Prediction of vault after implantable collamer lens implantation and its research progress / 国际眼科杂志(Guoji Yanke Zazhi)

Myopia is considered to be a disease occurred under the influence of genetic and environmental factors, and it can only be restored by corrective surgeries. The current surgical methods include laser surgeries and phakic intraocular lens(PIOL)implantation, and PIOL has the advantages of wide range of correction, repeatable procession and small damage to corneal tissue. Furthermore, good visual acuity can be achieved after implantation of intraocular lens. Implantable collamer lens(ICL)is the most common surgical method in this group. The vertical distance between the highest point of the posterior central surface of the implanted lens and the anterior surface of the crystalline lens is called vault. It will cause serious complications if the vault turns out to be abnormal. Up to now, there is no optimal prediction method. This research focuses on vault, discusses the ideal range of postoperative vault, the safety and effectiveness of this surgery, and analyzes the existing prediction methods to provide directions for future clinical research.

Efficacy comparison between rigid and foldable anterior iris-fixated phakic intraocular lens implantation for treating high myopia in Asian eyes / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To compare refractive and safety outcome of Artisan and Artiflex phakic intraocular lens(PIOL)for the correction of high myopia in Asian population.METHODS:Historical cohort study. A total of 81 high myopic eyes that underwent PIOL implantation from 2016 to 2020 at Yap Eye Hospital in Yogyakarta, Indonesia were reviewed. The patients were divided into two groups based on PIOL implanted, with 43 eyes using Artisan PIOL in Artisan group and 38 eyes using Artiflex PIOL in Artiflex group. Visual acuity, corneal biomicroscopy parameters, and intraocular pressure(IOP)were respectively recorded prior to the implantation and at 1d, 1 and 3mo after surgery. In addition, anterior chamber depth was documented before PIOL implantation.RESULTS:Mean follow-up period were 9.64±6.93mo and 8.96±4.28mo in Artisan an Artiflex group, respectively(P=0.736). The efficacy index was 1.03±0.47 in Artisan group, and 1.02±0.17 in the Artiflex group(P=0.119).The safety index was 1.10±0.45 and 1.05±0.21 in Artisan and Artiflex group, respectively(P<0.001). The mean spherical equivalent(SE)in Artisan group was -0.64±0.996D, and it was -0.22±0.58D in Artiflex group(P=0.076). In both groups, there was a significant loss of endothelial cell density(ECD)postoperatively compare to baseline(P<0.05), and the cumulative ECD loss was 7.44% and 5.79% in the Artisan and Artiflex groups, respectively(P=0.418).CONCLUSION:Artisan and Artiflex are comparable in terms of refractive outcome to correct high myopia in Asian eyes. Artisan had a slightly better safety index compare to Artiflex. However, the efficacy index and cumulative ECD loss was similar in both the Artisan and Artiflex groups.

Long term results of posterior chamber intraocular lens implantation for correction of myopia / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To evaluate the long-term safety, efficacy and stability of posterior chamber intraocular lens(ICL)implantation for the correction of myopia.<p>METHODS: This retrospective non-randomized study included 107 eyes of 64 patients who were performed ICL implantation from January 2013 to December 2014. The uncorrected visual acuity, corrected visual acuity, intraocular pressure, the lens vault, endothelial cell morphometry were collected preoperatively and followed at 1wk, 1mo, 3mo, 6mo, 12mo and every year postoperatively.<p>RESULTS: The uncorrected visual acuity(LogMAR)was 0(-0.076, 0)at 1a postoperatively, and the uncorrected visual acuity 0.096(0, 0.221)decreased until last visit after the surgery. The change of visual acuity was associated with the change of axial length. The safety index was 1.19±0.24 and the efficacy index was 1.00±0.29 at the last visit postoperatively. The toric ICL implantation was stable without rotation at the last visit postoperatively. The vault of the ICL changed significantly in 1a postoperatively, but its change was smaller after 1a postoperatively. The intraocular pressure and endothelial cell morphometry did not changed significantly in long term postoperatively. Two eyes developed anterior cataract in 3a and 5a after the ICL implantation. There were no case developed pupillary block glaucoma.<p>CONCLUSION: Posterior chamber ICL implantation was a safe and stable procedure for the correction of myopia and astigmatism.

Challenges during femtosecond laser assisted cataract surgery with posterior chamber phakic intraocular lens

Femtosecond laser-assisted cataract surgery was performed in a patient with high myopia, who had undergone posterior chamber phakic intraocular lens surgery (Implantable Collamer Lens, ICL). During docking the machine erroneously focused the laser on the anterior surface of ICL and laser for lens fragmentation was also defocused, which were correctly positioned before laser delivery. During laser application for capsulotomy, air bubbles were entrapped under the ICL prohibiting lens fragmentation. One must be careful during focusing the laser in eyes with ICL. Additionally, gas bubbles under the ICL may lead to difficulties in completion of nuclear disassembly.

Comparative analysis of clinical outcomes between two types of posterior chamber phakic intraocular lenses for correction of myopia and myopic astigmatism

Purpose: To compare clinical outcomes following implantation of two types of posterior chamber phakic intraocular lenses: Visian™ Implantable Collamer Lens with Centraflow (ICL, V4C Staar Surgical, Nidau, Switzerland) and Implantable Phakic Contact Lens (IPCL, V1, Caregroup Sight Solution, India) for the correction of myopia and myopic astigmatism. Methods: This retrospective case series included eyes which underwent phakic intraocular lens implantation with a minimum follow-up period of 1 year. Visual outcomes including safety, efficacy, refractive predictability, and stability were compared at 1 week and at 1, 6, and 12 months' postoperative visit. Complications and adverse events were analyzed. Results: The study included 119 and 203 eyes in the IPCL and ICL groups, respectively. At 1-year postoperative visit, median corrected distance visual acuity was 0.10 (interquartile range [IQR] 0,0.10) and 0 (IQR 0,0) in the IPCL and ICL cohorts, respectively (P = 0.066). An uncorrected visual acuity of 20/32 or better was achieved in 86.5% and 88.67% of the eyes, respectively (P = 0.574). Ninety and 94% of the eyes achieved a postoperative manifest spherical equivalent within ± 0.5D (P = 0.169, ?2 test). Three eyes (2.52%) in the IPCL group versus one eye (0.49%) in the ICL group developed visually significant cataract requiring surgical intervention (P = 0.113). No vision-threatening complications were noted in either cohort. The mean follow-up period was 94.69 ± 32.45 and 102.67 ± 61.82 weeks, respectively. Conclusion: Both groups demonstrated similar efficacy and safety profile. The IPCL is an effective and economically viable option for the correction of myopia.

Confounding sizing in posterior chamber phakic lens selection due to white-to-white measurement bias

Purpose: To assess the agreement in the white-to-white (WTW) measurement with two different devices, the reproducibility and the probability of confusing sizing (PCS) in selecting a different implantable collamer lens (ICL). Study Design: Retrospective observational case series. Methods: Images of 192 eyes were captured with both devices. The WTW was measured automatically (OA) and manually (OM) with the Orbscan and Keratograph (KA and KM) by one examiner who repeated a total of four measures. A second examiner conducted a single manual measure for each device over the same image. The ICL sizing was computed for each measure of WTW and the PCS was calculated as the percentage of cases for which the confronted or repeated measure resulted in a different size of the ICL. The critical WTWs with highest PCS were identified. Results: KM overestimated the WTW versus OM in 0.13 ± 0.18 mm (P < 0.001) but not in the automated method comparison, 0.01 ± 0.19 mm (P = 0.58). Inter-examiner reproducibility (R) was higher with OM than with KM, and the intra-examiner R decreased with the average of two measures in both cases. The PCS was higher with the increase of mean differences, the limits of agreement (LoAs), and R. WTWs from 11.1 to 11.2 mm, 11.6 to 11.7 mm, and 12.3 to 12.4 mm resulted in higher PCS. Conclusion: The mean difference is not enough to apply conversions between devices and the LoAs and R should be considered. Special attention should be taken for WTWs with higher PCS.

Agreement of central vault measurements between UBM and anterior segment OCT in posterior chamber intraocular lens implanted eyes / 中华实验眼科杂志

Objective To compare the agreement of central vault measurements between anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in the eyes with posterior chamber phakic intraocular lens implantation and analyze the association sculus to sculus (STS) diameter and white-to-white (WTW) diameter of cornea with central vault.Methods A cross-sectional study was carried out.Medical records of 150 phakic eyes of 75 myopic patients who underwent implantable collamer lens (ICL) surgery for the correction of myopia were collected in Chongqing Aier Eye Hospital from December 2017 to March 2018.The postoperative central vault were measured with AS-OCT and UBM.Intraclass correlation coefficient (ICC) and Bland-Altman plot were used to evaluate the repeatability and agreement of the measurements between two devices.The affecting factors of central vault measurements were assessed.Results Mean central vault in the 150 phakic eyes after ICL surgery was (0.73±0.25)mm by AS-OCT and (0.76-±0.31)mm by UBM,respectively with the ICC of 0.91 for the measurements of AS-OCT and UBM.Bland-Altman analysis showed that the 95％ limits of agreement of central vault measurements were-0.38-0.31 mm between the two devices.Five values were beyond the 95％ consistency interval,and the maximum absolute value of the difference was is 0.31 mm,which was beyond the clinical acceptable range,showing an non-interchangeable difference in the central vault measurements between the devices in ICL implanted eyes.WTW was a affecting factor for vault with a regression equation of Y=0.145 3X-0.960 1 (t =2.272,P＜0.05).Horizontal and vertical STS were the indirect affecting factors for vault by the association with WTW with the regression equation of Y=0.524 1X+5.362 4 and Y=0.613 4X+4.658 3,respectively.Conclusions Central vault measured by UBM is higher that than AS-OCT after ICL surgery,and the measurements are uninterchangeable between the two devices.Accurate measurement of STS distance is essential for the selection of appropriate lens before operation.

Modified technique and clinical application of central hole ICL implantation for 2a / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To explore the application of improved skills in central hole ICL V4c implantation and its clinical efficacy. <p>METHODS: This study included 141 eyes of 72 patients with myopia from September 2015 to August 2016. An implantable contact lens with a central hole(ICL V4c)was inserted by improved surgical skills including single 2.8mm clear corneal incision, no anterior chamber viscoelastics before ICL implantation. The intraocular pressure(IOP)was measured at the early stage within 6h after operation. The visual acuity, diopter, intraocular pressure and corneal endothelial cell density were observed after operation and follow up 2a. <p>RESULTS: ICL V4c was implanted successfully in all patients by this improved skills and fine clinical results were achieved. Elevated IOP is possible at early stage post-operation, especially within 2h after operation. 95.7% had normal IOP 6h after operation. The postoperative IOP was stable within 2a follow-up period. The cumulative corneal endothelial loss rates of 6mo, 1a and 2a were 4.70%, 7.59% and 9.63% respectively. There was no complications such as subcapsular cataract during the 2a follow-up period.<p>CONCLUSION: The improved skills used in our study is safe and feasible.

Visual quality in posterior chamber phakic intraocular lens implantation / 国际眼科杂志(Guoji Yanke Zazhi)

@#Posterior chamber intraocular lens implantation was effective for correcting refractive errors. More scientific studies about subjective visual quality(visual acuity, contrast sensitivity)and objective visual quality(wave front aberration, point spread function, Strehl ratio, modulmion transfer function)had showed that the improvement of subjective visual acuity was accompanied with the improvement of objective visual acuity after phakic intraocular lens implantation. However, the complications, such as anterior subcapsular cataract, glaucoma and decomposition of corneal endothelium needed to be long-term followed up. This article summarized the visual quality research after posterior chamber phakic intraocular lens implantation.

Long Term Corneal Endothelial Cell Density Loss after Iris-fixed Phakic Intraocular Lens Implantation

PURPOSE: To report three cases of severe endothelial cell density loss after iris claw phakic intraocular lens (Artisan® lens) implantation. CASE SUMMARY: A 32-year-old woman underwent iris claw intraocular lens implantation in both eyes. Preoperative corneal endothelial cell count was 2,556 cells/mm² in the right eye and 2,674 cells/mm² in the left eye. After 4 years, the corneal endothelial cell count was 1,968 cells/mm² in the right eye and 1,997 cells/mm² in the left eye. A 27-year-old woman underwent iris claw intraocular lens implantation in both eyes. Preoperative corneal endothelial cell count was 3,222 cells/mm² in the right eye and 3,122 cells/mm² in the left eye. After 4 years 8 months, the corneal endothelial cell count was 2,729 cells/mm² in the right eye and 2,488 cells/mm² in the left eye. A 39-year-old woman underwent phakic intraocular lens implantation in other clinic, and the lens of left eye was removed the same day because of elevated intraocular pressure. She underwent iris claw intraocular lens implantation in the left eye. Preoperative corneal endothelial cell count was 2,500 cells/mm² in the left eye, which decreased to 1,873 cells/mm² after 8 years. Six months after intraocular lens removal and cataract surgery, her cornea endothelial cell count was 1,412 cells/mm². CONCLUSIONS: Although iris-fixed intraocular lens implantation is safe and effective for correcting myopia, at least 4 years of long-term observation for evaluating corneal endothelial cell density maybe necessary.

Short-term efficacy of posterior chamber phakic intraocular lens implantation for moderate to high myopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To evaluate the short-term efficacy of posterior chamber phakic intraocular lens implantation for moderate to high myopia.METHODS:Fifty-three eyes of 27 patients with moderate to high myopia (-3.25 to-21.5D) were received posterior chamber phakic intraocular lens implantation with 2.8mm clear corneal incision.Changes of visual acuity, intraocular pressure(IOP), counts of endothelial cells and surgically induced astigmatism at 1mo after surgery were observed.RESULTS:The preoperative best corrected visual acuity (BCVA LogMAR) were 0.05±0.18, the postoperative BCVA at 1d were 0.02±0.14, the postoperative BCVA at 1wk were-0.05±0.11, the postoperative BCVA at 1mo were-0.07±0.10.The postoperative BCVA were statistically significant differences in different time(P<0.05).The preoperative endothelial cell count was 2932.5±270.8/mm2, the postoperative endothelial cell count at 1d was 2917.1±299.0/mm2;the postoperative endothelial cell count at 1wk was 2902.5±288.6/mm2;the postoperative endothelial cell count at 1mo was 2855.3±284.2/mm2.The postoperative endothelial cell count was not statistically significant differences in different time.The preoperative IOP was 15.8±2.5mmHg;the postoperative IOP at 1d was 15.3±2.9mmHg;the postoperative IOP at 1wk was 17.4±5.8mmHg;the postoperative IOP at 1mo were 15.8±2.6mmHg.The preoperative IOP was significantly different compared with postoperative IOP at 1d, 1wk and 1mo.The postoperative IOP at 1d and 1wk were statistically significant differences (P<0.05).The surgically induced astigmatism at 1d was 0.74±0.39D;the surgically induced astigmatism at 1wk was 0.57±0.28D;the surgically induced astigmatism at 1mo was 0.44±0.21D.The postoperative IOP were statistically significant differences in different time (P<0.05).The preoperative anterior chamber depth was 3.26±0.25mm;the postoperative central vault at 1d were 654.5±345.2μm;the postoperative central vault at 1mo were 683.0±211.7μm.The postoperative central vault were significantly different between that at 1d and 1mo after operations.Operations went without serious complications.CONCLUSION:Posterior chamber phakic intraocular lens implantation for moderate to high myopia were safe, effective and predictability.But long-term effect remains needed to be further follow-up.

Lente intraocular fáquica de cámara anterior de fijación angular / Anterior chamber phakic introcular lens with angle fixation

La emergencia de las lentes intraoculares fáquicas en las pasadas décadas mostró una nueva alternativa para las ametropías extremas. Desde el año 1950 han sido diseñados diferentes modelos de lentes intraoculares fáquicas con distintos diseños y complicaciones. Se presenta un caso con antecedente de miopía elevada, quien posterior a la colocación de una lente intraocular fáquica de cámara anterior de fijación angular presentó como complicación en el posoperatorio abundante pigmentación iridiana sobre el lente y sinequias anteriores en 360 grados. Nos motivamos a publicar este caso y de esta forma proporcionar una actualización sobre las complicaciones de la colocación de estos lentes, así como ofrecer algunas recomendaciones para detectar a tiempo los posibles riesgos de este procedimiento(AU)

The emergence of the phakic intraocular lenses in the last decades showed a new alternative for the extreme ametropias. Since1950 different models of phakic intraoduclar lenses have been designed with different designs and complications. Here is a patient with a history of high myopia who, after having undergone the implantation of an anterior chamber phakic intraocular lens with angle fixation, presented with abundant iridian pigmentation over the lens and anterior sinechia at 360 degrees. The objectives of this report were to provide an update on the complications of the implantation of these lenses as well as making some recommendations to timely detect the possible risks of this procedure(AU)

Wavefront aberration and contrast sensitivity after implantation of foldable and rigid iris claw phakic intraocular lenses: Artiflex versus artisan.

Aim of study: The aim of this study is to assess wavefront aberration and contrast sensitivity (CS) after implantation of foldable iris claw – artiflex‑ and rigid iris claw – artisan‑ phakic intraocular lenses (pIOLs). Materials and Methods: A nonrandomized prospective comparative case study was performed on 57 eyes; of which, 54 were myopia and 3 were hyperopia. Twenty‑four patients had artisan pIOL implantation and 33 had artiflex pIOL implantation. Higher‑order aberration (HOA) and CS were obtained 1 year after surgery. Results: Total HOA in artisan group was greater than artiflex group (P = 0.044) with a mean HOA of 0.44 ± 0.15 root mean square (RMS) for artisan and 0.35 ± 0.15 RMS for artiflex. Although, there were no significant differences in the vertical trefoil, vertical coma, horizontal trefoil, horizontal coma, secondary astigmatism, quatrefoil, and fourth order spherical aberration in two groups. CS in mesopic conditions was better in artiflex‑treated eyes at three spatial frequencies of 6, 12, and 18 cycles per degree (cpd) (P = 0.003, P = 0.007, and P = 0.00, respectively), and no significant difference was seen between two lenses at 3 cpd. Conclusion: Although the components of HOA were not significantly different between two groups, total HOA was higher in artisan group, which may be due to the slight differences in each component, increasing the HOA as a total. CS was significantly better in artiflex group.

Clinical evaluation of Toric phakic posterior chamber intraocular collamer lens implantation for ametropia following deep anterior lamellar keratoplasty for keratoconus / 中华实验眼科杂志

Background Postoperative ametropia, especially large astigmatism after deep anterior lamellar keratoplasty (DALK) for keratoconus often results in poor visual acuity.Though postoperative ametropia can be corrected by wearing glasses or performing corneal refractive surgery, the visual quality of patients is still poor, and the operations are difficult to implement because of insufficient corneal thickness.Toric intraocular collamer lens (TICL) implantation appears to have good corrective efficacy on severe astigmatism,but the research on the eyes after DALK is still less.Objective This study was to evaluate the efficacy and safety of TICL implantation for the ametropic eyes following DALK for keratoconus.Methods This study protocol was approved by Ethic Commission of Nanjing Drum Tower Hospital,and written informed consent was obtained from each patient prior to any medical procedure.A self-controlled serial observational research was carried out.Eight ametropic eyes of 8 patients who received the DALK for keratoconus before 18 months were enrolled in Nanjing Drum Tower Hospital from August 201 1 to March 2012, with the spherical diopter range from 0 D to-7.5 D and cylindrical diopter range from-2.5 D to-6.0 D.TICL implantation was performed on the eyes.The eye examinations were carried out before surgery and 1 week,3 months,6 months, 1 year and 2 years after surgery,including uncorrected visual acuity (UCVA) ,best corrected visual acuity (BCVA) ,comprehensive optometry, corneal astigmatism degree, the central corneal thickness and anterior chamber depth (ACD), corneal endothelial cell counts (ECD) ,intraocular pressure.The examination outcomes were compared before and after surgery.The intraoperative and postoperative complications were observed to evaluate the safety of TICL implantation for the ametropic eyes following DALK for keratoconus.Results The UCVA and BCVA were obviously improved at 6 months after TICL implantation in comparison with before surgery and maintained stable during the follow-up duration.The mean spherical diopter was from-0.5 D to-1.0 D and the mean cylindrical diopter was from-0.5 D to-2.0 D after surgery.The corneal endothelial cell counts were (2 520.2 ± 307.2) , (2 496.2 ± 306.2) , (2 469.6±304.5) , (2 432.0 ± 305.4), (2 383.4 ± 309.4)/mm2, and the intraoeular pressures were (14.57 ± 3.75), (16.62±4.21), (16.57±3.56), (15.66±3.37), (15.13±3.48) mmHg, showing insignificant differences among different time points (F =0.375,P =0.825;F =9.871, P =0.394).No significant differences were found in mean ACD and intraocular pressure between before and after surgery (t =1.56 ,P =0.16).The axial deviation of TICL was less than 10° in all the operated eyes 6 months after surgery.No intraoperative and postoperative complications were found during the follow-up duration.Conclusions TICL implantation is a safe and effective alternative and viable approach to myopic and astigmatism patients following DALK for keratoconus.

Incidence of Retinal Lesions before and after Refractive Surgery and Preoperative Prophylactic Laser Treatment

PURPOSE: We investigated the incidence of retinal lesions before and after surgery and the percentage of preoperative prophylactic laser treatment in patients who underwent corneal refractive surgery or phakic intraocular lens implantation (pIOLi). METHODS: The medical records of patients who underwent refractive surgery from January 2005 to June 2013 were reviewed retrospectively. We investigated the incidence and type of retinal lesions identified during the preoperative examination. Additionally, the percentage of preoperative prophylactic laser treatment and the incidence of postoperative newly developed retinal lesions were analyzed. RESULTS: A total of 894 eyes of 466 subjects (laser in situ keratomileusis [LASIK] 225 eyes, 117 subjects; laser-assisted subepithelial keratectomy [LASEK] or photorefractive keratectomy [PRK] 450 eyes, 231 subjects; pIOLi 219 eyes, 121 subjects) were enrolled in the present study. Retinal lesions were found in 268 eyes (29.98%) and of those, 144 eyes (16.11%) received prophylactic laser treatment. Postoperative newly developed retinal lesions were detected in 8 cases (LASEK or PRK, 5 cases; pIOLi, 3 cases) during the follow-up period. There was a significant correlation between preoperative spherical equivalent and the presence of retinal lesions. CONCLUSIONS: The patient population of refractive surgery is largely myopic and thus particularly vulnerable to retinal lesions. Additionally, a considerable number of patients required preoperative prophylactic laser treatment. Therefore, both surgeons and patients should be aware of the risks of developing postoperative retinal lesions.

Clinical observation of phakic intraocular lens implantation for patients with extreme highly myopia / 国际眼科杂志(Guoji Yanke Zazhi)

?AlM: To evaluate the clinical effects and security of posterior chamber implantable Collamer lens ( lCL ) implantation in patients with extreme highly myopia. ?METHODS:ln this study, 18 patients ( 32 eyes ) with extreme highly myopic patients who had undergone posterior chamber lCLs implantation from July 2010 to July 2013 were evaluated. Diopter -10. 5 ~ 19. 0D, and astigmia -0. 5 ~4. 5DC. Changes in intraocular pressure ( lOP ) , refraction, visual acuity and corneal endothelium, anterior chamber depth, iris, high arch, lens were noted at 1d, 1wk, 1, 3mo and 1a after surgery respectively, and follow-up was of 1a. ? RESULTS: Before surgery, the uncorrected visual acuity (UCVA) were 0. 01~0. 05, and the best spectacle-corrected visual acuity ( BSCVA) were 0. 4 ~ 1. 0. One month after surgery, the UCVA were 0. 5~1. 2. The mean vault were 547±222 μm (95%CI 442~672μm) and 528±268μm (95%CI 354 ~635μm) for 1mo and 1a, respectively (P = 0. 81), and there was no significant difference. Anterior subcapsular opacities in 1 eye, mild and transient increase in lOP in 3 eyes, and chronic pigment dispersion in 2 eyes were observed. There was no serious complication. ?CONCLUSlON: Posterior chamber phakic intraocular lens implantation is an effective and safe method for correcting patients with extreme highly myopia.

The Change of Retinal Nerve Fiber Layer Thickness after Posterior Chamber Phakic Intraocular Lens Implantation

PURPOSE: In the present study we evaluated the changes of measured retinal nerve fiber layer (RNFL) thickness using optical coherence tomography (OCT) after phakic intraocular lens (implantable collamer lens, ICL) implantation and analyzed the factors correlated with the changes of measured RNFL thickness. METHODS: Forty eyes of 40 patients (Group A: 20 patients using spectral domain OCT and Group B: 20 patients using time domain OCT) who underwent ICL implantation were included in this study. RNFL thickness was measured 1 week before surgery and 1 month postoperatively using OCT. The changes of measured RNFL thickness and the correlation between patients' data were analyzed. RESULTS: The postoperative measured RNFL thickness of the average, inferior, temporal, and superior quadrants were increased compared to preoperative measured RNFL thickness in Group A. Group B had similar results in the average, inferior, and superior quadrants (p 0.05). CONCLUSIONS: The measured RNFL thickness after ICL implantation may increase compared to the preoperative value. Caution should be taken when interpreting the RNFL thickness values measured by OCT in patients with myopia who undergo ICL implantation.

The Change of Retinal Nerve Fiber Layer Thickness after Posterior Chamber Phakic Intraocular Lens Implantation

PURPOSE: In the present study we evaluated the changes of measured retinal nerve fiber layer (RNFL) thickness using optical coherence tomography (OCT) after phakic intraocular lens (implantable collamer lens, ICL) implantation and analyzed the factors correlated with the changes of measured RNFL thickness. METHODS: Forty eyes of 40 patients (Group A: 20 patients using spectral domain OCT and Group B: 20 patients using time domain OCT) who underwent ICL implantation were included in this study. RNFL thickness was measured 1 week before surgery and 1 month postoperatively using OCT. The changes of measured RNFL thickness and the correlation between patients' data were analyzed. RESULTS: The postoperative measured RNFL thickness of the average, inferior, temporal, and superior quadrants were increased compared to preoperative measured RNFL thickness in Group A. Group B had similar results in the average, inferior, and superior quadrants (p 0.05). CONCLUSIONS: The measured RNFL thickness after ICL implantation may increase compared to the preoperative value. Caution should be taken when interpreting the RNFL thickness values measured by OCT in patients with myopia who undergo ICL implantation.

Variación del endotelio corneal en pacientes operados de alta miopía con implante de lentes fáquicas / Variation of the corneal endothelium in patients operated on from high myopia, with phakic lens implantation

Objetivo: determinar la variación que evidencia el endotelio corneal, en pacientes operados de alta miopía con la utilización de lentes intraoculares fáquicas de cámara anterior con soporte iridiano. Método: se realizó un estudio longitudinal, prospectivo y descriptivo en una muestra conformada por 26 ojos de 15 pacientes, operados de alta miopía con la utilización de lentes intraoculares fáquicas Artisan y Artiflex de cámara anterior con soporte iridiano, que se atendieron en el Servicio de Córnea y Cirugía Refractiva del Instituto Cubano de Oftalmología Ramón Pando Ferrer de septiembre de 2009 a mayo de 2010. Resultados: se evidenció una pérdida celular endotelial posterior a la cirugía seis meses de 6,9 por ciento. En el posoperatorio la hexagonalidad y el coeficiente de variación disminuyeron, mientras que la paquimetría no mostró diferencias significativas. Conclusiones: en el presente estudio se observó la presencia de un daño mínimo en el endotelio corneal con el uso de lentes fáquicas de cámara anterior, en la corrección quirúrgica de las altas miópias

Objective: to determine the variation of the corneal endothelium in those patients operated on from high myopia, with the use of iris claw anterior chamber phakic intraocular lenses. Methods: a prospective, longitudinal and descriptive study was carried out in a sample of 26 eyes from 15 patients. They had been operated on from high myopia with the use of iris claw anterior chamber phakic intraocular lenses Artisan and Artiflex at the Cornea and Refractive Surgery Service of Ramon Pando Ferrer Cuban Institute of Ophthalmology from September 2009 through May 2010. Results: it was evinced that there was endothelial cell loss after surgery six months of 6.9 percent. In the postoperative phase, hexagonality and variation coefficient diminished whereas pakimetry did not show significant differences. Conclusions: the present study indicated the existence of minimal damage in the corneal endothelium with the use of the anterior chamber phakic lenses for the surgical correction of high myopias

The Analysis of Vault Change after Posterior Chamber Phakic Intraocular Lens Size Exchange

PURPOSE: To evaluate the vault change after implantable collamer lens (ICL) size exchange according to the preoperative vault. METHODS: In 14 eyes of 13 patients, the vault change after ICL exchange operation due to unideal vault was compared in 2 groups, the smaller ICL exchanged group and larger ICL exchanged group. RESULTS: In 6 out of 14 eyes, the ICL was exchanged to a 0.5 mm smaller size and the vault was changed from 1.38 mm (1.18-1.70) to 0.71 mm (0.51-0.92) (p = 0.03). In 8 eyes, the ICL was exchanged to a 0.5 mm bigger size and the vault was changed from 0.07 mm (0.03-0.13) to 0.50 mm (0.12-1.01) (p < 0.01). The exchange operation was performed at 3.5 postoperative days (1-6) if the ICL was exchanged to 1 step smaller size, but the exchange operation was performed at 135 postoperative days (90-660) if the ICL was exchanged to 1 step bigger size (p < 0.01). CONCLUSIONS: ICL exchange to 1 step smaller or bigger size is an effective method to correct unideal postoperative vault to a more ideal vault size. The exchange to 1 step smaller size ICL tended to be performed sooner.