title: Viscoat versus Visthesia during phacoemulsification cataract surgery: corneal and foveal changes.
abstract: BACKGROUND
  Ophthalmic viscosurgical devices (OVDs) are widely used in phacoemulsification cataract surgery to maintain adequate intraocular space, stabilize ocular tissue during the operation and decrease the possible damage of the corneal endothelium. Our study has the purpose to compare the corneal and foveal changes of Viscoat and Visthesia in patients undergoing uneventful phacoemulsification cataract surgery.
  
  
  METHODS
  Participants in our study were 77 consecutive patients, who were randomized into two groups based on type of OVD used during phacoemulsification: Viscoat or Visthesia. All patients underwent a complete ophthalmological examination i.e., measurement of best corrected visual acuity (BCVA) by means of Snellen charts, intraocular pressure examination by Goldmann tonometry, slit lamp examination, fundus examination, optical coherence tomography, specular microscopy and ultrasound pachymetry preoperatively and at three time points postoperatively (day 3, 15, 28 postoperatively). The differences in baseline characteristics, as well as in outcomes between the two groups were compared by Mann-Whitney-Wilcoxon test and Student's t-test, as appropriate.
  
  
  RESULTS
  Intraoperatively, there was no statistically significant difference in the duration of the ultrasound application between the two groups, while Viscoat group needed more time for the operation performance. It is also worthy to mention that Visthesia group exhibited less intense pain than patients in Viscoat group. Postoperatively, there was a statistically significant difference in central corneal thickness, endothelial cell count and macular thickness between the two groups, but BCVA (logMAR) did not differ between the two groups.
  
  
  CONCLUSIONS
  Our study suggests that Viscoat is more safe and protective for the corneal endothelium during uneventful phacoemulsification cataract surgery, while Visthesia is in superior position regarding intraoperative pain. Patients of both groups acquired excellent visual acuity postoperative. Finally, this is the first study comparing OVDs in terms of macular thickness, finding that Visthesia cause a greater increase in macular thickness postoperatively than Viscoat, although it reaches normal ranges in both groups.
authors.affiliation: 1st Department of Ophthalmology, University of Athens, Athens, Greece. moschosmarilita@yahoo.fr
authors.forename: Marilita M
authors.initials: MM
authors.lastname: Moschos
authors.forename: Irini P
authors.initials: IP
authors.lastname: Chatziralli
authors.forename: Theodoros N
authors.initials: TN
authors.lastname: Sergentanis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002387:Cataract Extraction / Q000379:methods*; D002452:Cell Count; D002809:Chondroitin Sulfates / Q000008:administration & dosage*; D003315:Cornea / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology; D004338:Drug Combinations; D004728:Endothelium, Corneal / Q000187:drug effects; D005139:Eyeglasses; D005260:Female; D005500:Follow-Up Studies; D005584:Fovea Centralis / Q000187:drug effects*; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage*; D056965:Injections, Intraocular; D007429:Intraocular Pressure; D007430:Intraoperative Care; D008012:Lidocaine / Q000008:administration & dosage*; D008266:Macula Lutea / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D008297:Male; D009929:Organ Size; D018918:Phacoemulsification; D011184:Postoperative Period; D014463:Ultrasonography; D014787:Vision Tests; D014792:Visual Acuity / Q000187:drug effects
chemical_list: D004338:Drug Combinations; C501944:chondroitin sulfate, sodium hyaluronate drug combination; C561626:visthesia; D006820:Hyaluronic Acid; D002809:Chondroitin Sulfates; D008012:Lidocaine