To evaluate the influence of patient's age at the time of surgery on small incision lenticule extraction (SMILE) refractive outcomes.
This is a retrospective, consecutive, comparative study. We ...compared the refractive outcomes after myopic SMILE from two groups of patients divided by age (patients ≤35 and ≥40 years old). All eyes were evaluated preoperatively and at 1 and 6 months postoperatively. Main outcome measures were differences on efficacy, safety, predictability and astigmatic changes by vector analysis with ASSORT software between both study groups.
102 matched eyes of 53 patients were included. Preoperatively, we evidenced no differences in the mean SE or astigmatism between groups. However, 6 months postoperatively we observed a significantly worse mean astigmatism (p=0.019), while not regarding SE, in the older population, with a trend towards undercorrection of the refractive cylinder in the ≥40 group. We also observed a statistically significant difference in the efficacy (0.86-1 month and 0.97-6 months in ≥40group vs 0.97-1 month and 1.07-6 months in the ≤35 group; p=0.003) and safety indexes (0.93-1 month and 1.04-6 months in ≥40 group vs 1.0-1 month and 1.11-6 months in the ≤35 group; p=0.008) at 6 months among groups.
Post-SMILE refractive outcomes in those patients over 40 years of age, although acceptable, are not as good as those obtained in younger patients, showing a significantly lower efficacy and safety indexes, and poorer astigmatic outcomes, with a tendency towards undercorrection. We hypothetise that the increased corneal stroma stiffness in the aged group modifies the post-SMILE corneal stroma remodelling capacity, thus affecting the SMILE refractive and visual response.
Keratoconus (KC) is an ectatic corneal disorder that causes, as the irregular astigmatism progress, severe vision loss. Surgical options allow us to correct, partially or totally, the induced ...refractive error.
Intracorneal ring segments (ICRS) implantation represents a minimally invasive surgical option that improves visual acuity by modifying the corneal geometry. The success rate after ICRS implantation is high, and most importantly, the overall complication rate is low. Corneal allogenic intrastromal ring segments consists of ring segments derived from allogenic eye bank-processed donor corneas that can be combined simultaneously or sequentially with corneal cross linking (CXL) procedure in keratoconic patients intolerant to rigid gas permeable contact lenses.
Selective topography guided sequential and simultaneous excimer laser transepithelial photorefractive or phototherapeutic keratectomy combined with conventional and accelerated CXL is another way in selected cases to improve spectacles corrected distance visual acuity (CDVA) of keratoconic eyes. The microphotoablative remodeling of the central corneal profile is generally planned by using topo-guided excimer laser software, optimizing the optical zones, minimizing tissue consumption to a maximum 55 µm of corneal stroma and taking into account the contribution of the epithelium and posterior corneal surface thank to ray-tracing software thus avoiding overcorrections.
Phakic intraocular lens (PIOL) implant is considered in patients with stable disease, acceptable CDVA and with acceptable anatomical requirements. The two types of pIOLs, depending on their implantation inside the eye, are anterior chamber (AC)-pIOLs, with Artilens (Ophtec BV) representing the only commercially available model, which fixate to the anterior surface of the iris by using a polymethomethacrolate claw at the 2haptics, and posterior chamber (PC)-pIOLs, with ICL (Staar) concentrating almost all available scientific evidence about the use of PC-pIOL in KC.
Patients with both cataracts and KC present unique challenges for the surgeon, given the peculiar optical characteristics of the ectatic corneas. In the preoperative evaluation, the correct IOL power is difficult to obtain due to the irregular corneal shape and K values. IOL selection is a crucial moment in the surgery. Toric IOL is recommended, but carefully judging the topography and the possible need of subsequent keratoplasties.
This phase 1 study seeks to preliminarily evaluate the safety and efficacy of decellularized human corneal stromal lamina transplantation with or without autologous adipose-derived adult stem cell ...recellularization within the corneal stroma of patients with advanced keratoconus.
Phase 1 clinical trial.
Femtosecond-assisted 120-μm thickness and 9-mm diameter laminas were obtained from the anterior stroma of human donor corneas and decellularized with a sodium dodecyl sulfate solution. Autologous adipose-derived adult stem cells were obtained by elective liposuction and cultured onto both sides of the lamina. Five patients received the decellularized lamina alone and 4 patients the recellularized lamina into a femtosecond-assisted 9.5-mm diameter lamellar pocket under topical anesthesia. The total duration of follow-up was 6 months.
No case showed clinical haze or scarring by month 3. Six months after surgery, patients showed a general improvement of all visual parameters, with a mean unaided visual acuity from 0.109 to 0.232 (P = .05) and corrected distance visual acuity from 0.22 to 0.356 (P = .068). Refractive sphere improved in all patients (from −4.55 diopters D to −2.69 D; P = .017), but refractive cylinder remained stable (from −2.83 to −2.61; P = .34). An improvement tendency of all anterior keratometric values was observed. A mean improvement of 120 μm in all thickness parameters was confirmed (P = .008), as well as an improvement in the spherical aberration (P = .018), coma (P = .23) and total higher order aberrations (P = .31). No significant differences among groups were detected.
Decellularized human corneal stromal laminas transplantation seems safe and moderately effective for advanced keratoconus. Potential benefits of its recellularization with autologous adipose-derived adult stem cells remains unclear.
To study and compare the clinical optical image quality following implantation with different premium IOLs by analysing the point spread function (PSF) Strehl ratio using a pyramidal wavefront sensor ...(PWS)-based aberrometer.
This study included 194 eyes implanted with: (a) 19 AcrySof SA60AT (control group); (b) 19 Miniwell; (c) 24 LENTIS Mplus LS-313 MF30; d) 33 LENTIS Mplus LS-313 MF15; (e) 17 AkkoLens Lumina; (f) 31 AT LISA Tri 839MP; (g) 20 Precizon Presbyopic; (h) 20 AcrySof IQ PanOptix; (i) 11 Tecnis Eyhance. Main outcome measures were PSF Strehl ratio, PSF Strehl ratio excluding second-order aberrations (PSFw2), total root mean square (RMS), low-order aberration (LOA) and high-order aberration (HOA) RMS measured by PWS aberrometer.
AT LISA Tri had the highest PSFw2 Strehl ratio at both 3.0- and 4.0-mm pupil size (0.52 ± 0.14 and 0.31 ± 0.10; P < 0.05), followed by SA60AT (0.41 ± 0.11 and 0.28 ± 0.07) and PanOptix (0.4 ± 0.07 and 0.26 ± 0.04). AT LISA Tri was found to provide a significantly better retinal image quality than PanOptix at both 3.0 mm (P < 0.0001) and 4.0 mm (P = 0.004). Mplus MF15 was found to be significantly better than Mplus MF30 at both 3.0 mm (P < 0.0001) and 4.0 mm (P = 0.002). Total RMS, LOA RMS, HOA RMS, PSF Strehl ratio and PSFw2 varied significantly between the studied groups (P < 0.001).
Far distance clinical image quality parameters measured by PWS aberrometer differed significantly according to the technology of the implanted lens. AT LISA Tri, SA60AT and PanOptix showed the highest values of far distance retinal image quality, while the lowest PSFw2 Strehl ratios were displayed by Miniwell, Mplus MF30 and Precizon Presbyopic.
This study evaluated 1-year safety and efficacy outcomes of corneal stroma cell therapy. Therapy consisted of implanting autologous adipose-derived adult stem cells (ADASc) with or without sheets of ...decellularized donor human corneal stroma within the stroma of patients with advanced keratoconus.
This was a prospective interventional non-randomized series of cases.
Fourteen consecutive patients were selected and divided into 3 experimental groups. Group A patients underwent implantation of autologous ADASc alone (3 × 106 cells/1 mL) (n = 5). Group B patients received decellularized donor 120-μm-thick corneal stroma lamina alone (n = 5). Group C patients had implantation of recellularized donor lamina with 1 × 106 autologous ADASc plus another 1 × 106 cells/1 mL at the time of the surgery (n = 4). Autologous ADASc were obtained by elective liposuction. Implantation was performed in the corneal stroma through a femtosecond-assisted 9.5-mm diameter lamellar dissection with the patient under topical anesthesia. Twelve months of follow-up data are presented.
No complications were observed during the 1-year follow-up, and full corneal transparency was recovered within 3 months in all patients. No patient lost lines of visual acuity. Corrected distance visual acuity improved 0.231, 0.264, and 0.094 Snellen lines in groups 1, 2, and 3, respectively. In group 1, refractive parameters showed an overall stability, whereas in groups 2 and 3, sphere improved 2.35 diopter (D) and 0.625 D, respectively. Anterior keratometry remained stable (group 1) and improved in groups 2 and 3 (mean improvement of 2D). Corneal aberrometry improved significantly. In optical coherence tomography scans, corneal thickness showed a mean improvement of 14.5 μm (group 1) and 116.4 μm (groups 2 and 3) in the central thickness, and new collagen production was observed at the surgical plane (group 1). Confocal biomicroscopy confirmed the host recellularization of the implanted laminas.
Intrastromal implantation of autologous ADASc and decellularized human corneal stroma did not show complications at 1 year of follow-up and were moderately effective for the treatment of advanced keratoconus. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.
Keratoconus is a disease characterized by progressive thinning, bulging, and distortion of the cornea. Advanced cases usually present with loss of vision due to high irregular astigmatism. A majority ...of these cases require surgical intervention. This review provides an update on the current treatment modalities of corneal surgery available for the management of advanced corneal ectasias.
Presbyopia still remains the last frontier of refractive surgery. Its surgical management is under constant evolution due to the limitations that exist today with respect to its management, which is ...probably in relation with the multifactorial basis in which presbyopia is clinically developed in the human. Until currently, virtually all surgical techniques that have been proposed for its correction are based on the induction of pseudoaccommodation in the presbyopic eye, including multifocality. However, the real restoration of accommodation is more complex, and it has been tried by the use of different, so called, "accommodative" pseudophakic intraocular lenses (AIOL). Overall, the reported results with these lenses by independent authors have been modest in relation with the restoration of the accommodative power of the eye and these modest benefits are usually lost with time due to the long term changes in the capsular bag. This fact made these lenses to be almost abandoned in the last few years, but there are currently other AIOL models being used with innovative mechanisms of action and different anatomical support outside the capsular bag that offer encouraging preliminary results that could bring a new potential of application to these types of lenses. In this article, we will update the modern refractive surgeon about the fundamentals and provide updated information about the outcomes of AIOLs by reviewing the concept of accommodation, the different attempts that have been accomplished in the past, their demonstrated published results in human clinical trials, and the future alternatives that may arrive in the near future.
Blood derived products have demonstrated their capacity to enhance healing and stimulate the regeneration of different tissues and this enhancing effect is attributed to the growth factors and ...bioactive proteins that are synthesized and present in blood. Eye platelet rich plasma (E-PRP) provides higher concentration of essential growth factors and cell adhesion molecules by concentrating platelets in a small volume of plasma as compared with autologous serum, the latter being used widely in ophthalmology for epithelial wound healing of the cornea for the last two decades. These growth factors and cell adhesion molecules have a major role in wound healing and enhance the physiological process at the site of the injury/surgery via eye drops or clot. E-PRP has been used more recently, and has achieved successful outcomes in peer-review articles in the treatment of dormant ulcers (epithelial defects of the cornea that fail to heal), moderate to severe dry eye syndrome, ocular surface syndrome post Laser In Situ Keratomileusis (LASIK), and for surface reconstruction after corneal perforation associated with amniotic membrane transplantation. Preparation of E-PRP in the two available formulations, eyedrops and clot, is inexpensive and easy although it requires following strict sterility conditions using sterile and disposable materials and operating inside a laminar flow hood. No serious adverse effects have been described with the use of these products, and it is generally well tolerated. In summary, Platelet enriched plasma in the form obtained in ophthalmology, E-PRP, is a reliable and effective therapeutic tool to enhance epithelial wound healing in ocular surface disease.
Metal–organic frameworks (MOFs) have been evaluated as potential nanocarriers for intraocular incorporation of brimonidine tartrate to treat chronic glaucoma. Experimental results show that UiO-67 ...and MIL-100 (Fe) exhibit the highest loading capacity with values up to 50–60 wt %, whereas the performance is quite limited for MOFs with narrow cavities (below 0.8 nm, for example, UiO-66 and HKUST-1). The large loading capacity in UiO-67 is accompanied by an irreversible structural amorphization in aqueous and physiological media that promotes extended release kinetics above 12 days. Compared to the traditional drawbacks associated with the sudden release of the commercial drugs (e.g., ALPHAGAN), these results anticipate UiO-67 as a potential nanocarrier for drug delivery in intraocular therapeutics. These promising results are further supported by cytotoxicity tests using retinal photoreceptor cells (661W). Toxicity of these structures (including the metal nodes and organic ligands) for retinal cells is rather low for all samples evaluated, except for HKUST-1.
To present morphogeometric and volumetric characteristics of the cornea and its diagnostic value in pediatric patients with keratoconus (KC) using 3-dimensional (3-D) corneal modeling.
...Cross-sectional study.
This single-center (VISSUM Innovation, Alicante, Spain) study comprised 49 eyes of 49 pediatric patients (age ≤16 years) with KC and 31 eyes of 31 healthy pediatric controls. Eyes were graded as early (n = 21) and mild KC (n = 28) based on the RETICS (Thematic Network for Co-Operative Research in Health) classification system. The 3-D corneal model was generated using raw topographic data. Deviation of anterior (Dapexant) and posterior (Dapexpost) apex and minimum thickness points (Dmctant, Dmctpost), Dapexant-Dapexpost difference, total corneal volume (Vtotal), volumetric distribution (VOLAAP, VOLPAP, and VOLMCT), and percentage of relative volume increase (VOLAAPrel, VOLPAPrel, and VOLMCTrel) between 2 consecutive radii centered to anterior/posterior apex and thinnest point were evaluated.
Dapexpost and Dapexant-Dapexpost difference were higher in the early and mild KC groups compared to the control group (P < .05). Eyes with early and mild KC had decreased Vtotal compared with the control group (P < .05). Dapexpost, Dapexant-Dapexpost difference, and VOLMCTrel between 1.0 and 1.4 mm diameters had area under receiver operating characteristics curve (AUROC) values over 0.93 in discrimination of early KC from normal.
This is the first study presenting morphogeometric and volumetric characterization of cornea in pediatric patients with early and mild KC using a 3-D corneal model. Integration of the morphogeometric and volumetric parameters to topography software can add value in early detection of KC in pediatric patients.
PDF
