Enhancing after SMILE
A manuscript published in the recent issue of ophthalmology reports the incidence, risk factors, and outcomes of enhancement after small-incision lenticule extraction (SMILE). A retrospective cohort study w
as conducted in Singapore on 524 eyes of 307 patients who underwent SMILE. Few patients had to undergo enhancements all of which were carried out by performing an alcoholassisted photorefractive keratectomy (PRK) procedure with application of mitomycin C (MMC). The prevalence of enhancement was 2.7%, and 71.4% eyes had enhancement within 1 year of primary SMILE. The incidence of enhancement was 2.1% and 2.9% at 1 and 2 years, respectively. Age older than 35 years, preoperative MRSE more than -6.00 diopters (D), preoperative myopia more than 6.00 D, preoperative astigmatism more than 3.00 D, and intraoperative suction loss were significant risk factors for enhancement after SMILE. In the patients who underwent bilateral SMILE, the first-operated eye had a slighter higher chance for enhancement. There was no gender or racial difference. In the 14 eyes requiring enhancement, the uncorrected distance visual acuity before enhancement ranged from 20/80 to 20/25, and the mean attempted enhancement spherical equivalent was -0.50±0.86 D. The uncorrected distance visual acuity improved in nearly all patients after enhancement. The study concluded that the overall clinical outcomes of using PRK with application of MMC for enhancement are good.
Read More:
Liu YC, Rosman M, Mehta JS. Enhancement after Small-Incision Lenticule Extraction: Incidence, Risk Factors, and Outcomes. Ophthalmology. 2017 Jun;124(6):813-821.
Iris registration in FEMTOLASIK: To do or not to do
The gaze tracker is an essential aspect of any laser based keratorefractive surgery. Additionally, the option of iris registration and using that for tracking eye position is also available and used by many. A study was recently published to evaluate whether adding iris registration made an impact on the outcome of FemtoLASIK. The randomized, prospective, comparative, contralateral eye study compared 118 eyes of 59 patients with myopia and myopic astigmatism who underwent LASIK using the Femto LDV femtosecond laser (160 μm) and the MEL80 with or without iris registration in the eye. Patients were evaluated before and 12 months after the LASIK to look for uncorrected visual acuity, best-corrected visual acuity, manifest refraction, contrast sensitivity, and higher-order aberrations. At the end of 12months, both groups of eyes achieved similar outcomes for all these parameters. The study concluded that FEMTOLASIK with and without iris registration provides similar results in myopic and myopic astigmatism patients.
Read More:
Ghoreishi M, Beni ZN, Beni AN, Kianersi F. Effect of iris registration on outcomes of FEMTOLASIK for myopia and myopic astigmatism. Int Ophthalmol. 2017 Sep 5.
Anterior subcapsular cataract after ICL: an unusual cause
A study shed light on an unusual cause for the rare entity of anterior subcapsular cataract after implantation of a posterior chamber phakic intraocular lens (pIOL) with a central hole. Medical reports of patients with vision loss caused by anterior subcapsular cataract after implantation of the V4c Visian Implantable Collamer Lens with a central hole, were reviewed. Possible causative factors, such as microbial contamination of surgical instruments, type of ophthalmic viscosurgical device (OVD) and irrigation substance, intracameral application of mydriatics and antibiotics, duration of surgeries, and surgical technique were analyzed. Eleven eyes of 8 patients showed white opacification behind the anterior capsule of the crystalline lens 1 day postoperatively. This opacification led to a significant loss of corrected distance visual acuity in all eyes. In 9 eyes, the pIOL was explanted and in 8 eyes, phacoemulsification with IOL implantation was performed. All other analyzed possible causative factors were excluded; and the opacification was attributed to the surgical technique of OVD removal by irrigation with a cannula in the presence of a central hole in the pIOL. After the surgical technique was adapted, no further cases of anterior subcapsular cataract occurred. Irrigation is an unusual suspect for forming an anterior subcapsulr cataract but one that we need to ne alert about.
Read More:
Steinwender G, Varna-Tigka K, Shajari M, Kohnen T. Anterior subcapsular cataract caused by forceful irrigation during implantation of a posterior chamber phakic intraocular lens with a central hole. J Cataract Refract Surg. 2017 Jul;43(7):969-974.