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.

Anterior transposition of the superior oblique tendon in the treatment of oculomotor nerve palsy and its influence on postoperative hypertropia.

PURPOSE: To determine whether postoperative hypertropia after anterior transposition of the superior oblique tendon without trochleotomy could be avoided with a simplified surgical approach. METHODS: Eight patients with oculomotor nerve palsy (one patient was bilaterally affected) were retrospectively identified as having undergone anterior transposition of the superior oblique tendon without trochleotomy or vertical rectus muscle surgery between March 1992 and September 1998. The superior oblique tendon was cut at the medial border of the superior rectus muscle and placed 1-3.5 mm anterior to the medial insertion of the superior rectus muscle in each of these patients. Resection of the superior oblique tendon was not performed. The lateral rectus muscle was weakened, and no vertical rectus muscles were resected. RESULTS: Preoperative deviations with the uninvolved eye fixating in primary position ranged from 20-90 prism diopters (delta) of exotropia (mean: 49.3 delta) and from 0-20 delta of hypotropia (mean: 11.25 delta). Postoperative horizontal deviations in the primary gaze position ranged from 12 delta of exotropia to 20 delta of esotropia. Six cases were aligned within 10 delta of exotropia or esotropia. Postoperative vertical deviations in the primary gaze position ranged from 2 delta of hypertropia to 8 delta of hypotropia. Six cases were aligned within 2 delta of deviation. Significant postoperative restrictive hypertropia, or new postoperative paradoxical ocular movements, did not occur in any patient. Patients who underwent follow-up >4 months maintained stable eye alignment. CONCLUSION: Transposition of the superior oblique tendon without simultaneous resection or trochleotomy, or additional surgery to the vertical rectus muscle simplifies the surgical technique and eliminates subjective decision making regarding the amount of resection.

The incidence of ophthalmologic interventions in children with birth weights less than 1251 grams. Results through 5 1/2 years. Cryotherapy for Retinopathy of Prematurity Cooperative Group.

OBJECTIVE: This study aimed to report the frequency of ophthalmologic surgical and medical therapies provided to children with birth weights less than 1251 g who had all stages of retinopathy of prematurity (ROP). In addition, this study aimed to report the initial age at which such procedures are provided and to report the frequency of cerebrospinal fluid shunts. DESIGN: Observational case series with prospective data collection. PARTICIPANTS: Children from the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) with birth weights less than 1251 g served as subjects. Group A included 257 children from all 23 CRYO-ROP study centers who had threshold ROP, who had participated in the randomized trial of cryotherapy, and who had survived to age 1 year. Group B included 1208 children from 5 of the 23 study centers who had varying severity of ROP (69 had threshold ROP) and who had participated in a 5 1/2-year study of the natural history of ROP. MAIN OUTCOME MEASURES: Investigators documented medical and surgical ophthalmologic interventions through age 5 1/2 years as well as cerebrospinal fluid shunting surgery for hydrocephalus through age 2 years. RESULTS: Group A was composed of 257 children with threshold ROP who underwent 226 ocular interventions in addition to cryotherapy (0.9 intervention per child). The most common treatments performed on the randomized cohort of children were vitrectomy (26% of patients), lensectomy (18%), amblyopia therapy (20%), and strabismus surgery (10%). Cataract surgery not associated with vitrectomy was performed infrequently (2%) and was performed equally often in treated and control eyes. Amblyopia therapy was prescribed as often for treated as for control eyes. Cerebrospinal fluid shunts were placed in 11% of these children. Group B was composed of 1208 natural history patients who underwent 239 ophthalmologic interventions (0.4 intervention per child). Strabismus surgery was the most commonly performed procedure for the natural history cohort of children (6% of the children). Amblyopia therapy was prescribed for 7% of the natural history patients. Cerebrospinal fluid shunts were required by 3% of the natural history infants, more often in children with more severe ROP. CONCLUSIONS: These premature infants underwent a large number of ophthalmologic treatments during the first 5 1/2 years of life. The long-term costs of both extreme prematurity and ROP include not only the initial ablative therapy for ROP and societal loss due to blindness that still occurs in some cases, but also the ongoing costs of caring for eye problems.

Ocular abnormalities in the mucopolysaccharidoses after bone marrow transplantation. Longer follow-up.

OBJECTIVE: The purpose of the study was to provide longer follow-up of ocular findings in patients with mucopolysaccharidoses (MPS) after bone marrow transplantation (BMT). DESIGN: The study design was a retrospective 6-year cohort evaluation. PARTICIPANTS: Twenty-three patients with MPS (19 with MPS type I-H, 3 with MPS type III, 1 with MPS type VI) were studied. INTERVENTION: Bone marrow transplantation was performed. MAIN OUTCOME MEASURES: The following outcome measures were considered: vision, slit-lamp biomicroscopic and funduscopic examinations, intraocular pressure, electroretinography (ERG), and retinoscopy. RESULTS: Thirteen (81%) of 16 patients showed ERG improvement in the first year. However, all patients showed slowly progressive decline of the ERG over longer follow-up. Other ocular findings included optic atrophy (n = 7 patients), disc edema (n = 6 patients), strabismus (n = 6 patients), nystagmus (n = 6 patients), cataract (n = 3 eyes), keratoconjunctivitis sicca (n = 4 eyes), ocular hypertension (n = 2 eyes), and glaucoma (n = 2 eyes). CONCLUSIONS: The MPS are rare and heterogeneous disorders characterized by progressive retinal degeneration and blindness. Ocular abnormalities can occur as a result of the disease or as a consequence of BMT. Successful BMT has been shown to improve systemic health, but this may not reflect continuing ocular status and retinal function. Despite early improvement in ERG function, longer follow-up suggests progressive retinal decline.

Neonatal asteroid hyalosis.

Asteroid hyalosis, noted in 0.83% of routine eye examinations, is uncommon in younger patients and is more frequently seen in patients more than 60 years old. It has been considered to be related to an aging process, and when it occurs in younger patients, ocular disease is typically associated. We report a 4-week-old patient with Down syndrome and bilateral congenital cataracts who had unilateral asteroid hyalosis.