the other eye) -it is particularly useful for a child whose results with the unilateral cover test were questionable. ★ PROCEDURE: The patient is instructed to watch a penlight or ophthalmoscope bulb held by the examiner at a distance of 40 cm,while the examiner observes the corneal reflexes in the px eye If no tropia exists,each corneal reflex will be located approximately 0.5 mm nasal to the center of the pupil. -the reflex located 0.5mm to the center of the corneal reflex because the line of sight makes a small angle(about 5 degrees) with the pupillary axis.the angle,measured from the entrance pupil of the eyes called ANGLE LAMBDA. -whereas,the corneal reflex is normally 0.5 mm nasal to the center of the pupil, it may slightly move displaced nasally in some hyperopic eyes and it may be near the center of the pupil or even displaced temporally in some highlymyopic eyes. ★ Sample recording: OU=slightly nasal +