Modern Phacoemulsification and Intraocular Lens Implantation (Refractive Lens Exchange) Is Safe and Effective in Treating High Myopia

Extended depth of focus IOL in eyes with different axial myopia and targeted refraction

AIM

To evaluate the objective visual outcomes following implantation of extended depth of focus intraocular lens (EDOF IOL) in individuals with varying axial lengths (AL) and targeted refraction.

METHODS

This retrospective study comprised age-matched eyes that underwent implantation of the EDOF IOL. Eyes were categorized based on AL into groups: control group with AL < 26 mm; high myopia group with AL ≥ 26 mm. Each group was then subdivided based on postoperative spherical equivalent (SE). Follow-up at three months included assessment of uncorrected visual acuity at different distances, contrast sensitivity (CS), refractive outcomes, and spectacle independence.

RESULTS

Overall, this study included 100 eyes from 100 patients, comprising 50 males (50.00%) and 50 females (50.00%), with 20 eyes in each group. In the control group, the uncorrected distance visual acuity (UDVA) at 5 and 3 m (m) in the - 1.50 to -0.75 group was inferior to that of the - 0.75 to 0.00 group (P = 0.004). Conversely, the uncorrected near visual acuity (UNVA) at 33 cm in the - 1.50 to -0.75 group was superior to that of the - 0.75 to 0.00 group (P = 0.005). Within the high myopia group, the UDVA at 5 and 3 m in the - 2.25 to -1.50 group was worse than in the - 0.75 to 0.00 group (P = 0.009 and 0.008, respectively). However, the UNVA at 33 cm in the - 2.25 to -1.50 group was better than in the - 0.75 to 0.00 group (P = 0.020). No significant differences were observed among the groups for corrected distance visual acuity (CDVA) (P > 0.05). Additionally, in the high myopia group, the CS of the - 2.25 to -1.50 group was lower compared to that of the - 0.75 to 0.00 group (P = 0.017). Among high myopia patients, 90.00% with refraction ranging from - 1.50 to -0.75 reported achieving overall spectacle independence.

CONCLUSIONS

Implantation of extended depth of focus intraocular lenses (IOLs) yields satisfactory visual and refractive outcomes in eyes with axial myopia. Among high myopia patients, a refraction ranging from - 1.50 to -0.75 diopters achieves superior visual quality compared to other postoperative myopic diopters.

Retinal detachment after refractive lens exchange: A narrative review

Refractive lens exchange (RLE) allows to correct ametropias and presbyopia by replacing the crystalline lens with an extended depth of focus or multifocal intraocular lens (IOL). Retinal detachment (RD) is one of the most serious adverse events after RLE. This study aimed to review the evidence related to the risk of RD after RLE and clinical outcomes. A search using PubMed and a snowball search approach was conducted to identify articles and case reports. According to the literature, the risks of RD should be considered in patients <60 years old with axial lengths >23 mm. Only nine articles reported visual acuity (VA) after RD in RLE, and only 25% of eyes had a VA > 20/40. Considering that the decrease in VA might be uniform for all types of IOLs after RD, surgeons should focus on selecting the patient to prevent RD rather than on a particular IOL optical design based on the potential risk of DR.

Epidemiology of rhegmatogenous retinal detachment in commercially insured myopes in the United States

Myopia is a known risk factor for rhegmatogenous retinal detachment (RRD). Given global trends of increasing myopia, we aimed to determine the absolute risk (incidence rate) of RRD in non-myopes, myopes and high myopes in the United States over ten years. We performed a retrospective cohort study of 85,476,781 commercially insured patients enrolled in the Merative™ Marketscan® Research Database. The incidence rate of RRD in phakic patients in the United States was 39-fold higher in high myopes than non-myopes (868.83 per 100,000 person-years versus 22.44 per 100,000 person-years) and three-fold higher in myopes than non-myopes (67.51 per 100,000 person-years versus 22.44 per 100,000 person-years). The incidence rate was significantly higher in males in each category (P < 0.01). Combined, the incidence rate of RRD in phakic patients in the United States from 2007 to 2016 was 25.27 RRDs per 100,000 person-years, a rate higher than those in prior published studies in North America, South America, Europe, Asia, and Australia. The absolute risk of myopia and high myopia increased from 2007 to 2016. The risk of RRD in phakic high myopes rose with increasing age. Notably, the magnitude of increased risk of RRD in myopes varied substantially according to the minimum follow-up period in our models and should be accounted for when interpreting data analyses.

A quantitative study of the effect of ICL orientation selection on post-operative vault and model-assisted vault prediction

Background

Appropriate vault height of implantable collamer lens (ICL) implantation matters for it has risks of corneal endothelial cell loss, cataract formation and intraocular pressure elevation, which could lead to irreversible damage to optic nerve. Therefore, pre-operative prediction for an ideal vault height is a hotspot. However, few data exist regarding quantitative effect of ICL orientation on vault height. This study is aimed to quantitatively investigate the effect of ICL implantation orientation on vault height, and built a machine-learning (ML)-based vault prediction model taking implantation orientation into account.

Methods

473 consecutive case series treated with ICL implantation were retrospectively analyzed (408 were horizontally implanted, and 65 were vertically implanted). Multivariable logistic regression analysis was performed to determine the association between ICL orientation and achieved vault. ML was performed to develop a new vault height prediction model taking ICL orientation into account. Receiver operating characteristic curve (ROC) and net reclassification index (NRI) were obtained to assess the prediction ability.

Results

95% of all the patients achieved 20/20 uncorrected distance visual acuity (UDVA) or better. No complications including cataract formation, dispersion or optic nerve injury were observed in any cases. Sex, sphere power, cylinder power, axis, ICL size and ICL orientation were all significant risk factors associated to vault height, and age was positively co-related. Of note, ICL size and ICL orientation were the top-ranking risk factors. Comparing to conventional horizontal implantation, vertical implantation could reduce the achieved vault by 81.187 μm (p < 0.001). In regarding to different ICL sizes, vertical implantation had no good to vault reduction when using ICL of 12.1 mm. However, it could reduce the vault by 59.351 μm and 160.992 μm respectively when ICL of 12.6mm and 13.2 mm were implanted (p = 0.0097 and p = 0.0124). For prediction of vault height, ML based model significantly outperformed traditional multivariable regression model.

Conclusion

We provide quantitative evidence that vertical implantation of ICL could effectively reduce the achieved vault height, especially when large size ICL was implanted, comparing to traditional horizontal implantation. ML is extremely applicable in development of vault prediction model.

Clinical Characteristics and Early Visual Outcomes of Highly Myopic Cataract Eyes: The Shanghai High Myopia Study

Purpose: To report ocular characteristics and early visual outcomes of highly myopic cataract eyes, and to analyze the risk factors of low vision. Methods: A total of 2,027 eyes of 1,400 cataract patients with axial length (AL) ≥ 26 mm undergoing cataract surgery in Eye & ENT Hospital of Fudan University, who were registered in the Shanghai High Myopia Study, were analyzed. Routine pre-operative ophthalmic examinations were performed and macular scan of optical coherence tomography (OCT) were obtained. Macular complications, central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) were evaluated from OCT images. Ocular and surgical history and perioperative complications were also recorded. Uncorrected and best-corrected visual acuity (UCVA/BCVA) 1 month post-operatively and its influencing factors were evaluated. Results: The average AL of all involved eyes was 29.52 ± 2.26 mm, and 39.7% of which were with an AL > 30 mm and 26.4% of which were with a corneal astigmatism more than 1.5 D. Nuclear cataract accounted for the largest proportion (70.6%). The rate of overall macular complications was 27.6%. Postoperative UCVA and BCVA were 0.70 ± 0.46 and 0.25 ± 0.32 logMAR, respectively. BCVA improved significantly after surgery (vs. P < 0.001) and affected by the elongation of AL (P < 0.001) and thinning of CFT and SFCT (both P < 0.001). The risk factors of post-operative low vision (BCVA < 20/66) were macular atrophy, lamellar macular hole, high corneal astigmatism, long AL, thin SFCT and junior surgeons, odds ratios ranging from 1.54 to 54.87 (all P < 0.05). Conclusion: Cataract surgery could improve the VA of highly myopic eyes. Eye with macular complications, higher corneal astigmatism, longer AL, thinner SFCT, and who was treated by a junior surgeon, may have a high risk of low vision after surgery.

Real-time artificial intelligence evaluation of cataract surgery: A preliminary study on demonstration experiment

PURPOSE:

We demonstrated real-time evaluation technology for cataract surgery using artificial intelligence (AI) to residents and supervising doctors (doctors), and performed a comparison between the two groups in terms of risk indicators and duration for two of the important processes of surgery, continuous curvilinear capsulorhexis (CCC) and phacoemulsification (Phaco).

MATERIALS AND METHODS:

Each of three residents with operative experience of fewer than 100 cases, and three supervising doctors with operative experience of 1000 or more cases, performed cataract surgeries on three cases, respectably, a total of 18 cases. The mean values of the risk indicators in the CCC and Phaco processes measured in real-time during the surgery were statistically compared between the residents’ group and the doctors’ group.

RESULTS:

The mean values (standard deviation) of the risk indicator (the safest, 0 to most risky, 1) for CCC were 0.556 (0.384) in the residents and 0.433 (0.421) in the doctors, those for Phaco were 0.511 (0.423) in the residents and 0.377 (0.406) in the doctors. The doctors’ risk indicators were significantly better in both processes (P = 0.0003, P < 0.0001 by Wilcoxon test).

CONCLUSION:

We successfully implemented a real-time surgical technique evaluation system for cataract surgery and collected data. The risk indicators were significantly better in the doctors than in the resident's group, suggesting that AI can objectively serve as a new indicator to intraoperatively identify surgical risks.

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.

Review of current status of refractive lens exchange and role of dysfunctional lens index as its new indication

Advances in phacodynamics and intraocular lenses (IOLs) has given second life to clear lens extraction (CLE) or refractive lens exchange (RLE) in recent years for the treatment of patients with high degrees of myopia, hyperopia, and astigmatism who are unsuitable for laser surgery. Furthermore, presbyopia treatment with RLE supplemented with multifocal or accommodating IOLs gives the dual benefit of correcting refractive errors with eliminating the need for cataract surgery. RLE should be consistent and effective for a good refractive outcome along with safety during the surgical procedure and in the postoperative period. Therefore, proper patient selection and accurate preoperative protocols for IOL power calculations and selection are important along with an appropriate choice of surgical procedure. Dysfunctional lens index is a new objective tool that helps surgeon to aid in diagnosing, counseling, and educating patients with dysfunctional clear lens. In this article, we give a brief overview about the application of RLE for individuals with presbyopia and refractive errors like myopia, hyperopia, and astigmatism who are not suitable for laser correction.

Crossed versus conventional pseudophakic monovision for high myopic eyes: a prospective, randomized pilot study

Background

Aiming at spectacle independence, conventional pseudophakic monovision has been widely used in myopia patients with bilateral monofocal intraocular lens implantation. However, the crossed monovision, which is to correct the dominant eye for near vision and the non-dominant eye for distant vision, has been mentioned preferable for high myopic cataract patients by some studies.

We have conducted this study to compare clinical results to assess the feasibility of conventional and crossed monovision for high myopic pseudophakic patients by comparing patient satisfaction, visual function and spectacle independence.

Method

Forty-sixth high myopia patients were divided into two groups: 22 in crossed monovision group with patients whose refraction targeted to − 2.00 diopters (D) in the dominant eye and − 0.50D in the non-dominant eye; 24 in conventional monovision group with patients whose refraction targeted to − 0.50D in the dominant eye and − 2.00D in the non-dominant eye. Binocular uncorrected distance visual acuity (BUDVA), binocular uncorrected near visual acuity (BUNVA), binocular corrected distant visual acuity (BCDVA), binocular corrected near visual acuity (BCNVA), contrast visual acuity and stereoacuity were examined at postoperative 2 weeks, 1 month and 3 months. Questionnaires were completed by patients 3 months after binocular surgery to evaluate patients’ satisfaction and spectacle independence.

Results

The conventional monovision and the crossed monovision group showed no significant differences of mean BUDVA, BUNVA, BCDVA, BCNVA 2 weeks, 1 month or 3 months postoperatively (P > 0.05). There was no difference in the bilateral contrast sensitivity or stereoscopic function between the convention conventional and crossed monovision groups (P > 0.05). Patient satisfaction with near and distant vision, as well as spectacle dependence did not differ significantly between the two groups (P > 0.05).

Conclusion

Crossed pseudophakic monovision exhibited similar visual function when compared with conventional monovision technique, which indicates that it is an effective option to improve the visual functionality and quality of life for high myopic patients who considering bilateral cataract surgery.

Trial registration

The Institutional Review Board and Ethics committee of the First Affiliated Hospital of Chongqing Medical University, Chongqing, China. The trial registration was submitted in September 2018 and passed on March 18, 2020, and the registration number is: ChiCTR2000030935.

Performance and Safety of the Extended Depth of Focus Implantable Collamer® Lens (EDOF ICL) in Phakic Subjects with Presbyopia

Purpose

To evaluate the performance and safety of the Extended Depth of Focus Implantable Collamer^® Lens (EDOF ICL) for improvement of uncorrected near, intermediate and distance visual acuity in phakic subjects with myopia and presbyopia.

Design

Prospective multicenter study.

Methods

Presbyopic subjects who required an EDOF ICL in the range of −0.50 D to −18.00 D, exhibited ≤ 0.75 D refractive astigmatism and required from +1.00 to +2.50 D reading add were implanted bilaterally. Assessments at 6 months included uncorrected near, intermediate and distance visual acuities, defocus curves, contrast sensitivity, responses to the National Eye Institute Refractive Error Quality of Life Questionnaire and a Task Assessment Questionnaire.

Results

A total of 34 subjects completed the study. Investigators targeted emmetropia in all eyes. Mean binocular uncorrected near, intermediate and distance visual acuities measured logMAR −0.01 ± 0.05 (20/20), −0.02 ± 0.08 (20/19) and 0.07 ± 0.10 (20/23), respectively. Mean monocular uncorrected near, intermediate and distance visual acuities measured logMAR 0.068 ± 0.09 (20/23), 0.062 ± 0.10 (20/23) and 0.16 ± 0.12 (20/29). There were no clinically or statistically significant differences in contrast sensitivity between baseline and 6 months under any testing conditions. Subjects reported significant improvements in measures of vision-related quality of life and ability to perform tasks at all distances without glasses or contact lenses. Overall, satisfaction with the EDOF ICL was high: postoperatively, 91.2% of subjects were satisfied with their vision.

Conclusion

This multicenter, prospective clinical investigation demonstrated the ability of the EDOF ICL to correct myopia and presbyopia, resulting in improvement of uncorrected near, intermediate and distance visual acuity without compromising the quality of vision. The EDOF ICL allowed subjects to perform tasks of daily living without glasses or contact lenses. Subjects reported significant improvements in quality of life with high levels of spectacle independence and satisfaction.

Implantation of a Trifocal Intraocular Lens in High Myopic Eyes with Nasal-Inferior Staphyloma

Purpose

To assess visual outcomes in high myopic eyes with nasal-inferior staphyloma implanted with a pseudophakic trifocal intraocular lens (IOL).

Methods

We retrospectively analyzed the visual outcomes of 50 eyes of 45 patients who had cataract surgery after AT LISA trifocal IOL implantation. Twenty-five eyes diagnosed with posterior staphyloma (nasal-inferior, type IV and V), and 25 eyes as long eyes. Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) values were used to assess the efficacy and safety of the surgery. Refraction and defocus curves were also evaluated at 6 months.

Results

No intra- or post-operative problems occurred during the 6 months of follow-up. After the surgery, the mean Snellen decimal UDVA ranged from 0.50 to 1.00, and CDVA from 0.60 to 1.00 for both groups. CDVA was 0.91 and 0.74 for the long eye and nasal-inferior staphyloma groups, respectively. Efficacy and safety indexes were 1.22 and 1.32 for the long eye, and 1.26 and 1.43 for the nasal-inferior staphyloma group, respectively. All eyes of both groups showed a postoperative spherical equivalent within ±1.00D. The long eye group showed the highest percentage of spherical equivalent between −0.13D and +0.13D (56%) and the nasal-inferior staphyloma group was between −0.51D and −0.14D (40%).

Conclusion

The outcomes of the present study show that a trifocal IOL provides good visual acuity in high myopic eyes, being worse for nasal-inferior staphyloma eyes. The degree of tilt of the macular plane is related with the expected visual acuity.

Incidence of Intraoperative and Early Postoperative Adverse Events in a Large Cohort of Consecutive Refractive Lens Exchange Procedures

PURPOSE

To evaluate the incidence of adverse events (AEs) in patients who underwent refractive lens exchange.

DESIGN

Retrospective case series.

METHODS

Setting: Private refractive surgery clinics. Patients/Study Population: Patients who underwent refractive lens exchange between July 1, 2014, and June 30, 2016. Intervention/Observation Procedures: All AEs recorded in the electronic medical record were extracted and retrospectively reviewed. The total incidence of AEs and serious AEs was calculated. Loss of 2 or more lines of corrected distance visual acuity (CDVA) was calculated for the entire cohort of patients that attended a minimum of 3 months follow-up.

MAIN OUTCOME MEASURES

AEs.

RESULTS

The total number of patients included was 10,206 (18,689 eyes). A multifocal intraocular lens (IOL) was implanted in 84.3% of eyes; 15.7% of eyes received a monofocal IOL. A total of 1164 AEs were recorded (1112 eyes of 1039 patients, incidence 6.0% of eyes, 1:17 eyes). The most common AE was posterior capsular opacification (PCO; 748 eyes, incidence 4.0%). Of all AEs, 171 events (occurring in 165 eyes of 151 patients, incidence 0.9%, 1:113 eyes) were classified as serious, potentially sight threatening. Loss of 2 or more lines of CDVA was 0.56% when excluding eyes where the loss of CDVA was due to PCO; the majority of these were due to macular causes.

CONCLUSION

The incidence of sight-threatening AEs and significant loss of CDVA in elective refractive lens exchange surgery was low. Other than PCO, postoperative macular issues were the most common cause of vision loss in this cohort.