Developmental delay and poverty in the strabismus clinic

Developmental Delay and Poverty in the Strabismus Clinic George B. Peters III, MD,a John W. Simon, MD,a Jitka Zobal-Ratner, MD,a and Anthony Malone, MDb Background: Strabismus and poverty are more common among developmentally delayed children. Poverty is difficult to define, but qualification for Medicaid benefits has been used as an indicator in the past. Methods: There was a retrospective review of 95 patients with strabismus younger than 7 years who were seen in the Department of Pediatric Ophthalmology at the Albany Medical Center for a 12-month period and were reviewed for the presence or absence of developmental delay. These patients were selected from 2 groups: one with Medicaid coverage and one without. Results: Developmental delays were noted in 13 patients without Medicaid (27.0%) and in 26 patients with Medicaid (55.3%) (P = .0096). Patients with Medicaid were less likely to name Allen pictures by age 3 years (P = .0003). Conclusions: Poverty is more commonly associated with delays in patients with strabismus, and this should alert ophthalmologists who work with Medicaid patients to seek to identify the presence of developmental delay in managing the care of these patients. (J AAPOS 1999;3:363-5)

number of reports have shown that strabismus is more common among developmentally delayed children than in the population at large.1-4 The strabismus in this group is different in character and in prognosis, leading some to postulate that a different mechanism may be responsible for its development.5-7 Other reports, mainly in the pediatric literature, have shown that poverty is more common among developmentally delayed children than among the population at large.8-12 Although this phenomenon has been noted in a number of developmental areas, its extent is not easily specified, because defining both poverty and developmental delay is problematic.13,14 Recognizing that both strabismus and poverty are associated with developmental delay, we suspected that poverty among children with strabismus might be a particular risk factor for developmental problems. We compare the incidence of developmental delay among children who have strabismus with and without poverty, using coverage under the Medicaid program as an indicator of poverty.15

A

SUBJECTS AND METHODS We identified the names of 866 consecutive patients during the 12 months proceeding September 1998 who were seen in the Albany Medical Center Department of Ophthalmology because of any type of strabismus. Patients

From the Department of Ophthalmologya and the Department of Pediatrics,b Albany Medical Center, Albany, New York. Submitted March 25, 1999. Revision accepted July 14, 1999. Reprint requests: John W. Simon, MD, Department of Ophthalmology, Albany Medical Center, 35 Hackett Boulevard, Albany, NY 12208. Copyright © 1999 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/99 $8.00 + 0 75/1/101867

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with pseudostrabismus or those with a history of strabismus but who had normal results on examinations were excluded. A random number generator was used to select 50 patients from the 192 patients with Medicaid and 50 patients from the 674 patients without Medicaid. Records were reviewed for evidence of developmental delay, for the type and treatment of strabismus and any associated structural eye pathology, and for the presence and outcome of amblyopia. Demographic information was tabulated. Insurance coverage was noted at registration and was available in all charts for both Medicaid and non-Medicaid patients. The examiner often but not routinely reviewed this information. Parents or other adults accompanying children for their appointments were routinely asked to complete a questionnaire including medical and developmental history; the need for special help at school; and occupational, physical, or speech therapy. This information was updated at each subsequent visit. Children were considered developmentally delayed if positive information was tabulated in any of these areas, if a specific development diagnosis (eg, attention deficit-hyperactivity disorder, speech and language delay) was listed, or if a unifying diagnosis with impact on development was recorded (eg, autism, cerebral palsy). Additionally, delays were inferred for children who were unable to identify Allen pictures by age 3 years or Snellen letters by age 6 years. All children underwent a full ophthalmologic examination, including motility evaluation, cycloplegic refraction, and assessment of best-corrected visual acuity. Amblyopia was diagnosed in verbal patients on the basis of an interocular visual acuity difference of at least 1 line. Amblyopia was diagnosed in preverbal patients on the basis of a definable fixation preference on cover testing using accommodative targets at distance and at near.

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Journal of AAPOS Volume 3 Number 6 December 1999

364 Peters et al TABLE 1. Developmental delay and Medicaid status in the strabismus clinic (P = .0096)

Medicaid Non-Medicaid

TABLE 2. Criteria for developmental delay

Developmental delay

No developmental delay

Total

26 (55.3%) 13 (27.0%)

21 (44.7%) 35 (73.0%)

47 48

RESULTS Charts were located for 48 of the non-Medicaid patients and for 47 of the Medicaid patients. Developmental delays were noted in 13 non-Medicaid patients (27.0%) and in 26 Medicaid patients (55.3%) (Table 1). This difference is statistically significant (P = .0096). The patients’ ages ranged from 6 months to 611⁄12 years (mean, 45⁄12 years) in the nonMedicaid group and 6 months to 69⁄12 years (mean, 37⁄12 years) in the Medicaid group. Among the 13 delayed patients in the non-Medicaid group, 11 patients had received physical, occupational, or speech therapy. Only 2 delayed patients had not received these interventions (Table 2). One carried the diagnosis of atypical autism; the other had a seizure disorder after intracranial hemorrhage at birth. Other specific developmental diagnoses ranged from mild speech delay to cerebral palsy. No patients were included solely because of concerns expressed by parents or ophthalmologists or because of the inability to name age-appropriate optotypes. Among the 26 delayed patients in the Medicaid group, 19 patients had received physical, occupational, or speech therapy. Of the 7 patients not receiving these interventions, 2 patients were identified as delayed by their parents (Table 2). Four of the remaining 5 patients had major impairments (eg, viral encephalomyelitis in infancy), which precluded participation in therapies. The last of the 7 patients, nearly aged 5 years, was included because she was unable to identify Allen pictures. Esodeviations were more common in both groups than exodeviations. However, the ratio of exodeviations to esodeviations was higher in the Medicaid group (13:24 or 35.1%:64.9%) than in the non-Medicaid group (7:37 or 15.9%:84.1%). This difference did not attain statistical significance (P = .0818). However, with the combination of the Medicaid and non-Medicaid groups, the ratio of exodeviations to esodeviations was significantly higher (P = .0290) among delayed children (12:18 or 40.0%:60.0%) than among nondelayed children (8:43 or 15.7%:84.3%). A similar number of patients in both groups underwent strabismus surgery (10 of 48 non-Medicaid and 11 of 47 Medicaid patients). Of all patients older than 3 years, 2 (5.3%) of 38 nonMedicaid children were unable to identify Allen pictures, whereas 13 (46.4%) of 28 Medicaid children (46.4%) were unable to do so. This difference is significant (P = .0003). Furthermore, among the delayed 3-year-old patients, 2 (20.0%) of 10 non-Medicaid children were unable to iden-

Special intervention(s) Specific developmental diagnosis Inability to identify age-appropriate optotypes

Medicaid

NonMedicaid

19 15 14

11 7 2

tify Allen pictures, whereas 13 (76.5%) of 17 Medicaid children were unable to do so (P = .0143). Amblyopia was diagnosed in 28 (58.3%) of 48 non-Medicaid patients but in only 21 (44.7%) of 47 Medicaid patients. This difference was not statistically significant (P = .2602). Resolution of amblyopia was noted at the last visit in 18 (64.3%) of 28 non-Medicaid patients with amblyopia but in only 5 (23.8%) of 21 Medicaid patients with amblyopia. This difference was statistically significant (P = .0012).

DISCUSSION Poverty is difficult to define from the information available in an outpatient medical office. Following the example of other authors, we chose to use Medicaid eligibility as an indicator of poverty.15 We recognize that many children not covered by Medicaid may nevertheless come from impoverished backgrounds, because the working poor are generally ineligible for Medicaid. Similarly, we recognize that families with children who have serious medical or developmental difficulties may more likely be covered under the Medicaid program. Despite these limitations, Medicaid eligibility is the most appropriate indicator of poverty available to the ophthalmologist. Although poverty is not the single criterion used to qualify for Medicaid assistance, most children receiving Medicaid in New York State qualify on the basis of family income criteria. Poverty has been associated with a variety of developmental delays, which are traditionally defined as performance in specific skill areas with a developmental quotient below 70.16 Children may have delays isolated in such areas as fine motor control of expressive speech, or they may have more global impairments. Identifying the specific type, range, and severity of delays can be difficult even for developmental specialists, because the criteria for delays can be arbitrary and culturally biased. In a pediatric ophthalmology practice, defining delay is especially problematic, because the information may not be available to or accurately transmitted from parents. However, the presence of a delay may have important implications for ophthalmologic care. Delayed children older than 3 years with Medicaid were less likely to be able to identify Allen pictures than their non-Medicaid counterparts. A variety of explanations may pertain to this observation, including cultural differences between Medicaid and non-Medicaid groups. It is also possible that delays in Medicaid patients tend to be more severe.

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Several reports have noted that strabismus is more common in the delayed population and that it is more likely to be an exodeviation.17,18 This latter finding is also corroborated by this study. Surgery for esotropia is more unpredictable and is more likely to result in an overcorrection in delayed patients.5,6 Some delayed children may have an underlying neurologic deficit affecting motor fusion that may compromise the results of strabismus surgery.7 It may be advisable to defer strabismus surgery or to decrease the surgical dose in children with esotropia who are delayed. 5,6 Our study did not specifically follow up patients to determine the success of amblyopia therapy in nonMedicaid and Medicaid patients. Nevertheless, we did observe that amblyopia was resolved or was inapparent at the last visit more frequently in non-Medicaid patients. This observation is consistent with the study of Hudak and Magoon,15 who demonstrated that poverty is associated with poorer outcomes of amblyopia therapy. It is possible that some of the differences in outcome, and even in the definition of delay, may be influenced by the examiner’s bias toward Medicaid patients. It is possible that strabismus and poverty represent interdependent, synergistic risk factors of developmental delay. Because the quantification of the risk associated with each is difficult, it is not possible to prove this interdependence statistically in this study. Even if the risks are independent, poverty and strabismus together constitute more than a 50% risk of developmental delay. Our finding that poverty is more commonly associated with delays in patients with strabismus should alert ophthalmologists who work with Medicaid patients. Some children with delays may not have received a diagnosis at the time an ophthalmologic examination was performed. In addition to modifying strabismus therapy and taking care to ensure close follow-up of amblyopia treatment in such children, ophthalmologists may consider referrals for developmental assessment and for physical, occupational, and speech therapy, if indicated.

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