| Abstract | Kornealna histereza (CH) i kornealni faktor rezistencije (CRF) kornealna su biomehanička svojstva koja mogu utjecati na postoperativni astigmatizam nakon operacije katarakte. Pretpostavlja se da pacijenti s pseudoeksfolijativnim (PEX) sindromom imaju promijenjene, odnosno niže vrijednosti kornealnih biomehaničkih svojstava u odnosu na pacijente bez PEX sindroma. Cilj je ovog istraživanja bio razjasniti ponašanje rožnice i utjecaj njenih biomehaničkih svojstava na postoperativni astigmatizam kod pacijenata s PEX sindromom nakon operacije katarakte.
74 pacijenta (oka) kojima je operirana katarakta u Klinici za očne bolesti KBC-a Zagreb uključena su u ovo prospektivno opservacijsko istraživanje i praćena tijekom 30 dana. Operaciju katarakte je izveo jedan operater metodom fakoemulzifikacije kroz kornealnu inciziju veličine 2,75 mm smještenu na 12 sati. Svim su pacijentima preoperativno i postoperativno 1., 7. i 30. dana učinjeni oftalmološki pregled, mjerenje kornealne biomehanike i snimka kornealne topografije.
Analizom podataka utvrđeno je da pacijenti s PEX sindromom imaju niže vrijednosti CH-a i CRF-a u odnosu na kontrolnu skupinu, no razlika nije bila statistički značajna. Nadalje, pacijenti s PEX sindromom imali su na svim pregledima statistički značajno veći kornealni astigmatizam nego ispitanici kontrolne skupine. Pritom je u obje skupine postoperativni astigmatizam bio statistički značajno veći od preoperativnog astigmatizma.
Utjecaj operacije katarakte na biomehanička svojstva rožnice izraženiji je kod pacijenata s PEX sindromom. U prilog tome govore statistički značajno sniženje CH-a 1. postoperativnog dana i statistički značajno povećanje u razdoblju od 1. do 30. postoperativnog dana, kad su se vrijednosti CH-a vratile na preoperativne razine, dok se CRF nije značajno mijenjao tijekom postoperativnog razdoblja praćenja. U kontrolnoj je skupini došlo do smanjenja CH-a 1. postoperativnog dana uz njegov oporavak na preoperativne vrijednosti 30. dana nakon operacije, no promjene nisu dosegle statističku značajnost. CRF je u kontrolnoj skupini blago porastao 1. postoperativnog dana, nakon čega je nastupilo statistički značajno smanjenje između 1. i 7. postoperativnog dana te je 30. dana nakon operacije CRF ostao nižih vrijednosti u odnosu na preoperativnu razinu, ali se ta razlika također nije pokazala statistički značajnom.
Glavni prediktori postoperativnog astigmatizma 30. dana nakon operacije katarakte kod pacijenata s PEX sindromom utvrđeni regresijskom analizom bili su preoperativna vrijednost CH-a, vrijednost CRF-a 1. postoperativnog dana, preoperativni i rani postoperativni astigmatizam 1. i 7. dana, i preoperativna os astigmatizma, a u kontrolnoj skupini preoperativni i rani postoperativni astigmatizam, te vrijednost CRF-a 1. postoperativnog dana.
Iz utvrđenog proizlazi da biomehanika rožnice utječe na postoperativni astigmatizam samo kod pacijenata s PEX sindromom te da rožnica u ovih pacijenata pokazuje različito ponašanje pod utjecajem operacije katarakte za razliku od pacijenata bez PEX sindroma, no daljnja će istraživanja biti potrebna da bi se dodatno razjasnile točne patogenetske i kliničke promjene u rožnici i poboljšali postoperativni rezultati kod ovih pacijenata. |
| Abstract (english) | Corneal hysteresis (CH) and corneal resistance factor (CRF) are corneal biomechanical properties that may influence postoperative astigmatism after cataract surgery. It is assumed that patients with pseudoexfoliative (PEX) syndrome have altered, that is, lower values of corneal biomechanical properties compared to patients without PEX syndrome. The aim of this study was to clarify the behavior of the cornea and the influence of corneal biomechanical properties on postoperative astigmatism in patients with PEX syndrome after cataract surgery.
Seventy-four patients (eyes) who underwent cataract surgery at the UHC Zagreb Eye Clinic were included in this prospective observational study and followed for 30 days. Cataract surgery was performed using the phacoemulsification method through a 2.75 mm corneal incision located at 12 o'clock by one surgeon. Preoperatively and postoperatively on the 1st, 7th and 30th day, all patients underwent an ophthalmological examination, measurement of corneal biomechanics and a recording of corneal topography.
Data analysis revealed that patients with PEX syndrome had lower values of CH and CRF compared to the control group, but the difference was not statistically significant. Furthermore, patients with PEX syndrome had statistically significantly higher astigmatism than subjects of the control group at all examinations. In both groups, postoperative astigmatism was statistically significantly higher than preoperative astigmatism.
The impact of cataract surgery on the biomechanical properties of the cornea is more pronounced in patients with PEX syndrome. This is supported by a statistically significant decrease in CH on the 1st postoperative day, and a statistically significant increase from the 1st to the 30th postoperative day, when CH values returned to preoperative levels, while CRF did not change significantly during the postoperative follow-up period. In the control group, there was a decrease in CH on the 1st postoperative day with its recovery to preoperative values on the 30th day after surgery, but the changes did not reach statistical significance. In the control group, CRF increased slightly on the 1st postoperative day, then a statistically significant decrease occurred between the 1st and 7th postoperative days, and on the 30th day after surgery, CRF remained at lower values compared to the preoperative level, but this difference also did not show statistical significance.
The main predictors of postoperative astigmatism on the 30th day after cataract surgery in patients with PEX syndrome determined by regression analysis were the preoperative value of CH, the value of CRF on the 1st postoperative day, preoperative and early, 1st and 7th day, postoperative astigmatism, and preoperative axis of astigmatism, and in the control group preoperative and early postoperative astigmatism and the value of CRF on the 1st postoperative day.
From the findings, it follows that corneal biomechanics affects postoperative astigmatism only in patients with PEX syndrome and that the cornea in these patients shows different behavior under the influence of cataract surgery in contrast to patients without PEX syndrome, but further research will be needed to clarify the exact pathogenetic and clinical changes in the cornea and improve postoperative results in these patients. |
