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@#AIM: To investigate the clinical effect of transepithelial rapid cross-linking combined with wearing rigid gas permeable contact lens(RGPCL)in keratoconus patients.<p>METHODS: This was a retrospective study of patients with progressive keratoconus diagnosed in the Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine in October 2014, and underwent transepithelial rapid keratoplasty. After surgery 16 patients(25 eyes)used RGPCL. Average age was 25.31±5.92 years old, maximum preoperative corneal curvature was 58.96±6.76D, thinnest corneal thickness was 439.52±53.24μm. Rapid cross-linking was performed using riboflavin and 45mW/cm<sup>2</sup> ultraviolet light(UV)irradiation with a total energy of 7.2J/cm<sup>2</sup>. RGPCL was used after surgery. Follow up of 3-6a, average follow-up time was 52.44±11.39mo. The best corrected visual acuity \〖(BCVA), in RGPCL\〗, corneal curvature of flat meridian(K<sub>1</sub>), corneal curvature of steep meridian(K<sub>2</sub>), maximum corneal curvature(Kmax), corneal refractive power(MPP), Baiocchi Calossi Versaci index of anterior and posterior surface(BCVf and BCVb)asymmetry index of anterior surface curvature(SIf), asymmetry index of posterior surface curvature(SIb), the highest point of anterior cone cornea(KVf), the highest point of posterior cone cornea(KVb), the change of corneal thickness(ThkMin), lens opacity, and corneal endothelial cell count were observed.<p>RESULTS: All patients had a successful operation, and no intraoperative complications. On the first day after surgery, all cases felt slight tingling and slight photophobia tears. After 1d of operation, the corneal epithelium was removed in two eyes. While 3d after re-wearing the bandage, the epithelium healed. None of lens in the patients was opacified during follow-up, and there was no significant difference in corneal endothelial cell count compared with preoperative(<i>P</i>>0.05). The BCVA(wearing RGPCL)after operation is obviously improved compared with preoperative. All postoperative Kmax, SIf, KVf, BCVf, BCVb were lower than preoperative(<i>P</i><0.05). <p>CONCLUSION: Transepithelial rapid corneal cross-linking combined with RGPCL is safe and effective in controlling the progress of keratoconus. And the long-term effect is stable.
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@#AIM:To investigate the clinical effect of wearing rigid gas permeable contact lens(RGPCL)to correct the irregularity of anterior corneal surface after deep anterior lamellar keratoplasty(DALK).<p>METHODS: A prospective case-control study. 28 patients accepted RGPCL or frame glassed after DALK surgery during 2017-07/2019-01 in the General Hospital of Northern Theater Command were selected. We divided them into 2 groups according to the principle of non-random voluntariness. 18 patients(18 eyes)accepted RGPCL while 10 patients(10 eyes)accepted frame glasses were selected. Data were collected preoperative, 3mo, 6mo and 1a later, including uncorrected distant visual acuity(UCVA), corrected distant visual acuity(CDVA)and refractive diopter. Furthermore, the Oculus Pentacam Three-dimensional Anterior eye Analyzer was used to examine the corneal morphology. We calculated corneal anterior surface smooth curvature(K1), steep curvature(K2), maximum curvature(Kmax), anterior corneal surface astigmatism, Index of Surface Variance(ISV), Index of Height Asymmetry(IHA), Index of Vertical Asymmetry(IVA)and Index of Height Decentration(IHD). <p>RESULTS: We found no statistically significant differences between the two groups in UCVA, SE, K2, Kmax, anterior corneal surface astigmatism, IVA and IHD(<i>P</i>>0.05), but we found significant differences in CDVA, K1, ISV and IHA(<i>P</i><0.05). In terms of CDVA, the data at 3mo was(0.38±0.16, 45.40±3.19D, 35.48±18.46, 27.91±17.19), 6mo was(0.37±0.16, 43.73±3.39D, 30.48±16.28, 25.18±16.66)and 1a was(0.34±0.21, 43.64±3.30D, 25.97±15.23, 23.46±15.24)in the RGPCL group. The data at 3mo was(0.65±0.16, 45.82±3.52D, 49.39±15.73, 28.45±16.96), 6mo was(0.60±0.15, 45.11±3.06D, 48.18±15.13, 25.95±15.93)and 1a was(0.58±0.16, 45.61±3.30D, 46.67±15.45, 25.48±15.51)(<i>P</i><0.05).<p>CONCLUSION: RGPCL is safe and effective to improve CDVA and correct the regularity of anterior corneal surface after DALK and has advantage over frame glasses.
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@#AIM: To observe the safety and efficacy of epithelium-off corneal collagen cross-linking(CXL)combined with rigid gas permeable contact lens(RGPCL)in treatment of progressive keratoconus.<p>METHODS: From January 2015 to January 2017, 51 cases(51 eyes)of patients diagnosed with keratoconus and epithelium-off CXL treatment at the Eye Hospital of Nanjing Medical University were collected. The patients were divided into two groups according to whether they wore RGPCL or not after treatment. Group A: 30 eyes, epithelium-off CXL was removed and wear a framed mirror after treatment; Group B: 21 eyes, epithelium-off CXL was removed and RGPCL was worn after the condition was stable. Observed the best corrected visual acuity(BCVA), spherical equivalent(SE), minimum keratometry of the anterior corneal surface(K1), maximum keratometry of the anterior corneal surface(K2), mean keratometry(Km), maximal keratometry(Kmax), corneal vertex thickness, thinnest corneal thickness(TCT)before and 12mo after treatment.<p>RESULTS: No statistically significant differences were found before the therapy between the two groups in BCVA, SE, K1, K2, Km, Kmax, corneal vertex thickness, and TCT between the two groups(<i>P</i>>0.05). 12mo after treatment, BCVA in group B was significantly higher than that in group A(0.11±0.03 <i>vs</i> 0.26±0.16), the corneal vertex thickness of group B was lower than that of group A(431.8±14.41μm <i>vs</i> 461.38±32.68μm)(<i>P</i><0.05), there was no significant difference in other parameters between the two groups.<p>CONCLUSION: Epithelium-off CXL can effectively delay or control the progression of keratoconus. Wearing RGPCL after treatment can effectively improve BCVA.
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Objective To evaluate the efficacy,safety of rigid gas permeable contact lens (RGPCL) wearing for over 5 years in different degrees of keratoconus eyes.Methods A retrospective case study was performed.The clinical data of 217 eyes with different degree of keratoconus from 126 keratoconus patients who fitted with RGPCL in Beijing Tongren Hospital from 2000-2010 over 5 years were analyzed.The eyes were divided into mild keratoconus group (Ks≤45.0 D),moderate keratoconus group (45.0 D＜ Ks ＜ 52.0 D) and severe keratoconus group (Ks ≥52.0 D) according to the severity.Uncorrected visual acuity (UCVA,LogMAR),spectacle corrected visual acuity (SCVA) and RGP corrected visual acuity (RGPVA) was examined before RGPCL wearing and the end of followingup after RGPCL wearing.The refraction,corneal curvature,corneal astigmatism were measured with auto-refractomer/keratometer and keratoconus screening analysis system of computer-assisted corneal topography.Comparisons of the changes of corrected visual acuity and corneal parameters were assessed.Results The RGPVA was 0.09±0.17,0.05±0.07 and 0.07 ±0.07 in the mild,moderate and severe keratoconus group,respectively,showing a significant difference among the three groups (F=0.522,P=0.594);The △Ks was (2.25±5.42),(0.26±3.44) and (-4.52±3.44)D,and △Kf was (2.06±4.98),(1.02±3.41) and (-2.03±5.05)D,and the change value of corneal astigmatism was (0.19±2.87),(-0.78±2.84) and (-2.44±3.77)D in the mild,moderate and severe keratoconus group(all at P＜ 0.05),respectively,with the minimum amount of change in the severe keratoconus group.The variation of differential sector index (△DSI) was-0.33 ± 1.64,0.14±3.01 and-2.11 ±4.28;the variation of center/ surround index (△CSI) was-0.41 ± 1.07,0.03±2.22 and-2.49±4.15;the variation of standard deviation of power (△SDP) was-0.43 ±0.64,-0.02 ±0.89 and-1.67 ± 1.68;the variation of keratoconus prediction index (△KPI)was 0.00±0.07,0.03±0.09 and-0.05±0.11 in the mild,moderate and severe keratoconus group,respectively,and the reduced amount in above parameters was much more in the severe keratoconus group than that in the mild and moderate keratoconus group (all at P＜0.01).Mild conjunctivitis and corneal affection occurred in 12 eyes (5.5％)during the follow-up.Conclusions Long-term wearing RGPCL can improve the visual acuity and slow the tendency of corneal curvature increase in keratoconus eyes,and this procedure is safe and effective for the correction of different degree of keratoconus.
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AIM:To evaluate flight attendants' ocular surface after different refractive corrections. ·METHODS:Forty-two flight attendants (84 eyes) were enrolled in the study. Those flight attendants, who were followed up from September 2014 to September 2016, all followed the doctor's orders. According to different refractive corrections, those flight attendants were divided into 4 groups: corneal refractive surgery group, soft contact lens group, rigid gas permeable contact lens ( RGP) group and control group without any refractive corrections. OSDI scores, tear meniscus heights, BUTs, fluorescein staining scores and Schirmer's tests were taken and analyzed. ·RESULTS: Compared with the control group, OSDI scores were worse, tear meniscus heights ( TMH ) were reduced, BUTs were shortened, fluorescein staining(FS) scores were worse, Schirmer's Tests ( SⅠt) were shorter in soft contact lens group and corneal refractive surgery group (P0. 05 ) . There was no significant difference in lid margin abnormalities among the four groups (F=3. 82, P=0. 45). ·CONCLUSION: RGP can improve flight attendants'ocular surface micro-environment.
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Objective To observe the clinical efficacy of rigid gaspermeable contact lens (RGPCL) for correcting keratoconus and analyze the predictors for the base curve of RGPCL.Methods Data of 86 patients (143 eyes) with keratoconus fitted with RGPCL were retrospectively analyzed.All eyes were divided into the mild (n =18 eyes),moderate (n =73 eyes),advanced (n =34 eyes) and severe group (n =18 eyes).After evaluating the lens fitting,best corrected visual acuity of eyes wearing spectacle lenses and RGPCL among the 4 groups was statistically compared.And the correlation between the fitting guidance index and HL-K RGPCL base curve in each group was analyzed according to keratometry.Results All patients wearing RGPCL gained significantly better corrected vision in the mild (t =-3.336,P =0.004),moderate (t =-11.213,P ＜0.001),advanced (t =-13.959,P ＜0.001) and severe groups(t =-11.047,P ＜0.001) than those with spectacles.Equivalent spherical degree of spectacle lenses was lower than the diopter of HL-K RGPCL in the moderate (P =0.043) and severe group (P =0.006).The mean base curve of RGPCL was (50.52 ±5.64) diopter,and it was correlated with corneal curvature parameters.In mild group,the RGPCL base curve was correlated with the steep keratometry (P ＜ 0.001).The average K and relative steep K of 0.2 mm (Rm-0.2) were highly correlated with RGPCL base curve in moderate group (r =0.798,P ＜ 0.001;r =0.798,P ＜ 0.001),in advanced group (r =0.745,P ＜ 0.001;r =0.745,P ＜ 0.001) and in severe group (r =0.616,P =0.007;r =0.617,P =0.006).Conclusion Patients with keratoconus wearing HL-K RGPCL can obtain ideal corrected vision.Determination of RGPCL base curve by adjusting the corresponding indicators is conducive to improving the long-term wearing safety of the lens and enhancing the efficiency of lens fitting.
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?AlM: To discuss the differences in accommodative lag of different stimulation between the adolescent myopes who wore rigid gas permeable contact lens ( RGPCL ) and spectacles for one year. ?METHODS: Totally 85 myopes between 10-16y were enrolled in the study. Every subject was examined with the visual function test, medical optometry, corneal topography and ocular health check etc. of eyes. According to the above measurements and the compliance of children and their parents, 41 subjects were selected to wear RGPCL, 44 subjects were chosen to wear spectacles. Based on maximum plus to maximum visual acuity ( MPMVA) , accommodative lag was determined by dynamic retinoscopy method in two groups. The subjects were examined once every 3mo, accommodative lag was measured again using the same method for comparative analysis after one year. Wearing a year later, myopia progression of the two groups was measured and compared. ?RESULTS: There was no significant difference between two groups of initial accommodative lag (P>0. 05). After wearing one year, there was also no significant difference between the accommodative lag examined and the initial lag in RGPCL group (P>0. 05), the results demonstrate significant difference between the accommodative lag examined after wearing one year and the initial lag in spectacles group ( P ?CONCLUSlON:After wearing RGPCL and spectacles one year in high accommodative stimulus, there is an obviously decreased in accommodative lag in RGPCL group, which suggests that RGPCL can control the progression of myopia in adolescents. The accommodative lag of the two groups increase obviously with increasing stimulation, which suggest that the adolescents need keeping good habits of reading.
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AlM: To evaluate the effect of rigid gas permeable contact lens ( RGP ) in correcting high myopia and astigmatism.METHODS: Forty-one patients ( 65 eyes ) with myopia (-9. 03 ± 6. 19DS, maximum -23. 00DS) and astigmatism (-1. 41 ± 1. 32DC, maximum -5. 50DC) were fitted with RGP after strict routine ophthalmological examination, objective refraction and subjective refraction. All these patients were followed after 1wk, 1, 3mo and half one year.RESULTS:Sixty-five eyes were fitted with RGP (-9. 92± 5. 96DS). RGP base curve ( BC) was majorly located within the range 7. 20 ~8. 25mm. 46. 2% eyes with RGP achieved 1. 0 ( BCVA ) and 80. 1% achieved above 0. 6 ( BCVA) . However, with spectacles, the percent was 28%(1. 0) and 60% (>0. 6), respectively. BCVA of RGP was 0. 81 ± 0. 22, but BCVA with spectacles was 0. 66 ± 0. 28, there was statistical significance (P<0. 01). There were 40 eyes (62%) fitted with RGP whose vision were enhanced more than 1 line, 24 eyes ( 37%) whose vision were not changed and 1 eye (2%) whose vision were dropped 1 line.CONCLUSlON:RGP effectively improves visual acuity of high myopia and astigmatism compared with spectacles.
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Background Rigid gas permeable (RGP) contact lens,as a kind of new correction of refraction error,has been wildly used,but whether it will cause eye optical system of the change and influence on the visual acuity is unclear.Objective Present study was to evaluate and compare the visual quality of low to moderate myopia following wearing of RGP contact lens and spectacles.Methods Sixty-eight eyes of 35 subjects with low or mediate myopia were included in this study.Wave-front aberrations and visual acuities under the different contrasts (10％,30％,40％,52％,76％,92％) in the light or dark environment were examined before and 3 months after wearing of RGP corneal contact lens.These parameters were compared with those after wearing of spectacles with paired t test.Results The best corrected visual acuity (BCVA) was improved significantly from 0.94±0.10 to 1.26±0.03 3 months after wearing of RGP corneal contact lens (t=-9.266,P=0.000).After fitting of RGP corneal contact lens,the total higher order wave-front aberrations,the 3rd and 4th order aberrations were significantly declined in comparison with those of before fitting (total:t=4.683,P=0.000;RMS3:t=4.656,P=0.000;RMS4:t=3.929,P=0.000).However,no significant differences were detected in the 5th and 6th order aberrations between RGP corneal contact lens fitting and spectacles wearing (RMS5:t=1.766,P=0.083 ;RMS6:t=1.150,P=0.256).In both bright and dark environments,BCVA values were much better in the eyes with RGP corneal contact lens wearing than that in the eyes with spectacles wearing (all P＜0.05).The BCVA was always reduced with the decline of contrast level whether bright or dark backgrounds both in RGP corneal contact lens wearing eyes and spectacles wearing eyes.Conclusions Wearing of RGP corneal contact lens provides better visual quality for low to moderate myopia than the spectacles wearing.
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Background Even though the change in wavefront aberrations with correction modality is well documented in the literature,little is known about the underlying mechanism.Complete understanding of the causes responsible for the wavefront change in the combined lens-eye system is important since it provides basic knowledge for further improving the technique to correct refractive error by correcting lenses.Objective The aim of this study was to investigate the influence of refractive correction lens on optical property of the eye by analyzing Zernike aberrations in myopic eyes with contact lens correction.Methods This study was approved by the Ethic Committee of Wenzhou Medical College.Written informed consent was obtained from each subject before entering this study.Zernike aberrations of 52 myopic eyes of 26 subjects with the spherical equivalent-1.75 to-8.50 D were measured using a Hartmann-Shock wavefront sensor.The human eye aberrations were examined at the uncorrected condition,rigid-gas-permeable contact lens (RGP-CL) corrected condition and soft contact lens (Soft-CL) corrected condition.The differences of wavefront aberrations and Zernike coefficients were compared by repeated measurement of single factor variance analysis,and correlation of the aberration changes between uncorrected condition and RGP-CL corrected condition or Sofi-CL corrected condition,between the right eyes and left eyes in different conditions were analyzed by Pearson linear correlation.Results Mean total root-mean-square (tRMS) was (0.71 ± 0.30)μm,(0.54±0.19)μm and (0.74±0.32)μm in the uncorrected condition,RGP-CL corrected condition and Soft-CL corrected condition,with a significant difference (F =8.758,P＜0.001),and tRMS was significant declined under the RGP-CL corrected condition compared with uncorrected condition (t =2.746,P =0.008),and tRMS in RGP-CL corrected condition was significantly lower than that in Soft-CL corrected condition (t =3.428,P =0.001).The high RMS (hRMS) was (0.34±0.12) μm,(0.28 ±0.12) μm,(0.40±0.14) μm in the uncorrected condition,RGP-CL corrected condition and Soft-CL corrected condition,with a significant difference among them (F =10.681,P＜0.001).An insignificant decrease of hRMS was seen in the RGP-CL corrected condition compared with uncorrected condition (t =1.987,P=0.053),but hRMS value was significant higher in the Soft-CL corrected condition than that in the uncorrected condition (t=2.101,P=0.041) and RGP-CL corrected condition (t=4.266,P＜0.001).Compared with uncorrected condition,the axis astigmatism (C5) and spherical aberration (C12) in the RGP-CL corrected condition and spherical aberration (C12) in the Soft-CL corrected condition were significantly reduced (P＜0.05),and the absolute values of trefoil (C6),vertical coma (C7) and tetrafoil (C10) in the RGP-CL corrected condition were lower than those of the uncorrected condition,but vertical coma (C7) absolute value in the Soft-CL corrected condition was increased (P＜0.05).A significantly positive correlation was seen in the spherical aberration (C12) between the RGP-CL corrected condition and uncorrected condition (r =0.763,P＜0.001),and less significant correlation was in the secondary astigmatism (C11) between the Soft-CL corrected condition and uncorrected condition(r=0.469,P＜0.001).Conclusions Different contact lens corrected conditions exert their effects on ocular wavefront structure due to its unique interaction with the eye.RGP-CL wearing has strong modification on wavefront aberrations probably due to its molding effect on corneal surface,which reduces the bilateral symmetry.High order wavefront aberration can be modified by Soft-CL wearing.
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Objective To investigate the effects of rigid gas permeable contact lens (RGPCL) wearing 3 years on ocular surface in keratoconus.Design Retrospective case series.Participants 73 patients with keratoconus.Methods From July 2001 to July 2004,73 patients (142 eyes) wearing RGPCL for more than 3 years were collected in Peking University Optometry & Ophthalmology Center.Be- fore and at 1 year,2 years and 3 years of RGPCL wearing,density and morphologic changes of corneal endothelium were examined with non-contact specular microscope.Eye axial length,central and peripheral thickness of cornea were measured with A-scan pachymeter. All eyes were examined with slit-lamp microscope periodically.Main Outcome Measures Corneal endothelial density and morphology, corneal thickness,eye axial length,ocular surface changes.Results Before and at 1 year,2 years and 3 years of RGPCL wearing,aver- age corneal endothelial density was 2901.92?445.20,2862.78?497.13,2854.71?526.80,3015.61?421.22 (cells/mm~2)without significant difference statistically (F=1.571,P=0.20).Morphologic changes were not significant during 3 years.Eye axial length was 25.15?1.50, 24.93?1.36,24.78?1.25,25.39?1.31 (mm) without significant difference statistically (F=2.218,P=0.10).Corneal central thickness was 489.09?59.64,484.02?60.80,496.61?59.74,487.44?54.25(?m)without significant difference statistically (F=0.991,P=0.40).Peripheral thickness changes were also not significant statistically during 3 years.69 eyes with mild conjunctival congestion,12 eyes with corneal fluorescence stain and 6 eyes with corneal epithelial rough were found with slit-lamp microscope during follow-up.Conclusions For the patients with keratoconus,long term of RGPCL wear will not lead to significant ocular changes or severe ocular complications.
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Objective To observe the 3 years or more effects on optical correction,refraction,and orthokeratology with rigid gas permeable contact lens(RGPCL) wearing in patients with keratoconus.Design Retrospective case series.Participant 73 keratoconus patients(136 eyes) fitted with RGPCL.Methods Patients wearing RGPCL for 3 years or more in Peking University Optometry & Ophthalmology Center were observed.Correct visual acuity was determined before and at 1,2 and 3 years of lens wearing,and the refractive power,corneal curvature,corneal astigmatism and corneal morphological changes were measured with auto-refractomer/keratometer and keratoconus screening analysis system of computer-assisted corneal topography at the same time.The changes of base curve and RGPCL power were also compared.All patients were divided into mild keratoconus group(Group A),moderate and severe keratoconus group (Group B).Main Outcome Measures Visual acuity,refractive power,base curve of RGPCL,corneal topography parameters.Results The patients wore RGPCL for 49.3?15.3 months(36-76 months).At the initial visit,uncorrected visual acuity(UVA) was 3.76?0.45, corrected visual acuity with spectacles(SPVA) was 4.57?0.53,and with RGPCL(RGPVA) was 4.89?0.14.RGPVA was improved significantly (F=171.994,P=0.000).RGPVA at last visit(4.95?0.11) was better than that at initial visit(t=-6.733,P=0.000),which was more significant in group B than that in group A.The rate for RGPVA more than 0.8 at the initial,1 year,2 years and 3 years of lens wearing was 85.13%,86.76%,85.60%and 84.62%respectively.At the initial visit and last visit,the myopia diopters and the corneal astigmatism were 7.13?4.01D vs.6.23?3.42D(P=0.014) and 6.23?3.24D vs.4.42?2.34D(P=0.000) respectively.The RGPCL base curve and lens power were 7.38?0.50 mm vs.7.54?0.42 mm(P=0.000),and -6.22?3.59 D vs.-5.33?3.09 D(P=0.000) respectively. The changes of power and base curve of lens in group B were more significant than that in group A.The decrease of 9 corneal topography parameters between initial visit and last visit was significant statistically(all P