Medicine Section - Ocular Photoscreening in the Primary Care Physician's Office as a Screening Tool to Detect Amblyogenic Factors

IMPORTANT REMINDER

This Medical Policy has been developed through consideration of medical necessity, generally accepted standards of medical practice, and review of medical literature and government approval status.

Benefit determinations should be based in all cases on the applicable contract language. To the extent there are any conflicts between these guidelines and the contract language, the contract language will control.

The purpose of medical policy is to provide a guide to coverage. Medical Policy is not intended to dictate to providers how to practice medicine. Providers are expected to exercise their medical judgment in providing the most appropriate care.

Description

Amblyopia is a disorder of visual development, manifested as decreased visual acuity in one or both eyes. It affects more than 2% of the population, and is the leading cause of monocular vision loss in children and young adults. However, if detected before 8 to 10 years of age, it can often be effectively treated by occlusion of the sound eye or atropine penalization. A variety of organizations have recommended routine vision screening throughout childhood. Organizations include the American Academy of Pediatrics, the US Preventive Services Task Force, the American Academy of Ophthalmology, and the American Association for Pediatric Ophthalmology and Strabismus. Detection of amblyopia itself requires assessment of visual acuity, which is difficult in preverbal children. Ocular photoscreening has been investigated as an alternative screening method, not to detect amblyopia itself, but instead to detect risk factors for amblyopia, which include strabismus, high refractive errors, anisometropia, and media opacities.

Ocular photoscreening is based on comparison of the images obtained when light directed through one undilated pupil is reflected by the ocular fundus of both eyes simultaneously.   The images can then be analyzed along with the position of the corneal light reflex.  Comparing the two images provides information on refractive error, ocular alignment, pupil size and clarity of ocular media.  Any asymmetry between the two eyes indicates the possible presence of amblyopia and the need for a comprehensive eye exam by a pediatric ophthalmologist.  Patients are photographed in a darkened room while looking directly at the camera. The photographs must be sent to a central laboratory for analysis, either by ophthalmologists or specifically trained personnel. Results are typically graded as pass, fail, or repeat photoscreening.

Several different systems are commercially available. In this country, the majority of published studies have used the MTI PhotoScreener (Medical Technology, Inc., Cedar Falls, Iowa).

Note: Ocular photoscreening can be performed in several settings. For example, photoscreening can be performed in a public health setting, as part of school screening programs or in primary care offices.  In addition, photoscreening may be performed by ophthalmologists as an adjunct to an ophthalmologic exam. This policy only addresses the use of photoscreening in the setting of the primary care physician’s office, where it is performed as an adjunct or alternative to the standard visual exam. It is anticipated that the results of photoscreening would be used by the primary care physician to determine whether the patient required referral to a pediatric ophthalmologist for further evaluation.

Policy/Criteria

Ocular photoscreening in the primary care physician’s office is considered investigational as a screening tool to detect amblyogenic factors in children.

Scientific Background

As noted in the Description, this policy only addresses ocular photoscreening when performed in the primary care physician’s office, either as an adjunct or alternative to standard visual assessment. Aside from assessment of visual acuity, using age-appropriate optotypes, (Snellen charts, letters, or other techniques), primary care physicians typically assess fixation and following movements and perform the red reflex test. Specifically the red reflex test can detect visual opacities in the visual axis and abnormalities of the back of the eye, such as retinoblastoma or retinal detachment. When the red reflex is assessed simultaneously, potentially amblyopic conditions, such as abnormal refractive errors anisometropic or bilaterally ametropic) or strabismus, can also be identified. The test is performed in a darkened room, with the direct ophthalmoscope focused on each pupil individually and then both eyes simultaneously. The family and clinical history may also identify a child at higher risk of amblyopia. For example, high-risk children include those with a family history of strabismus, amblyopia, high refractive errors, or childhood eye disorders. Premature children, or those with neurologic and developmental conditions, are also at higher risk. (2)

It is assumed that the results of photoscreening would be used to prompt referral to an ophthalmologist for further evaluation. Therefore, assessment of photoscreening in this setting requires population-based studies to determine whether the results of photoscreening result in a higher referral rate to ophthalmologists, with an associated improvement in sensitivity and specificity for detection of potential amblyogenic factors that lead to earlier diagnosis and treatment with a decrease in lifelong visual impairment. To date, these studies have not been performed. The majority of the published studies have focused on the technical feasibility of ocular photoscreening, setting diagnostic parameters for interpretation of the photographs and its use in public health settings. For example, Tong and colleagues from the Wilmer Eye Institute published a series of three studies of the MTI PhotoScreener. The first study of 100 children was designed to determine whether or not healthcare professionals or lay volunteers could interpret and grade photoscreening photographs. (3) A total of 18 volunteers including both pediatric ophthalmologists and lay personnel interpreted the photoscreening results, which included 26 children with normal ophthalmologic exams and 74 with abnormalities. Results from the graders varied, with sensitivities ranging from 37%–88% and specificity from 40%–80%. No single grader achieved sensitivity and specificity both greater than 70%. The authors concluded that these results reflected either inconsistent photographic interpretation skills or deficient grading criteria.

A subsequent study was published in 2000, which included 392 preverbal children who were referred to an ophthalmologist for examination; 103 had normal examination findings, while the remaining 284 children had conditions of interest for pediatric screening. (4) In this study, the photographs were graded by a representative of the manufacturer, Medical Technologies, Inc., and the determination compared with the results of the ophthalmologic exam. The overall sensitivity was 65% and the specificity 87%. The results were further analyzed according to the abnormality present, i.e., external examination abnormality (e.g., ptosis), media opacity, strabismus, and refractive error. The sensitivity for refractive error was low (33%), while the sensitivity for strabismus was 55%. The authors conclude that while photoscreening with the MTI system is promising, further research on grading criteria, particularly to detect refractive errors, is needed.

The third study by Tong and colleagues investigated a new grading system for hyperopia, based on the conclusions from a previous study that the criteria for hyperopia indicating a failing grade were too low and would result in an undesirably high referral rate. (5) This study reexamined the 392 photographs from the previous study and developed new grading criteria that resulted in a sensitivity and specificity of 100% and 88%, respectively. Simons and colleagues studied the MTI PhotoScreener in 100 children, aged four months to twelve years, who were recruited either from a pediatric ophthalmology referral practice, children suspected to have developmental delay or a behavior disorder, or patients from a day care center. (6) All 100 photographs were independently graded by six observers, including four pediatric ophthalmologists, a nurse, and a research coordinator, and compared to the results of a complete ophthalmologic examination. For detecting any abnormal results, the sensitivity ranged from 80%–91% and the specificity ranged from 20%–67%. This study included verbal children, who presumably could participate in visual acuity tests.

It should be noted that all of the above studies recruited patients from a pediatric ophthalmology practice or other settings such that the studied population had a high incidence of patients with pathologic conditions. While these populations are useful to determine the initial sensitivity of photoscreening, this population does not duplicate the general population of children presenting to the primary care physicians’ office. Presumably, the patients in the above studies were referred to a pediatric ophthalmologist due to a clinical abnormality noted in the physical exam or a history that placed them at high risk. To determine the utility of photoscreening in the primary care physician’s office, the sensitivity and specificity of the photoscreening should be compared to the sensitivity and specificity of measuring acuity in this setting.

Ocular photoscreening has also been investigated in a public health care setting, where presumably the photoscreening is the only type of vision screening that is available to participants. For example, Donahue and colleagues reported on the results of a public health screening program which evaluated 15,000 preschool children in Tennessee. (7) This program used volunteers from local Lions Clubs to take the photographs, and all photographs were interpreted at a central reading station by professional photo readers. The positive predictive value ranged from 84% when a diagnosis of strabismus was suggested by the photoscreen, to 41% for astigmatism. While this public health setting is not applicable to this policy, it is anticipated that ocular photoscreening may be predominantly used in this setting.

Other Information

In 2002, the American Academy of Pediatrics published a commentary on photoscreening. (8)  This document noted the following:

• Photoscreening does not represent a single technique or piece of equipment.  Different optical systems can be used for photoscreening. Interpretation of screened images may be performed in the physician's office, in a reading center, or with an automated system.
• Each photoscreening system may have its own advantages and disadvantages, and it appears that results published in the literature for one system are not necessarily valid for others.
• It is difficult to compare efficacies of various vision-screening methods, such as stereoacuity testing, auto refraction, red reflex testing and cover testing, and then determine if photoscreening has better positive and negative predictive values. This is attributable in part to a lack of uniformity in pass-fail criteria for significant refractive errors.
• Photoscreening needs to be studied more extensively. The AAP favors additional research of photoscreening devices and other vision-screening methods in large, controlled studies to elucidate validity of results, efficacy, and cost effectiveness to identify amblyogenic factors in different age groups as well as subgroups of children.

In 2003, the American Academy of Pediatrics issued a policy statement on eye examination as performed by pediatricians, which included discussion of ocular photoscreening. (9) This document noted that “photoscreening is not a substitute for accurate visual acuity measurement but can provide significant information about the presence of sight threatening conditions such as strabismus, refractive errors, media opacities (cataract) and retinal abnormalities (retinoblastoma). Photoscreening techniques are still evolving.”

In 2003, the American Association for Pediatric Ophthalmology and Strabismus published a position statement on photoscreening, which reads in part, “It is important to remember that photoscreening detects many problems that predispose the developing visual system to amblyopia, rather than providing a direct test of visual acuity and binocularity, and that, therefore these latter tests are preferable once a child can cooperate with such testing. For the preliterate child, however, photoscreening systems show significant potential. Current photoscreeners still suffer from relatively low sensitivity, high false positive referral rates, and relatively high usage costs. Advances in technology will eventually lead to the development of systems having higher sensitivities and positive predictive values. AAPOS encourages the development of such systems. We believe that further research may produce systems that have sufficient reliability to achieve widespread acceptance and usage, not only for children who do not receive primary medical care, but also in the primary care physician’s office.” (10)

An updated search of the MEDLINE database through October 15, 2007 failed to identify any additional published literature that alter the conclusions reached above.  The published literature continues to focus on settings other than the primary care physician’s office (e.g., schools, mobile units. (11-14) In 2005, a Cochrane review focused on the role of screening for amblyopia in general.  The authors noted that the absence of data from randomized controlled trials comparing the prevalence of amblyopia in screened vs. unscreened trials precludes analysis of the impact of screening programs on the prevalence of amblyopia. (15) A single study was identified that examined the use of photoscreening in the primary care setting. (16) Kemper and colleagues conducted a national survey of 377 pediatricians (55% response) to determine the rate of acuity screening in preschool children. It was reported that vision screening was conducted in 35%, 73%, and 66%, of 3, 4, and 5-year olds, respectively. Few (8%) of the respondents reported using either autorefraction or photoscreening. Donahue reported that younger children with anisometropia had a lower prevalence of amblyopia than older children. (17) This retrospective study, which should be considered preliminary, suggested that earlier detection of anisometropia might allow earlier intervention, and may prevent or retard development of amblyopia.

The National Eye Institute is sponsoring a three-phase multicenter prospective clinical trial to evaluate screening tests for identifying preschool children in need of comprehensive eye examinations. (18) The category of screening personnel and the specific screening tests will be determined in Phases I and II of the Vision in Preschoolers (VIP) Study. Phase III will evaluate the performance (sensitivity and specificity) of the tests in identifying specific vision disorders in 6400 Head Start preschoolers.

References

1. BlueCross and BlueShield Association Medical Policy Reference Manual, Policy No. 9.03.12
2. Simon JW, Kaw P. Vision screening performed by the pediatrician. Pediatr Ann 2001;30(8):446-52
3. Tong PY, Enke-Miyazaki E, Bassin RE, et al. Screening for amblyopia in preverbal children with photoscreening photographs. National Children’s Eye Care Foundation Vision Screening Study Group. Ophthalmology 1998;105(5):856-63
4. Tong PY, Bassin RE, Enke-Miyazaki, et al. Screening for amblyopia in preverbal children with photoscreening results: II. Sensitivity and specificity of the MTI PhotoScreener. Ophthalmology 2000;107(9):1623-9
5. Tong PY, Macke JP, Bassin RE, et al. Screening for amblyopia in preverbal children with photoscreening photographs. III. Improved grading criteria for hyperopia. Ophthalmology 2000;10(9)7:1630-6
6. Simons BD, Siatkowski RM, Schiffman JC, et al. Pediatric photoscreening for strabismus and refractive errors in a high-risk population. Ophthalmology 1999;106(6):1073-80
7. Donahue SP, Johnson TM, Leonard-Martin TC. Screening for amblyogenic factors using a volunteer lay network and the MTI photoscreener. Initial results from 15,000 preschool children in a statewide effort. Ophthalmology 2000;107(9):1637-46
8. Committee on Practice and Ambulatory Medicine and Section on Ophthalmology; American Academy of Pediatrics. Use of photoscreening for children’s vision screening. Pediatrics 2002;109(3):524-5
9. Committee on Practice and Ambulatory Medicine, Section on Ophthalmology. American Association of Certified Orthoptists; American Association for Pediatric Ophthalmology and Strabismus; American Academy of Ophthalmology. Eye examination in infants, children, and young adults by pediatricians. Pediatrics 2003;111(4 Pt 1):902-7
10. American Association for Pediatric Ophthalmology and Strabismus. Photoscreening to detect amblyogenic factors (AAPOS Photoscreening Position Statement). Accessible at http://www.aapos.org/displaycommon.cfm?an=1&subarticlenbr=104  (Verified 10/15/07)
11. Savage HI, Lee HH, Zaetta D et al. Pediatric Amblyopia Risk Investigation Study (PARIS). Am J Ophthalmol 2005;140(6):1007-13
12. Leman R, clausen MM, Bates J, et al. A comparison of patched HOTV visual acuity and photoscreening. J Sch Nurs 2006;22(4):237-43
13. Chen YL, Lewis JW, Kerr N, et al. Computer-based real-time analysis in mobile ocular screening. Telemed J E Health 2006;12(1):66-72
14. Donahue SP, Baker JD, Scott WE, et al.  Lions Clubs International Foundation Core Four Photoscreening: results from 17 programs and 400,000 preschool children. J AAPOS  2006;10(1):44-8
15. Powell C, Porooshani H, Bohorquez MC et al. Screening for amblyopia in childhood. Cochrane Database Syst Rev 2005;CD005020
16. Kemper AR, Clark SJ. Preschool vision screening in pediatric practices. Clin Pediatr (Phila) 2006; 45(3):263-6
17. Donahue SP. Relationship between anisometropia, patient age, and the development of amblyopia. Am J Ophthalmol 2006; 142(1):132-40
18. Vision In Preschoolers Study (VIP Study). Accessible at http://www.clinicaltrials.gov/ct/show/NCT00038753  (Verified 10/16/07)

Cross References

None

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