Histologic effect of mitomycin C on strabismus surgery in the rabbit.

PURPOSE: To evaluate the efficiency of mitomycin C (MMC) in limiting the postoperative inflammatory response and scarring after strabismus surgery. METHODS: A prospective, two-stage, masked, controlled trial was conducted. In the first stage, the inflammatory response at the extraocular muscle reattachment site was increased after inferior rectus recession in eight rabbits. In the second stage, MMC (0.4 mg/ml) was applied during surgery to the eyes of 22 rabbits with inferior rectus recession. As a control, contralateral eyes were treated with saline solution. Seven weeks later, exenteration was performed, and the sites of muscle reattachment were processed for histologic examinations. The sums of the areas of the granulomas in the extraocular muscle reattachment sites of control and treated eyes were compared. RESULTS: There was no significant inhibitory effect of MMC on the inflammatory response of treated eyes compared with that of control eyes. CONCLUSIONS: The intraoperative use of MMC (0.4 mg/ml) was not effective in controlling the postoperative inflammatory response in rabbit eyes after extraocular muscle surgery. These data do not support the hypothesis that MMC reduces postoperative adhesions after strabismus surgery.

Quantification (grading) of inferior oblique muscle recession for V-pattern strabismus.

PURPOSE: To determine the effectiveness of grading such surgery according to the magnitude of the V pattern and inferior oblique muscle overaction (IOOA). METHODS: We retrospectively reviewed all 53 cases we operated since 1984 for V pattern with IOOA, who had undergone graded inferior oblique recession, recessed according to the anatomical recession table of Apt and Call, ranging from 8mm for V pattern of 12 PD with +1 IOOA to 12mm for 30+ PD with +3 IOOA. RESULTS: A "satisfactory outcome" (defined as = V pattern of 8 PD or less) was observed in 75% of the cases with a preoperative V pattern less than 20 PD, in 70% of those with a preop' V pattern between 20 PD and 29 PD, and in 57% of those with a preop' V pattern greater than 29 PD. There were no overcorrections. All unsatisfactory outcomes were undercorrections. CONCLUSIONS: The principle of grading this surgery is supported and affirmed by these results. However, the results also suggest a need to increase the amount of surgery for all categories and add anterior transposition for larger V patterns.

Characteristics of a pediatric low-vision population.

BACKGROUND: Assessment of the causes of childhood blindness is important to develop preventive and therapeutic strategies that can reduce the incidence of visual impairment. METHODS: A retrospective survey of the clinical records of 395 consecutive children younger than 14 years of age who were attended by the Low Vision Service of State University of Campinas (UNICAMP) was conducted. Data on the age distribution, the causes of low vision, the types of low vision aids prescribed, the follow up of their use, and improvement in visual acuity were obtained. RESULTS: Congenital bilateral toxoplasmic macular scars, optic atrophy, and congenital cataracts were the major causes of low vision in this population. The optical aid most frequently prescribed was a telescope. The improvement of visual acuity with the use of aids was highly significant.

Visual fields in 4- to 10-year-old children using Goldmann and double-arc perimeters.

We report the comparison of field extent measured using two kinetic perimeters: 1) a double-arc perimeter developed by van Hof-van Duin for use in infants and young children, and 2) the standard Goldmann apparatus. Targets used were the V-4-e target on the Goldmann and both 2- and 6-degree targets on the double-arc perimeter. Visual fields were measured by assessing looking responses toward targets presented in a pseudorandom order at 45 degrees, 135 degrees, 225 degrees, and 315 degrees. Fifty-six children (mean age: 6.8 years, range: 4 to 10 years) were tested, with retests undertaken in 20%. The extent of total field size was highly correlated among the three tests (P less than .001) and test-retest reliability was high for all three targets (P less than .001). Our previous observation of continued growth with age in visual field extent using the 6-degree target in 4- to 10-year-old children was confirmed and also seen with the 2-degree target in arc perimetry and with the V-4-e in the Goldmann apparatus. Kinetic perimetry using a double-arc perimeter with 2- and 6-degree target sizes appears reliable and comparable, in the four meridia tested, to conventional kinetic perimetry techniques in 4- to 10-year-old children.

Visual loss in patients with craniofacial synostosis.

We reviewed the ocular findings in patients with cranial stenosis, who were seen in the Craniofacial Clinic at The Children's Hospital of Philadelphia, to determine the prevalence, pattern, and etiology of visual loss. There were 15 patients with Apert syndrome, 25 patients with Crouzon syndrome, and 18 patients with other forms of craniofacial synostoses. Visual loss occurred in 17 eyes of 11 patients with Apert syndrome, 14 eyes of 11 patients with Crouzon syndrome, and 12 eyes of 8 patients with other craniofacial synostosis syndromes. Refractive errors and strabismus were present in the majority of these patients. Amblyopia due to strabismus, ametropia, or ptosis was the major reason for visual loss in all three groups of patients. Structural abnormalities contributed to loss of vision in six eyes.