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ABSTRACT Purpose: To investigate the impact of different sizes of steep meridian clear corneal incisions for phacoemul sification on anterior corneal higher-order aberrations. Methods: Medical records of patients who underwent 2.2-mm coaxial micro-incision cataract surgery or 2.75-mm coaxial small-incision cataract surgery were retrospectively reviewed. Only patients with preexisting anterior corneal astigmatism <2.00 diopters (D) and ≥0.50 D who underwent a steep meridian clear corneal incision were included. Primary outcomes were 3rd- to 6th-order anterior corneal higher-order aberrations with an 8-mm pupil. Anterior corneal astigmatism and effective phaco time were evaluated as secondary outcomes. Preoperative and 3-month postoperative outcomes were evaluated. Results: Anterior corneal astigmatism significantly decreased after both procedures; however, there was no significant difference found in surgically induced anterior corneal astigmatism between the two procedures (p=0.146). Although the total higher-order aberrations did not significantly change after both procedures, the group comparison showed a significant difference in surgically induced total higher-order aberrations (a decrease of 0.337 ± 1.156 mm in 2.2-mm coaxial micro-incision cataract surgery and an increase of 0.106 ± 0.521 mm in 2.75-mm coaxial small-incision cataract surgery, p=0.046). Spherical aberrations significantly decreased after 2.2-mm coaxial micro-incision cataract surgery (p=0.001), whereas they did not change significantly after 2.75-mm coaxial small-incision cataract surgery (p=0.564). Coma did not significantly change after either of the procedures. Trefoil did not significantly change after 2.2-mm coaxial micro-incision cataract surgery (p=0.361), whereas it significantly increased after 2.75-mm coaxial small-incision cataract surgery (p<0.001). There was no significant difference shown in effective phaco time between the procedures. A significantly positive correlation was shown between surgically induced anterior corneal astigmatism and coma in 2.75-mm coaxial small-incision cataract surgery (r=0.387, p=0.006). There was no significant correlation found between any surgically induced higher-order aberration changes and effective phaco time. Conclusions: The results showed that 2.2-mm coaxial micro-incision cataract surgery and 2.75-mm coaxial small-incision cataract surgery did not significantly degrade the total higher-order aberrations of the anterior cornea. However, the surgically induced changes in total higher-order aberration showed a significant difference between the two procedures, with a slight reduction after 2.2-mm coaxial micro-incision cataract surgery and a slight increase after 2.75-mm coaxial small-incision cataract surgery. Phaco time and power used during surgery had no impact on corneal aberrations.

RESUMO Objetivo: Investigar o impacto de diferentes ta manhos de incisões em córnea clara com meridiano íngreme para facoemulsificação com aberrações de mais alta ordem da córnea anterior. Métodos: Foram retrospectivamente revisados os prontuários médicos de pacientes que se submeteram a cirurgias de catarata com microincisões coaxiais de 2,2 mm ou com incisões coaxiais pequenas de 2,75 mm. Foram apenas incluídos pacientes com astigmatismo preexistente da córnea anterior <2,00 dioptrias (D) e ³0,50 D, e submetidos a incisões em córnea clara com meridiano íngreme. Os desfechos primários foram aberrações da córnea anterior da 3ª à 6ª ordem com uma pupila de 8 mm. O astigmatismo da córnea anterior e o tempo efetivo de facoemulsificação foram avaliados como desfechos secundários. Os desfechos pré-operatório e pós-operatório aos 3 meses também foram avaliados. Resultados: O astigmatismo da córnea anterior diminuiu significativamente após ambos os procedimentos, mas não se encontrou nenhuma diferença significativa entre os dois procedimentos quanto ao astigmatismo da córnea anterior, induzido pela cirurgia (p=0,146). Embora as aberrações totais de mais alta ordem não se tenham alterado significativamente após ambos procedimentos, a comparação entre os grupos revelou uma diferença significativa nas aberrações totais de mais alta ordem, induzidas pela cirurgia (uma diminuição de 0,337 ± 1,156 mm na cirurgia de catarata por microincisão coaxial de 2,2 mm e um aumento de 0,106 ± 0,521 mm na cirurgia de catarata por incisão coaxial pequena de 2,75 mm; p=0,046). A aberração esférica diminuiu significativamente após cirurgia de catarata por microincisão coaxial de 2,2 mm (p=0,001), mas não se alterou significativamente após cirurgia de catarata por incisão coaxial pequena de 2,75 mm (p=0,564). A aberração de coma não mudou significativamente após qualquer dos procedimentos. O trifólio não se alterou significativamente após cirurgia de catarata por microincisão coaxial de 2,2 mm (p=0,361), mas aumentou significativamente após cirurgia de catarata por incisão coaxial pequena de 2,75 mm (p<0,001). Nenhuma diferença significativa se evidenciou quanto ao tempo efetivo de faco-emulsificação entre os dois procedimentos. Houve uma correlação positiva significativa entre o astigmatismo da córnea anterior, induzido pela cirurgia e a aberração de coma na cirurgia de catarata por incisão coaxial pequena de 2,75 mm (r=0,387, p=0,006). Não foi encontrada correlação significativa entre as alterações nas aberrações totais de mais alta ordem, induzidas pela cirurgia e o tempo efetivo de faco-emulsificação. Conclusões: Nem a cirurgia de catarata por microincisão coaxial de 2,2 mm, nem aquela por incisão coaxial pequena de 2,75 mm degradaram significativamente as aberrações totais de mais alta ordem da córnea anterior. Porém, as alterações nas aberrações totais de mais alta ordem, induzidas pela cirurgia mostraram uma diferença significativa entre os dois procedimentos, com uma ligeira redução na cirurgia de catarata por microincisão coaxial de 2,2 mm e um pequeno aumento na cirurgia de catarata por incisão coaxial pequena de 2,75 mm. O tempo de facoemulsificação e a potência utilizada durante a cirurgia não tiveram impacto nas aberrações corneanas.

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PURPOSE: To investigate whether optical quality could be improved by cylindrical correction for low astigmatic eyes with different amounts and axis orientations in patients with myopia up to - 3.00 diopters (D). METHODS: A cross-sectional study enrolling healthy young eyes with 0 to - 3.00 D myopia and - 0.50 to - 0.75 D myopic astigmatism was implemented. With a repeated-measures design, outcome measures were sequentially obtained for each subject under two correction modalities: spherocylindrical correction and spherical correction. Subjective refraction was used to determine the refractive prescriptions accordingly in the two correction modalities to obtain optimal subject-reported visual acuity. Primary outcomes were optical quality parameters including objective scatter index (OSI), modulation transfer function (MTF) cut-off, Strehl ratio (SR), and a simulated contrast visual acuity-optical quality analysis system (OQAS) values (OV) obtained by a double-pass system. Corrected distance visual acuity (CDVA) was measured as a secondary outcome. Outcome comparisons between the two correction modalities were performed by grouping in different amounts (- 0.50 D, - 0.75 D) and axes (with the rule, WTR; against the rule, ATR; oblique, OBL) of astigmatism. RESULTS: A total of 194 eyes of 194 subjects were evaluated. Significantly better CDVA were shown by spherocylindrical correction for all types of astigmatism except for - 0.50 D WTR astigmatism (P = 0.831). For eyes with - 0.50 D WTR astigmatism, better outcome was only shown in OSI with spherocylindrical correction (P = 0.019). For eyes with - 0.50 D ATR and OBL astigmatism, spherocylindrical correction demonstrated better outcomes in all parameters except for SR (P > 0.05). For eyes with - 0.75 D astigmatism, significantly better outcomes in all optical quality parameters were shown with spherocylindrical correction regardless of the axis (P < 0.05). CONCLUSIONS: Eyes with ATR or OBL myopic astigmatism may benefit in optical quality and visual acuity by combining a cylindrical correction even with a low amount down to - 0.50 D. However, optical quality and visual acuity improvement are limited for WTR astigmatic eyes when the amount of astigmatism is less than - 0.75 D.

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PURPOSE: To investigate the impact of different sizes of steep meridian clear corneal incisions for phacoemul sification on anterior corneal higher-order aberrations. METHODS: Medical records of patients who underwent 2.2-mm coaxial micro-incision cataract surgery or 2.75-mm coaxial small-incision cataract surgery were retrospectively reviewed. Only patients with preexisting anterior corneal astigmatism <2.00 diopters (D) and ≥0.50 D who underwent a steep meridian clear corneal incision were included. Primary outcomes were 3rd- to 6th-order anterior corneal higher-order aberrations with an 8-mm pupil. Anterior corneal astigmatism and effective phaco time were evaluated as secondary outcomes. Preoperative and 3-month postoperative outcomes were evaluated. RESULTS: Anterior corneal astigmatism significantly decreased after both procedures; however, there was no significant difference found in surgically induced anterior corneal astigmatism between the two procedures (p=0.146). Although the total higher-order aberrations did not significantly change after both procedures, the group comparison showed a significant difference in surgically induced total higher-order aberrations (a decrease of 0.337 ± 1.156 mm in 2.2-mm coaxial micro-incision cataract surgery and an increase of 0.106 ± 0.521 mm in 2.75-mm coaxial small-incision cataract surgery, p=0.046). Spherical aberrations significantly decreased after 2.2-mm coaxial micro-incision cataract surgery (p=0.001), whereas they did not change significantly after 2.75-mm coaxial small-incision cataract surgery (p=0.564). Coma did not significantly change after either of the procedures. Trefoil did not significantly change after 2.2-mm coaxial micro-incision cataract surgery (p=0.361), whereas it significantly increased after 2.75-mm coaxial small-incision cataract surgery (p<0.001). There was no significant difference shown in effective phaco time between the procedures. A significantly positive correlation was shown between surgically induced anterior corneal astigmatism and coma in 2.75-mm coaxial small-incision cataract surgery (r=0.387, p=0.006). There was no significant correlation found between any surgically induced higher-order aberration changes and effective phaco time. CONCLUSIONS: The results showed that 2.2-mm coaxial micro-incision cataract surgery and 2.75-mm coaxial small-incision cataract surgery did not significantly degrade the total higher-order aberrations of the anterior cornea. However, the surgically induced changes in total higher-order aberration showed a significant difference between the two procedures, with a slight reduction after 2.2-mm coaxial micro-incision cataract surgery and a slight increase after 2.75-mm coaxial small-incision cataract surgery. Phaco time and power used during surgery had no impact on corneal aberrations.

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