Efficacy and Safety of Implantable Collamer Lens V4c Implantation in 1,834 Myopic Eyes for 1 Year of Follow-up.

PURPOSE: To evaluate visual outcomes of patients with myopia after EVO Implantable Collamer Lens (ICL) (STAAR Surgical) implantation and predict risk factors of postoperative vault abnormalities. METHODS: In this single-center, retrospective analysis, 1,834 eyes of 926 patients with myopia who underwent EVO ICL implantation were recruited between 2020 and 2021. Patients were followed up for 1 year, during which surgery outcomes were evaluated. In addition, 31 eyes with vault abnormalities who underwent secondary surgery were enrolled to form a generalized linear model, which aimed to predict risk factors contributing to vault abnormalities. RESULTS: At the final follow-up visit, safety and efficacy indexes were 1.12 ± 0.17 and 1.10 ± 0.19, respectively, and there was no statistical significance between the low and high myopia groups. Furthermore, 79.18% of eyes achieved a residual spherical equivalent within ±0.50 diopters. Except for the temporary elevation of intraocular pressure at 1 week postoperatively, IOP and endothelial cell density remained stable during follow-up visits. The rate of postoperative adverse events was 21.97% and most adverse events were transient. Vault abnormalities accounted for the majority of complications (9.54%). Results of generalized linear model showed that age was a risk factor for postoperative vault abnormalities, and the anterior chamber depth served as a protective factor (P < .05). CONCLUSIONS: Visual outcomes of EVO ICL implantation were satisfactory in safety and efficacy indexes in both the low and high myopia groups for 1 year of follow-up, with acceptable stability in postoperative spherical equivalent, intraocular pressure, and endothelial cell density. This study emphasized cautious ICL size selection for older patients and those with shallow anterior chamber depth. [J Refract Surg. 2023;39(10):694-704.].

Visual and patient-reported outcomes of a diffractive trifocal intraocular lens in highly myopic eyes: a prospective multicenter study.

BACKGROUND: To investigate the visual and patient-reported outcomes of a diffractive trifocal intraocular lens (IOL) in highly myopic eyes. METHODS: Patients with planned cataract removal by phacoemulsification and implantation of a trifocal IOL (AT LISA tri 839MP) were enrolled in the prospective, multicenter cohort study. Patients were allocated into three groups according to their axial length (AL): control group, AL < 26 mm; high myopia group, AL 26-28 mm; extreme myopia group, AL ≥ 28 mm. At 3 months post-surgery, data for 456 eyes of 456 patients were collected, including visual acuity, defocus curve, contrast sensitivity (CS), visual quality, spectacle independence, and overall satisfaction. RESULTS: After surgery, the uncorrected distance visual acuity improved from 0.59 ± 0.41 to 0.06 ± 0.12 logMAR (P < 0.001). In all three groups, about 60% of eyes achieved uncorrected near and intermediate visual acuity of 0.10 logMAR or better, but significantly fewer eyes in the extreme myopia group achieved uncorrected distance visual acuity of 0.10 logMAR or better (P < 0.05). Defocus curves revealed that the visual acuity was significantly worse in the extreme myopia group than others at 0.00, - 0.50, and - 2.00 diopters (P < 0.05). CS did not differ between the control and high myopia groups but was significantly lower in the extreme myopia group at 3 cycles per degree. The extreme myopia group also had greater higher-order aberrations and coma, lower modulation transfer functions and VF-14 scores, more glare and halos, worse spectacle independence at far distance, and consequently lower patient satisfaction than others (all P < 0.05). CONCLUSIONS: In eyes with a high degree of myopia (AL < 28 mm), trifocal IOLs have been shown to provide similar visual outcomes to those in non-myopic eyes. However, in extremely myopic eyes, acceptable results may be obtained with trifocal IOLs, but a reduced level of uncorrected distance vision is expected.

Comparison of visual effects of FS-LASIK for myopia centered on the coaxially sighted corneal light reflex or the line of sight.

AIM: To compare visual quality after femtosecond laser in situ keratomileusis (FS-LASIK), between the coaxially sighted corneal light reflex (CSCLR) group and conventional ablation line of sight (LOS) group. METHODS: In total, 243 eyes (122 patients) were treated with centration on the CSCLR (visual axis) and 238 eyes (119 patients) treated with centration on the pupil center (LOS). Postoperative outcomes [uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA)], safety index, efficacy index, refractive outcome, ablation center distance from the visual axis, corneal high-order aberrations, subjective discomfort glare and shadowing incidence rate, and contrast sensitivity at 1, 3, and 6mo were measured and compared. RESULTS: The mean age was 27.77±7.1y in the CSCLR group and 26.03±7.70y in the LOS group. Preoperatively, the manifest refraction spherical equivalent (MRSE) was -6.68±2.60 D in the CSCLR group and -6.65±2.68 D in the LOS group. The postoperative UCVA, BSCVA, MRSE (-0.03±0.263 D in the CSCLR group, -0.05±0.265 D in the LOS group), efficacy index (1.04, 1.03), and safety index (1.09, 1.08) were not significantly different between the groups (all P>0.05). In total, 3% lost one line and more of BSCVA in the CSCLR group, as 9% in the LOS group postoperatively (P<0.05). The ablation center deviation was 0.20±0.15 mm from the visual axis (Pentacam system default setting; range, 0-0.75 mm) in the CSCLR group, and 0.43±0.22 mm (range, 0-1.32 mm) in the LOS group (P<0.0001). Statistically significant greater augmentation of total corneal higher-order aberrations (0.15±0.10 µm and 0.20±0.12 µm respectively, P=0.03) and vertical and horizontal coma (P<0.0001) were noted in the LOS group. Subjective discomfort glare and shadowing incidence rates were 8.59% and 17.5% in the CSCLR and LOS groups, respectively (P<0.05). The 1-month postoperative contrast sensitivity visual acuity in the CSCLR group was significantly higher than that in the LOS group on contrast (100%, 25%, 10%) with a dark background, but there was no significant difference between the groups at 3 or 6m. CONCLUSION: Myopic LASIK centered on the CSCLR achieves significantly lower induction of loss of BSCVA, corneal high-order aberrations, and lower risk of subjective discomfort glare and shadowing, and lower decline in early contrast sensitivity by comparison with centration on the LOS, giving advantages in visual quality postoperatively.

Comparison of corneal flap thickness using a FS200 femtosecond laser and a moria SBK microkeratome.

AIM: To evaluate differences in flap thickness resulting from use of an Alcon Wavelight FS200 femtosecond laser and a MORIA SBK microkeratome when making a 110-µm-thick corneal flap and to identify the potential factors that affect corneal flap thickness. METHODS: A prospective case study was performed on 120 eyes of 60 patients who were divided into two groups for LASIK, each group consisting of 60 eyes (30 patients). The corneal flaps were created using an Alcon Wavelight FS200 femtosecond laser or a MORIA SBK microkeratome. The central corneal flap thickness was calculated by subtraction pachymetry. Age, central corneal thickness (CCT), spherical equivalent refraction, mean keratometry, and corneal diameter were recorded preoperatively for analysis. RESULTS: Cutting of all flaps was easily performed without intraoperative complications. In the Alcon Wavelight FS200 femtosecond laser group, the mean right and left corneal flap thicknesses were 114.0±6.6 µm (range: 98-126) and 111.4±7.6 µm (range: 98-122), respectively. The difference (2.6±9.1 µm) in the corneal flap thickness between the right and left eyes was not significant (t=1.59, P=0.12). Stepwise regression analysis indicated that the resulting corneal flap thickness was unrelated to the patient's age, preoperative CCT, spherical equivalent refraction, mean keratometry, or corneal diameter. In the MORIA SBK microkeratome group, the mean right and left corneal flap thicknesses were 110.6±7.4 µm (range: 97-125 µm) and 108.2±6.1 µm (range: 78-123 µm), respectively. The difference in the corneal flap thickness between the right and left eyes (2.4±6.5µm) was not significant (t=2.039, P=0.0506). The corneal flap thickness was positively correlated with the preoperative CCT through stepwise regression analysis (r=0.297, P=0.021). The corneal flap thickness was not related to age, spherical equivalent refraction, mean keratometry, or corneal diameter. The corneal flap thickness was estimated using the following equation: Tflap=67.77+0.076 CCT (F=5.63, P=0.021). CONCLUSION: Both the Alcon Wavelight FS200 femtosecond laser and the MORIA SBK microkeratome produced 110-µm-thick corneal flaps. The central corneal flap thickness was positively correlated with the preoperative CCT in MORIA SBK microkeratome surgery.

[Comparison of cornea flap made by femtosecond laser and microkeratome in laser in situ keratomileusis].

OBJECTIVE: To determine flap thickness variation in 110 µm thickness flap made by FS200 femtosecond laser and sub-Bowman keratomileusis (SBK) microkeratome for studying the potential factors that affect the flap thickness. METHODS: It was a case-control study. Sixty patients were divided into two groups for laser in situ keratomileusis. The corneal flaps were made by using Alcon Wavelight FS200 femtosecond laser or MORIA SBK microkeratome. Central corneal flap thickness was calculated by subtraction pachymetry. Age, central corneal thickness (CCT), spherical equivalent refraction, mean keratometry and corneal diameter were recorded preoperatively for statistics. RESULTS: This study comprised 120 eyes of 60 patients; 60 eyes were treated with each group. In Alcon Wavelight FS200 femtosecond laser group, the mean corneal flap thickness in the right and left eyes was (114.0 ± 6.6) and (111.4 ± 7.6) µm, respectively. The difference in corneal flap thickness between the right eye and the left eye (2.6 ± 9.1) µm was not statistically significant (t = 1.59, P = 0.12). Corneal flap thickness had no relationship with the age, preoperatively CCT, spherical equivalent refraction, corneal curvature and corneal diameter through stepwise regression analysis. In SBK microkeratome group, the mean corneal flap thickness in the right eye and the left eye was (110.6 ± 7.4) and (108.2 ± 6.1) µm respectively. The difference in corneal flap thickness between the right eye and the left eye (2.4 ± 6.6) µm was not statistically significant (t = 2.019, P = 0.054). Corneal flap thickness was positively correlated with preoperative CCT through stepwise regression analysis (r = 0.29, P = 0.021). Corneal flap thickness equaled to 67.77 + 0.076· CCT (F = 5.63, P = 0.021). Corneal flap thickness had no relationship with the age, spherical equivalent refraction, corneal curvature and corneal diameter. CONCLUSIONS: Both FS200 femtosecond laser and SBK microkeratome can be used for making a good 110 µm thickness flap. Central corneal flap thickness was positively correlated with the preoperative CCT using the SBK microkeratome.

High prevalence of myopia and high myopia in 5060 Chinese university students in Shanghai.

PURPOSE: Myopia is an important cause of correctable visual impairment worldwide. Genetic and environmental factors contribute to its development. The population of Chinese university students consists of approximately 30 million young people characterized by academic excellence and similar ages. To date, little is known about their refractive status. Our study is designed to investigate the prevalence of myopia in this specific population. METHODS: This is a cross-sectional study of myopia among university students in Shanghai, China; 5083 students from Donghua University were enrolled. All participants first responded to a detailed questionnaire, including questions on ethnicity, birth date, and family history, and then undertook a standardized ophthalmologic examination, including visual acuity, a slit-lamp examination, and non-cycloplegic autorefraction. RESULTS: The mean spherical equivalent refraction (SER) of the university students was -4.1 diopters (D). Of the subjects 95.5% were myopic (SER < -0.50 D), 19.5% were highly myopic (SER < -6.0 D), and only 3.3% were emmetropic (-0.5 D ≤ SER ≤ 0.5 D). The postgraduates were more myopic than the undergraduates (96.9% and 94.9%, respectively). Being female (-4.1 ± 2.4 D in female versus -3.8 ± 2.4 D in male subjects), of Han ethnicity (-4.1 ± 2.4 D in Han versus -3.4 ± 2.2 D in minorities), and of older age were associated with a higher probability of myopia only in the undergraduate population. CONCLUSIONS: The prevalence of myopia and high myopia in this university student population was high. The refractive status of this population deserves further attention.

Heat shock protein 70 expression induced by diode laser irradiation on choroid-retinal endothelial cells in vitro.

PURPOSE: To investigate the biologic effect of an 810 nm diode laser on the induction of heat shock protein 70 (Hsp70) in choroid-retinal endothelial cells in vitro. METHODS: Cultured rhesus macaque choroid-retinal endothelial cells (RF/6A) were irradiated using an 810 nm diode laser (spot size, 10 mm; duration, 60 s; power, 400-1,500 mW). Cell viability was assessed by annexin V- fluorescein isothiocyanate (FITC) and propidium iodide flow cytometric assay. Hsp70 expression was determined by western blot at 6, 12, 18, 24, and 48 h following laser exposure. Intracellular distribution of Hsp70 was examined by immunofluorescence staining. RESULTS: The laser-induced cell injury threshold was found to be at a power of 1,100 mW power (fluence, 84.08 J/cm(2)), above which there was significant cell death. Under this power, Hsp70 expression elevated obviously and was stronger at 600-1,000 mW power settings (fluences, 45.86-76.43 J/cm(2)). The expression of Hsp70 peaked at 12-18 h postirradiation, and returned to baseline by 48 h. Immunofluorescence staining indicated the induced Hsp70 expression in both the cytoplasm and the nucleus. CONCLUSIONS: Subthreshold 810 nm diode laser exposure can induce Hsp70 hyperexpression from 12 to 18 h postirradiation in cultured choroid-retinal endothelial cells without obvious cell death. The results could be useful for investigating and designing more effective laser therapies.

[Three kinds of phakic intraocular lens for correction of high myopia].

OBJECTIVE: To evaluate the efficacy, safety and stability of three kinds of phakic intraocular lens implantation for the correction of high myopia. METHODS: This study included 208 eyes of 110 patients with a mean age of 31 years (21 - 53) from December 2003 to December 2009. Angle-supported lens (Phakic 6H, OII) were inserted into 113 eyes, iris-fixated lens (Artisan, OPHTEC) were inserted into 53 eyes and implantable contact lens (ICL) (V4, STAAR) were inserted into 41eyes. The average follow-up time of the three groups were 54.0 months (3 - 72 months), 15.7 months (3 - 24 months) and 7.2 months (3 - 15 months) respectively. RESULTS: At 3 months and 12 months, the efficacy indexes of the three groups were all above 1.00. Only the angle-supported group was followed up to 72 months postoperatively when the efficacy index dropped to 0.85, but still UCVA was 1.0 (20/20) or better in 16% eyes and 0.5 (20/40) or better in 85% eyes. The safety indexes of the three groups were always above 1.00 during the follow up. In the angle-supported group, 46% eyes were within ± 0.50 D of the desired refraction and 68% eyes were within ± 1.00 D at 5 years postoperatively. In the iris-fixated group, 78% eyes were within ± 0.50 D of the desired refraction and 100% eyes were within ± 1.00 D at 1 years postoperatively. In the ICL group, 95% eyes were within ± 0.50 D of the desired refraction and 100% eyes were within ± 1.00 D at 3 months postoperatively. No statistically significant differences were found between preoperative and 3-month postoperative endothelial cell density in the ICL group. Also, there was no statistically significant reduction in endothelial cell density at 1 years in the iris-fixated group. However, when preoperative and 5-year postoperative measurements were compared in the angle-supported group, the total decrease in cell density is statistically significant (t = 9.769, P = 0.000). 16 eyes developed high IOP within 1 month postoperatively which resolved after intervention. In the three groups (angle-supported, iris-fixated and ICL), the most common complications were pupil ovalization, iris atrophy plus pigment dispersion and lens opacification respectively. CONCLUSION: Although phakic IOL implantation is predictable and safe for treatment of high myopia in short-term, the long-term complications should be concerned and treated well.

Flap thickness variation with 3 types of microkeratome heads.

PURPOSE: To determine flap thickness variation with 3 types of microkeratome heads and identify the potential factors that affect flap thickness. SETTING: Ruijin Hospital, Department of Ophthalmology, Shanghai, China. DESIGN: Comparative case series. METHODS: Laser in situ keratomileusis was performed using the Moria microkeratome with the One Use-Plus SBK, M2 90, or M2 110 head. Flap thickness was calculated by subtraction pachymetry. Age, central corneal thickness (CCT), spherical equivalent refraction, mean keratometry, and horizontal corneal diameter were recorded preoperatively. RESULTS: The study comprised 180 eyes of 90 patients; 60 eyes were treated with each head. The difference in mean flap thickness between right and left eyes was not significant in the SBK group (97.50 µm ± 11.39 [SD] versus 96.73 ± 10.45 µm; P = .44) but was significant in the M2 90 group (128.03 ± 12.03 µm versus 123.40 ± 12.38 µm; P = .0071) and the M2 110 group (140.53 ± 15.14 µm versus 135.23 ± 18.03 µm, P = .0035). The difference from the intended flap thickness (right eyes and left eyes) was 2.50 ± 11.39 µm and 3.27 ± 10.45 µm, respectively, in the SBK group; -8.03 ± 12.03 µm and -3.40 ± 12.38 µm, respectively, in the M2 90 group; and -0.53 ± 15.14 µm and 4.77 ± 18.03 µm, respectively, in the M2 110 group. Flap thickness was positively correlated with baseline CCT in each group. CONCLUSIONS: Flap thickness was positively correlated with the preoperative CCT using the Moria microkeratome. The SBK head demonstrated the most accurate flap thickness, followed by the M2 90 head and the 110 head. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

[Anterior chamber phakic intraocular lens implantation in highly myopic eyes].

OBJECTIVE: To investigate the stability, predictability and safety of angle-supported phakic intraocular lens (IOL) implantation in high myopia. METHODS: Seventy-six myopic eyes of 40 patients treated with anterior chamber angle-supported phakic IOL (Phakic6H) implantation were followed. The average myopia diopter was (-15.89 +/- 3.78) D (-9.50 to -26.25 D) and the best corrected visual acuity (BCVA) was (0.82 +/- 0.20) (0.5 to 1.0). The average follow-up time was 12 months. All the treated eyes were observed for anterior segment changes, uncorrected visual acuity (UCVA), BCVA, refraction, intraocular pressure (IOP) and corneal endothelium preoperatively and postoperatively. All data were analyzed in statistics. RESULTS: One year after the surgery, the average UCVA was (1.00 +/- 0.35) (0.3 to 1.5) and BCVA was (1.18 +/- 0.29) (0.5 to 1.5). The average residual refraction was (-0.40 +/- 0.64) D (-2.00 to +0.50 D). In 96.1% of eyes, the average residual refraction was within +/- 1.0 diopter. The average corneal endothelial count before and one year after the surgery was (3174 +/- 248)/mm(2) and (3067 +/- 320)/mm(2) (P < 0.01) respectively. The intraocular pressure before and one year after the surgery was (16.12 +/- 2.32) mmHg and (15.29 +/- 3.38) mmHg (P < 0.05) respectively. Two patients (4 eyes) complained of halo and glare. One patient's (2 eyes) pupils were oval and another one (2 eyes) showed decentered phakic IOL. Macular hemorrhage occurred in one patient (2 eyes) after eight months of surgery. CONCLUSIONS: Angle-supported phakic IOL implantation is effective for treatment of high myopia and the results are predictable. It deserves further clinical investigation. The effectiveness and safety of this kind of phakic IOL should be further observed for a long period of time.

Laser in situ keratomileusis for correction of hyperopia and hyperopic astigmatism with the Technolas 117C.

PURPOSE: To evaluate the effectiveness, predictability, and safety of laser in situ keratomileusis (LASIK) for correction of hyperopia and hyperopic astigmatism. METHODS: Fifty-four hyperopic eyes of 35 patients with a spherical equivalent refraction between +1.00 and +6.00 D were followed for at least 12 months following LASIK. All surgery was performed with the scanning Chiron Technolas Keracor 117C excimer laser. Data on uncorrected and spectacle-corrected visual acuity, predictability, stability of refraction, and complications were analyzed. RESULTS: At 12 months, the average residual refraction was +0.29 +/- 0.78 D; 83.3% of eyes (45 eyes) were in the range of +/- 1.00 D and 61.1% of eyes (33 eyes) were within +/- 0.50 D of emmetropia. Fifty eyes (92.6%) had uncorrected visual acuity of 20/40 or better and 34 (63.0%) eyes had 20/20 or better. One eye (1.9%) lost two lines of best spectacle-corrected visual acuity and two eyes (3.7%) gained two or more lines. Two patients (two eyes, 3.7%) had complaints of halos and one patient (one eye, 1.9%) had glare at 12 months after LASIK for hyperopia. CONCLUSIONS: LASIK was used to treat hyperopia from +1.00 to +6.00 D with good predictability and safety. Primary and second hyperopia require different nomograms, according to our experience.

[An analysis of regression after laser in situ keratomileusis for treatment of myopia].

OBJECTIVE: To evaluate the regression relevant reasons of laser in situ kertomileusis (LASIK) for treatment of myopia. METHODS: Four hundred and eight eyes of 250 patients with myopia who received LASIK were studied. They were divided into 2 groups according to preoperative diopters (-6.25- -10.00 D in 194 eyes; -10.25 -15.00 D in 214 eyes). The mean follow-up was 12 months, and the results of the postoperative visual acuity, refractive diopter, corneal thickness and the diameter of the ablation zone were statistically analyzed. RESULTS: (1) A group: There were 173 normal operative eyes (89.2%, post-operative diopter < -1.00 D), the mean pre-operative corneal thickness was (549.5 +/- 31.5) microm, the mean intra-operative laser ablation diameter was (4.96 +/- 0.35) mm, and the post-operative refractive diopter was +0.50- -0.75 D. The regressive operative eyes: There were 21 eyes (10.8%, post- operative diopter >/= -1.00D), the mean preoperative corneal thickness was (547.7 +/- 37.0) microm (P > 0.05 in comparison with that of the normal operative eyes), the mean intra-operative laser ablation diameter was (4.64 +/- 0.41 ) mm (P < 0.01 in comparison with that of the normal operative eyes), and the mean post-operative diopter was (-1.33 +/- 0.58)D. (2) B group: There were 136 normal operative eyes (63.5%), the mean pre-operative corneal thickness was (560.9 +/- 30.9) microm, the mean intra-operative laser ablation diameter was (4.51 +/- 0.28) mm, and the post-operative diopter was +0.50- -0.75 D. The regressive operative eyes: There were 78 eyes (36.5%), the mean pre-operative corneal thickness was (538.0 +/- 31.0) microm (P < 0.01 in comparison with that of the normal operative eyes), the mean intra-operative laser ablation diameter was (4.22 +/- 0.34) mm (P < 0.01 in comparison with that of the normal operative eyes), and the mean post-operative diopter was (-1.99 +/- 1.01) D. CONCLUSIONS: In cases with small laser ablation diameter and the thin pre-operative corneal thickness of high myopia, after the surgery refractive regression is easy to occur. Some modification of the surgical algorithms and laser nomogram will help to improve predictability and reduce regression.