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Gaurisankar ZS, van Rijn GA, Luyten GP, van den Berg TJ. Straylight As The Result Of Refractive Correction. Clin Ophthalmol 2019; 13:2195-2201. [PMID: 31814704 PMCID: PMC6858836 DOI: 10.2147/opth.s224970] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 09/16/2019] [Indexed: 12/11/2022] Open
Abstract
Purpose To investigate the effect of refractive correction on straylight. Patients and methods Straylight values were measured with the C-Quant (Oculus Optikgeräte, GmbH, Wetzlar, Germany) in 1) near-emmetropic eyes (n=30) with various negative powered refractive lenses and in 2) myopic eyes (n=30) corrected with prescribed eyeglasses and contact lenses. The straylight measurements in each group were compared in the different conditions. Results In the near-emmetropic group, a significant effect (p<0.001) of each added negative diopter was found to increase straylight values with 0.006 log-units. In the second group, no significant correlation with type of correcting lens was found on straylight values. Conclusion Refractive correction with high minus power (contact) lenses result in subtle increase of straylight values. These changes are relatively small and do not lead to visual disability in a clinical setting.
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Affiliation(s)
- Zoraida S Gaurisankar
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Gwyneth A van Rijn
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Gregorius Pm Luyten
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Thomas Jtp van den Berg
- Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, the Netherlands
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Fluctuation in straylight measurements during the visual recovery phase after small incision lenticule extraction. Eye (Lond) 2019; 34:366-373. [PMID: 31399702 DOI: 10.1038/s41433-019-0552-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 05/11/2019] [Accepted: 06/14/2019] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To investigate the postoperative straylight changes during the visual recovery phase after small incision lenticule extraction (SMILE) and their association. METHODS Seventy consecutive eyes from 37 patients with a mean age of 30.92 ± 7.26 years and a mean preoperative spherical equivalent of -5.24 ± 1.90 dioptres undergoing myopic or myopic astigmatism SMILE correction were included in this prospective study. Patients were followed up at days 1, 3, 7, 14, 21 and 28 after standard SMILE. Straylight was measured using the C-Quant straylight meter (Oculus GmbH, Germany) preoperatively and at each postoperative visit. RESULTS Preoperatively, the mean straylight measurement was 1.16 ± 0.16. After SMILE, the mean straylight values were 1.12 ± 0.14 and 1.13 ± 0.13 at days 7 and 14, which were significantly reduced compared to preoperative values (p ≤ 0.028). Straylight returned to baseline by week 3 (p = 0.160) and remained stable onwards (p = 0.651). A lower ablation ratio was associated with less straylight level at days 1, 3, 14 and 21 (p ≤ 0.0497) in the multivariable regression model. Likewise, better visual acuity was associated with lower straylight at days 7, 14 and 28 postoperatively (p ≤ 0.038). A small proportion of eyes (range: 0-12.86%) had ≥0.30 log(s) increase in postoperative straylight within the first month after SMILE. CONCLUSIONS SMILE induced a temporary decrease in straylight. It gradually returned to the preoperative level, which could be related to a number of dynamic processes during corneal healing. In the small proportion of patients with an increase in straylight postoperatively, this can affect their visual recovery during the early postoperative period.
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Study of light scattering using C-Quant ® in patients with Fuchs' endothelial dystrophy: A pilot study. ACTA ACUST UNITED AC 2017; 92:516-520. [PMID: 28320557 DOI: 10.1016/j.oftal.2016.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 10/19/2022]
Abstract
OBJECTIVE The purpose of this study was to determine the light scattering in patients with Fuchs' endothelial dystrophy without clinically significant corneal oedema, and evaluate its relationship with endothelial cell count, corneal thickness, and corneal biomechanical parameters. MATERIALS AND METHODS The values of light scattering were measured by C-Quant® (Oculus Optikgeräte GmbH, Germany) in 32 eyes of 17 patients diagnosed with Fuchs' endothelial dystrophy without clinically significant corneal oedema. Corneal biomechanical properties were determined using ORA (ocular response) and Corvis ST® (tonometry). RESULTS A light scattering value outside the normal range was observed in 93.8% of eyes studied. No statistically significant association (P>.05) was found between the values of the measured light scattering by C-Quant® and endothelial count, pachymetry, or corneal biomechanical properties. CONCLUSIONS In this study, changes were found in the values of light scattering values of patients with corneal Fuchs' endothelial dystrophy. This change does not appear to correlate significantly with disease severity.
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Xu L, Wang Y, Li J, Liu Y, Wu W, Zhang H, Wu Y, Khan GA. Comparison of Forward Light Scatter Changes Between SMILE, Femtosecond Laser-assisted LASIK, and Epipolis LASIK: Results of a 1-Year Prospective Study. J Refract Surg 2016; 31:752-8. [PMID: 26544563 DOI: 10.3928/1081597x-20151021-04] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 08/18/2015] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate the characteristics of forward light scatter changes after small incision lenticule extraction (SMILE) and to compare these changes with those after femtosecond laser-assisted LASIK (femto-LASIK) and epipolis LASIK (epi-LASIK). METHODS A total of 303 eyes (SMILE group = 118 eyes, femto-LASIK group = 90 eyes, epi-LASIK group = 95) of 157 patients were included in this study. Forward straylight was measured preoperatively and 1 month, 6 months, and 1 year postoperatively using a C-Quant straylight meter (Oculus Optikgeräte, Wetzlar, Germany). RESULTS A significant increase in straylight was found in the femto-LASIK group only at 1 month after the procedure (P = .002), whereas significant increases were found in the epi-LASIK group at 1 month, 6 months, and 1 year after the procedure (P < .001). There were no significant increases in the straylight values after SMILE (P = .310) compared with the preoperative values, although the straylight values were slightly increased at 1 month. Significant differences in the postoperative-preoperative straylight value (Δlog[s]) changes were found between the SMILE, femto-LASIK, and epi-LASIK groups over the follow-up period (P < .001 for all). The correlations between the ablation depth/central corneal thickness ratios and the straylight values were statistically significant in the femto-LASIK and epi-LASIK groups, whereas no significant correlation between the lenticule thickness/central corneal thickness ratios and the stray-light values was found in the SMILE group. CONCLUSIONS Forward straylight was slightly increased in the early stage after the femto-LASIK procedure and was significantly increased throughout the follow-up period after epi-LASIK surgery. The SMILE procedure appeared to have a smaller effect on forward light scatter within the 1-year follow-up period.
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Watanabe S, Oie Y, Fujimoto H, Soma T, Koh S, Tsujikawa M, Maeda N, Nishida K. Relationship between Corneal Guttae and Quality of Vision in Patients with Mild Fuchs' Endothelial Corneal Dystrophy. Ophthalmology 2015; 122:2103-9. [PMID: 26189189 DOI: 10.1016/j.ophtha.2015.06.019] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 06/08/2015] [Accepted: 06/08/2015] [Indexed: 11/28/2022] Open
Abstract
PURPOSE To investigate the effect of the severity of corneal guttae on quality of vision (QOV) in patients with mild Fuchs' endothelial corneal dystrophy (FECD). DESIGN Cross-sectional study. PARTICIPANTS Twenty-three eyes of 14 patients with mild FECD without corneal edema on slit-lamp examination (5 pseudophakic eyes and 18 phakic eyes with mild lens opacity; grade 1.0-2.0 nuclear opalescence, grade 1.0-2.0 nuclear color, grade 1.0 cortical cataract, and grade 1.0 posterior subcapsular cataract on the Lens Opacities Classification System, version III). METHODS The area ratio of the corneal guttae (ARCG) in the endothelial cells was measured by multifocal specular microscopy. The QOV parameters, that is, corrected distance visual acuity (CDVA), letter contrast sensitivity (LCS), and intraocular straylight, also were measured. The correlations were assessed between the ARCG and QOV parameters and between the straylight and CDVA and LCS. MAIN OUTCOME MEASURES The ARCG, logarithm of the minimum angle of resolution CDVA, LCS, and straylight. RESULTS Univariate analysis showed that the ARCG was correlated significantly with the CDVA, LCS, and straylight (R(2) = 0.41, P = 0.001; R(2) = 0.55, P = 0.001; and R(2) = 0.39, P = 0.002, respectively). Univariate analysis also showed that straylight was correlated significantly with the CDVA and LCS (R(2) = 0.47, P = 0.001 and R(2) = 0.41, P = 0.001, respectively). CONCLUSIONS Corneal guttae without edema caused the QOV to deteriorate in eyes with FECD. Patients with higher straylight had worse CDVA or LCS. Intraocular forward light scatter caused by corneal guttae may result in visual disturbances. Quantification of corneal guttae can be useful to evaluate the effect of guttae on the QOV and determine the surgical indications of endothelial keratoplasty for eyes with mild FECD.
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Affiliation(s)
- Shinya Watanabe
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Yoshinori Oie
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
| | - Hisataka Fujimoto
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Takeshi Soma
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Shizuka Koh
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Motokazu Tsujikawa
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Naoyuki Maeda
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Kohji Nishida
- Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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Long-term changes in straylight induced by corneal refractive therapy: A pilot study. Cont Lens Anterior Eye 2014; 37:144-8. [DOI: 10.1016/j.clae.2013.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 08/18/2013] [Accepted: 09/16/2013] [Indexed: 11/23/2022]
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Patryn EK, Vrijman V, Nieuwendaal CP, van der Meulen IJE, Mourits MP, Lapid-Gortzak R. Indications for and outcomes of tertiary referrals in refractive surgery. J Refract Surg 2013; 30:54-61. [PMID: 24168790 DOI: 10.3928/1081597x-20131023-05] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 08/05/2013] [Indexed: 11/20/2022]
Abstract
PURPOSE To review the spectrum of disease, symptomatology, and management offered to patients referred for a second opinion after refractive surgery. METHODS A prospective cohort study was done on all patients referred from October 1, 2006, to September 30, 2011, to a tertiary eye clinic after refractive surgery of any kind (ie, corneal laser surgery, conductive keratoplasty, radial keratotomy, phakic implants, refractive lens exchanges, or any combination thereof). Data analysis was performed on all demographic and clinical aspects of this cohort, including the initial complaint, type of referral, number of complaints, procedure previously performed, diagnosis at our center, type of advice given, and rate and type of surgical intervention. RESULTS One hundred thirty-one eyes (69 patients) were included. Corneal refractive surgery was performed in 82% (108 eyes), and 11% (14 eyes) were seen after phakic intraocular lens (PIOL) implantation and 7% (9 eyes) after refractive lens exchange. The most common diagnoses were tear film dysfunction (30 eyes, 23%), residual refractive error (25 eyes, 19%), and cataract (20 eyes, 15%). Most patients (42 patients, 61%) were treated conservatively. In 27 patients (39%), 36 eyes (28%) were managed surgically. Severe visual loss was seen in 1 eye. CONCLUSIONS No major problems were found in most second opinions after refractive surgery referral. Dry eyes, small residual refractive error, or higher-order aberrations were the most common complaints. Surgical intervention was needed in 36 eyes (28%), almost half of which were cataract extractions. Severe visual loss was seen in 1 eye with a PIOL. There was no incidence of severe visual loss in keratorefractive and refractive lens exchange procedures.
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Wang Y, Li J, Liu Y, Xie L. Intraocular Straylight After Thin-Flap LASIK With a Femtosecond Laser Versus a Mechanical Microkeratome. J Refract Surg 2013; 29:534-9. [DOI: 10.3928/1081597x-20130719-03] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 04/18/2013] [Indexed: 11/20/2022]
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Lee K, Ahn JM, Kim EK, Kim TI. Comparison of optical quality parameters and ocular aberrations after wavefront-guided laser in-situ keratomileusis versus wavefront-guided laser epithelial keratomileusis for myopia. Graefes Arch Clin Exp Ophthalmol 2013; 251:2163-9. [PMID: 23652467 DOI: 10.1007/s00417-013-2356-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 03/05/2013] [Accepted: 04/18/2013] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND To compare optical quality, ocular scattering, and higher-order aberrations (HOAs) after laser in-situ keratomileusis (LASIK) versus laser epithelial keratomileusis (LASEK). METHODS A total of 47 eyes from 47 participants who had undergone LASIK (group I) or LASEK (group II) procedure at least 6 months prior were enrolled. Ocular aberrations and modulation transfer function (MTF) values measured using iTrace, a ray-tracing type aberrometer, were compared to MTF (modulation transfer function) cut-off values, Strehl ratio, and objective indices of scattering obtained using the Objective Quality Analysis System II (OQAS II). RESULTS There was no significant correlation between the postoperative optical quality parameters and the HOAs between both groups. In group I, the MTF cut-off value was significantly correlated with cylinder refraction (p = 0.037), and the objective scattering index (OSI) was positively correlated with spherical equivalent (p = 0.023). In group II, there was a statistically significant correlation between the OSI and achieved refractive correction (p = 0.001). Regression analysis showed that the OSI was the most significant predictor of MTF cut-off values after refractive surgery. Additionally, MTF values measured by OQAS were significantly lower than those measured by iTrace without correlation. CONCLUSION Optical quality after refractive surgery may be influenced by not only ocular aberrations but also by scattering. Even though the accuracies of the machines used in this study to measure optical quality have yet to be proven, this study showed limited correlation among the values measured using the two different machines after refractive surgery. Therefore, for more generalized evaluation of visual function after refractive surgery, more advanced optical devices still need to be developed.
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Affiliation(s)
- Kwanghyun Lee
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea
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van Bree MC, van den Berg TJ, Zijlmans BL. Posterior Capsule Opacification Severity, Assessed with Straylight Measurement, as Main Indicator of Early Visual Function Deterioration. Ophthalmology 2013; 120:20-33. [DOI: 10.1016/j.ophtha.2012.07.050] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 07/17/2012] [Accepted: 07/17/2012] [Indexed: 11/16/2022] Open
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van den Berg TJTP, Franssen L, Kruijt B, Coppens JE. History of ocular straylight measurement: A review. Z Med Phys 2012. [PMID: 23182462 DOI: 10.1016/j.zemedi.2012.10.009] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The earliest studies on 'disability glare' date from the early 20(th) century. The condition was defined as the negative effect on visual function of a bright light located at some distance in the visual field. It was found that for larger angles (>1 degree) the functional effect corresponded precisely to the effect of a light with a luminosity equal to that of the light that is perceived spreading around such a bright source. This perceived spreading of light was called straylight and by international standard disability glare was defined as identical to straylight. The phenomenon was recognized in the ophthalmological community as an important aspect of the quality of vision and attempts were made to design instruments to measure it. This must not be confused with instruments that assess light spreading over small distances (<1 degree), as originating from (higher order) aberrations and defocus. In recent years a new instrument has gained acceptance (C-Quant) for objective and controllable assessment of straylight in the clinical setting. This overview provides a sketch of the historical development of straylight measurement, as well as the results of studies on the origins of straylight (or disability glare) in the normal eye, and on findings on cataract (surgery) and corneal conditions.
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Affiliation(s)
- Thomas J T P van den Berg
- Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands.
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Correlation of Straylight and Visual Acuity in Long-Term Follow-up of Manual Descemet Stripping Endothelial Keratoplasty. Cornea 2012; 31:380-6. [DOI: 10.1097/ico.0b013e31823f8ab7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
PURPOSE To compare intraocular straylight and contrast sensitivity determined before corneal refractive therapy and after 15 days and 1 month of treatment. METHODS A single-center, prospective, and longitudinal study was performed in 30 subjects undergoing corneal refractive therapy. In each subject, high-contrast visual acuity (HCVA), low-contrast visual acuity (LCVA), straylight, and contrast sensitivity were determined at baseline and after 15 days and 1 month after the treatment. Straylight was measured using the van den Berg straylight meter (third generation). Contrast sensitivity was determined under both photopic and mesopic conditions using the VCTS 6500 instrument (Vision Contrast Test System). EDTRS charts (logMAR units) were used to measure HCVA and LCVA. RESULTS Straylight (mean ± standard deviation) significantly fell from baseline (0.94 ± 0.14) to the values recorded at 1 month (0.85 ± 0.11, p = 0.009). Photopic contrast sensitivity remained stable yet mesopic contrast sensitivity measured at high spatial frequencies was significantly reduced. No correlations between intraocular straylight and contrast sensitivity, HCVA, or LCVA were observed 15 days and 1 month after corneal refractive therapy. CONCLUSIONS Our findings suggest improved intraocular straylight readings 1 month after starting the treatment, although the changes observed in straylight could not be related to changes in mesopic and photopic contrast sensitivity or HCVA and LCVA. Mesopic contrast sensitivity was more affected by the treatment intervention than photopic contrast sensitivity.
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Paarlberg JC, Doors M, Webers CA, Berendschot TT, van den Berg TJ, Nuijts RM. The effect of iris-fixated foldable phakic intraocular lenses on retinal straylight. Am J Ophthalmol 2011; 152:969-975.e2. [PMID: 21871599 DOI: 10.1016/j.ajo.2011.05.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 05/24/2011] [Accepted: 05/25/2011] [Indexed: 10/17/2022]
Abstract
PURPOSE To determine changes in straylight after iris-fixated phakic intraocular lens implantation (pIOL) and to investigate the relationship between straylight and several preoperative and postoperative variables. DESIGN Institutional, prospective cross-sectional study. METHODS Artiflex (Ophtec B.V.) pIOL implantation was performed in 61 eyes (36 patients). Straylight values were measured before surgery and 3 months after surgery using the Oculus C-Quant (Oculus Optikgeräte). Furthermore, correlations were analyzed between straylight and the following parameters: keratometry, axial length, spherical equivalent, astigmatism, pIOL power, best spectacle-corrected visual acuity, and pupil size. RESULTS Mean straylight decreased from 1.18 ± 0.17 log units before surgery to 1.13 ± 0.17 after surgery (P = .016). Higher preoperative straylight values were associated with larger postoperative decreases in straylight (r = -0.534; P < .001). Higher postoperative straylight values were correlated to higher axial length (r = 0.444; P = .001) and lower keratometry values in diopters (r = -0.414; P = .001). After regression analysis, only axial length was found to be an independent predictor of preoperative and postoperative straylight (P < .001 and P = .001, respectively). After correcting for the axial length of an emmetropic eye (23.44 mm), all straylight correlations disappeared, indicating that an increase in distance from cornea to retina explains the increase in straylight values in longer eyes. CONCLUSIONS Retinal straylight was reduced significantly after Artiflex pIOL implantation. Besides age, axial length was the only predictor of preoperative and postoperative straylight values. The increased tissue length light has to pass from cornea to retina, might explain the increase in straylight values in longer eyes.
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Rozema JJ, Trau R, Verbruggen KHM, Tassignon MJ. Backscattered light from the cornea before and after laser-assisted subepithelial keratectomy for myopia. J Cataract Refract Surg 2011; 37:1648-54. [PMID: 21752589 DOI: 10.1016/j.jcrs.2011.03.043] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 03/04/2011] [Accepted: 03/07/2011] [Indexed: 10/18/2022]
Abstract
PURPOSE To study corneal backscatter changes after laser-assisted subepithelial keratectomy (LASEK) and to search for correlations between the changes in forward and backward corneal light scatter. SETTING Antwerp University Hospital, Edegem, Belgium. DESIGN Prospective interventional case series. METHOD Corneal backscatter was determined with a commercial Scheimpflug device and purpose-written image-analysis software. The mean backscatter profile and gray value distributions of the images for a 1.0 mm zone around the corneal apex were obtained preoperatively and 6 months after LASEK for myopia. This was compared with forward light scatter (or straylight) using measurements obtained with the compensation comparison method. RESULTS The study enrolled 80 eyes (40 patients; mean age 34.2 years ± 10.4 [SD]). Very strong correlations were found between the backscatter profiles of right eyes and left eyes preoperatively. Hence, only right eyes were used for further calculations. The epithelial-Bowman peak of the backscatter profile decreased significantly after LASEK (mean decrease -2.2 ± 4.7 grayscale units) (P=.002, paired t test), which corresponded to the ablation of Bowman layer. Significant changes in the gray-value distribution were observed postoperatively, corresponding to the decreases in the epithelium-Bowman peak. Forward light scatter decreased significantly after LASEK (mean decrease -0.10 ± 0.13) (P<.001); however, no significant correlation with corneal backscatter was observed. CONCLUSIONS The anterior part of the corneal backscatter profile decreased significantly after LASEK. A significant reduction in forward light scatter was also seen, although it was not correlated to backward light scatter.
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Affiliation(s)
- Jos J Rozema
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium.
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van Bree MC, van Verre HP, Devreese MT, Larminier F, van den Berg TJ. Straylight Values after Refractive Surgery: Screening for Ocular Fitness in Demanding Professions. Ophthalmology 2011; 118:945-53. [DOI: 10.1016/j.ophtha.2010.09.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 09/14/2010] [Accepted: 09/16/2010] [Indexed: 11/26/2022] Open
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Straylight before and after hyperopic laser in situ keratomileusis or laser-assisted subepithelial keratectomy. J Cataract Refract Surg 2010; 36:1919-24. [DOI: 10.1016/j.jcrs.2010.06.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 04/23/2010] [Accepted: 06/02/2010] [Indexed: 11/18/2022]
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