Project description:IntroductionCombined phacovitrectomy is gaining popularity due to efficiency and immediate visual improvement. However, concerns regarding erroneous intraocular lens (IOL) calculation in combination surgery are increasing, such as myopic shift owing to a thick macula and consequent underestimation of the axial length. Therefore, this study aimed to compare the refractive outcomes of combined phacovitrectomy in patients with highly myopic and non-highly myopic eyes.MethodsA retrospective chart review was performed on patients who received combined phacoemulsification, intraocular lens implantation, and small gauge pars plana vitrectomy for cataract and macular pathologies in highly myopic and non-highly myopic eyes. Pre- and postoperative evaluation and ocular parameters were recorded, and analyses were performed using the Student's t test and regression analysis.ResultsA total of 133 patients with macular pathologies, including myopic tractional maculopathy, macular hole, and epiretinal membrane, were enrolled. SRK II or SRK/T models were used for calculating IOL. The mean absolute error of refraction change was 0.65 D; 83.5% of patients were within 1-D error, 57.9% within 0.5-D error, and 35.3% within 0.25-D error, with SRK/T showing better precision and yielding more myopic shift. Furthermore, the predictive accuracy of SRK II or SRK/T was better in patients with non-highly myopic eyes. Moreover, Barrett's universal II formula was not superior to SRK II or SRK/T in the prediction of postoperative refractive error (p = 0.48).ConclusionRefractive outcomes were satisfactory in the cohort of patients with highly myopic eyes. The combined implementation of SRK II and SRK/T was not inferior to Barrett's universal II formula in predicting satisfactory refractive outcomes. Combination surgery can be an option for patients with both cataract and macular pathologies.
Project description:BackgroundTo compare the accuracy of intraocular lens power calculation formulae after laser refractive surgery in myopic eyes.MethodsWe searched the databases on PubMed, EMBASE, Web of Science and the Cochrane library to select relevant studies published between Jan 1st, 2009 and Aug 11th, 2019. Primary outcomes were the percentages of refractive prediction error within ±0.5 D and ±1.0 D.ResultsThe final meta-analysis included 16 studies using seven common methods (ASCRS average, Barrett True-K no history, Double-K SRK/T, Haigis-L, OCT formula, Shammas-PL, and Wang-Koch-Maloney). ASCRS average yielded significantly higher percentage of refractive prediction error within ±0.5 D than Haigis-L, Shammas-PL and Wang-Koch-Maloney (P = 0.009, 0.01, 0.008, respectively). Barrett True-K no history also yielded significantly higher percentage of refractive prediction error within ±0.5 D than Shammas-PL and Wang-Koch-Maloney (P = 0.01, P < 0.0001, respectively), and a similar result was found when comparing OCT formula with Haigis-L and Shammas-PL (P = 0.03, P = 0.01, respectively).ConclusionThe ASCRS average or Barrett True-K no history should be used to calculate the intraocular lens power in eyes after myopic laser refractive surgery. The OCT formula if available, can also be a good alternative choice.
Project description:PurposeThe purpose of this study was to examine characteristics of lamina cribrosa (LC) configuration in highly myopic (HM) eyes.MethodsParticipants from the Beijing Eye Study 2011, free of optic nerve or retinal diseases, were randomly selected to examine LC depth (LCD) and LC tilt (LCT) using three-dimensional optical coherent tomography images of the optic nerve head (ONH). LCD and LCT were measured as the distance and angle between the LC plane with two reference planes, including the Bruch's membrane opening (BMO) plane and the peripapillary sclera (PPS) plane, respectively. Each parameter was measured in both horizontal and vertical B-scans.ResultsThe study included 685 individuals (685 eyes) aged 59.6 ± 7.7 years, including 72 HM eyes and 613 non-HM eyes. LCD measurements showed no significant differences between HM eyes and non-HM eyes in both horizontal (LCD-BMO = 421.83 ± 107.86 µm for HM eyes vs. 447.24 ± 104.94 µm for non-HM eyes, P = 0.18; and LCD-PPS = 406.39 ± 127.69 µm vs. 394.00 ± 101.64 µm, P = 1.00) and vertical directions (LCD-BMO = 435.78 ± 101.29 µm vs. 450.97 ± 106.54 µm, P = 0.70; and LCD-PPS = 401.62 ± 109.9 µm vs. 379.85 ± 110.35 µm, P = 0.35). However, the LCT was significantly more negative (tilted) in HM eyes than in non-HM eyes horizontally (LCT-BMO = -4.38 ± 5.94 degrees vs. -0.04 ± 5.86 degrees, P < 0.001; and LCT-PPS = -3.16 ± 5.23 degrees vs. -0.94 ± 4.71 degrees, P = 0.003), but not vertically (P = 1.00).ConclusionsAlthough LCD did not differ significantly between HM and non-HM eyes, LCT was more negative in HM eyes, suggesting that the temporal or inferior side of the LC was closer to the reference plane. These findings provide insights into morphological and structural changes in the LC and ONH between HM and non-HM eyes.
Project description:PurposeTo examine 2-year progression rate and associated biometric changes in highly myopic eyes.MethodsThis is a longitudinal, observational cohort study that included 657 participants aged 7 to 70 years with bilateral high myopia (≤-6.00 diopters [D]) and followed for 2 years. All participants underwent ocular biometry and cycloplegic refraction examinations. Main outcome measures were changes in spherical equivalent refraction (SE) and ocular biometry in the right eyes.ResultsMean age of participants was 21.6 ± 12.2 years. At baseline, mean SE was -9.82 ± 3.28 D and ocular biometric measurements were 27.40 ± 1.56 mm for axial length, 3.16 ± 0.27 mm for anterior chamber depth, 3.60 ± 0.35 mm for lens thickness, and 20.09 ± 1.50 mm for vitreous chamber depth. After 2 years of follow-up, there was a trend toward more myopia and greater axial elongation in all age groups. Younger participants (≤20 years) had significantly (P < 0.001) greater rates of myopic shift and axial elongation compared with older participants (>20 years). However, highly myopic adults aged 40 to 70 years continued to demonstrate refractive progression, particularly if they had extremely high myopia (≤-10.00 D). In the multiple regression analysis, each additional diopter of myopia at baseline was associated with a 11% higher risk of a >1.00-D/y myopic shift (odds ratio, 1.11; 95% confidence interval, 1.04-1.18; P = 0.002).ConclusionsLongitudinal data from this large Chinese cohort suggest that highly myopic eyes continue to progress in SE throughout life, with the greatest rates of progression observed in younger participants. Axial elongation rates appeared to stabilize after 20 years of age and were predominantly due to an increase in the vitreous chamber depth. Other risk factors for a myopic shift included a higher degree of myopic refraction at baseline.
Project description:This study assesses the agreement between intraocular pressure (IOP) measurements taken with the Goldmann applanation tonometer (GAT) and a new experimental applanation tonometer with a convexly shaped apex (CT) after laser myopic refractive surgery. Two different CT radii (CT1 and CT2) were designed with a finite element analyser, and a prospective double masked study on 102 eyes from 102 patients was carried out. A Bland-Altman plot and intra-class correlation coefficient (ICC) were calculated to assess the agreement between GAT measurements and the measurements of both CT1 and CT2 before and after myopic laser assisted in situ keratomileusis (LASIK; n = 73) and photorefractive keratectomy (PRK; n = 29). We evaluated a subset of two subgroups (n = 36 each) for intra and inter-observer (IA/IE) error. From the whole cohort, the best IOP agreement was observed between GATpre and CT1post surgery: 16.09 ± 2.92 vs 16.42 ± 2.87 (p < 0.001); ICC = 0.675 (95% CI: 0.554-0.768). In the analysis of LASIK vs PRK, GATpre and CT1post showed the highest agreement, although LASIK measurements were more accurate than PRK, as the ICC = 0.718 (95% CI: 0.594-0.812) and ICC = 0.578 (95% CI: 0.182-0.795) respectively. Excellent agreement was observed for IA/IE, and there was an ICC > 0.8 (95% CI) in all cases. CT1 proved more accurate in the LASIK subgroup. In conclusion, our new version of GAT could be used with post-surgery LASIK patients as a more accurate measurement device compared to the current reference tonometer.
Project description:Clinical observations suggest increased size of lens in highly myopic subjects compared with emmetropic subjects. The layer of anterior lens epithelial cell membrane, being the most metabolically active part of the lens, can be easily acquired during standard lens surgery and is an ideal sample to study the gene expression difference between lens of different populations. In this study, to investigate the possible molecular mechanisms underlying different features of lens between highly myopic and emmetropic subjects, gene expression profiling of lens epithelia of corresponding population was conducted.
Project description:BackgroundPrevalence of high myopia is continuously increasing, thus, patients affected with staphyloma are abundant worldwide. Assessment of the quality of vision in these patients is mandatory for a proper clinical counselling, specially when undergoing surgical procedures that require intraocular lenses implantation. Thus, the purpose of the study was to assess monochromatic higher order aberrations (HOAs) in highly myopic eyes with staphyloma with or without a dome-shaped macula.MethodsParticipants underwent spectral-domain optical coherence tomography, ocular axial biometry, dual Scheimpflug photography and integrated Placido disk topography, and Hartmann-Shack wavefront analysis. Five groups were evaluated: a low-moderate myopia control group (< 6.00 diopters, n = 31) and four high myopia (≥6.00 diopters) groups: eyes without staphyloma (n = 18), eyes with inferior staphyloma (n = 14), eyes with posterior staphyloma without dome-shaped macula (n = 15) and eyes with posterior staphyloma with dome-shaped macula (n = 17). Subsequently, two new groups (including all participants) were created to assess differences between myopia with and without staphyloma. One-way analysis of covariance was performed using age and lens densitometry as covariates.ResultsStatistically significant (p ≤ 0.05) differences in anterior corneal fourth-order HOAs were observed between the low-moderate myopia and no-dome-shaped macula (Mean: 0.16 μm) and dome-shaped macula posterior staphyloma groups (Mean: 0.12 μm) in younger patients (≤45 years old). The same groups also showed (p ≤ 0.05) significant differences for anterior corneal primary spherical aberration (Mean: 0.19 and 0.13 μm, respectively). In addition, anterior corneal tetrafoil was significantly higher (p = 0.04) in dome-shaped macula compared to no-dome-shaped macula (Mean: 0.18 vs 0.06 μm, respectively). When all participants were grouped together, significantly lower mean anterior corneal primary spherical aberration (0.15 μm vs. 0.27 μm, p = 0.004) and higher internal primary spherical aberration (0.04 μm vs. -0.06 μm, p = 0.04) was observed in staphyloma compared to no-staphyloma myopic patients.ConclusionsEyes with high myopia and staphyloma have less positive anterior corneal primary spherical aberration and less negative internal primary spherical aberration, suggesting that the anterior corneal surface tends to mimic in a specular fashion the posterior pole profile. This corneal behaviour appears to change in patients older than 45 years.
Project description:Laser refractive surgery for myopia increases the eye's higher-order wavefront aberrations (HOA's). However, little is known about the impact of such optical degradation on post-operative image quality (IQ) of these eyes. This study determined the relation between HOA's and IQ parameters (peak IQ, dioptric focus that maximized IQ and depth of focus) derived from psychophysical (logMAR acuity) and computational (logVSOTF) through-focus curves in 45 subjects (18 to 31 yrs) before and 1-month after refractive surgery and in 40 age-matched emmetropic controls. Computationally derived peak IQ and its best focus were negatively correlated with the RMS deviation of all HOA's (HORMS) (r≥-0.5; p<0.001 for all). Computational depth of focus was positively correlated with HORMS (r≥0.55; p<0.001 for all) and negatively correlated with peak IQ (r≥-0.8; p<0.001 for all). All IQ parameters related to logMAR acuity were poorly correlated with HORMS (r≤|0.16|; p>0.16 for all). Increase in HOA's after refractive surgery is therefore associated with a decline in peak IQ and a persistence of this sub-standard IQ over a larger dioptric range, vis-à-vis, before surgery and in age-matched controls. This optical deterioration however does not appear to significantly alter psychophysical IQ, suggesting minimal impact of refractive surgery on the subject's ability to resolve spatial details and their tolerance to blur.
Project description:IntroductionTo evaluate the characteristics of optic nerve head (ONH) in highly myopic eyes and its role in predicting intraocular pressure (IOP) spikes after cataract surgery.MethodsPatients who are highly myopic and were scheduled for cataract surgery were enrolled in this prospective case series study. IOP was measured preoperatively and at 1 day and 3 days postoperatively. ONH characteristics including area, tilt ratio, lamina cribrosa (LC) thickness, and depth, and the presence of LC defects were evaluated with enhanced depth imaging optical coherence tomography. Factors influencing LC defects and early IOP spike were investigated using multivariate stepwise logistic regression.ResultsIn total, 200 highly myopic eyes of 200 patients were analyzed: 35.00% had small ONH, 53.00% had ONH tilt, and 14.00% had LC defects. Multivariate analysis demonstrated female patients with larger ONH area and deeper LC tended to have LC defects (all P < 0.05). As to postoperative IOP, IOP change, and incidence of IOP spikes, eyes with small ONH, ONH tilt, and LC defects had similar (all P > 0.05), higher (all P < 0.05), and lower (all P < 0.05) outcomes compared with those without the corresponding characteristic, respectively. Multivariate analysis showed that presence of LC defects and thicker LC were protective factors for early IOP spikes, and axial length > 28 mm was a risk factor (all P < 0.05).ConclusionFemale patients with larger ONH area and deeper LC tend to have LC defects, which, together with thicker LC, was correlated with less IOP spikes in highly myopic eyes.Trial registrationThis study was conducted as part of a larger project, the Shanghai High Myopia Study, registered at www.Clinicaltrialsgov (accession number NCT03062085).
Project description:PurposeTo investigate changes of the axial length in normal eyes and highly myopic eyes and influence of myopic macular complications in Japanese adults.Study designRetrospective longitudinal case series.MethodsThe changes in the axial length of 316 eyes from 316 patients (mean age, 63.8 ± 9.0 years; range, 34-82; 240 females) examined using IOLMaster with a follow-up period of at least 1 year were studied. This study included 85 non-highly myopic eyes (|refractive error| ≤ 5 diopters; 63 females; non-highly myopic group), 165 highly myopic eyes (refractive error ≤ -6 diopters or axial length ≥ 26 mm; 124 females) without macular complications (no complications group), 32 eyes (25 females) with myopic traction maculopathy (MTM group), and 34 eyes (28 females) with myopic choroidal neovascularization (CNV group).ResultsAll groups showed a significant increase in the axial length during the follow-up period (mean follow-up, 28.7 ± 16.8 months; range, 12-78) (P < 0.01). Changes in the axial length/year in the no complications group (0.041 ± 0.05 mm) were significantly greater than those in the non-highly myopic group (0.007 ± 0.02 mm) (P < 0.0001). Furthermore, changes in the CNV group (0.081 ± 0.04 mm) were significantly greater than those in the no complications (P < 0.0001) and MTM (0.040 ± 0.05 mm) (P = 0.0059) groups, whereas no significant difference was found between the changes in the MTM and no complications groups (P = 0.91). Multiple regression analyses indicated that CNV eyes (P < 0.0001) and female patients' eyes (P = 0.04) showed greater changes in the axial length/year.ConclusionsAll groups showed an increase in the axial length, which was greater for highly myopic eyes. In particular, CNV eyes showed greater increases, indicating that larger changes in the axial length may require careful follow-up.