Artigo Original | Original article INTRODUCTIONAstigmatism is a common refractive error that generates multiple focal points over the retina. It's frequently caused by an asymmetry in the corneal curvature. When the two corneal meridians are at right angle, the ametropia can be corrected with spectacles (regular astigmatism). When there are irregularities in the meridians or they are not at right angle, it's called irregular astigmatism, and does not allow correction with spectacles (1) .Mild torsional alignment errors in the astigmatism axis (greater than 3°), can lead to a clinically significant reduction in the efficiency of the laser treatment in eyes with moderate to high astigmatism (2) .The torsional movements are defined as: a) excycloversion -when the upper pole of the eye rotates to the temporal side; b) incycloversion -when the upper pole of the eye rotates to the nasal side (3) . The inferior oblique and inferior rectus muscles are responsible for the excycloversion and the superior oblique and superior rectus muscles ABSTRACT Purpose: The aim of this study was to verify the presence of cyclotorsion in eyes that underwent laser refractive surgery. Methods: This was a comparative observational study, which analyzed the medical records of 61 patients (104 eyes) who underwent laser refractive surgery and compared the axis of astigmatism of the sitting and the supine positions. Regarding the gender, 37.5% were male and 62.5% were female. The age ranged from 20 to 54 years old, with the median of 29 years. The lowest degree of astigmatism was -0.75 cylinder diopters (DC) and the highest was -6.50 DC, with a mean of -3.06 ± 1.16 DC. First, the axis of astigmatism of the seated patient was captured by the Schwind's ORK-CAM. In a second moment, inside the operating room, the axis of astigmatism of the patient in supine position was captured by the laser equipment's own camera (Schwind Amaris®), which was then compared with the previous measure. The incyclotorsion was defined by a minus sign (-) and the excyclotorsion, by a plus sign (+). Results: The maximum excyclotorsion was +7.7 and the maximum incyclotorsion was -11.0 degrees. The mean torsion (excyclo or incyclo) was 2.74 (56.7%), with a standard deviation of 2.30 degrees. There was no statistically significant change (p=0.985) in the axis of astigmatism between patients sitting versus supine. Conclusion: There was clinically significant cyclotorsion in 36.5% of the eyes submitted to laser correction.

Objective: To evaluate the correlation of flow and stopping time intraoperative loss of attachment factors as hypertension or hipocorreções of refractive errors after Lasik. Methods:The age ranged between 19 and 61 years (mean= 31.27 ± 9.99 (mean= 0.23 ± 0.69) and postoperative uncorrected 0.40-0 (x= 0.30 ± 0, 68). (mean= 0.545 ± 0.01), p = 0.762) between the flow and spherical equivalent (mean = -0.04 ± 0.38) in eyes operated. The minimal downtime during surgery was 02 seconds and maximum was 12 seconds (mean= 4.90 ± 3.47). Making a correlation (r = 0.08865, p = 0.411) p=0,424). No equivalente esférico pré e pós-operatório, notou-se uma óbvia diferença (p< 0,0001), no pré-operatório com média de -4,09 ± 2,83 e o pós com média de -0,04 ± 0,38. A mediana foi de -4,75 no pré e de 0 no pós-operatório. Sessenta e nove casos (78,3%) ficaram plano ± 0,25. A fluência mínima foi de 0,513 mJ/cm 2 e a máxima de 0,581 mJ/cm 2 com média de 0,545 ± 0,01, não se percebendo correlação (r= -0,03266; IC 95% -0,241 a 0,178; p= 0,762) entre a fluência e o equivalente esférico final (média= -0,04 ± 0,38) nos olhos operados. O tempo mínimo de parada transoperatória foi de dois segundos e o máximo de 12 segundos com média de 4,90 ± 3,47. Fazendo-se uma correlação (r= 0,08865; IC 95%= -0,123 a 0,293; p= 0,411) entre o equivalente esférico pós-operatório e o tempo de parada transoperatória, não se percebeu diferenças. Conclusão: Não houve correlação entre a fluência do laser e o tempo de parada transoperatória por perda de fixação, com hiper ou hipocorreções nas ametropias pós-Lasik. The Median= 0 logMAR for both time points (p= 0.424). For spherical equivalent before and after surgery, we found an obvious difference, with the pre (mean= -4.09 ± 2.83) and post (mean= -0.04 ± 0.38). The Median was -4.75 in the pre and zero postoperatively (p <0.0001). Sixty-nine cases (78.3%) were plan ± 0.25. Fluency minimum= 0.513 mJ/cm2 and maximum= 0.581 mJ/cm2Descritores (1) . Pallikaris was the first to promote the removal of corneal stromal tissue with excimer laser to correct refractive errors (2) . The use of excimer laser to correct myopia, hyperopia and astigmatism evolved in recent years, mainly due to the technological advancement of devices.Laser-assisted in situ keratomileusis (LASIK) is still the most widely used technique; it is a painless, safe, and accurate method for treating refractive errors with quick recovery (3)(4)(5) . By preserving epithelial integrity in the central region of the cornea, it promotes a milder wound healing reaction. The healing response triggered by the laser and the creation of a flap are important to the safety and efficacy of the procedure. However, it is a significantly complex event (6) . The literature reports great refractive stability from the 3 rd month after surgery (7)(8)(9) . However, do intraoperative factors such as daily variations in laser fluence and interruptions during laser application due to loss of fixation influence the refractive outcome?The aim of this study was to ev...