Intraocular pressure changes and corneal biomechanics after hyperopic small-incision lenticule extraction

Abstract Background: To compare intraocular pressure (IOP) measurements by a dynamic Scheimpflug analyzer (Corvis ST), a non-contact tonometer, and the ocular response analyzer following hyperopic small-incision lenticule extraction (SMILE).Methods: Thirteen patients underwent hyperopic SMILE in one eye each were prospectively enrolled. IOP and corneal biomechanical parameters were measured preoperatively and 1 week, 1 month, and 3 months after surgery with a non-contact tonometer (IOPNCT), Corvis ST (biomechanical corrected IOP, bIOP), and the ocular response analyzer (Goldmann-correlated intraocular pressure [IOPg], cornea compensated IOP [IOPcc]). A linear mixed model was used to compare IOP and biomechanical values among the methods at each time point.Results: IOPNCT, IOPg, and IOPcc dropped significantly after surgery, with the amplitude being 3.15±0.48 mmHg, 5.49±0.94 mmHg, and 4.34±0.97 mmHg, respectively, at the last visit. IOPNCT decreased by 0.11±0.06 mmHg per µm of removed central corneal thickness. bIOP did not change significantly after surgery. Before surgery, no difference was found among the measurements (P> 0.05). After surgery, IOPNCT and bIOP were higher than IOPg and IOPcc. bIOP is independent of cornea thickness at the last visit, while correlated significantly with corneal biomechanics as other three IOP values did.Conclusion: bIOP (biomechanical corrected IOP as measured with the Corvis ST) seems to be an accurate parameter to measure IOP after hyperopic SMILE.

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Evaluation of Corneal Biomechanical Properties Modification after Small Incision Lenticule Extraction Using Scheimpflug-Based Noncontact Tonometer

BioMed Research International ◽

10.1155/2014/290619 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 16

Author(s):

Leonardo Mastropasqua ◽

Roberta Calienno ◽

Manuela Lanzini ◽

Martina Colasante ◽

Alessandra Mastropasqua ◽

...

Keyword(s):

Intraocular Pressure ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Biomechanical Properties ◽

Corneal Biomechanics ◽

Small Incision Lenticule Extraction ◽

Small Incision ◽

Lenticule Extraction ◽

Noncontact Tonometer ◽

Corneal Biomechanical Properties

Purpose.To quantify the effect of small incision lenticule extraction (SMILE) on the corneal biomechanics using Scheimpflug noncontact tonometer (Corvis ST).Methods.Twenty eyes of twenty patients, evaluated as eligible for surgery, with high myopia and/or moderate myopic astigmatism, underwent small incision lenticule extraction (SMILE). All patients underwent Corvis ST preoperatively and postoperatively after 1 week, and 1 and 3 months to observe alterations of corneal biomechanical properties. The main outcome measures were Deformation Amplitude, 1st-AT, and 2nd-AT. The relationship between the amount of stroma removed and the percentage variation of the measured parameters from baseline was evaluated with generalized linear model from each time point. For completeness also intraocular pressure (IOP), central corneal thickness (CCT), and their variations after surgery were evaluated.Results.The ratio between the amount of removed refractive error and, respectively, changes of Deformation Amplitude, 1st-AT, and 2nd-AT were significantly modified at the 1st week after surgery(P=0.005; P=0.001; P=0.024). At 1 and 3 months these values did not show statistically significant alterations. Intraocular pressure and central corneal thickness showed statistically significant changes during follow-up.Conclusions.No significant modifications in biomechanical properties were observed after SMILE so this procedure could induce only minimal transient alterations of corneal biomechanics.

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Intraocular pressure changes and corneal biomechanics after hyperopic small-incision lenticule extraction

10.21203/rs.2.18089/v2 ◽

2020 ◽

Author(s):

Dan Fu ◽

Meiyan Li ◽

Michael C. Knorz ◽

Shengsheng Wei ◽

Jianmin Shang ◽

...

Keyword(s):

Intraocular Pressure ◽

Linear Mixed Model ◽

Corneal Thickness ◽

Corneal Biomechanics ◽

Ocular Response Analyzer ◽

Small Incision Lenticule Extraction ◽

Corvis St ◽

Small Incision ◽

Lenticule Extraction

Abstract Background: We aimed to compare the intraocular pressure (IOP) measurements by a dynamic Scheimpflug analyzer (Corvis ST), a non-contact tonometer, and an ocular response analyzer after hyperopic small-incision lenticule extraction (SMILE).Methods: Thirteen patients who underwent hyperopic SMILE in one eye were enrolled prospectively. IOP and corneal biomechanical parameters were measured preoperatively and at 1 week, 1 month, and 3 months postoperatively with a non-contact tonometer (IOPNCT), Corvis ST (biomechanical corrected IOP and biomechanical corrected IOP measured with Corvis ST [bIOP]), and an ocular response analyzer (Goldmann-correlated intraocular pressure [IOPg] and cornea compensated IOP [IOPcc]). A linear mixed model was used to compare the IOP and biomechanical values among methods at each time point.Results: IOPNCT, IOPg, and IOPcc dropped significantly after surgery, with the amplitude being 3.15±0.48 mmHg, 5.49±0.94 mmHg, and 4.34±0.97 mmHg, respectively, at the last follow-up visit. IOPNCT decreased by 0.11±0.06 mmHg per µm of excised central corneal thickness. bIOP did not change significantly after surgery. Preoperatively, no difference was found among the measurements (P> 0.05). Postoperatively, IOPNCT and bIOP were higher than IOPg and IOPcc. bIOP was independent of cornea thickness at last follow-up visit, whereas it correlated significantly with corneal biomechanics similar to the other three IOP values.Conclusion: bIOP is a relative accurate measure of IOP after hyperopic SMILE.

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Corneal biomechanics after small-incision lenticule extraction versus Q-value–guided femtosecond laser-assisted in situ keratomileusis

Journal of Current Ophthalmology ◽

10.1016/j.joco.2016.08.004 ◽

2016 ◽

Vol 28 (4) ◽

pp. 181-187 ◽

Cited By ~ 12

Author(s):

Jun Zhang ◽

Li Zheng ◽

Xia Zhao ◽

Yang Xu ◽

Shu Chen

Keyword(s):

Femtosecond Laser ◽

Corneal Biomechanics ◽

Q Value ◽

Small Incision Lenticule Extraction ◽

Small Incision ◽

Lenticule Extraction

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A Review on Different Tonometers for Intraocular Pressure Measurement After Photorefractive Keratectomy or Small Incision Lenticule Extraction

Clinical Ophthalmology ◽

10.2147/opth.s278167 ◽

2020 ◽

Vol Volume 14 ◽

pp. 3305-3323

Author(s):

Shing Chuen Chow ◽

Barry Yat Ming Yeung

Keyword(s):

Intraocular Pressure ◽

Pressure Measurement ◽

Photorefractive Keratectomy ◽

Small Incision Lenticule Extraction ◽

Small Incision ◽

Lenticule Extraction

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Comparison of corneal biomechanics after microincision lenticule extraction and small incision lenticule extraction

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2016-308636 ◽

2016 ◽

Vol 101 (5) ◽

pp. 650-654 ◽

Cited By ~ 4

Author(s):

Zhiqing Wu ◽

Yan Wang ◽

Jiamei Zhang ◽

Tommy C Y Chan ◽

Alex L K Ng ◽

...

Keyword(s):

Corneal Biomechanics ◽

Small Incision Lenticule Extraction ◽

Small Incision ◽

Lenticule Extraction

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The Correlation Analysis between Corneal Biomechanical Properties and the Surgically Induced Corneal High-Order Aberrations after Small Incision Lenticule Extraction and Femtosecond Laser In Situ Keratomileusis

Journal of Ophthalmology ◽

10.1155/2015/758196 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 11

Author(s):

Wenjing Wu ◽

Yan Wang

Keyword(s):

Femtosecond Laser ◽

High Order ◽

Corneal Biomechanics ◽

Laser In Situ Keratomileusis ◽

Small Incision Lenticule Extraction ◽

Small Incision ◽

Lenticule Extraction ◽

Surgically Induced ◽

High Order Aberrations

Background. To investigate the correlation between corneal biomechanics and the surgically induced corneal high-order aberrations (HOAs) after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK).Methods. A total of 150 right myopic eyes that underwent SMILE or FS-LASIK surgery were included in this retrospective study, 75 eyes in each group. The corneal hysteresis (CH) and the corneal resistance factor (CRF) with the corneal HOAs of the anterior, posterior, and total cornea were assessed preoperatively and three months postoperatively. Multivariate linear regression was applied to determine the correlations.Results. The preoperative CRF was significantly correlated with the induced 3rd–6th-order HOAs and spherical aberration of the anterior surface and the total cornea after SMILE and FS-LASIK surgeries (P<0.05), postoperatively. The CRF was significantly correlated with the induced vertical coma of the anterior and posterior surfaces and the total cornea after SMILE surgery (P<0.05). There was a significant correlation between the CRF and the induced posterior corneal horizontal coma after FS-LASIK surgery (P=0.013).Conclusions. The corneal biomechanics affect the surgically induced corneal HOAs after SMILE and FS-LASIK surgery, which may be meaningful for screening the patients preoperatively and optimizing the visual qualities postoperatively.

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