Corneal Epithelium Thickness and Refractive Changes After Myopic Laser Corneal Refractive Surgery.

PURPOSE: To evaluate the postoperative changes in corneal epithelium thickness and refractive power after femtosecond laser-assisted laser in situ keratomileusis (LASIK) and small incision lenticule extraction (SMILE) for myopia correction using anterior segment optical coherence tomography (OCT) with an integrated Placido disc topographer. METHODS: The VisuMax 500-kHz femtosecond laser (Carl Zeiss Meditec AG) and Amaris 750 excimer laser (SCHWIND eye-tech-solutions) were used. Central, paracentral, and 6-mm epithelial thickness values were obtained, and the change in the value of epithelial thickness was calculated. Changes in the refractive power of the epithelium were also evaluated. The repeatability of this new measurement was also analyzed using the intraclass correlation (ICC). The total follow-up period was 6 months. RESULTS: A total of 77 LASIK eyes were matched with 77 SMILE eyes. Mean spherical equivalent was -3.92 ± 1.67 diopters (D) for LASIK versus -4.02 ± 1.63 D for SMILE (P = .356). Epithelial thickness parameters significantly and equally thickened in both types of surgery. The change in the value of epithelial thickness was positively correlated with spherical aberration. Analysis of the refractive power of the corneal epithelial layer (ICC > 0.70) showed a tendency for the postoperative myopization of the refractive component of this layer (-0.11 D for SMILE and -0.53 D for LASIK at 3 mm) and an increase in its cylinder and aberrometry. Increasing postoperative spherical aberration and epithelial thickness increased myopization of the epithelial refractive sphere (P < .05). CONCLUSIONS: Corneal epithelium thickens similarly after LASIK and SMILE, being slightly higher after SMILE. This correlates with the induced spherical aberration. Corneal epithelium thickening induces myopization of its refractive power, which accounts for a slight regression of the net refractive power change on the treated cornea. [J Refract Surg. 2022;38(9):602-608.].

Corneal stromal thickness changes after myopic laser corneal refractive surgery.

PURPOSE: To evaluate the postoperative behavior of the central corneal stromal thickness after myopic femto-laser-assisted in-situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE) by using combined anterior segment optical coherence tomography and a Placido disk topographer and to compare the accuracy of both laser machines in predicting the real stromal change. SETTING: Vissum Miranza, Alicante, Spain. STUDY DESIGN: Prospective, observational, comparative study. METHODS: The VisuMax 500 kHz femtosecond laser (FS) and the Amaris 750 excimer laser were used for the correction of myopia with or without myopic astigmatism. Central and paracentral stromal thicknesses (ST) and 6.0 mm corneal aberrometry were obtained with the MS39 topographer. Laser-predicted stromal consumption was recorded (maximum lenticule thickness for SMILE and central ablation depth for LASIK). Visual and refractive outcomes were also evaluated. Total follow-up was 6 months. RESULTS: 77 LASIK eyes were matched with 77 SMILE eyes. Mean preoperative spherical equivalent (SE) was -3.92 ± 1.67 diopters (D) for LASIK and -4.02 ± 1.63 D for SMILE (P = .356). After LASIK, ST parameters showed significant rethickening between months 1 and 3 (+4.38 µm for central ST; P < .001), remaining stable thereafter. After SMILE, all ST parameters remained stable from month 1. Stromal ablation prediction was higher for SMILE compared with LASIK for all SE ranges, although postoperatively such differences were significant only for ametropias ≤4 D. At 6 months, mean SMILE laser prediction error was -13.21 ± 7.00 µm, whereas LASIK prediction showed better accuracy (+0.92 ± 8.16 µm; P < .001). CONCLUSIONS: The accuracy of the Amaris 750 excimer laser in predicting the stromal consumption after LASIK was better than the VisuMax FS laser for SMILE. Although SMILE ST remained stable from month 1, after LASIK, mild stromal rethickening was observed up to the third month.

Introduction of longstanding complicated sulcus intraocular lens into the intact capsular bag.

AIM: To propose a surgical technique that successfully reopened the empty and intact capsular bag after long periods of closure, with repositioning of the intraocular lens (IOL) from the ciliary sulcus into its preferred habitat inside the capsular bag. METHODS: This is a case series, prospective, and interventional study. The technique was first performed on an aphakic high myope with a closed posterior capsule for 18y. Afterwards, five patients with recurrently displaced sulcus IOLs for a range of 1mo to 7y were performed for the same technique. During surgery, identifying a "telltale white line" was an important landmark for detecting the site of major adhesions between the edge of the capsulorhexis and the posterior capsule. These adhesions were freed using combined manual and viscoelastic dissection, followed by an easier freeing of adhesions along the whole capsular bag. The IOL was safely implanted, exchanged, or introduced from the sulcus into the fibrotic and closed capsular bag. Patients were followed up for a period ranging from 6 to 17mo postoperatively. RESULTS: All the patients experienced a remarkable improvement in their subjective refraction. Slit lamp examination showed a postoperative centralized IOL in the bag. The follow up visits confirmed visual and IOL stability. CONCLUSION: This newly-introduced surgical technique facilitates the reopening of the empty yet intact capsular bag that has been closed by fibrotic proliferations, with secured implantation of the IOL inside the capsular bag. Patients with inadvertent implantation of IOLs into the ciliary sulcus, yet having an intact capsular bag, can benefit from this technique.

Evaluation of the efficacy, safety, and stability of posterior chamber phakic intraocular lenses for correcting intractable myopic anisometropic amblyopia in a pediatric cohort.

BACKGROUND: Myopic anisometropic amblyopia in pediatrics is one of the most challenging clinical situations that can face an ophthalmologist. Conventional correction modalities for myopic anisometropia, using spectacles, contact lenses, and/or occlusion therapy, may not be suitable for some pediatric patients or for some ocular conditions. This may lead to the development of anisometropic amblyopia. The aim of the present study was to evaluate the visual and the refractive efficacy, safety, and stability of Posterior Chamber Phakic Intraocular Lenses (PC-pIOLs) for correcting myopic anisometropic amblyopia in a pediatric cohort. METHODS: This case series, prospective, interventional study was conducted at Watany Eye Hospital, Cairo, Egypt. It comprised children and teenagers with myopic anisometropic amblyopia and unsuccessful conventional therapy. After implantation of Intraocular Collamer Lenses "ICLs" (Visian ICL, Model V4c, STAAR Surgical, Monrovia, California, USA), postoperative follow-up visits were scheduled, with automated refraction and Pentacam imaging performed. RESULTS: The study enrolled 42 eyes of 42 patients. The age range was 3 to 18 years (mean ± SD = 10.74 years ±4.16). The mean preoperative spherical equivalent (SE) was - 12.85 D ± 2.74. The results declared a significant improvement in the postoperative Corrected Distance Visual Acuity "CDVA" (P value < 0.01) and SE (P value < 0.01). The efficacy index had a value of 1.18 ± 0.3 and the safety index was 1.09 ± 0.24. The follow-up visits had a mean ± SD of 14.67 months ±16.56 (range of 1 to 54 months). The results showed a refractive stability, with statistically insignificant improvements in the patients' visual acuity and refractive status on evaluating the enrolled pediatrics during the follow-up visits compared to the first postoperative visits. No postoperative complications were encountered. Worthy of mention is that there was a significant (80%) non-compliance with the prescribed postoperative occlusion therapy. CONCLUSIONS: The present study, with the longest reported follow-up range, declared the long-term efficacy, safety, and stability of Visian ICLs for correcting myopic anisometropic amblyopia in pediatrics. The reported non-compliance with occlusion therapy validates the early implantation of Visian ICLs in cases with failed conventional therapy to guard against anisometropic amblyopia.

FLACS in Congenital Iris Coloboma: A Useful Technique.

This paper reports the technique and outcome of femtosecond laser-assisted cataract surgery (FLACS) in an iris coloboma patient (59-year-old male patient) with bilateral grade 3 cataractous lens and a shallow anterior chamber. Best-corrected visual acuity (BCVA) was 0 on logMAR with spherical equivalent (SE) 9 D in the right eye, and BCVA of 0.3 logMAR with a SE 8.75 D in the left. FLACS was performed on the left then the right eye using the Catalys platform of Johnson & Johnson (intraocular lens implantation of AMO Tecnis 1 ZCB00). Customized parameters were constructed to create capsulotomies of 4.54.7 mm for the left and right eyes, respectively, with manual centration of the distorted pupils. On the second day of follow-up, left-eye BCVA was 0.5 with SE 1 D, and right-eye BCVA was 1 with SE -0.75 D. At the 1-year follow-up, eyes showed stable bilateral Tecnis 1 IOL and refraction. FLACS is a safe surgical option with stable outcomes in cases of cataract with iris coloboma.

Five-slice technique for the explantation of complicated BrightOcular© cosmetic iris implants.

PURPOSE: Our purpose is to describe a safe and easy technique for the removal of the BrightOcular cosmetic iris implants. Our technique involves cutting the implant into five parts rather than removal as a whole with less intraocular manipulation and no rotation of the implant. METHODS: We have used this technique in two eyes of a 28-year-old patient who presented to us with progressive drop of vision and acute attacks of ocular pain. Best-corrected distance visual acuity (BCVA) was found to be 6/18 and 6/9 on Snellen chart in her right and left eyes, respectively. Intraocular pressure was 40 mmHg and 20 mmHg in the right and left eyes, respectively, with visual field and retinal nerve fiber layer changes in the right eye. RESULTS: After removal of both implants, 1-week post-operative BCVA improved to 6/6 bilaterally. After 3 months of regular follow-ups, IOP remains uncontrolled in the right eye despite medical treatment, and surgical intervention is planned. CONCLUSION: Our five-slice technique for removal of iris implants can be done effectively through a small corneal wound thus avoiding most wound-related problems. Our technique also includes no rotation or excessive manipulation inside the anterior chamber and can be carried out easily and safely with both the NewColorIris and BrightOcular implant designs.

Keratopigmentation to Change the Apparent Color of the Human Eye: A Novel Indication for Corneal Tattooing.

BACKGROUND: Recently developed surgical techniques of keratopigmentation, assisted by femtosecond laser technology, using adequately developed micronized mineral pigments, have been reported to be efficient and conveniently safe as they are not associated with significant sight-threatening complications for changing the apparent color of the eye in cases of cosmetic therapeutic and functional keratopigmentation. We report the use of intrastromal keratopigmentation for electively changing the apparent color of the eyes, for purely cosmetic reasons. METHODS: In a case series, 7 patients underwent purely cosmetic keratopigmentation to change the apparent color of the eye. The indication was compassionate and the procedure was conducted under the tenets of the Helsinki Declaration. Superficial automated keratopigmentation, manual intralamellar keratopigmentation, and femtosecond-assisted keratopigmentation were used. In this study cosmetic outcome, patient satisfaction, visual outcomes, stability of pigmentation, and presence of any related complications are reported. RESULTS: In this study 42.8% were females, with a mean age of 40 years (27-63). In 4 patients, pigment retouch was done to improve the cosmetic outcome. Results were monitored by an independent observer with follow-up ranging from 6 months to 2.5 years. All patients expressed high satisfaction with the cosmetic outcomes, with no complications and stable visual acuity during the period of follow-up. CONCLUSIONS: As a novel indication, purely cosmetic keratopigmentation demonstrated stable pigmentation with no visual disability, high patient satisfaction, and favorable outcomes in all patients. Elective keratopigmentation seems to be a viable and convenient modality for changing the apparent color of the eye in selected cases.

Excimer laser 6(th) generation: state of the art and refractive surgical outcomes.

After nearly three decades of innovation in excimer laser, today we are presented with a state of the art generation targeting minimally invasive refractive surgery with high speed laser, faster trackers, pupil monitoring systems and better customization profiles. These systems are capable of delivering better treatments with less induced postoperative high order aberrations. The results reported by many authors had confirmed the superiority in efficiency and safety profiles of this generation compared to previous generations. Still, current technology is facing major challenges in the correction of high hyperopic errors and in presbyopic treatments, with upgrades in ablation centration and thermal control needed, which will ensure better biomechanical results, as a step closer to perfection in refractive surgery.