Distinct macular thickness changes after femtosecond laser-assisted cataract surgery of age-related cataract and myopia with cataract

Comparative study of FLACS vs conventional phacoemulsification for cataract patients with high myopia

PURPOSE

To compare the short-term changes in cornea, retina, and choroid of femtosecond laser-assisted cataract surgery (FLACS) with conventional phacoemulsification (CPS) in high myopia patients with cataract.

SETTING

Affiliated Hospital of Nantong University, Jiangsu Province, China.

DESIGN

Prospective single-center study.

METHODS

Demographics, ocular clinical features, ultrasound power, absolute phacoemulsification time, and effective phacoemulsification time were recorded for each patient. Endothelial cell density (ECD), central corneal thickness (CCT), corrected distance visual acuity (CDVA), intraocular pressure (IOP), center foveal thickness (CFT), subfoveal choroidal thickness (SFCT), and choroidal vascularity index (CVI) were evaluated preoperatively and at 1 week, 1 month, and 3 months postoperatively. Intraoperative parameters and intraoperative/postoperative complications were recorded.

RESULTS

97 eyes (46 eyes and 51 eyes in the FLACS and CPS groups, respectively) were included and analyzed. Effective phacoemulsification time was lower in the FLACS group compared with the CPS group ( P < .05). The increase in CCT was significantly lower in the FLACS group compared with the CPS group at 1 week and 1 month ( P < .05). CDVA and IOP were similar in both groups at the final visit ( P > .05). The ECD decreased was lower among CPS patients compared with FLACS patients. CFT, SFCT, and CVI increase in both groups but were increased more in the CPS group with high myopia patients. No serious complications occurred in either group.

CONCLUSIONS

FLACS is a more safety and effective in cataract patients with high myopia. It has advantages in effectively reducing EPT and promoting faster recovery of the cornea, macular, and choroidal thickness.

Comparison of macular changes and visual outcomes between femtosecond laser-assisted cataract surgery and conventional phacoemulsification surgery for high myopic cataract patients

BACKGROUND

To evaluate differences in log MAR best-corrected visual acuity (BCVA) improvement and postoperative central foveal thickness (CFT) and choroidal thickness (CT) changes between conventional phacoemulsification surgery (CPS) and femtosecond laser-assisted cataract surgery (FLACS) for high-myopia cataracts.

METHODS

This was a retrospective and observational study. One hundred and two eyes of 102 patients with high-myopia cataracts were examined. CPS was performed in 54 eyes, and FLACS was performed in 48 eyes. All eyes underwent logMAR BCVA, CFT and CT of three different sectors preoperatively and one week and six months postoperatively.

RESULTS

The logMAR BCVA improved significantly after surgery in both groups (both P < 0.001), but no difference was observed in BCVA improvement between the groups (P = 0.554). Moreover, no significant differences were reflected in the changes in CFT, nasal 1 mm CT or temporal 1 mm CT between the two groups, and only subfoveal choroidal thickness (SFCT) in the CPS group decreased significantly compared with that in the FLACS group at any postoperative time (P = 0.003 and 0.026). AL, preoperative logMAR BCVA, and CT of the three regions exhibited a notable correlation with postoperative BCVA (all P < 0.05) according to univariate logistic regression analysis. However, only the AL, preoperative logMAR BCVA and SFCT remained significant in the multivariate model. Postoperative logMAR BCVA revealed a positive correlation with AL and preoperative logMAR BCVA but a negative correlation with SFCT.

CONCLUSIONS

FLACS was not superior to CPS in improving BCVA but had less impact on SFCT in the treatment of high-myopia cataracts. Eyes with a longer AL, worse preoperative logMAR BCVA and thinner SFCT had a high risk of worse postoperative BCVA.

Comparison of Conventional and Femtosecond Laser-Assisted Cataract Surgery Regarding Macula Behavior and Thickness

Background: The aim of the study was to compare macular thickness behavior and clinical outcomes after femtosecond laser-assisted cataract surgery (FLACS) versus phacoemulsification conventional surgery (PCS). Methods: Macular Optical Coherence Tomography OCT was analyzed in 42 patients preoperatively, 1 day, 12 days, 4 weeks and 6 weeks postoperatively according to the 9-field Early Treatment Diabetic Retinopathy Study (ETDRS) grid. Clinical findings were collected in both the FLACS group and the PCS group. Results: There was no significant difference in macular thickness between the FLACS and PCS groups (p > 0.05). However, from postoperative day 12 onwards, there was a significant increase in macular thickness observed in both groups (p < 0.001). In the FLACS group, a significant increase in visual acuity was observed on the first postoperative day, as compared to the PCS group (p = 0.006). Conclusions: The use of a low-energy high-frequency femtosecond laser has potentially no effect on postoperative macular thickness. In the FLACS group, visual rehabilitation was significantly faster as compared to the PCS group. No complications occurred intraoperatively in either group.

Role of long noncoding RNA KCNQ1 overlapping transcript 1/microRNA-124-3p/BCL-2-like 11 axis in hydrogen peroxide (H2O2)-stimulated human lens epithelial cells

Age-related cataract (ARC) is one of the most common causes of vision loss in aging people. This research analyzed the functions and mechanism of long noncoding RNA KCNQ1 overlapping transcript 1 (KCNQ1OT1) in hydrogen peroxide (H₂O₂)-stimulated human lens epithelial cells (SRA01/04 cells) in ARC. SRA01/04 cells were stimulated with 200 µM H₂O₂ to establish oxidative damage in the ARC model. A MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and flow cytometry analysis were conducted to evaluate cell growth and apoptosis. The relevance between KCNQ1OT1 and microRNA (miR)-124-3p or miR-124-3p and BCL-2-like 11 (BCL2L11) was measured through Starbase and a dual luciferase reporter gene assay. The levels of KCNQ1OT1 and miR-124-3p were assessed via quantitative real-time polymerase chain reaction (qRT-PCR). We observed that KCNQ1OT1 was over-expressed and miR-124-3p was low-expressed in H₂O₂-stimulated SRA01/04 cells. KCNQ1OT1 interacted with miR-124-3p and negatively mediated its levels. In addition, KCNQ1OT1-siRNA reversed the effects of H₂O₂ on SRA01/04 cells, evidenced by enhanced cell viability, inhibited apoptotic cells, promoted Bcl-2 expression, and reduced Bax levels. Nevertheless, these observations were inverted after miR-124-3p inhibitor treatment. Likewise, miR-124-3p mimic had a protective effect on H₂O₂-stimulated SRA01/04 cells. Our data suggested that BCL2L11 targeted miR-124-3p directly. In summary, the data indicated that lncRNA KCNQ1OT1 down-regulation protected SRA01/04 cells from oxidative stress stimulated damage via the miR-124-3p/BCL2L11 pathway.

Phacoemulsification: Proposals for Improvement in Its Application

A cataract is defined as opacity of the crystalline lens. It is currently one of the most prevalent ocular pathologies and is generally associated with aging. The most common treatment for cataracts is surgery. Cataract surgery is a quick and painless process, is very effective, and has few risks. The operation consists of removing the opacified lens and replacing it with an intraocular lens. The most common intraocular lens removal procedure that is currently used is phacoemulsification. The energy applied in this process is generated by ultrasonic waves, which are mechanical waves with a frequency higher than 20 kHz. A great deal of research on the different ways to perform the stages of this surgical procedure and the analysis of the possible side effects of the operation has been published, but there is little information on the technical characteristics, the intensities applied, and the use of ultrasound-emitting (U/S) equipment for cataract removal. More studies on the method and depth of absorption of ultrasonic waves in our visual system when performing the phacoemulsification procedure are needed. It would be advisable for health authorities and medical professionals to develop guidelines for the handling and use of ultrasonic wave-emitting equipment, such as those that exist for ultrasound and physiotherapy. This could help us to reduce undesirable effects after the operation.

Efficacy and complications of cataract surgery in high myopia

To evaluate the efficacy and complications of cataract surgery in high myopia, a comprehensive search query was conducted from January 2000 to August 2020. A total of 19 586 highly myopic eyes from 28 studies were included. Modern cataract surgery turns out efficacious in highly myopic eyes with significant improvement of visual acuity. However, phacoemulsification-related complications such as posterior capsular rupture (3.91%, 95% CI, 1.98%-6.37%), retinal detachment (1.74%, 95% CI, 1.36%-2.15%), progressed myopic traction maculopathy (5.07%, 95% CI, 1.80%-9.37%), capsular contraction syndrome (2.1%), intraocular lens dislocation (0.58%), and transient intraocular pressure elevation (28.15%, 95% CI, 20.29%-36.70%) occurred more frequently in the highly myopic population. Separate analyses were also conducted based on follow-up period. In conclusion, modern cataract surgery was effective for highly myopic cataract patients, whereas careful precautions and sufficient follow-ups were of great value because of higher incidences of intraoperative and postoperative complications.

Cataract: Advances in surgery and whether surgery remains the only treatment in future

Background

Cataract is the world's leading eye disease that causes blindness. The prevalence of cataract aged 40 years and older is approximately 11.8%-18.8%. Currently, surgery is the only way to treat cataracts.

Main Text

From early intracapsular cataract extraction to extracapsular cataract extraction, to current phacoemulsification cataract surgery, the incision ranges from 12 to 3 ​mm, and sometimes to even 1.8 ​mm or less, and the revolution in cataract surgery is ongoing. Cataract surgery has transformed from vision recovery to refractive surgery, leading to the era of refractive cataract surgery, and premium intraocular lenses (IOLs) such as toric IOLs, multifocal IOLs, and extended depth-of-focus IOLs are being increasingly used to meet the individual needs of patients. With its advantages of providing better visual acuity and causing fewer complications, phacoemulsification is currently the mainstream cataract surgery technique worldwide. However, patient expectations for the safety and accuracy of the operation are continually increasing. Femtosecond laser-assisted cataract surgery (FLACS) has entered the public's field of vision. FLACS is a combination of new laser technology and artificial intelligence to replace fine manual clear corneal incision, capsulorhexis, and nuclear pre-fragmentation, providing new alternative technologies for patients and ophthalmologists. As FLACS matures, it is being increasingly applied in complex cases; however, some think it is not cost-effective. Although more than 26 million cataract surgeries are performed each year, there is still a gap in the prevalence of cataracts, especially in developing countries. Although cataract surgery is a nearly ideal procedure and complications are manageable, both patients and doctors dream of using drugs to cure cataracts. Is surgery really the only way to treat cataracts in the future? It has been verified by animal experiments that lanosterol therapy in rabbits and dogs could make cataract severity alleviated and lens transparency partially recovered. Although there is still much to learn about cataract reversal, this groundbreaking work provided a new strategy for the prevention and treatment of cataracts.

Conclusions

Although cataract surgery is nearly ideal, it is still insufficient, we expect the prospects for cataract drugs to be bright.

Femto-assisted versus conventional phacoemulsification differently impact on choroid structure after surgery

PURPOSE

To report potential choroidal changes in eyes undergoing femtosecond laser cataract surgery (FLACS) and phacoemulsification surgery (PCS) by OCT.

METHODS

The patients were images by means Spectral Domain OCT imaging with EDI technology which may obtain OCT image. We exported a single EDI-OCT scan passing through the fovea and then it was imported into ImageJ program to perform a quantitative analysis.

MAIN OUTCOME MEASURES

The main outcome measures were: (i) sub foveal choroidal thickness (SFCT); (ii) the choroidal vascularity index (CVI); and (iii) central retinal thickness (CRT).

RESULTS

At postoperative 1 week, FLACS group showed an increased CRT (241.2 ± 31.6-245.5 ± 36.4 µm; p = 0.016). Likewise, CVI and SFCT exhibited a slight increase but no statistically differences were highlighted (p > 0.05). At the follow-up visit of 1 month, all OCT parameters did not display any significant difference (p > 0.05). At post-operative 1 week, the PCS group displayed a significant increase in CRT, SFCT, and CVI. On the contrary, at the follow-up visit of 1-month, all choroidal parameters were characterized by a no statistically significant reduction (p > 0.05).

CONCLUSIONS

Our study exhibited a significant increase in CT and CVI in eyes that underwent conventional cataract surgery. Femtosecond laser-assisted cataract extraction did not result in macular change due to less postoperative inflammation.

Analysis of macular microvasculature and thickness after ICL implantation in patients with myopia using optical coherence tomography

AIM

To investigate changes in macular vessels and thickness in myopic eyes after intraocular collamer lens (ICL) implantation using quantitative optical coherence tomography angiography (OCTA).

METHODS

This retrospective included 73 myopic eyes of 73 patients (average age, 27.53±6.16y) who underwent ICL implantation (28 eyes were Toric ICL). Axial length (AL), uncorrected visual acuity (UCVA), refractive dioptre (RD), intraocular pressure (IOP) and OCTA were measured and compared with before and 1wk, 1, and 3mo after surgery. OCTA was used to image vessel density (VD) and skeleton density (SD) in both the superficial (SCP) and deep capillary plexus (DCP). Central retinal thickness (CRT) and ganglion cell-inner plexiform layer thickness (GCT) were also measured. Changes between pre- and postoperative measurements were analysed by repeated measures analysis of variance.

RESULTS

Compared with preoperative data, postoperative data on UCVA revealed significant improvements in all patients (P<0.05). However, there was no significant difference in IOP. After the operation, CRT and GCT exhibited significant changes (P<0.05). Among these measures, CRT was significantly higher at one and three months postoperative (all P<0.01). GCT was significantly higher at 1wk, 1, and 3mo postoperative (all P<0.01). Changes in VD and SD were nonsignificant in both the SCP and DCP. There was no difference in postoperative changes between the ICL and Toric ICL groups.

CONCLUSION

ICL and Toric ICL implantation both have good efficacy and safety for myopic eyes, but macular area changes that occur after surgery need attention.

[Morphological and functional condition of the macula after different types of phaco cataract surgeries]

One of the directions of advancing phaco technology is related to adoption of hybrid phacoemulsification for clinical practice. Potential postsurgical changes in the macular area, when other factors are equal, can be seen as a conditional criterion for the injury rate of phaco surgeries.

PURPOSE

To evaluate morphological and functional condition of the macular area after different types of phaco cataract surgeries.

MATERIAL AND METHODS

Two groups were formed for comparative study in accordance with criteria for standardization and maximum mitigation of the impact of other factors on the condition of the retina - with standard ultrasound and hybrid (femtolaser-assisted) phacoemulsification (30 operations in each group). Examinations were performed initially, then 7-10 days, and 2-3 month after the surgery. Optical coherence tomography (OCT) and multifocal electroretinography (mfERG) were performed for evaluation of the morphological and functional condition of the macular area.

RESULTS

There was no statistically significant dependence of linear and volumetric measures in the macular area on phaco surgery method, and the few variations were most likely related to increasing the time of ultrasound action in standard phacoemulsification. Revealed changes turned out to be significantly less marked than what is considered critical for development of macular edema. Improvement of baseline multifocal electroretinography measurements (increase of the density of retinal biopotential and decrease of latent time) just after the surgery results from the effect the lens opacification has on basic parameters, regardless of phacoemulsification technique. There were no significant differences in postsurgical measurements of multifocal electroretinography obtained in similar periods of postsurgical assessment after standard ultrasound and hybrid phacoemulsification.

CONCLUSION

The results prove the safety of phaco surgery methods and the absence of negative impact of femtolaser component of hybrid phacoemulsification on structural and functional condition of central retina.

Comparison of optical quality and distinct macular thickness in femtosecond laser-assisted versus phacoemulsification cataract surgery

Background

Optical quality and macular thickness changing optical quality is rarely reported after femtosecond laser-assisted cataract surgery (FLACS). In current research, we evaluated optical quality recovery and distinct macular thickness changes after FLACS and phacoemulsification cataract surgery (PCS).

Methods

A total of 100 cataract patients (100 eyes) were included (50 eyes for the FLACS group and 50 eyes for the PCS group). Modulation transfer function (MTF), point spread function (PSF) and dysfunctional lens index (DLI) were measured by a ray-tracing aberrometer (iTrace). Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were also assessed pre-operation,1 week and 1 month after surgery. The MTF values at spatial frequencies of 5, 10, 15, 20, 25 and 30 cycles/degree (c/d) were selected. We used optical coherence tomography (OCT) to assess the macular thickness of different regions pre-operatively and1month after the surgery.

Results

In PCS group, we found the statistically significant differences between pre-operation and post-operation in DLI (p < 0.0001), PSF (strehl ratio, SR) (p = 0.027) and MTF (p = 0.028), but not intraocular pressure (IOP) (p = 0.857). The differences between pre-operation and post-operation for DLI (p = 0.031), SR (p = 0.01) and IOP (p = 0.03), but not MTF (p = 0.128) were also found in FLACS group. The differences were statistically significant when the spatial frequencies were at 5, 10 and 25 (p = 0.013, 0.031 and 0.048) between pre-operation and post-operation in PCS group but not FLACS group at 1 month. In PCS group, we found the differences between pre-operation and post-operation in nasal inter macular ring thickness (NIMRT) (p = 0.03), foveal volume (FV) (p = 0.034) and average retinal thickness (ART) (p = 0.025) but not FLACS group at 1 month.

Conclusion

FLACS is safe that did not cause significant increase of macular thickness in current study. However, it also cannot produce better optical quality. In contrast, PCS can produce macular thickness changes, but better optical quality recovery. The slightly retinal change may not affect optical quality.

[Effect of cataract extraction with intraocular lens implantation in patients with myopia on optical coherence tomography measurements]

INTRODUCTION

One important question for patients with both myopia and glaucoma is comparability of optical coherence tomography (OCT) data obtained before and after a significant change in eye refraction following cataract extraction surgery with implantation of intraocular lens (IOL).

PURPOSE

To assess the impact of correcting moderate and high myopia during cataract phacoemulsification with IOL implantation (Phaco/IOL) on the parameters measured by OCT.

MATERIAL AND METHODS

OCT was performed in 31 patients (31 eyes) with axial eye length of more than 25.5 mm before and the day after Phaco/IOL. Changes in 17 parameters of the retina, retinal ganglion cells-inner plexiform layer (GCIPL), peripapillary retinal nerve fiber layer (RNFL) and optic nerve head (ONH) were analyzed.

RESULTS

Axial eye length was 26.94±1.09 mm in average (25.57-29.39 mm). The average refractive effect of the intervention was 8.44±4.16 D (3.75-19.0 Diopters). Signal strength in all OCT protocols was no lower than 5. Changes in the average values of OCT parameters after surgery were insignificant. They exceeded 1% of the pre-operation values only in 7 cases, including all 5 parameters of the ONH, and were significant only in 5 out of 17 parameters. For GCIPL and RNFL thickness, the changes on average did not exceed 0.9 μm, for retinal thickness in the macular area - 2.1 μm. In relative terms, the largest decrease (an average of -0.03 mm²; -2.5%) was in the optic disc area.

CONCLUSION

In patients with high and moderate myopia, the parameters of the retina, RNFL, GCIPL, and ONH, as measured by OCT, changed insignificantly on the first day after Phaco/IOL (considering the signal strength of Cirrus HD-OCT device was not lower than 5).