Eight-Year Outcomes of Implantation of Posterior Chamber Phakic Intraocular Lens With a Central Port for Moderate to High Ametropia

Purpose: To assess the 8-year clinical outcomes of implantation of an implantable collamer lens (ICL) with a central port (KS-Aquaport; EVO-ICL) for moderate to high myopia and myopic astigmatism.Methods: This retrospective study comprised a total of 177 eyes of 106 patients with spherical equivalents of −7.99 ± 3.33 D [mean ± standard deviation], who underwent EVO-ICL implantation. We evaluated the safety, efficacy, predictability, stability, and adverse events of the surgery, at 1 month, and 1, 2, 4, 6, and 8 years postoperatively.Results: The logarithm of the minimal angle of resolution (LogMAR) uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were −0.07 ± 0.17 and −0.20 ± 0.09, respectively, at 8 years postoperatively. The safety and efficacy indices were 1.18 ± 0.24 and 0.89 ± 0.28, respectively. At 8 years, 83 and 93% eyes were within ± 0.5 D and ± 1.0 D of the targeted correction, respectively. Change in manifest refraction from 1 month to 8 years postoperatively was −0.13 ± 0.30 D. Three eyes (1.7%) that developed cataracts had a slight pre-existing peripheral anterior subcapsular cataract formation required simultaneous ICL extraction and cataract surgery at 2 or 3 years or ICL size change (1 size up) at 7 years postoperatively. We found that neither significant intraocular pressure (IOP) rise (including pupillary block) nor significant endothelial cell loss occurred in any case throughout the 8-year observation period.Conclusions: Current ICL implantation with central port technology offered good continuous outcomes for all measures of safety, efficacy, predictability, and stability for correcting moderate to high myopic errors over a long period, thereby suggesting its long-term viability as a surgical approach for the treatment of such eyes.

Impact of Ocular Residual Astigmatism On Anterior Corneal Astigmatism In Children With Low And Moderate Myopia

Background: To assess the influence of ocular residual astigmatism to anterior corneal astigmatism in children with low and moderate myopia.Methods: Refractive astigmatism was obtained by subjective manifest refraction. Anterior corneal astigmatism was obtained by IOL Master. Using Thibos vector analysis to calculate ocular residual astigmatism. Correlation analysis was used to assess the relationship between the magnitude of ocular residual astigmatism and anterior corneal astigmatism. The influence of ocular residual astigmatism to anterior corneal astigmatism was evaluated by Physical method.Results: The study analyzed 241 right eyes of 241 children aged 8 to 18 years old. In this study, the median magnitude of ocular residual astigmatism was 1.02 D, with interquartile range was 0.58 D. Against-the-rule ocular residual astigmatism was seen in 232 eyes (96.3%). There was a significant and moderate correlation between ocular residual astigmatism and anterior corneal astigmatism (r = 0.50, P < 0.001). The ocular residual astigmatism in 240 eyes (99.6%) had a compensatory effects on anterior corneal astigmatism. The mean compensation value was 1.00 ± 0.41 D (rang 0.02 D to 2.34 D). Based on this effect, 37 eyes had different axial classification of anterior corneal astigmatism and refractive astigmatism. By contrast, one eye (0.4%) had oblique ocular residual astigmatism and superimposed with-the-rule anterior corneal astigmatism.Conclusions: The magnitude of ocular residual astigmatism was relatively huge in myopia children and predominantly compensated anterior corneal astigmatism. The ocular residual astigmatism should be assessed first before fitting orthokeratology.

Changes in post-keratoplasty astigmatism after suture removal: refraction vs tomography vs aberrometry

AIM: To analyse the changes in magnitude and orientation of astigmatism after suture removal (SR) in keratoplasty eyes as measured by refraction, tomography, and aberrometry. METHODS: Twenty-six eyes of 25 patients after optical keratoplasty requiring SR to reduce the astigmatism during the follow-up period were prospectively included. Eyes with poor quality topography scans or if there were no sutures in the steepest semi meridian were excluded. Corrected distance visual acuity (CDVA), manifest refraction, corneal tomography and aberrometry were performed on all patients before and after SR. RESULTS: The mean age of the patients was 40.8±14.4y. Penetrating keratoplasty was performed in 23 eyes (89%) and deep anterior lamellar keratoplasty was done in 3 eyes (11%). There was a statistically significant reduction in the magnitude of refractive, tomographic and aberrometry astigmatism after SR (P<0.001) at 2h after suture removal. The mean net reduction of the astigmatism was greater as measured by corneal tomography compared to refractive astigmatism (P<0.05). There was no statistically significant change in refractive astigmatism between 2h and 2mo after SR (P=0.55). Vector calculations demonstrated a greater amount of undercorrection in the tomography group and the rotational error was more towards counterclockwise direction. Mean monocular logMAR CDVA improved from 0.57 D to 0.49 D after SR (P=0.002). CONCLUSION: The net reduction in the magnitude of astigmatism after SR is greater in the tomography and aberrometry groups. With one episode of SR, there is no difference in the aberration profile.

Accuracy of intraocular lens power calculation formulas in a steep cornea: A case report

There is no enough knowledge about the accuracy of intraocular lens (IOL) power calculation formulas in steep corneas. This study may be the first one that compares the accuracy of the SRK II formula with Holladay1, Hoffer Q and Haigis formulas in steep corneas. We reported a case of a 60-year-old female, with a cataract in the left eye and with a steep cornea. We used the modern formulas; Holladay1, Hoffer Q and Haigis. The result (+7.0D) was unexpected compared to the manifest refraction and to the IOL power calculated in the right eye using the same formulas which was (+17.0D). We implanted (+12.0D) Sensar 1-piece IOL depending on our clinical experience. The post-operative refraction was (+0.00/-1.75axis106). Postoperative, we used the patient data to find the best formula in this case. We found that the SRK II (A118) result was (+11.5D) and thus this formula was the most accurate in this case. Keywords: SRK II; Holladay1; Hoffer Q; Haigis

Visual differences in topography-guided versus wavefront-optimized LASIK in the treatment of myopia: a Meta-analysis

AIM: To investigate the potential differences between topography-guided (TG) and wavefront-optimized (WFO) laser in situ keratomileusis (LASIK) for the treatment of myopia. METHODS: A systematic literature search was performed to determine relevant trials comparing LASIK with TG and WFO from the time of library construction to August 2020, and The PubMed, Cochrane, Web of Science, EMBASE and Chinese databases (i.e. CNKI, CBM, WAN FANG and VIP) were accessed. The data on visual acuity, refractive status and wavefront aberration were retrieved and evaluated from three to six months after surgery. STATA (version 14.0) software was used for statistical analysis. A cumulative Meta-analysis was simultaneously performed. RESULTS: Eleven studies with a total of 1425 eyes were incorporated. No statistically significant differences were evident between TG and WFO ablation in the proportion of eyes achieving an uncorrected distance visual acuity (UCVA) of 20/20 or better (P=0.377), gaining one line or more (P=0.05), postoperative cylinder (P=0.40), vertical coma (P=0.593) and horizontal coma (P=0.957). After TG ablation, the proportion of the patients’ eyes of which postoperative refraction is within ±0.5 diopter of the target refraction was significantly higher than that undergoes WFO (P=0.003). As opposed to the WFO group, manifest refraction spherical equivalent (MRSE; P=0.000) was lower, and UCVA (P=0.005) was better in the TG group. The higher-order aberrations (HOAs; P=0.000), spherical aberration (P=0.000) and coma (P=0.000) were significantly lower in TG group. The cumulative Meta-analysis illustrated that the proportion of eyes achieving UCVA of 20/20 or better, postoperative refraction within ±0.5 diopter, and MRSE has steady between the two groups. CONCLUSION: Both TG-LASIK and WFO-LASIK are safe, effective, and predictable for correcting myopia. TG-LASIK may produce fewer aberration and is more precise than WFO-LASIK.

Two-year results after combined phacoemulsification and iris-fixated phakic intraocular lens removal

Purpose To describe and present results after a technique for cataract surgery combined with explantation of an iris-fixated phakic intraocular lens (IF-pIOL). Methods The medical records of all patients, who had undergone cataract surgery combined with IF-pIOL explantation and subsequent implantation of a posterior chamber IOL by the Single Incision Technique (SIT), were reviewed. Data collection included preoperative and postoperative corrected distance visual acuity (CDVA), manifest refraction, and endothelial cell density (ECD) up to a follow-up time of 24 months. Results Fifty myopic eyes (34 patients) and 9 hyperopic eyes (6 patients) had undergone a SIT procedure mainly because of cataract (67%). Postoperative CDVA improved in both the myopic eyes to 0.16 ± 0.37 logMAR, as in the hyperopic eyes to − 0.10 ± 0.55 logMAR with no eyes having loss of Snellen lines. Mean postoperative spherical equivalent was − 0.34 ± 0.72 D and − 0.10 ± 0.55 D, respectively. ECD loss 6 months after surgery was 5% and remained stable thereafter. Conclusion SIT for combined phacoemulsification and IF-pIOL removal yields good visual and refractive results and is a safe procedure in regard to ECD loss. The technique has advantages over the conventional procedure and is easy to perform.

Comparison between Small Incision Lenticule Extraction and Wavefront-Guided Femtosecond Laser-Assisted In Situ Keratomileusis in Correction of Myopic Astigmatism

Aim of the Work To compare visual acuity, refractive and topographic outcome between small incision lenticule extraction (SMILE) and wavefront-guided femtosecond laser-assisted in situ keratomileusis (WFG FS-LASIK) in patients with myopic astigmatism. Patients and methods This prospective, non-randomized, comparative clinical study included 60 eyes of 30 patients with simple or compound myopic astigmatism presenting for refractive error correction. Femtosecond assisted LASIK group included 30 eyes and SMILE group included 30 eyes. The following tests were done for all patients preoperatively and at 3 months postoperatively: full ophthalmological examination, manifest refraction, UDVA, CDVA, corneal topography using combined schimflug and placcido disc imaging namely Pentacam. (Oculus Inc.) and wavefront analysis using ATLAS 9000 (Carl Zeiss Meditec) Main Outcome Measures: Uncorrected distance visual acuity (UDVA), corrected disctance visual acuity (CDVA), manifest refraction, Efficacy, safety, predictability, corneal higher order aberrations. Results At 3 months, the mean manifest refractive spherical equivalent (MRSE) in SMILE group was -0.33 ± 0.34 D and the mean MRSE in FS- LASIK group was 0.23 ± 0.35 D and there was a statistically significant difference between both groups (P &lt; 0.05). mean postoperative cylinder was -0.56 ± 0.28 D in SMILE group and -0.53 ± 0.38D in FS-LASIK with statistically significant difference ( P = 0.254 ) 93% and 93% of eyes in the SMILE and FS-LASIK groups were within ± 0.5 D; 96.67% and 100% of eyes in the SMILE and FS-LASIK groups, respectively, were within ± 1 D. There were 86.66% of treated eyes in the SMILE group, and 93.33% treated eyes in the FS-LASIK group that had 20/25 or better UDVA. Regarding safety, the CDVA in the SMILE group, 20 eyes (66.67%) showed no change, 8 eyes (27%) gained 1 line, 2 eyes (7%) lost 1 line, and no eyes lost more than 1 line. whereas in the FS-LASIK group, 27 eyes (90%) exhibited no change, 2 eyes (6.66%) gained 1 line, 1 eye (3.33%) lost 1 line, and no eyes lost more than 1 line and There was no statistically significant difference between both groups (P = 0. 554 ). Regarding corneal asphericity, both procedures increased Q-value with no statistically significant difference between both groups (P = 0. 052). Regarding corneal higher order aberrations, both procedures significantly increased total corneal aberrations but there was no statistically significant difference in the change in RMS of total corneal higher order aberration (P = 0.434) .but SMILE increased RMS of coma aberration significantly more than FS-LASIK (P = 0. 029). Conclusion both SMILE and FS-LASIK procedures have shown excellent efficacy, safety, and predictability for the correction of myopia and myopic astigmatism. SMILE was closer to emmetropia regarding sphere and spherical equivalent, However, astigmatic undercorrection was noted after both surgeries with increased astigmatism. Both procedures increased the total corneal higher order aberrations with no statistically significant difference between both groups. A higher vertical coma was found in SMILE than WFG FS-LASIK.

The evaluation of a web-based tool for measuring the uncorrected visual acuity and refractive error in keratoconus eyes: A method comparison study

Purpose To evaluate the outcome of a web-based digital assessment of visual acuity and refractive error, compared to a conventional supervised assessment, in keratoconus patients with complex refractive errors. Material and methods Keratoconus patients, aged 18 to 40, with a refractive error between -6 and +4 diopters were considered eligible. An uncorrected visual acuity and an assessment of refractive error was taken web-based (index test) and by manifest refraction (reference test) by an optometrist. Corrected visual acuity was assessed with the prescription derived from both the web-based tool and the manifest refraction. Non-inferiority was defined as the 95% limits-of-agreement (95%LoA) of the differences in spherical equivalent between the index and reference test not exceeding +/- 0.5 diopters. Agreement was assessed by a Bland-Altman analyses. Results A total of 100 eyes of 50 patients were examined. The overall mean difference of the uncorrected visual acuity measured -0.01 LogMAR (95%LoA:-0.63–0.60). The variability of the differences decreased in the better uncorrected visual acuity subgroup (95%LoA:-0.25–0.55). The overall mean difference in spherical equivalent between the index and reference test exceeded the non-inferiority margin: -0.58D (95%LoA:-4.49–3.33, P = 0.008). The mean differences for myopic and hyperopic subjects were 0.09 diopters (P = 0.675) and -2.06 diopters (P<0.001), respectively. The corrected visual acuities attained with the web-based derived prescription underachieved significantly (0.22±0.32 logMAR vs. -0.01±0.13 LogMAR, P <0.001). Conclusions Regarding visual acuity, the web-based tool shows promising results for remotely assessing visual acuity in keratoconus patients, particularly for subjects within a better visual acuity range. This could provide physicians with a quantifiable outcome to enhance teleconsultations, especially relevant when access to health care is limited. Regarding the assessment of the refractive error, the web-based tool was found to be inferior to the manifest refraction in keratoconus patients. This study underlines the importance of validating digital tools and could serve to increase overall safety of the web-based assessments by better identification of outlier cases.

Long-term Visual Quality after Small Incision Lenticule Extraction (SMILE) and Laser Epithelial Keratomileusis (LASEK) for Low Myopia

Background: Few studies have reported the visual outcomes of small-incision lenticule extraction (SMILE) and laser-assisted epithelial keratomileusis (LASEK) for myopia correction. This study aims to compare the visual quality and corneal wavefront aberrations after SMILE and LASEK for low-myopia correction.Methods: In this prospective study, we included 29 eyes of 29 patients who received SMILE, and 23 eyes of 23 patients who received LASEK between June 2018 and January 2019. The following measurements were assessed: uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction, corneal wavefront aberrations, and subjective visual quality. All patients were followed up for two years.Results: All procedures were uneventful. An efficacy index of 1.19 ± 0.17 was established in the SMILE group and 1.23 ± 0.20 in the LASEK group. No eyes lost more than two lines of CDVA. We found that 93% (27/29) of the treated eyes in the SMILE group and 91% (21/23) in the LASEK group had spherical equivalent (SE) within ± 0.25D. The increases in the total corneal spherical aberration and the corneal front spherical aberration were lower in the SMILE group than in the LASEK group (P < 0.01). In contrast, the increases in the total corneal vertical coma and the corneal front vertical coma in the SMILE group were greater than those in the LASEK group (P < 0.01).Conclusion: Both SMILE and LASEK have good safety, stability, and patient-reported satisfaction for low myopia. SMILE induced less corneal spherical aberration but greater vertical coma than LASEK.