Keratoconus
Conditions
Keywords
Corneal collagen cross-linking, Deep lamellar keratoplasty, Keratoconus
Brief summary
The Study was designed as a randomized controlled study with the following objectives: To investigate whether use of donors predisposed by corneal collagen cross-linking (CXL) reduced myopic refractive errors for keratoconic eyes after Deep anterior lamellar keratoplasty (DALK). Overall 70 patients are planned to recruit., the patients were assigned to CXL graft group, in which corneal donors predisposed by CXL were used, or the conventional graft group, in which corneal donors stored in corneal storage media were used. The patients will be followed-up for 24 months.
Detailed description
Keratoconus is a progressive ecstatic corneal disease characterized by forward bulging of the cornea, thinning of the corneal stroma, and irregular astigmatism. Corneal transplantation is necessary for patients with advanced keratoconus when spectacles and contact lens are inadequate for visual correction. Deep anterior lamellar keratoplasty is a conventional procedure for the treatment of keratoconus. However, DALK itself frequently causes abnormality of refraction, such as high degrees of astigmatism owing to irregular corneal surface for keratoconic eyes. Possible mechanisms of this progressive astigmatism include the recurrence of keratoconus in the grafts, progressive corneal thinning of the host cornea, or progressive misalignment of the graft- host interface over time, which prevents the achievement of satisfactory vision. Corneal collagen cross-linking is believed to have the ability to halt or decrease the progression of keratoconus. CXL treats keratoconus by strengthening corneal stromal collagen bonds with riboflavin activated by ultraviolet A (UVA), and is now a first-line treatment for progressive keratoconus. In this randomized controlled trial, we performed CXL on corneal donor tissues with the aim of achieving corneal stromal stiffening, thereafter DALK was conducted for the patients with advanced keratoconus using the tissues predisposed by CXL. The goal of this study is evaluating whether the strengthening grafts could reduce postoperative myopic refractive errors or arrest the progression of keratoconus for the patients with DALK.
Interventions
PROCEDURECorneal donors predisposed by CXL
Corneal donors predisposed by CXL and DALK procedure was conducted in patients
PROCEDURECorneal donors stored in corneal storage media
Corneal donors stored in corneal storage media and DALK procedure was conducted in patients
Sponsors
Zhongshan Ophthalmic Center, Sun Yat-sen University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
* 1.The best corrected visual quality of frame glasses is less than 0.3，2.The best corrected visual quality of rigid gas permeable contact lens (RGPCL) is less than 0.5/ RGPCL intolerance，3.The anterior corneal surface curvature \>55D，4.The thinnest corneal thickness is less than 400 μm. One of the above four items is met * Patients must be willing and able to return for scheduled follow-up examinations for 36 months after surgery * Ages：over 18 Years
Exclusion criteria
* History of intraocular surgery * Severe dry eye * Severe eyelid and conjunctival scar * Loss of vision in contralateral eye * Pregnant and lactating women
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Simulated keratometry | up to 36 months | Simulated keratometry measured by topography |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Corrected distance visual acuity （CDVA） | 36 months | CDVA (by using Snellen acuity charts) before surgery, at 1 week, 1, 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after surgery |
| Spherical equivalent (SE) | 36 months | SE will be detected by combined optometry and phoroptor refractometer before surgery, at 1 week, 1, 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after surgery |
| Manifest cylinder | 36 months | Manifest cylinder will be detected by topography before surgery, at 1 week, 1, 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after surgery |
| Uncorrected distance visual acuity（UDVA） | 36 months | UDVA (by using Snellen acuity charts) before surgery, at 1 week, 1, 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after surgery |
| Corneal endothelium cells | 36 months | Corneal endothelium cells will be detected by confocal microscopy before surgery, at 1 week, 1, 3, 6, 9, 12, 15, 18, 21, 24 ,30 and 36 months after surgery |
| Intraocular pressure | 36 months | Intraocular pressure was measured by non-contact tonometer before surgery, at 1 week, 1, 3, 6, 9, 12, 15, 18, 21, 24,30 and 36 months after surgery |
| Corneal thickness | 36 months | Corneal thickness of the thinnest area will be detected by Optical Coherence tomography before surgery, at 1 week, 1, 3, 6, 9, 12, 15, 18, 21, 24, 30 and 36 months after surgery |
Countries
China
Contacts
Primary ContactTing Huang, MD, PHD
Backup ContactXiaojuan Dong, MD, PHD
Outcome results
None listed