Visual acuity at 10 years in Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study eyes: effect of retinal residua of retinopathy of prematurity

OBJECTIVE

To describe recognition (letter) acuity at age 10 years in eyes with and without retinal residua of retinopathy of prematurity (ROP).

DESIGN

Presence and severity of ROP residua were documented by a study ophthalmologist. Masked testers measured monocular recognition visual acuity (Early Treatment of Diabetic Retinopathy Study) when the children were 10 years old. Two hundred forty-seven of 255 surviving Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) randomized trial patients participated. A reference group of 102 of 104 Philadelphia-based CRYO-ROP study participants who did not develop ROP was also tested.

RESULTS

More severe retinal residua were associated with worse visual acuity, regardless of whether retinal ablation was performed to treat the severe acute-phase ROP. However, within each ROP residua category, there was a wide range of visual acuity results.

CONCLUSIONS

This is the first report of the relation between visual acuity (Early Treatment of Diabetic Retinopathy Study charts) and structural abnormalities related to ROP in a large group of eyes that developed threshold ROP in the perinatal period. Visual deficits are greater in eyes with more severe retinal residua than in eyes with mild or no residua. However, severity of ROP residua does not predict the visual acuity of an individual eye because within a single residua category, acuity may range from near normal to blind.

The natural history of glaucoma and ocular hypertension after pediatric cataract surgery

INTRODUCTION

We sought to define the prevalence and natural history of ocular hypertension and glaucoma for at least a 10-year period after pediatric cataract surgery.

METHODS

We conducted a prospective observational study of patients who received pediatric cataract surgery. Inclusion criteria included 2 directed ophthalmologic examinations performed at a minimum of 5 and 10 years after surgery.

RESULTS

A total of 63 patients (22 with bilateral cataracts and 41 with unilateral cataracts) were examined at a median of 15.1 year (range, 10.3-21.3 years) after surgery. A majority of the subjects had glaucoma or ocular hypertension (ie, 59%; 37/63). Nineteen percent (12/63) had glaucoma (5/22 with bilateral cataracts and 7/41 with unilateral cataracts). Approximately half (7/12) had developed glaucoma during the first 5-year observational period and the remainder (5/12) developed it during the following observational period. Forty percent (25/63) of the patients had ocular hypertension in at least one aphakic eye (9/23 with bilateral cataracts and 16/40 with unilateral cataracts). The rate of progression from ocular hypertension to glaucoma over a mean observational period of 7.2 years (range, 6.2-8.1 years) was 23% (5/22).

DISCUSSION

Patients who receive surgery for pediatric cataracts are at very high risk of developing ocular hypertension and glaucoma. Patients can develop late-onset glaucoma and ocular hypertension more than 10 years after surgery. Years of ocular hypertension may precede the diagnosis of late-onset glaucoma.

Prevalence of myopia at 9 months in infants with high-risk prethreshold retinopathy of prematurity

PURPOSE

To examine the prevalence of myopia and high myopia at 9 months corrected age in premature infants who participated in the multicenter randomized trial of Early Treatment for Retinopathy of Prematurity (ETROP).

DESIGN

Randomized, controlled clinical trial.

PARTICIPANTS

Four hundred one infants with birth weights of <1251 g in whom prethreshold ROP developed in one or both eyes and who were determined to have a significant risk (> or =15%) of poor structural outcomes without treatment, based on the risk management for ROP program.

INTERVENTION

Infants with bilateral high-risk prethreshold ROP (n = 317) had 1 eye randomized to early treatment, and the fellow eye was managed conventionally. In asymmetric cases (n = 84), the eye with high-risk prethreshold ROP was randomized to early treatment or conventional management (control). Eyes randomized to early treatment at high-risk prethreshold ROP and eyes randomized to conventional management in which threshold ROP developed received peripheral retinal photocoagulation or cryotherapy. Conventionally managed eyes in which threshold ROP did not develop were observed. Cycloplegic retinoscopy data were obtained at 9 months corrected age from 321 eyes treated early and 307 eyes managed conventionally.

MAIN OUTCOME MEASURES

Prevalence of myopic (spherical equivalent > or = 0.25 diopters [D]) and highly myopic (> or =5.00 D) eyes in each group.

RESULTS

The prevalence of myopia (64.5% vs. 69.4%; P = 0.06) and high myopia (25.5% vs. 28.3%; P = 0.20) was similar between eyes treated at high-risk prethreshold and high-risk prethreshold eyes managed conventionally. Among high-risk eyes managed conventionally, the prevalence of myopia (78.2% vs. 53.3%) and high myopia (37.6% vs. 11.2%) was higher when threshold ROP developed than when regression without treatment occurred. Among eyes treated at high-risk prethreshold ROP, the prevalence of myopia (93.3% vs. 91.7% vs. 60.6%) and of high myopia (53.3% vs. 33.3% vs. 20.8%) was higher in eyes with abnormal angle of temporal retinal vessels or macular ectopia than in eyes with no retinal residua. This also held true for conventionally managed eyes.

CONCLUSIONS

Early treatment at high-risk prethreshold did not place eyes at greater risk of myopia and high myopia than did conventional management of eyes with high-risk prethreshold ROP.

Functional and structural outcomes following lensectomy for ectopia lentis

PURPOSE

High refractive errors and optical aberrations reduce vision when the lens edge bisects the pupil. We studied outcomes of eyes with ectopia lentis following lensectomy.

METHODS

Charts of 11 consecutive patients with bilateral ectopia lentis who underwent lensectomy-anterior vitrectomy in at least one eye from 1985 to 2004 were reviewed. Eighteen eyes were operated. One eye was excluded due to short-term follow-up (<2 years).

RESULTS

Mean age at surgery was 7.7 years (2 to 17 years). Median follow-up after lensectomy was 10 years (range 2 to 16 years). Six eyes were followed for 6 to 10 years, and another six eyes were followed for 11 to 16 years. Patient diagnoses included Marfan syndrome (nine eyes), ectopia lentis et pupillae (three eyes), simple ectopia lentis (two eyes), homocystinuria (two eyes), and sporadic spherophakia (one eye). Preoperative best-corrected visual acuity (BCVA) ranged from 20/60 to light perception, and postoperative BCVA ranged from 20/20 to 20/100 (14 eyes were at least 20/30). Complications included posterior vitreous detachment (two eyes, 12%), glaucoma (one eye, 6%), transient ocular hypertension (one eye, 6%), wound dehiscence with iris incarceration (one eye, 6%), transient vitreous hemorrhage (one eye, 6%), and peripheral anterior synechiae (one eye, 6%). No retina detached.

CONCLUSIONS

Our cohort of patients with long-term follow-up shows that pars plana lensectomy can be successful in restoring vision when conservative measures fail.

15-year outcomes following threshold retinopathy of prematurity: final results from the multicenter trial of cryotherapy for retinopathy of prematurity

OBJECTIVE

To report the ocular structure and visual acuity outcomes at age 15 years, and the incidence of retinal detachment between 10 and 15 years of age, for patients in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP).

METHODS

Subjects were 254 survivors from 291 preterm children with birth weights less than 1251 g and severe (threshold) retinopathy of prematurity (ROP) in one or both eyes, who participated in the CRYO-ROP trial. At age 15 years, unfavorable ocular structure was posterior retinal fold or worse judged by study-certified ophthalmologists. Unfavorable distance visual acuity was 20/200 or worse measured by study-certified testers using Early Treatment of Diabetic Retinopathy Study recognition acuity charts.

RESULTS

Thirty percent of treated eyes and 51.9% of control eyes (P<.001) had unfavorable structural outcomes. Between 10 and 15 years of age, new retinal folds, detachments, or obscuring of the view of the posterior pole occurred in 4.5% of treated and 7.7% of control eyes. Unfavorable visual acuity outcomes were found in 44.7% of treated and 64.3% of control eyes (P<.001).

CONCLUSION

The benefit of cryotherapy for treatment of threshold ROP, for both structure and visual function, was maintained across 15 years of follow-up. New retinal detachments, even in eyes with relatively good structural findings at age 10 years, suggest value in long-term, regular follow-up of eyes that experience threshold ROP.

Referral patterns for common amblyogenic conditions

PURPOSE

The early detection and management of common pediatric ophthalmic problems is crucial to assure successful visual maturation and best potential for development of binocular vision. The referring physician plays a pivotal role in this process. This study was designed to investigate the prevailing referral patterns for common amblyogenic conditions in a defined geographic region.

METHODS

We sent a short questionnaire to 300 pediatricians and 1500 family practitioners (FPs) in Minnesota, asking them to use a multiple choice system to indicate how long after diagnosis they would wait before referring a child to an ophthalmologist for exotropia, esotropia, ptosis, nystagmus, and abnormal red reflex.

RESULTS

The response rate was 46.9% ( n = 117) for pediatricians and 17.9% ( n = 240) for FPs. Of respondents, 64.6% of pediatricians and 50.2% of FPs would refer patients with exotropia within 2 months of diagnosis ( P < 0.001). For esotropia, 58.8% of pediatricians would refer within 2 months, while 38.6% would wait up to 12 months. In comparison, 48.7% of FPs would refer sooner, while 47.9% would refer later. These differences in referral patterns for pediatricians and FPs were statistically significant ( P = 0.037). There was less variation for referral of ptosis, nystagmus, and abnormal red reflex. These referral patterns were unaffected by years in practice.

CONCLUSIONS

Pediatricians referred patients with strabismus significantly more promptly than FPs. The majority of primary care providers (PCPs) appropriately timed their referrals for these amblyogenic conditions. However, many children continue to be referred late, underscoring the need for continued education of PCPs.

Glaucoma following cataract surgery in children: surgically modifiable risk factors

PURPOSE

To determine the incidence of glaucoma following cataract surgery in children and to identify surgically modifiable risk factors that may influence the development of glaucoma in these eyes.

METHODS

All lensectomies performed in patients 18 years old or younger over a 7-year period (1995 through 2001) were identified by conducting a database search. A retrospective chart review was performed for every patient identified. Data extraction included patient's age at surgery, intraocular lens implantation at cataract extraction, date of glaucoma onset, and length of follow-up. Statistical methods included risk ratio calculations and Kaplan-Meier analyses for the "time to glaucoma" for eyes undergoing lensectomy.

RESULTS

We identified 116 eyes of 79 children in whom lensectomy was performed. The median age at cataract surgery was 178 days (approval 6 months). Mean follow-up time was 2.7 years. The overall incidence of glaucoma was 11%. Kaplan-Meier analysis demonstrated that eyes operated on at less than 30 days of age were statistically more likely to develop glaucoma than eyes operated on at age 30 days or older (P < .001). For those operated on at less than 30 days of age, the risk ratio was 11.8 for subsequent glaucoma development compared with those operated on at 30 days of age or older. Forty-nine eyes (42%) had primary intraocular lens implantation, and none of these developed glaucoma (P = .001).

CONCLUSIONS

Timing of surgery at less than 30 days of age and lack of implantation of an intraocular lens at lensectomy were both associated with an increased risk of subsequent glaucoma. Knowledge of modifiable risk factors is essential to allow ophthalmic surgeons to make cogent decisions regarding the care of children with cataracts.

Efficacy of spectacles in persons with albinism

INTRODUCTION

Patients with albinism have varying degrees of reduced vision, strabismus, iris transillumination, nystagmus, fundus hypopigmentation, and foveal hypoplasia. High refractive errors are common, but reduced vision persists due to nonrefractive factors, causing reluctance by some clinicians to prescribe spectacles. We sought to evaluate the effect of spectacle correction of refractive error on clinical findings and recorded compliance with refractive corrections, as little detailed data exist.

METHODS

We prospectively examined 35 consecutive patients with albinism for whom glasses had been prescribed to determine if objective improvement in recognition visual acuity (VA), strabismus, anomalous head posture (AHP), fusion, or stereoacuity occurred with refractive correction. Parents or patients reported compliance with glasses wear (excellent: >75% of awake hours; good: 50-75% of awake hours; fair: 26-50% of awake hours; poor: <25%).

RESULTS

Median age was 9.5 years (range: 3 to 30). Median refractive correction was 1.875 D spherical equivalent (range: -9.75 to +8.88 D). Glasses wear was initiated at a median age of 14 months (range: 3 months to 14 years). Mean binocular VA at distance was 20/80.9 corrected and 20/107.6 uncorrected ( P < 0.001). Mean VA at near was 20/28.4 corrected and 20/41 uncorrected ( P < 0.001). Mean strabismic deviation was 7.2 PD with glasses and 10.0 PD without glasses at distance ( P = 0.006) and 10.8 PD with glasses and 14 PD without glasses at near ( P = 0.042). Mean AHP at distance was 8.3 degrees with glasses and 7.3 degrees without glasses at distance ( P = 0.327) and 4.7 degrees both with and without glasses at near ( P = 0.308). Twenty-one patients had fusion with or without glasses, two had fusion only with glasses, and one patient had fusion only without glasses. The other patients did not have any detectable degree of fusion. Twenty-seven individuals had no stereoacuity with or without glasses, five had gross stereoacuity of 3000 seconds of arc both with and without glasses, and three had gross stereoacuity only while wearing glasses. Compliance was excellent in 29 patients, fair in four, and poor in two.

CONCLUSION

This prospective study showed a significant improvement in corrected VA and alignment in persons with albinism, despite overall subnormal acuity. Some individuals also experienced improvement in binocular alignment and AHP. Compliance with spectacles was generally good. Therefore, refractive correction should be encouraged in persons with albinism as improvement in visual function is likely to occur.

Health-related quality of life at age 10 years in very low-birth-weight children with and without threshold retinopathy of prematurity

OBJECTIVE

To describe parental perspectives on health status and health-related quality of life (HRQL) at age 10 years in children with birth weights less than 1251 g who participated in the multicenter Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study.

METHODS

In 244 participants in the randomized CRYO-ROP trial and 102 CRYO-ROP participants who did not develop ROP, the Health Utilities Index (HUI) system was used to characterize health status for the following 8 attributes: vision, hearing, speech, ambulation, dexterity, emotion, cognition, and pain. Using a utility formula, HRQL was determined for each child on a scale from 0.0 (dead) to 1.00 (perfect health).

RESULTS

The proportion of the ROP-randomized group with limitations in 4 attributes or more was 20.6% compared with 2.0% for the no-ROP group. Within the ROP-randomized group, the proportion of "sighted" children with limitations in 4 attributes or more was 6.4% vs 46.5% in the "blind/low vision" group. The median HRQL score for the ROP-randomized children was lower than for the no-ROP children (0.72 vs 0.97, P<.001); the median HRQL score for the sighted-randomized children was 0.87 vs 0.27 for the blind/low vision children (P<.001).

CONCLUSIONS

Threshold ROP was associated with functional limitations in health attributes and reduction in HRQL scores at age 10 years. Furthermore, among children who developed threshold ROP, a greater reduction in HRQL scores was found among children with a poor visual outcome compared with those with better sight.

Ophthalmic manifestations of Wolf-Hirschhorn syndrome

PURPOSE

Wolf-Hirschhorn syndrome is caused by partial deletion of the short arm of chromosome 4 (4p-). Common features include developmental delay, microcephaly, seizures, craniofacial anomalies, mental retardation, and cardiac defects. This article further describes the ocular manifestations of this rare disorder.

METHODS

Charts of patients with 4p- from the University of Arkansas (n = 3) and the University of Minnesota (n = 7) were reviewed. Diagnosis was made by a geneticist and was confirmed by karyotype. Cytogenetic reports were available for review in eight patients.

RESULTS

Ten patients (six females and four males) aged 4 months to 11 years were included. Ophthalmic findings included exodeviation (9/10), nasolacrimal obstruction (6/10), shallow orbits (3/10), epicanthal folds (3/10), foveal hypoplasia (3/10), upper lid coloboma (2/10), optic disk anomalies (2/10), downslanting palpebral fissures (2/10), microcornea (2/10), hypertelorism (1/10), nystagmus (1/10), and chorioretinal coloboma (1/10). Eight patients with 4p- had break points ranging from band 4p14 to 4p16.3.

CONCLUSIONS

This study expands on previous reports of the ophthalmic phenotype in 4p- and includes the additional findings of foveal hypoplasia, nystagmus, shallow orbits, epicanthal folds, and upper lid colobomas. Ophthalmic findings in 4p- are variable, likely related to the size of the deletion.

Unilateral inferior oblique anterior transposition for dissociated vertical deviation

PURPOSE

This study analyzes the outcomes after unilateral inferior oblique anterior transposition (IOAT) for manifest dissociated vertical deviation (DVD).

METHODS

A retrospective chart review was conducted for all patients who had unilateral or markedly asymmetric DVD, ipsilateral overaction of the inferior oblique muscle, lack of alternating fixation, and underwent unilateral IOAT surgery between March 1997 and March 2001. In each case, the bunched inferior oblique muscle was anteriorly transposed to the lateral edge of the insertion of the inferior rectus muscle. The primary outcome variable was change in DVD. Secondary outcome variables included inferior oblique muscle action, graded from -4 to +4, and vertical deviation in primary gaze.

RESULTS

Ten consecutive patients met the inclusion criteria. Median age at the time of surgery was 14 years (range, 2 to 41 years.) Mean follow-up was 25 months (range, 6 to 60 months). Ipsilateral DVD in primary position decreased from a mean of 20.2 prism diopters (PD) (range, 14 to 33 PD) to 3.7 PD (range, 0 to 9 PD) (t test, P <.001). Nine (90%) of the patients had an excellent postoperative result (residual DVD of 0 to 4 PD) and one (10%) had a good result (5 to 9 PD). Inferior oblique overaction was eliminated in all patients. Mean inferior oblique muscle action decreased from +2.4 to -1.3. Three patients developed a transient or permanent 4 to 5 PD postoperative ipsilateral hypotropia in primary position. Dissociated vertical deviation in the fellow eye did not develop, or if present preoperatively, did not increase.

CONCLUSIONS

Unilateral IOAT is an effective treatment for unilateral or markedly asymmetric DVD in patients with a strong, contralateral fixation preference. This surgery reduces inferior oblique overaction but may cause an ipsilateral hypotropia.

Positive angle kappa in albinism

BACKGROUND

Albinism is an inherited disorder of deficient melanin production. There is a high prevalence of strabismus in patients with albinism. We investigated the prevalence of a positive angle kappa in patients with albinism and report its effect on assessment of binocular alignment.

METHODS

We retrospectively reviewed the charts of 207 consecutive patients with the diagnosis of albinism seen at the University of Minnesota between 1984 and 2002. Angle kappa and alignment using prism and alternate-cover test (PACT) and Krimsky measurements were recorded.

RESULTS

In 99.6% of our patients with albinism, angle kappa was noted to be positive. The mean difference between PACT and Krimsky measurements was 17.11 prism diopters in the more exotropic (or less esotropic) direction per Krimsky test. Because of the high prevalence of a positive angle kappa, esodeviations often appeared less and exodeviations appeared greater than when measured using PACT.

CONCLUSIONS

Positive angle kappa can be considered another clinical feature of albinism. Consideration should be given to the effect of positive angle kappa on alignment as observed by Krimsky measurement when planning extraocular muscle surgery, particularly when preoperative sensory testing suggests binocular potential.

Educational and social competencies at 8 years in children with threshold retinopathy of prematurity in the CRYO-ROP multicenter study

OBJECTIVE

To describe the educational status and special education services at 8 years among children who had threshold retinopathy of prematurity (ROP).

METHODS

A prospective study was conducted of a cohort of children who had birth weight of <1251 g and threshold ROP in the Cryotherapy for Retinopathy of Prematurity multicenter study. At age 5.5 years, visual status, functional skills, and social information were obtained. At 8 years, special education classes, developmental disabilities, rehabilitation therapies, and academic and social competencies were determined by questionnaire. Visual status was considered favorable/unfavorable on the basis of the better eye.

RESULTS

Of 255 survivors, 216 (85%) were evaluated at both 5.5 and 8 years. Major impairments were significantly more prevalent in children with unfavorable versus favorable visual status: cerebral palsy (39% vs 16%), developmental disability (57% vs 22%), autism (9% vs 1%), and epilepsy (23% vs 3%). Special education services (63% vs 27%), below-grade-level academic performance (84% vs 48%), and school-based rehabilitation services were significantly less common in children with favorable visual status. Favorable visual status, favorable functional ratings at 5.5 years, markers of higher socioeconomic status, and nonblack race were associated with significantly lower rates of both special education placement and below-grade-level academic performance at age 8. On multivariate logistic regression, only favorable visual status and functional status remained significant predictors for decreasing special education placement.

CONCLUSION

Threshold ROP is associated with high rates of developmental, educational, and social challenges in middle childhood; preserved vision was associated with a clear advantage, with more than half of the children with favorable visual status performing at grade level.

Risk analysis of prethreshold retinopathy of prematurity

OBJECTIVE

To present a new multifactorial algorithm to integrate important risk factors for unfavorable retinal outcome in eyes that reached prethreshold retinopathy of prematurity (ROP) in the Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study. A computerized risk model (RM-ROP2) was developed from this algorithm to identify high-risk prethreshold eyes for enrollment in the Early Treatment for Retinopathy of Prematurity randomized trial.

METHODS

Data were analyzed from 613 eyes (1 eye per infant) in the natural history cohort of the Multicenter Trial for Cryotherapy for Retinopathy of Prematurity. These eyes were selected from infants in whom 1 or both eyes progressed to prethreshold ROP. Eyes that progressed to threshold ROP and were randomized to cryotherapy were excluded from this study, but control eyes that reached threshold ROP were included. The course of ROP for 1 prethreshold eye for each infant was tracked until the evaluation of its structural outcome at 3 months' postterm. Tables present structural outcome by selected risk characteristics. A multiple logistic risk model is used to summarize the combined effect of all of these known prognostic risk factors as they relate to structural outcome.

RESULTS

Eyes were classified by predicted outcome into 10 risk categories, lowest to highest. Both the observed and predicted outcomes in each category showed an increasingly unfavorable outcome when viewed from lowest to highest risk. Prethreshold ROP eyes were then divided into 2 groups, high-risk, eyes (risk, 0.15-1.0) and low-risk eyes (risk, <0.15). High-risk eyes had an unfavorable outcome of 36% at 3 months' postterm; whereas, only 5% of the low-risk eyes had an unfavorable outcome.

CONCLUSION

The model effectively identifies prethreshold ROP eyes that have a relatively high risk and eyes that have a lower risk of an unfavorable structural outcome at 3 months.

Tyrosinase gene mutations in oculocutaneous albinism�1 (OCA1): definition of the phenotype

Oculocutaneous albinism (OCA) is a common human genetic condition resulting from mutations in at least twelve different genes. OCA1 results from mutations of the tyrosinase gene and presents with the life-long absence of melanin pigment after birth (OCA1A) or with the development of minimal-to-moderate amounts of cutaneous and ocular pigment (OCA1B). Other types of OCA have variable amounts of cutaneous and ocular pigment. We hypothesized that white hair at birth indicates OCA1 and tested this in a sample of 120 probands with OCA and white hair at birth. We found that 102 (85%) of the probands had OCA1 with one or two identifiable tyrosinase gene mutations, with 169 (83%) of the 204 OCA1 tyrosinase gene alleles having identifiable mutations and 35 (17%) having no identifiable change in the coding, splice junction, or proximal promoter regions of the gene. The inability to identify the mutation was more common with OCA1B (24/35, 69%) than with OCA1A (11/35, 31%) alleles. Seven probands with no tyrosinase gene mutations were found to have OCA2 with one or two P gene mutations, and in eleven, no mutations were detected in either gene. We conclude that (1) the presence of white hair at birth is a useful clinical tool suggesting OCA1 in a child or adult with OCA, although OCA2 may also have this presentation; (2) the molecular analysis of the tyrosinase and P genes are necessary for precise diagnosis; and (3) the presence of alleles without identifiable mutations of the tyrosinase gene, particularly in OCA1B, suggests that more complex mutation mechanisms of this gene are common in OCA.

MC1R mutations modify the classic phenotype of oculocutaneous albinism type 2 (OCA2)

The heterogeneous group of disorders known as oculocutaneous albinism (OCA) shares cutaneous and ocular hypopigmentation associated with common developmental abnormalities of the eye. Mutations of at least 11 loci produce this phenotype. The majority of affected individuals develop some cutaneous melanin; this is predominantly seen as yellow/blond hair, whereas fewer have brown hair. The OCA phenotype is dependent on the constitutional pigmentation background of the family, with more OCA pigmentation found in families with darker constitutional pigmentation, which indicates that other genes may modify the OCA phenotype. Sequence variation in the melanocortin-1 receptor (MC1R) gene is associated with red hair in the normal population, but red hair is unusual in OCA. We identified eight probands with OCA who had red hair at birth. Mutations in the P gene were responsible for classic phenotype of oculocutaneous albinism type 2 (OCA2) in all eight, and mutations in the MC1R gene were responsible for the red (rather than yellow/blond) hair in the six of eight who continued to have red hair after birth. This is the first demonstration of a gene modifying the OCA phenotype in humans.

Grating acuity in albinism in the first three years of life

PURPOSE

To compare grating acuity of children 1 to 3 years old with albinism with that of age-matched normal children, and to determine whether ocular pigment and macular structure are predictive of grating visual acuity.

METHODS

In this retrospective cross-sectional review of 64 children with albinism, binocular grating acuity was measured with Teller acuity cards at 1, 2, or 3 years of age. Iris transillumination and macular transparency were graded according to published scales. The presence or absence of macular melanin pigment and a rudimentary foveal reflex were assessed with direct and indirect ophthalmoscopy, respectively.

RESULTS

Mean grating acuities of the children with albinism at ages 1 (2.48 cycles (cy)/degrees), 2 (3.62 cy/degrees), and 3 (5.87 cy/degrees) were 2.3, 2.1, and 1.7 octaves lower than published norms (all with P <.001). The studied variables did not correlate with visual acuity except for macular transparency at age 2 (r = 0.40; P =.030).

CONCLUSIONS

Grating acuity can be used to assess the reduction in visual function in albinism in the first 3 years of life. However, grading of iris transillumination and macular transparency and recognition of an annular reflex or macular melanin do not consistently correlate with the development of vision measured by grating acuity.

Management of corn leafhopper (Homoptera: Cicadellidae) and corn stunt disease in sweet corn using reflective mulch

Plastic reflective mulches significantly reduced populations of corn leafhopper, Dalbulus maidis (DeLong & Wolcott), adults and the incidence of corn stunt disease caused by Spiroplasma kunkelii (CSS) in late planted sweet corn (Zea mays L.). The reflective mulches were more effective than were either foliar or soil applied insecticides in managing both the leafhopper and the pathogen it transmits. Yields of marketable ears were 1.5 to 2 times greater in reflective mulch plots than from fallow plots. This was due to larger ears (individual ear weight and length) rather than an increase in the number of ears. The use of reflective mulches provides an alternative strategy to insecticides in the management of both D. maidis and corn stunt disease. Such a strategy may prove useful to growers in Latin America and to limited resource growers and organic growers in the United States who wish to grow corn without the use of insecticides.

Efficacy of inferior oblique anterior transposition placement grading for dissociated vertical deviation

OBJECTIVE

To determine if graded anterior placement of a transposed inferior oblique muscle is beneficial for treating variable amounts of dissociated vertical deviation (DVD).

DESIGN

Retrospective, consecutive, comparative case series.

PARTICIPANTS

Patients who underwent inferior oblique muscle anterior transposition (IOAT) for DVD at one institution between 1991 and 1999.

METHODS

Chart review. All patients had IOAT procedures of graded placement at 1, 2, or 3 mm anterior to the inferior rectus muscle insertion or standard placement at the level of the inferior rectus muscle insertion.

MAIN OUTCOME MEASURES

The effect of graded and standard placement was assessed by measuring the difference between preoperative and postoperative DVD and was defined as DVD correction. The success of surgery was judged by the residual DVD at long-term follow-up of 6 months or more. Excellent, fair, and poor outcomes were defined as residual DVD of 0 to 5 prism diopters (PD), 6 to 12 PD, and 13 or more PD, respectively.

RESULTS

Fifty-five patients (106 eyes) underwent IOAT for DVD. The comparison of DVD correction for the standard versus graded group yielded significance at long-term follow-up (P = 0.001). This result became nonsignificant after adjusting for preoperative DVD (P = 0.178). The power to detect a 5-PD difference between graded and standard placement was 90%. The surgical success was similar for patients receiving graded and standard IOAT. Patients with 0 to 15 PD of preoperative DVD fared better than those with more than 15 PD of preoperative DVD.

CONCLUSIONS

This study does not demonstrate increased correction of DVD with graded IOAT versus standard IOAT. We do not recommend placement of the inferior oblique muscle anterior to the inferior rectus muscle insertion. Inferior oblique muscle anterior transposition for DVD was clinically more effective for smaller amounts of DVD.

Change in refractive error after unilateral levator resection for congenital ptosis

PURPOSE

To analyze refractive change in children with congenital ptosis who have undergone unilateral levator resection.

METHODS

All charts of patients with congenital ptosis who underwent one levator resection performed by 2 pediatric ophthalmologists at the University of Minnesota from 1981 through 1995 were reviewed. Postoperative refractive changes were analyzed within the group of eyes that underwent ptosis repair and within the group of fellow eyes that served as age-matched controls. The preoperative and postoperative refractive error of each operated eye was also compared with its paired unoperated eye.

RESULTS

Complete preoperative and postoperative refractive data were available for 28 patients with congenital ptosis requiring only one levator resection. The mean age at surgery was 3 years 8 months. The preoperative mean ptosis was 3.5 mm (range, 1.5-6 mm). At the last postoperative visit (mean, 20 months; SD, 11 months), the mean refractive change in the operated eye was 1.23 D sphere (range, 0-3.50 D; P =.061) and 0.83 D cylinder (range, 0-3.00 D; P =.002). Within the group of control eyes, no significant mean spherical or cylindrical changes were found at the last postoperative visit. Fourteen eyes with preoperative ptosis had a cylindrical change of 0.75 D or more, compared with a similar change in 4 control eyes. When refractive errors were compared interocularly, no statistically significant differences were found.

CONCLUSIONS

Our results showed significant cylindrical change in eyes that underwent levator resection for unilateral congenital ptosis. Careful refraction is necessary after unilateral levator resection.

High injection pressure during intralesional injection of corticosteroids into capillary hemangiomas

BACKGROUND

Intralesional injection of corticosteroids is an effective treatment for tumors of the head and neck. Complications are rare but include permanent loss of vision. We designed a study to investigate the mechanism for this complication.

METHODS

Three fellowship-trained pediatric ophthalmologists participated in the study in a nonmasked fashion. Four patients received 5 separate treatment sessions of an intralesional injection of a 50-50 mixture of triamcinolone diacetate (40 mg/mL) and betamethasone sodium phosphate and betamethasone acetate (6 mg/mL) into capillary hemangiomas. Injection pressure was obtained in real time using a cannula designed for this purpose. Maximum pressure, mean pressure, and volume of corticosteroid were measured from each injection.

RESULTS

A total of 71 injections (range, 8-33 injections per patient) was performed. The total volume of corticosteroid ranged from 0.9 to 2.1 mL. In 63 of 71 injections, the maximum pressure exceeded 100 mm Hg (range, 18.65-842.18 mm Hg). Each surgeon produced injection pressures greater than the systemic arterial pressures of each patient.

CONCLUSIONS

Injection pressures exceeding the systemic arterial pressures routinely occur during intralesional injections of corticosteroids into capillary hemangiomas. Experienced surgeons participating in a nonmasked protocol were unable to prevent high injection pressures of corticosteroid. A sufficient volume of corticosteroid injected at high injection pressure would account for the embolization of corticosteroid particles into the ocular circulation from retrograde arterial flow. We recommend limiting the volume of corticosteroid and performing indirect ophthalmoscopy on all patients receiving injections of long-acting corticosteroids into the orbit and periorbital soft tissue.

Stereopsis in patients with albinism: clinical correlates

PURPOSE

A hallmark of albinism is excessive decussation of retinostriate projections at the optic chiasm. This misprojection might lead to abnormalities in the retinal correspondence and may account for the usual absence of stereovision. We report on 2 groups of patients with albinism who have either fine or gross stereopsis and compare the clinical findings of these groups to other patients with albinism with similar visual acuities but no stereopsis.

METHODS

A retrospective chart review of patients with albinism was used to segregate those with a letter visual acuity of 20/100 or better in one eye, assessment of stereopsis, and strabismus < or = 10 PD. Forty-five patients were identified. Albinism type, best-corrected visual acuity, motility, Titmus vectograph stereoacuity, iris and macula transparency grades, and the presence or absence of both melanin and an annular reflex in the macula were tabulated. A comparison of the clinical characteristics of the groups with and without stereopsis was made.

RESULTS

Those albino subjects who demonstrated stereopsis had better visual acuity, less iris transillumination, more frequent presence of melanin in the macula, less nystagmus, and less marked foveal hypoplasia than the albino subjects without stereopsis. No nystagmus was clinically detected in 5 patients with fine stereopsis. All these differences were statistically significant. Macular transparency grade was not significantly different between the groups.

CONCLUSIONS

Patients with albinism who demonstrate stereopsis tend to have better visual acuity, more iris pigment, and more melanin pigment in the macula than their counterparts without stereopsis.

Does cryotherapy affect refractive error? Results from treated versus control eyes in the cryotherapy for retinopathy of prematurity trial

PURPOSE

To evaluate the effect of cryotherapy on refractive error status between ages 3 months and 10 years in children with birth weights of less than 1251 g in whom severe retinopathy of prematurity (ROP) developed in one or both eyes during the neonatal period.

DESIGN

Randomized clinical trial.

PARTICIPANTS

Two hundred ninety-one children in whom severe ROP developed during the neonatal period.

INTERVENTION

Cryotherapy for ROP.

MAIN OUTCOME MEASURES

Cycloplegic Refraction

METHODS

The children underwent repeated follow-up eye examinations, including cycloplegic retinoscopy, between 3 months and 10 years after term due date. Refractive error data from all eyes that were randomized to cryotherapy were compared with data from all eyes that were randomized to serve as controls. Refractive error data were also compared for a subset of children who had both a treated and a control eye that could be refracted.

RESULTS

At all ages, the proportion of treated eyes that were unable to be refracted because of retinal detachment, media opacity, or pupillary miosis was approximately half the proportion of the control eyes that were unable to be refracted. When data from all eyes that could be refracted were considered, the distribution of refractive errors between fewer than 8 diopters (D) of myopia and more than 8 D of hyperopia was similar for treated and control eyes at all ages. The proportion of eyes with 8 D or more of myopia was much higher in treated than in control eyes at all ages after 3 months. In the subset of children who had a treated eye and a control eye that could be refracted, distributions of refractive errors in treated versus control eyes were similar at most ages.

CONCLUSIONS

In both treated and control eyes, there was an increase in the prevalence of high myopia between 3 and 12 months of age. Between 12 months and 10 years of age, there was little change in distribution of refractive error in treated or control eyes. The higher prevalence of myopia of 8 D or more in treated eyes, as compared with control eyes, may be the result of cryotherapy's preservation of retinal structure in eyes that, in the absence of cryotherapy, would have progressed to retinal detachment.