第二章 全球基层眼保健的进展
Primary Care Optometry
George Woo，OD，PhD.
Emeritus Professor School of Optometry
University ofWaterloo and
The Hong Kong Polytechnic University
Optometry has been recognized by theWorld Health Organization(WHO)as an independent eye care profession in the joint WHO and the International Agency for Prevention of Blindness(IAPB)'s Vision 2020 program.Its history in many parts of the world dates back more than a hundred years ago.As the profession evolves in different regions of the world，the profession gained more recognition and became regulated by governments and professional councils.In many countries，it has been integrated into government health structures in both the public and private sectors.The profession'smain thrust is in primary eye care in many developed countries.It also plays a secondary role supporting health care workers and co-managing diseaseswith ophthalmologists in developing countries.
The Institute of Medicine in the US defines primary care as“the provision of integrated，accessible health care services by clinicians who are accountable for addressing a large majority of personal health care needs，developing a sustained partnership with patients，and practicing in the context of family and community”.The statementwasmade in 1996 and Optometry is one of the health professions thatmeet the definition.Primary care is a complicated，intricate and complex form of the health caremodel.Primary care practitioners should acquire a strong commitment to both the professions and their patients.In order to qualify as a primary care professional，one must be able to conduct assessments and to diagnose on all patients who showed up for care.Approximately 90%of them should receive effective and comprehensive services including treatment and coordination.The practitioner therefore needs the ability to care for most of the patient's health needs and to take continuous care of all patients and refer to hose patientswhomay require specialized secondary and tertiary care to other appropriate health care professionals.
TheWorld Council of Optometry(WCO)defines Optometry as“an autonomous，educated and regulated(licensed/registered)healthcare profession.Optometrists are primary health care practitioners of the eye and visual system who provide comprehensive eye and vision care.This includes refraction and dispensing，detection/diagnosis and management of diseases in the eye，as well as rehabilitation of conditions of the visual system.”
The WCO has recently developed a Global Competency-Based Model of Scope of Practice in Optometry.Its Governing Board in 2011 adopted the broad competencies of dispensing，refracting，prescribing and the detection of disease as being the minimum required for individuals to call themselves optometrists.Levels of practice include Optical Technology，Visual Function，Ocular Diagnostic and Ocular Therapeutic Services.It provides a vertical career ladder for individuals seeking to expand their scope of clinical responsibility.
The competency model is designed for improved optometric education，competency of individual optometrists，and optometric standards and assessment in a systematic fashion while being able to accommodate awide range of different scopes of practice and levels of education.Themodel assumes a certain level of professional competence from optometrists，which is essential for public safety.Its global commonality facilitates objective comparisons of optometric scope of practice among countries for mapping out future developmental directions.Adaption of the modelmust be sensitive to local needs and take account of existing infrastructure and resources if they are to take root successfully.However，any upgrading of primary eye and vision care also depends on the concerted and coordinated efforts of government，health professionals and the public.
The current status of Optometry depends largely on the health system in individual countries.Eye care professionals generally include ophthalmologists，optometrists，orthoptists，opticians and ophthalmic nurses.The role of optometrists varies from country to country due to the uneven development of the profession in different parts of the world.Nevertheless，the basic elements of the primary eye care routine are largely made up of six parts in accordance with the modified classification proposed by Grosvenor in his textbook entitled Primary Care Optometry.They are①the patienthistory，②the preliminary examination，③the refractive examination，④the binocular vision examination，⑤the ocular health examination and⑥the low vision examination.
In this textbook，each of these six elements is presented in detail by various experts.Below is a brief description of each of them.
The Patient History
One of themost important aspects of case history is listening to the patient.Most of the time，a tentative diagnosis of the patient's problem can bemade based solely on the history.This tentative diagnosis can of course be reconsidered and refined on the available information obtained in the preliminary examination，the refractive examination，the binocular vision examination，the ocular health examination and the low vision examination.
The process of primary eye care is viewed as an investigation，in which each piece of evidence obtained is used to diagnose the nature of the patient's problems and then the treatment options.The case history is therefore simply treated as a data collecting procedure.It is，however，important for the practitioner to listen carefully to the patient's articulation of his/her eye and vision problem.
The Prelim inary Exam ination
Keen observation is required in the preliminary examination.It is to find any gross anomaly of the visual system such as high refractive error，ocularmotility anomaly，binocular vision disturbance or a systemic or ocular disease.While observationsmay not require precise quantitativemeasurements，they give an indication to the practitionerwhat to look for during the refractive examination，the binocular examination，the ocular health examination and the low vision examination.
The Refractive Exam ination
Measurements aremade during the refractive examination.The procedures have changed little in the last 50 years.They contain essentially the procedures of keratometry/corneal topography，retinoscopy，and subjective refraction.The development of binocular refraction procedure has changed the subjective refraction routine.
Objective and subjective computer assisted refractors in recent years are bringing further changes in the routine refractive examination.
On the basis of the history and the evaluation made during the preliminary examination，a tentative diagnosis of refractive error is further refined，modified or confirmed.The outcome may lead to spectacle，contact lens and Orthokeratology lens prescribing as treatmentoptions.Co-management of patients undergoing LASIK，PRK and RLE with refractive surgeons is also one of the outcomes.
The Binocular Vision Exam ination
In the preliminary examination，any observation on binocular anomalies is further investigated during the binocular vision examination.Typical measurements include phorias and tropias.Other well established measurements include stereopsis，AC/A，fusional reserves，amplitude of accommodation，positive and negative relative accommodation and fixation disparity to bemeasured binocularly.It is also an integral part in pediatric examination.The outcomemay result in different forms of vision therapy including orthoptistwork for the patients.Co-managementwith ophthalmologistswho specialize in strabismus surgery is another possibility.
The Ocular Health Exam ination
After the completion of the refractive and the binocular examinations，a thorough assessment of the patient's ocular health status ismade by employing diagnostic agents such asmydriatics and cycloplegics.In addition，a host of diagnostic pharmaceutical agents(DPAs)and therapeutic pharmaceutical agents(TPAs)are being used by optometrists throughout North America，Australia，New Zealand and the UK not only to diagnose but also to treat a variety of ocular diseases.Procedures include perimetry，tonometry，biomicroscopy，direct ophthalmoscopy，monocular or binocular indirect ophthalmoscopy and optical coherence tomography.Any outcome in regard to treatmentoptionsmay bedone on the basis of co-managementwith ophthalmologistswho specialize in cataract surgery，retinal surgery and other areas of ocular diseases.
The Low Vision Exam ination
It is often an extension of geriatric vision care.It begins when the patient's problem can neither be treatedmedically nor surgically following the previous five parts of examinations.Low vision assessment is tometiculouslymeasure the remaining vision of the patient.One of the common treatment plans is prescribing optical and electronic low vision aids for the patient to use his/her remaining vision more efficiently and effectively.
Having conducted the primary eye care examination in accordance with the five or six parts described in the above paragraphs，the practitioner then makes a diagnosis and decides on the best treatment option for the patient.
It has been generally known that90 to 95 percent of patientswho seek the services of an optometrist are due to optometric problems.The percentage of patients having medical problems is substantially smaller.Much of the optometrist's efforts during the case history and the preliminary examination must be spent in differentiatingwhether the patient has an optometric ormedical problem thus enabling the patient to receive prompt and appropriate quality eye ormedicalcare.
Further Future Development of Primary Eye Care
Primary eye care has evolved from measurement of refraction and visual acuity.Now with the addition of visual function tests，diagnostic and therapeutic services incorporated into the scope of practice，what is the future path of development of primary eye care?Iwould like to quote the writings of Irvin Borish who was highly regarded as a vision care world leader and visionary in vision care in the last fifty years.“Themeasure of excellence is no longer singularlymanifested in the skill performance of data gathering procedures.The practitioner should take a further step from being a technician and has learned to consider delegation and use of automated instruments for the data gathering procedures.The indiscriminately applied，uniform，and hallowed comprehensive routine，employed without specific regard，is being supplanted by selected procedures that are carefully chosen to provide specific information pertinent to each patient's problem.Emphasis has，of necessity，shifted to the importance of clinical diagnosis and management of visual problems.The developing role is that of analyst，diagnostician，problem solver，manager and counselor.”
It appears that sound professional judgmentbased on the results of the primary eye care examination by a qualified practitioner should lead to successful resolution of the patient's problem.In addition to a comprehensive eye examination，problem based eye examinationmentioned by Borish is also to be promoted.In this way，the primary eye care practitioner serves as the gatekeeper of eye care in the various aspects of promotive，preventive，curative and rehabilitative vision care.
Whether it is comprehensive primary eye care or problem based eye care，it should invariably be patient centered.The primary eye care practitionermustbe flexible in his/her approach towards patient care.Prior to the arrival of the patient，an appointment system should indicate the purpose of visit so that the practitioner can render the appropriate care required by the patient so as tomanage the patient accordingly.Upon receiving the patient，it is the practitioner's professional judgment to either provide primary eye care or problem based eye care to the patient.
In summary，the challenge of primary eye care is as difficult as it is rewarding.It requires a commitment that some cannotmake，and an educational process that some cannot attain.It requires notonly updated knowledge and skills inmanaging the patients butalso equally important in caring for them.When commitment to the concept or philosophy of primary eye care ismade in accepting the challenges and responsibilities，the reward is that their contributionswill be appreciated by the enormous number of people in their community needing such services.Through this multi-authored textbook，it is hoped that the readers can integrate their knowledge in primary eye care and translate them into routine clinical practice in their workplace.
References:
1.Borish I.M.(1987)Foreword.In:Diagnosis and management in vision care，edited by J.F.Amos.Boston:Butterworths，Ⅻ.
2.World Council of Optometry(1993).Concept of Optometry［monograph on the Internet］United Kingdom.
3.World Council of Optometry(2005).Case Statement［monograph on the Internet］United Kingdom.
4.World Council of Optometry(2005).Global Competency Model(monograph on the Internet).United Kingdom.
5.T.Grosvenor.Primary Care Optometry.5th ed.Butterworth-Heinemann，an imprint of Elsevier，2007