Intraocular Lens Power Calculation for Combined Phaco-vitrectomy Procedures

Combined Phaco-vitrectomy Clinical Trial

Official title:

Intraocular Lens Power Calculation for Combined Phaco-vitrectomy Procedures: Calculation of a New Constant for Biometry IOL-formulas

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT03856346
• Other study ID #: Phaco-vity-biometry study
• Status: Not yet recruiting
• Start date: June 1, 2019
• Est. completion date: September 30, 2020

Study information

• Verified date: April 2019
• Source: Cantonal Hospital of St. Gallen
• Contact: Josef Guber, MD
• Phone: +41 71 494 17 54
• Email: josef.guber[@]hotmail.com
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The aim of the study is to evaluate the degree of refractive error postoperatively in combined procedures and to calculate a new constant in order to improve current state of the art biometry calculations.

Description:

The IOL power calculation in combined phaco-vitrectomy has been performed similar to that in cataract surgery alone. In patients who undergo combined phaco-vitrectomy, deviations in refractive outcomes may be observed because of possible errors in measurement of axial length, changes in the properties of the vitreous cavity after removal of the vitreous, or intraocular tamponade. Most of the previous studies have reported variable degrees of myopic shift after phaco-vitrectomy for diabetic retinopathy, epiretinal membrane, and macular hole. Furthermore, use of intraoperative gas may increase further the risk of anterior displacement of the intraocular lens which may induce a higher myopic shift. However, these publications did not provide any quantification of the spherical deviations nor calculate any specific constant in order to improve currents state of art biometry calculations.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 200
• Est. completion date: September 30, 2020
• Est. primary completion date: June 30, 2020
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 99 Years

Eligibility

Inclusion Criteria:

• Patients who undergo a combined procedure with phacoemulsification and pars plana vitrectomy

Exclusion Criteria:

• Sulcus fixation of the IOL, sulcus suture of the IOL, or intra-scleral IOL fixation because of intraoperative posterior capsule rupture

• corneal disease, such as keratoconus, that interfered with refractive results

• IOL implantation with a toric IOL or multifocal IOL

• History of previous vitrectomy or corneal transplantation

• Other coexisting ocular disease such as proliferative diabetic retinopathy, advanced age-related macular degeneration, uveitis, acute retinal necrosis, Coat's disease, proliferative vitreous retinopathy, or trauma

• Intraocular tamponade using silicon oil

Related Conditions & MeSH terms

• Combined Phaco-vitrectomy
• Intraocular Lens Calculation

Intervention

Diagnostic Test:
• Biometry
Biometry for phaco-vitrectomy procedures pre- and postoperatively

Locations

Country	Name	City	State
Switzerland	Cantonal Hospital of Sankt Gallen	Sankt Gallen

Sponsors (1)

Lead Sponsor	Collaborator
Cantonal Hospital of St. Gallen

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Refractive prediction error (measured by subjective refraction, in diopters)	postoperative actual subjective refraction minus preoperative planned refraction in spherical equivalence (in diopters)	6 weeks postoperatively
Primary	Absolute prediction error (measured by subjective refraction, in diopters)	absolute value of the difference between postoperative actual refraction and preoperative planned refraction (in diopters)	6 weeks postoperatively
Primary	Changes in Axial Length (measured by biometry, in milimeters)	Change of axial length postoperatively (in milimeter)	6 weeks postoperatively
Primary	Changes in corneal curvature (measured by corneal topography, in diopters)	change in corneal curvature (in diopters)	6 weeks postoperatively