Clinical trial NCT03001401: Comparison of Next Generation Laser Techniques of Myopia Correction: iDesign vs. SMILE
Official title: Comparison of Next Generation Laser Techniques of Myopia Correction: iDesign vs. SMILE
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE4
Conditions: Myopia
Lead sponsor: Narayana Nethralaya
Sponsor class: OTHER
First posted: 2016-12-23
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The proposed study seeks to compare visual acuity, tomographic outcomes, biomechanical changes and inflammatory profile of normal eyes (matched for age, refraction and corneal thickness) undergoing iDesign and SMILE procedure. The hypothesis is that iDesign may deliver equivalent or better clinical outcomes than SMILE, by removing less tissue and correcting for higher order aberrations.

Detailed description: iDesign is a promising new technique to treat myopia with astigmatism using ocular aberrations measured with a high resolution wavefront sensor.\[1,2\] Early studies with iDesign platform has established its safety and efficacy in correction of myopia with fewer patients reporting night vision problems.\[1,2\] In keratoconus, iDesign has also provided excellent outcomes following collagen crosslinking.3 SMILE is a recent technique that eliminates creation of flap and appears to achieve similar refractive outcomes as conventional LASIK but with less dryness, less inflammation and faster wound healing.\[4,5\] SMILE corrects lower order aberrations only.\[4,5\] Thus, a comparative assessment of iDesign and SMILE is necessary since iDesign can potentially give better visual outcomes with lower volume of tissue removal. If lower volume of tissue is removed, it is also hypothesized that the corneal would be more stable biomechanically.\[5\] Further, SMILE does not provide any correction of higher order aberrations. With the inclusion of higher order aberrations in the iDesign treatment plan, it is hypothesized that both short and long term outcomes will be better with iDesign than with SMILE.

Eligibility criteria: Inclusion Criteria:

1. Patients should be between 18 to 50 years of age.
2. Patient must have stable myopia for a minimum period of one year (a change of 0.25D or less) as documented by prior clinical records or current spectacle correction.
3. Patient must have a corrected distance visual acuity (CDVA) of 20/25 or better,
4. Patient must have a spherical equivalent refraction less than -10D
5. Patient must have refractive astigmatism less than 3D.

Exclusion Criteria:

1. Patient must not have a central corneal thickness (CCT) less than 480 micrometer
2. Patient must not have a calculated residual stromal bed thickness of less than 250 micrometer after the surgery
3. Patient must not have symptoms or signs of keratoconus, diabetes, collagen vascular disease, pregnancy, breastfeeding and any prior ocular surgery.
4. Patient must not have an inter-ocular difference of more than 1.00 diopter (D) of spherical or 0.50 D of cylindrical refractive error.
5. Patient must not be on chronic systemic steroids or other medication that can affect wound healing.
6. Patient must not be allergic to primary or alternative medications.
7. Patient must not be using rigid contact lenses for the last three weeks or soft contact lenses for at least 1 week before the preoperative evaluation.

Primary outcomes:
measure: Change in visual acuity measured as Logarithm of manifest refraction
timeFrame: Post surgery over a period of 1 year
Secondary outcomes:
measure: Change in Corneal curvature in Diopter
timeFrame: Post surgery over a period of 1 year
measure: Change in deformation of the cornea
timeFrame: Post surgery over a period of 1 year
measure: Change in ocular surface dryness and/or pain
timeFrame: Post surgery over a period of 1 year
measure: Change in wavefront aberrations described by Zernike Polynomials
timeFrame: Post surgery over a period of 1 year
Other outcomes:
Locations:
city: Bangalore
country: India
facility: Narayana Nethralaya
state: Karnataka
Study officials:
affiliation: Narayana Nethralaya
name: Rohit Shetty, MD, PHD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Schallhorn SC, Venter JA, Hannan SJ, Hettinger KA. Outcomes of wavefront-guided laser in situ keratomileusis using a new-generation Hartmann-Shack aberrometer in patients with high myopia. J Cataract Refract Surg. 2015 Sep;41(9):1810-9. doi: 10.1016/j.jcrs.2015.10.007.
citation: Schallhorn SC, Venter JA, Hannan SJ, Hettinger KA. Wavefront-Guided Photorefractive Keratectomy with the Use of a New Hartmann-Shack Aberrometer in Patients with Myopia and Compound Myopic Astigmatism. J Ophthalmol. 2015;2015:514837. doi: 10.1155/2015/514837. Epub 2015 Oct 4.
citation: Shaheen MS, Shalaby Bardan A, Pinero DP, Ezzeldin H, El-Kateb M, Helaly H, Khalifa MA. Wave Front-Guided Photorefractive Keratectomy Using a High-Resolution Aberrometer After Corneal Collagen Cross-Linking in Keratoconus. Cornea. 2016 Jul;35(7):946-53. doi: 10.1097/ICO.0000000000000888.
citation: Denoyer A, Landman E, Trinh L, Faure JF, Auclin F, Baudouin C. Dry eye disease after refractive surgery: comparative outcomes of small incision lenticule extraction versus LASIK. Ophthalmology. 2015 Apr;122(4):669-76. doi: 10.1016/j.ophtha.2014.10.004. Epub 2014 Nov 22.
citation: Reinstein DZ, Archer TJ, Gobbe M. Small incision lenticule extraction (SMILE) history, fundamentals of a new refractive surgery technique and clinical outcomes. Eye Vis (Lond). 2014 Oct 16;1:3. doi: 10.1186/s40662-014-0003-1. eCollection 2014.
citation: McNabb RP, Farsiu S, Stinnett SS, Izatt JA, Kuo AN. Optical coherence tomography accurately measures corneal power change from laser refractive surgery. Ophthalmology. 2015 Apr;122(4):677-86. doi: 10.1016/j.ophtha.2014.10.003. Epub 2014 Dec 6.
citation: Matalia J, Francis M, Tejwani S, Dudeja G, Rajappa N, Sinha Roy A. Role of Age and Myopia in Simultaneous Assessment of Corneal and Extraocular Tissue Stiffness by Air-Puff Applanation. J Refract Surg. 2016 Jul 1;32(7):486-93. doi: 10.3928/1081597X-20160512-02.
citation: Sinha Roy A, Kurian M, Matalia H, Shetty R. Air-puff associated quantification of non-linear biomechanical properties of the human cornea in vivo. J Mech Behav Biomed Mater. 2015 Aug;48:173-182. doi: 10.1016/j.jmbbm.2015.04.010. Epub 2015 Apr 20.