The influence of routine uncomplicated phacoemulsification on the orthogonality of the cornea.

Autor: Tutchenko L; Department of Ophthalmology, Shupyk National Medical Academy of Postgraduate Education; Kyiv City Clinical Ophthalmological Hospital 'Eye Microsurgical Center', Kyiv, Ukraine., Patel S; NHS National Services Scotland, Edinburgh, United Kingdom., Voytsekhivskyy O; Kyiv City Clinical Ophthalmological Hospital 'Eye Microsurgical Center', Kyiv, Ukraine., Skovron M; Kyiv City Clinical Ophthalmological Hospital 'Eye Microsurgical Center', Kyiv, Ukraine., Horak O; Kyiv City Clinical Ophthalmological Hospital 'Eye Microsurgical Center', Kyiv, Ukraine.
Jazyk: angličtina
Zdroj: Indian journal of ophthalmology [Indian J Ophthalmol] 2021 May; Vol. 69 (5), pp. 1073-1079.
DOI: 10.4103/ijo.IJO_1168_20
Abstrakt: Purpose: The aim of this study was to determine the effect of routine uncomplicated phacoemulsification on the orthogonal distribution of mass within the central optical zone of the cornea.
Methods: Astigmatism at both corneal surfaces was evaluated using Orbscan II (Bausch &and Lomb) before and up to 3 months after routine phacoemulsification (one eye/patient). The data were subjected to vector analysis to estimate the pre-and postoperative total astigmatism of the cornea (TCA).
Results: Reporting the chief findings in minus cylinder (diopters, DC) over the central 3 mm (A) and 5 mm (B) optical zones. Mean TCA powers (±sd) at pre- and 3-months postop were A) -4.45DC (±2.00) and -5.69DC (±2.69), B) -2.91DC (±2.22) and -2.71DC (±1.60). Change in mean power was significant over 3 mm (P < 0.01, n = 49) but not over 5 mm. Inter-zonal differences were significant (P < 0.01). There was a significant linear relationship between the change in TCA power (y = preoperative-postoperative) and TCA at preoperative stage (x) where, A) y = 0.45x + 3.12 (r = 0.336, n = 49, P = 0.018), B) y = x + 2.65 (r = 0.753, n = 49, P = <0.01). Over the central 3 mm zone only, change (preoperative-postoperative) in axis (°) of TCA (y 1 ) was significantly associated with TCA axis at preoperative stage (x 1 ) where y 1 = 1.391x 1 -0.008x 1 2 -0.701 (r = 0.635, n = 49, P < 0.01).
Conclusion: Changes in TCA power and axis at 3 months postop, determined using Orbscan II, are indicative of orthogonal alterations in the distribution of corneal tissue. Over the central 3 mm zone, the association between y 1 and x 1 shows that a change in TCA axis is more profound when preoperative axis is near 90° i.e., against-the-rule.
Competing Interests: None
Databáze: MEDLINE
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