Clinical characteristics and long-term postoperative results of infantile esotropia and myopia.

PURPOSE: To determine the short-term (6 month) and long-term (4 year) surgical results of infantile esotropia in a control group of 100 patients, as compared to a myopia (-2.0 to -5.0 diopters [D]) group of 13 patients and to a high-myopia (greater than -8.0 D) group of 14 patients. METHOD: A retrospective chart review with selection according to inclusion criteria. RESULTS: All 14 high-myopic patients (100%) achieved short-term unacceptable result of large-angle (greater than 20 prism diopters) deviation as compared to 29 (29%) and four (31%) of the patients in the control and myopia groups, respectively (P < 0.0001). Eighty (80%) of the patients in the control group and 10 (77%) in the myopia group achieved long-term favorable postoperative results of subnormal binocular vision, microtropia, or small-angle (less than 20 prism diopters) deviation, with no statistical differences between the two groups. In contrast, 10 (71%) of the patients in the high-myopia group achieved a final unacceptable result of large-angle deviation, as compared to 20 (20%) and three (23%) in the control and myopia groups, respectively (P < 0.0001). Persistent preoperative amblyopia was associated with a higher percentage of unfavorable surgical results and was more frequent in the high-myopia group (50%) as compared to the control group (14%) (P = 0.0004). CONCLUSIONS: Careful attention must be directed preoperatively toward reversing amblyopia and correcting refractive errors because persistent amblyopia at the time of surgery was associated with a higher percentage of unacceptable postoperative large-angle deviation. The conventional amount of recession or resection of muscles should be increased in high-myopic cases with infantile esotropia, because less effect is produced per millimeter of recession/resection initially and, in the long-term, the constant stimulus to accommodative convergence apparently causes recurrent esotropia.

Clinical characteristics and long-term postoperative results of infantile esotropia.

We classified 103 patients (206 eyes) with infantile esotropia and an average of 8.7 years of postoperative follow-up into four outcome groups. Of 103 patients, 28 (27%) had subnormal binocular vision; 24 (23%) had microtropia; 43 (42%) had small-angle deviation (< 20 prism diopters); and eight (8%) had large-angle deviation. A chi 2 analysis showed a significant difference (chi 2 = 16.22, P = .005) in the distribution of amblyopia among these four outcome groups. Visual acuity of 20/30 or better was attained in 174 of the 206 eyes (84%). The eyes of all 28 patients in the subnormal binocular vision group remained aligned after an average of eight years. In contrast, the eyes of six of 30 patients (20%) in the microtropia group and 11 of 43 (26%) in the small-angle deviation group lost the stability of horizontal alignment. We found that the two variables of latent-manifest nystagmus and persistent amblyopia at the time of surgery lead to less satisfactory outcomes. In contrast, patients with smaller preoperative angle of deviation or surgery completed before 1 year of age demonstrated an increased incidence of optimal (subnormal binocular vision) or desirable (microtropia) results. We recommend performing surgery after amblyopia has been thoroughly treated, and, whenever possible, completing the surgical treatment by 1 year of age.

Ocular and systemic characteristics of Duane syndrome.

The clinical features of 63 patients with Duane syndrome are described in this report. All data in the study were gathered retrospectively except for measurements of vertical palpebral fissure and axial eye length, which were investigated prospectively. The following new aspects of the syndrome are emphasized: 1) In most cases with heterotropia, the angle of deviation was not large (< or = 25 prism diopters). 2) Visual acuity of 0.66 (20/30) or better was recorded in 94% of the affected eyes. 3) Smaller palpebral fissure (by 1 mm or more) of the affected eye was measured in primary position among 9 of 40 (22%) unilateral cases. 4) The axial length of the affected eye (mean, 22.8 +/- 0.6 mm) was not significantly different from the uninvolved eye. 5) Two cases of heterochromia iridis (3.2%) were found among the Duane syndrome patients. 6) A 4.8% prevalence of high-tone hearing loss was detected, in addition to 4.8% of sensorineural deafness.

Tenon's capsule: ultrastructure of collagen fibrils in normals and infantile esotropia.

No detailed information about the ultrastructure of Tenon's capsule has been published. The purpose of the present study was to compare the ultrastructural features of collagen fibrils from Tenon's capsule in a nonstrabismic control group (seven children) to those in an infantile esotropic group (10 children). Small biopsy specimens from Tenon's capsule were taken during various operations to be examined by electron microscopy. On electron microscopy, the capsule was found to be composed of groups of collagen fibrils arranged irregularly in different orientations, forming a three-dimensional network that provides tissue resistance to stress. The cross-sectioned collagen fibrils were studied by an image analyzer. In both study groups, all fibrils had a round, regular contour. In the esotropic group, the Tenon's collagen fibrils were thicker, as reflected by their significantly greater mean diameter: 101 +/- 5 nm (mean +/- standard deviation) compared to 86 +/- 5 nm in the control group. Also, significantly greater heterogeneity was found in the collagen fibril thickness of each individual in the esotropic group compared to the control group. Moreover, the mean number of collagen fibrils per unit area was significantly higher in the esotropic group: 98 +/- 13 fibrils per 10(6) nm2 compared to 73 +/- 5 fibrils per 10(6) nm2 in the control group. These ultrastructural changes may be stress-induced secondary alterations of the Tenon's collagen fibrils resulting from prolonged deviation of the eye in infantile esotropia. The significantly denser collagen fibrils may cause a decrease in the elasticity of Tenon's capsule in infantile esotropia.

End-stage fibrosis of the lateral rectus muscle in myopia with esotropia. An ultrastructural study.

The fibrotic lateral rectus muscle and the medial rectus muscle of 4 patients with esotropia and myopia who underwent surgical correction were studied ultrastructurally. All patients revealed underactivity of the lateral rectus muscle. In 3 patients the underactive lateral rectus was completely fibrotic; in 1 patient there was 80% fibrosis, and the rest of the muscle showed different stages of degeneration. The fibrotic lateral recti were composed of collagen fibrils and remnants of degenerated organelles. The collagen fibrils of the lateral recti were of different sizes, and the mean diameter varied from 65 to 92 nm. On the other hand, the interstitial collagen fibrils of nonfibrotic medial rectus muscles of these patients and also of control muscles showed less variation in size, and the mean diameter was smaller as compared with the fibrotic lateral rectus. It is suggested that the collagen fibrils that compose the fibrotic lateral rectus muscle probably develop under conditions which differ from the normal development of collagen fibrils.