Visual quality observation of transepithelial photorefractive keratectomy and femtosecond small incision lenticule extraction for the correction of low myopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To observe the changes in corneal aberrations and the characteristics of visual quality after transepithelial photorefractive keratectomy(T-PRK)and femtosecond small incision lenticule extraction(SMILE)in the correction of low myopia.METHODS: Prospective cohort study. A total of 32 cases(32 eyes)with low myopia who underwent T-PRK surgery and 45 cases(45 eyes)of SMILE surgery at Weifang Eye Hospital from April 2021 to April 2022 were selected. The uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), spherical equivalent(SE), corneal higher-order aberrations(HOAs)and objective visual quality were compared between the two groups.RESULTS:All patients completed the surgery successfully without complications such as infection. At 3mo postoperatively, the safety index was 1.13±0.16 and 1.16±0.17(P=0.48)and the efficacy index was 1.10±0.20 and 1.15±0.18(P=0.27)in the T-PRK and SMILE groups, respectively. The percentage of UCVA(LogMAR)≤0 in the T-PRK and SMILE groups was 94% and 98%, respectively. The percentage of the residual SE within ±0.5D was 88% and 87% in the two groups, respectively. The HOAs and spherical aberration in both groups were significantly increased(P≤0.01), and the increase was not statistically significant between the two groups(P=0.31, 0.89). There was no significant change in horizontal coma, horizontal trefoil and vertical trefoil in both groups(P>0.05). The vertical coma in SMILE group was significantly increased(P<0.001), while there was no significant change in T-PRK group(P>0.05), and the increase was significantly greater in SMILE group than in T-PRK group(P<0.001). There was no significant difference in objective scattering index(OSI), modulation transfer function cut off frequency(MTFcut off), Strehl ratio(SR), visual acuity(VA)100%, VA20% and VA9% between the two groups(P>0.05).CONCLUSION:Both T-PRK and SMILE showed good safety, efficacy, and visual quality in correcting low myopia, while SMILE induced more vertical coma than T-PRK.

Short-term visual quality observation of femtosecond laser small incision lenticule extraction and evolution implantable collamer lens implantation in the correction of moderate myopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the short-term visual quality outcomes after femtosecond laser small incision lenticule extraction(SMILE)and evolution implantable collamer lens(EVO-ICL)implantation for the correction of moderate myopia.METHODS: Prospective control study. A total of 51 cases(51 eyes)with moderate myopia who underwent SMILE or EVO-ICL implantation surgery at Weifang Eye Hospital from April 2021 to February 2022 were selected. They were divided into SMILE group(30 patients, 30 eyes)and EVO-ICL group(21 patients, 21 eyes)according to the surgical methods. The changes of visual acuity [uncorrected distance visual acuity(UDVA), corrected distance visual acuity(CDVA)], diopter [spherical equivalent(SE)] and related parameters of optical quality analysis system(OQAS Ⅱ)were observed before surgery and at 1wk, 1 and 3mo after surgery, and the quality of vision(QoV)questionnaire was completed.RESULTS: At 3mo after surgery, the safety index(postoperative CDVA/preoperative CDVA)of SMILE gruop and EVO-ICL group were 1.20(1.00, 1.20)and 1.20(1.00, 1.38), respectively, the efficacy index(postoperative UDVA/preoperative CDVA)were 1.00(1.00, 1.20)and 1.00(1.00, 1.20), respectively, and the percentage of SE within ±0.50D was 87% and 100%, respectively. In SMILE group, the objective scattering index(OSI)was increased after surgery, while modulation transfer function cutoff frequency(MTF cutoff), contrast visual acuity(VA)100%, and VA20% at 1wk and 1mo after surgery, and Strehl ratio(SR)and VA9% at each time point after surgery were all decreased compared with those before surgery(all P<0.05). The OSI, MTF cutoff, SR and VA of EVO-ICL group showed no difference at each time point after surgery compared with those before surgery(all P>0.05). The most common visual symptoms after SMILE and EVO-ICL implantation were visual haze and halos, respectively.CONCLUSION: Both SMILE and EVO-ICL implantation have good safety, efficacy and predictability in the short term after the correction of moderate myopia. Both groups had visual symptoms after surgery, but the overall satisfaction of patients was high. Furthermore, EVO-ICL implantation has better objective visual quality performance.

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.

Choice of intraocular lens power calculation formula after refractive corneal surgery / 国际眼科杂志(Guoji Yanke Zazhi)

To the cataract patient after corneal refractive surgery, if the intraocular lens power was determined by conventional formulas, different refractive errors may be produced after intraocular lens implantation.This inaccuracy of the lens power mainly came from 2 aspects-errors of corneal refractive power measurement and errors of formulas.Besides, imprecise of ocular axial length measurement and invalid lens position calculation also contributed to the inaccuracy of lens power.Therefore, in order to reduce refractive errors of cataractous surgery in patient underwent refractive surgery, appropriate method should be used to estimate the refractive power of corneal, and proper formula should be selected to calculate intraocular lens power.

Histopathologic changes of Reis-Bücklers corneal dystrophy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the histopathologic changes of Reis-Bücklers corneal dystrophy ( RBCD) . · METHODS: Cornea buttons were obtained from patients in 1 pedigree who underwent lamella keratoplasty. Sections with HE and special staining which included symplectic blue staining and Masson staining and Congo red staining were observed under light microscope. Two normal cornea specimens ( donated corneas from eye bank) were used as control. ·RESULTS:In those patients, the bowman's membrane disappeared. The main lesion was in bowman's membrane through HE staining, positive through PAS Congo red staining and Masson staining, negative through symplectic blue staining. ·CONCLUSION: The Reis-Bücklers corneal dystrophy is characterized as geographic map-like lesion of bowman's membrane, and the abnormal extracellular deposit is amyloid protein fiber.

Comparison of dry-eye disease after the femtosecond laser and mechanical microkeratome for laser in situ keratomileusis / 国际眼科杂志(Guoji Yanke Zazhi)

To analyze dryeye disease after the femtosecond laser and mechanical microkeratome for laser in situ keratomileusis ( LASlK ) by Oculus dry eye analyzer examination.METHODS: The people who had femtosecond LASlK ( FS-LASlK ) and mechanical microkeratome LASlK in Weifang Eye Hospital from January 2014 to April 2014 were observed. Sixty patients ( 120 eyes ) who had corneal refractive surgery were collected. The average age of patients was 27. 46 ± 6. 65 years old. The LASlK group had 28 patients ( 56 eyes ) and the FS-LASlK group had 32 patients ( 64 eyes ) . The tears river altitude, first tear break up time ( BUT) , and average BUT at preoperative, 1wk and 1mo after operation were observed by Oculus dry eye analyzer.RESULTS:By Oculus dry eye analyzer examination, the preoperative tears river altitude of patients was 0. 25 ± 0. 10mm. First BUT was 6. 70 ± 3. 86s. Average BUT time was 10. 14 ± 4. 51s. At 1wk after operation, the tears river altitude of patients was 0. 19±0. 04mm. The first BUT time was 4.87±1.71s. The average BUT time was 7.77±2.30s. There was significant difference between preoperative and 1wk after operation (P<0. 05). At 1mo after operation in two groups, the tears river altitude of patients was 0. 19 ± 0. 18mm . The average BUT 8. 72 ± 2. 54s. The BUT was 5. 02 ± 2. 30s. There was significant difference between preoperative and 1mo after operation (P<0. 05). The two groups had significant difference in average tears river altitude and average BUT between 1mo and 1wk after operation. There was no significant difference in the first BUT between 1mo and 1wk after operation. There was no significant difference between LASlK and FS - LASlK groups at any time of the test (P<0. 05).CONCLUSlON: LASlK and FS - LASlK patients have different degree of dry eye symptom after operation. Dry eye symptoms mainly display in the decrease of tear production and the stability of tear film. lt will be better after giving artificial tears. Oculus dry eye analyzer is a non-invasive examination equipment. lt can reflect the amount of tears and the stability of tear film. lt is usefull in rapid diagnosis of dry eye and judgment of the degree of dry eye symptom after LASlK operation.