Use of Botulinum Toxin A in the Treatment of Intermittent Exotropia: Factors Affecting Treatment Outcome.

PURPOSE: To evaluate the efficiency of botulinum toxin A (BTA) injection in the treatment of intermittent exotropia (IXT) and determine factors affecting treatment outcome. MATERIALS AND METHODS: A total of 74 patients diagnosed with any type of IXT were included in the study. BTA injection was administered into both lateral rectus muscles. Gender, refractive error, age, pre- and post-injection measurements of ocular deviation, age at the time of the first BTA injection, number of injections, duration of misalignment, age at the onset of misalignment, presence of amblyopia, presence of anisometropia, preterm birth history, type of delivery, presence of any neurological disorder, follow-up period, postoperative ptosis, and vertical deviation were recorded. The final angle of deviation was used in the statistical analysis. Successful motor alignment was defined as a deviation of ≤10 prism diopters (PD) at distance. The relationship of all factors with treatment success was analyzed using the binary logistic regression analysis. RESULTS: A total of 74 patients, 40 female and 34 male, were included in the study. All the patients were followed up for six to 53 months after the first BTA injection, and the mean follow-up was 16.1 ± 11.1 months. Before the first BTA injection of the patients, the mean amount of deviation was measured as 25.7 ± 14.2 (range, 0-60) PD at near and 37.1 ± 10.9 (range, 16-65) PD at distance. According to the most recent examination of the patients, the mean amount of deviation was 10.6 ± 9.8 (range, 0-45) PD at near and 16.4 ± 10.2 (range, 0-45) PD at distance. There was a statistically significant difference between the first and last examinations of the patients in relation to the amount of deviations measured at both near and distance (p < .001). Successful motor alignment (orthotropia within 10 PD for exodeviation) was achieved in 42 patients (56.7%). Thesuccess of treatment increased with the decreased amount of deviation at distance before the BTA injection. CONCLUSIONS: In patients with IXT, BTA injection into the lateral rectus muscles is an effective procedure, which is also less invasive and taking shorter time than surgery, and it can be considered as an alternative treatment option in those with small-medium angle IXT.

The Effect of Acute Hypovolemia on the Eye.

INTRODUCTION: To investigate the effects of acute hypovolemia induced by blood donation on the eye. Methods or Study Design: This prospective, observational study included a single eye from each of 48 healthy men between 20 and 40 years of age who had donated 500 ml of blood and 28 eyes of 28 healthy, age- and gender-matched control subjects. The ocular parameters including ocular perfusion pressure (OPP), intraocular pressure (IOP), axial length (AL), central corneal thickness (CCT), choroidal and retinal thicknesses, and retinal nerve fiber layer (RNFL) were measured before blood donation and at 10 min and 1, 2, 3, and 4 h after blood donation. RESULTS: The mean OPP was significantly reduced following blood donation (baseline, 43.4 ± 4.9 vs. 40.8 ± 4.6 mmHg; p = 0.003). The mean subfoveal choroidal thickness (SFCT) was measured as 322.96 ± 76.23, 291.63 ± 77.85, 309.77 ± 75.72, 312.31 ± 75.98, 315.73 ± 75.43, and 317.75 ± 75.73 µm before blood donation, at baseline, 10 min, and 1, 2, 3, and 4 h following donation, respectively [F(2.462, 115.731) = 22.618, p < 0.001]. In the control group, the SFCT was measured as 302.04 ± 32.04, 301.43 ± 35.16, 298.07 ± 37.33, 298.96 ± 39.17, 302.54 ± 39.24, and 301.61 ± 40.41 µm at baseline, 10 min, and 1, 2, 3, and 4 h following donation, respectively [F(2.124, 57.340) = 0.592, p = 0.566]. There was no difference in AL, CCT, RNFL, retinal thicknesses, and IOP measurements performed before and after blood donation (p > 0.05). CONCLUSIONS: Acute hypovolemia caused a significant reduction in SFCT which persisted for 3 h. This study may pave way for better understanding of choroidal thickness changes in disease states.

Evaluation of subfoveal choroidal thickness in pregnant women using enhanced depth imaging optical coherence tomography.

PURPOSE: To evaluate the subfoveal choroidal thickness (SFCT) measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in pregnant women. METHODS: In this prospective and cross-sectional study, 100 pregnant women and 100 age-matched nonpregnant women were enrolled. The SFCT was measured by EDI-OCT. The refractive error, intraocular pressure (IOP), axial length (AL), central corneal thickness (CCT), systolic and diastolic blood pressure, and ocular perfusion pressure (OPP) were also measured. Pregnancy-related factors including gestational age, maternal weight gain, and fetal weight were noted. RESULTS: Mean SFCT was 371.1 ± 61.8 µm in the study group and 337.2 ± 62.4 µm in the control group (p < 0.001). No significant correlation was found between SFCT and spherical refraction, IOP, AL, CCT, OPP, gestational age, maternal weight gain, or fetal weight. CONCLUSION: Our results suggest that subfoveal choroidal thickness increases in pregnant women compared with age-matched nonpregnant women.

Subfoveal choroidal thickness in preeclampsia: comparison with normal pregnant and nonpregnant women.

PURPOSE: To compare the subfoveal choroidal thickness (SFCT) in preeclampsia, normal pregnancy, and non-pregnant women using enhanced depth imaging optical coherence tomography (EDI-OCT). METHODS: One hundred nineteen volunteers were enrolled in this prospective and comparative study. The participants were divided into three groups: group 1 (33 preeclamptic women), group 2 (46 normal pregnant), and group 3 (40 non-pregnant healthy women). The SFCT was measured by EDI-OCT. The refractive error, intraocular pressure (IOP), axial length (AL), central corneal thickness (CCT), systolic and diastolic blood pressure, and ocular perfusion pressure (OPP) were also measured. Medical records of pregnant women, including gestational age, maternal weight gain, weight, and proteinuria, were noted. RESULTS: Mean SFCT of groups 1, 2, and 3 were 333.8 ± 55.3 µm (range 235-440 µm), 368.6 ± 67.6 µm (range 223-517 µm), and 334.8 ± 59.9 µm (range 197-432 µm), respectively. The mean SFCT was thicker in group 2 than that in groups 1 and 3 (p = 0.045 and p = 0.038, respectively), whereas no significant difference was seen between groups 1 and 3 (p = 1.0). In group 1, SFCT showed a negative correlation with the CCT (p = 0.009, r = -0.493). In group 2, SFCT showed a positive correlation with OPP (p = 0.030, r = 0.321) and a negative correlation with gestational age and fetal weight (p = 0.008, r = -0.387 and p = 0.011, r = -0.373, respectively). CONCLUSION: Our results suggested that SFCT was significantly thicker in normal pregnant women than non-pregnant women. However, SFCT values of preeclamptic women were similar to those of non-pregnant women.