Cataract surgery on the previous corneal refractive surgery patient

Bilateral Light-Adjustable Lens Implantation in a Patient With 50-Cut Radial Keratotomy

Purpose

To report a case of Light Adjustable Lens™ (LAL, RxSight, Aliso Viejo, CA) implantation in a patient with bilateral 50-cut radial keratotomy (RK) and discuss related preoperative, intraoperative, and postoperative considerations.

Methods

A 78-year-old patient with history of bilateral 50-cut RK underwent phacoemulsification with implantation of LALs in both eyes one month apart. Although LAL technology was not approved specifically for addressing limitations in intraocular lens calculation post-RK due to corneal topography irregularity, the patient opted for this lens due to its ability to make post-operative adjustments to its refractive power. At postoperative month one following the second eye surgery, YAG capsulotomy was performed in both eyes. At postoperative month two following the second eye surgery, the patient began LAL adjustments spaced 1-2 weeks apart for a total of 2 LAL adjustments and 2 lock-in sessions.

Results

Our patient achieved a final refraction of -0.25 +0.25 × 110 with an UDVA of 20/20-2 in the right eye and -0.25 +0.50 × 135 with an UDVA 20/25-1 in the left eye.

Conclusions

The LAL may be a promising option for patients undergoing cataract surgery after RK, although further studies are needed to understand long-term changes in eyes with RK and the inability of LAL to address all aspects of corneal aberration.

BCLA CLEAR presbyopia: Management with intraocular lenses

Cataract surgery including intraocular lens (IOL) insertion, has been refined extensively since the first such procedure by Sir Harold Ridley in 1949. The intentional creation of monovision with IOLs using monofocal IOL designs has been reported since 1984. The first reported implantation of multifocal IOLs was published in 1987. Since then, various refractive and or diffractive multifocal IOLs have been commercialised. Most are concentric, but segmented IOLs are also available. The most popular are trifocal designs (overlaying two diffractive patterns to achieve additional focal planes at intermediate and near distances) and extended depth of focus designs which leave the patient largely spectacle independent with the reduced risk of bothersome contrast reduction and glare. As well as mini-monovision, surgical strategies to minimise the impact of presbyopia with IOLs includes mixing and matching lenses between the eyes and using IOLs whose power can be adjusted post-implantation. Various IOL designs to mimic the accommodative process have been tried including hinge optics, dual optics, lateral shifts lenses with cubic-type surfaces, lens refilling and curvature changing approaches, but issues in maintaining the active mechanism with post-surgical fibrosis, without causing ocular inflammation, remain a challenge. With careful patient selection, satisfaction rates with IOLs to manage presbyopia are high and anatomical or physiological complications rates are no higher than with monofocal IOLs.

BCLA CLEAR Presbyopia: Management with corneal techniques

Corneal techniques for enhancing near and intermediate vision to correct presbyopia include surgical and contact lens treatment modalities. Broad approaches used independently or in combination include correcting one eye for distant and the other for near or intermediate vision, (termed monovision or mini-monovision depending on the degree of anisometropia) and/or extending the eye's depth of focus [1]. This report reviews the evidence for the treatment profile, safety, and efficacy of the current range of corneal techniques for managing presbyopia. The visual needs and expectations of the patient, their ocular characteristics, and prior history of surgery are critical considerations for patient selection and preoperative evaluation. Contraindications to refractive surgery include unstable refraction, corneal abnormalities, inadequate corneal thickness for the proposed ablation depth, ocular and systemic co-morbidities, uncontrolled mental health issues and unrealistic patient expectations. Laser refractive options for monovision include surface/stromal ablation techniques and keratorefractive lenticule extraction. Alteration of spherical aberration and multifocal ablation profiles are the primary means for increasing ocular depth of focus, using surface and non-surface laser refractive techniques. Corneal inlays use either small aperture optics to increase depth of field or modify the anterior corneal curvature to induce corneal multifocality. In presbyopia correction by conductive keratoplasty, radiofrequency energy is applied to the mid-peripheral corneal stroma, leading to mid-peripheral corneal shrinkage and central corneal steepening. Hyperopic orthokeratology lens fitting can induce spherical aberration and correct some level of presbyopia. Postoperative management, and consideration of potential complications, varies according to technique applied and the time to restore corneal stability, but a minimum of 3 months of follow-up is recommended after corneal refractive procedures. Ongoing follow-up is important in orthokeratology and longer-term follow-up may be required in the event of late complications following corneal inlay surgery.

Cataract surgery following refractive surgery: Principles to achieve optical success and patient satisfaction

A growing number of patients with prior refractive surgery are now presenting for cataract surgery. Surgeons face a number of unique challenges in this patient population that tends to be highly motivated to retain or regain functional uncorrected acuity postoperatively. Primary challenges include recognition of the specific type of prior surgery, use of appropriate intraocular lens (IOL) power calculation formulas, matching IOL style with spherical aberration profile, the recognition of corneal imaging patterns that are and are not compatible with toric and/or presbyopia-correcting lens implantation, and surgical technique modifications, which are particularly relevant in eyes with prior radial keratotomy or phakic IOL implantation. Despite advancements in IOL power formulae, corneal imaging, and IOL options that have improved our ability to achieve targeted postoperative refractive outcomes, accuracy and predictability remain inferior to eyes that undergo cataract surgery without a history of corneal refractive surgery. Thus, preoperative evaluation of patients who will and will not be candidates for postoperative refractive surgical enhancements is also paramount. We provide an overview of the specific challenges in this population and offer evidence-based strategies and considerations for optimizing surgical outcomes.

Implantation of a toric intraocular lens after repeated radial keratotomy procedures: A case report

Corneal alterations due to radial keratotomy (RK) complicate intraocular lens calculations, which may explain why there have been few reports of toric intraocular lens (TIOL) implantation after excessive or multiple operations. A 71-year-old male with a history of repeated RKs and at least 30 corneal incisions in each eye was referred for cataract surgery. Preoperatively, the best-corrected distance visual acuity was 0.7 decimal (0.15 logMAR) in the right eye and 0.9 decimal (0.05 logMAR) in the left eye. The refractive errors were -8.00 -3.00 × 80 and -6.00 -3.50 × 80, respectively. The total corneal cylindrical powers (real power; anterior and posterior) were, respectively, -0.90 D and -3.60 D at 9 a.m., compared to -1.60 D and -3.80 D at 1 p.m. Corneal astigmatism in the left eye was considered symmetric and diurnally stable; therefore, an XY1AT6 TIOL (Hoya, Tokyo, Japan; cylindrical power at the plane, +3.75 D) was implanted. A non-toric intraocular lens, the XY1 (Hoya), was implanted in the right eye. Six-month postoperative best-corrected distance visual acuities were 1.2 decimal (-0.08 logMAR) and 1.0 decimal (0.00 logMAR) in the right and left eyes, respectively. Post-operative manifest refractions were +0.00 -3.00 × 70 and -1.00 -2.00 × 85, respectively. The TIOL reduced refractive astigmatism in the left eye; therefore, we believe that even after multiple RKs, the TIOL can be a suitable candidate to correct astigmatism if the corneal astigmatism is diurnally stable and symmetric.

Comparing Visual Outcomes of Light Adjustable Intraocular Lenses in Patients With and Without Prior History of Corneal Refractive Surgery

PURPOSE

To assess visual outcomes of light adjustable intraocular lens (LAL; Calhoun Vision, Inc) implantation after cataract extraction in patients with a history of corneal refractive surgery.

METHODS

The records of patients who received LALs with and without a history of corneal refractive surgery were retrospectively reviewed. Data for 51 eyes (30 patients) with a history of corneal refractive surgery and 52 eyes (44 patients) without refractive surgery were analyzed. A total of 36 eyes of patients with and 43 eyes of patients without a history of corneal refractive surgery had 12-month follow-up data available. The primary outcomes evaluated were uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA).

RESULTS

At 12 months, 31% of eyes with a history of corneal refractive surgery had a UDVA of 20/20 or better and 97% of eyes were 20/40 or better. In contrast, 63% of patients with no history of corneal refractive surgery had 20/20 UDVA or better at 12 months and 100% were 20/40 or better. Of patients with a history of corneal refractive surgery, 55% and 83% of eyes at 12 months were within ±0.50 and ±1.00 diopters, respectively, of the target refraction compared to 89% and 96% of eyes without a history of corneal refractive surgery.

CONCLUSIONS

LALs are a promising platform for achieving excellent visual outcomes following cataract surgery. Patients with a prior history of corneal refractive surgery can achieve excellent visual outcomes with the LAL. However, this study found that patients with a history of corneal refractive surgery demonstrated less predictable visual acuity outcomes when compared to patients without a history of corneal refractive surgery. [J Refract Surg. 2023;39(5):311-318.].

Comparing the accuracy of the new-generation intraocular lens power calculation formulae in axial myopic eyes: a meta-analysis

PURPOSE

To compare the accuracy of the new-generation intraocular lens power calculation formulae in axial myopic eyes.

METHODS

Four databases, PubMed, Web of Science, EMBASE and Cochrane library, were searched to select relevant studies published between Apr 11, 2011, and Apr 11, 2021. Axial myopic eyes were defined as an axial length more than 24.5 mm. There are 13 formulae to participate in the final comparison (SRK/T, Hoffer Q, Holladay I, Holladay II, Haigis for traditional formulae, Barrett Universal II, Olsen, T2, VRF, EVO, Kane, Hill-RBF, LSF for the new-generation formulae). The primary outcomes were the percentage of eyes with a refractive prediction error in ± 0.5D and ± 1.0D.

RESULTS

A total of 2273 eyes in 15 studies were enrolled in the final meta-analysis. Overall, the new-generation formulae showed a relatively more accurate outcome in comparison with traditional formulae. The percentage of eyes with a predictive refraction error in ± 0.5D (± 1.0D) of Kane, EVO and LSF was higher than 80% (95%), which was only significantly different from Hoffer Q (all P < 0.05). Moreover, another two new-generation formulae, Barrett Universal II and Olsen, had higher percentages than SRK/T, Hoffer Q, Holladay I and Haigis for eyes with predictive refraction error in ± 0.5D and ± 1.0D (all P < 0.05). In ± 0.5D group, Hill-RBF was better than SRK/T (P = 0.02), and Holladay I was better than EVO (P = 0.03) and LSF (P = 0.009), and Hoffer Q had a lower percentage than EVO, Kane, Hill-RBF and LSF (P = 0.007, 0.004, 0.002, 0.03, respectively). Barrett Universal II was better than T2 (P = 0.02), and Hill-RBF was better than SRK/T (P = 0.009). No significant difference was found in other pairwise comparison.

CONCLUSION

The new-generation formula is more accurate in intraocular lens power calculation for axial myopic eyes in comparison with the third- or fourth-generation formula.

Intraoperative aberrometry: an update on applications and outcomes

PURPOSE OF REVIEW

There is now a large body of experience with intraoperative aberrometry. This review aims to synthesize available data regarding intraoperative aberrometry applications and outcomes.

RECENT FINDINGS

The Optiwave Refractive Analysis (ORA) System utilizes Talbot-moiré interferometry and is the only commercially available intraoperative aberrometry device. There are few studies that include all-comers undergoing intraoperative aberrometry-assisted cataract surgery, as most studies examine routine patients only or atypical eyes only. In non-post-refractive cases, studies have consistently shown a small but statistically significant benefit in spherical equivalent refractive outcome for intraoperative aberrometry versus preoperative calculations. In studies examining axial length extremes, most studies have shown intraoperative aberrometry to perform similarly to preoperative calculations. Amongst post-refractive cases, post-myopic ablation cases appear to benefit the most from intraoperative aberrometry. For toric intraocular lenses (IOLs), intraoperative aberrometry may be used for refining IOL power (toricity and spherical equivalent) and alignment, and most studies show intraoperative aberrometry to achieve low postoperative residual astigmatism.

SUMMARY

Intraoperative aberrometry can be utilized as an adjunct to preoperative planning and surgeon's judgment to optimize cataract surgery refractive outcomes. Non-post-refractive cases, post-myopic ablation eyes, and toric intraocular lenses may have the greatest demonstrated benefit in intraoperative aberrometry studies to date, but other eyes may also benefit from intraoperative aberrometry use.

Outcomes of the Haigis-L formula for calculating intraocular lens power in extreme long axis eyes after myopic laser in situ keratomileusis

PURPOSE

To evaluate the accuracy of refractive prediction by the Haigis-L formula compared to four other IOL power calculation formulas in eyes with extremely long axial lengths (AL > 29.0 mm) after LASIK.

SETTING

Shanghai Eye Disease and Prevention Treatment Center, Shanghai, China.

DESIGN

Retrospective case series.

METHODS

Twenty-nine eyes from 19 patients were available for analysis. The primary outcome measure was the arithmetic refractive prediction error (RPE), defined as the difference between the actual postoperative refractive error and the intended formula-derived refractive target. The main outcome measure was the median absolute refraction prediction error (MedAE). The accuracy of the Haigis-L was compared with Barrett True K No History, Shammas-PL, SRK/Tcorrected K, and Holladay 2corrected K methods to calculate IOL power.

RESULTS

The Haigis-L formula had a significantly larger MedAE than Shammas-PL and SRK/Tcorrected K formulas (P = 0.005 and P = 0.015, respectively), a smaller percentage of eyes within ±1.50 diopter (D) of predicted error in refraction compared with Shammas-PL and SRK/Tcorrected K formulas (P = 0.014 and P = 0.005, respectively). The refractive prediction errors of 6 eyes with corneal keratometry of less than 35 D by Haigis-L all had more than 1.95 D of myopic overestimation, while none of the other four methods resulted in an absolute error over 1.95 D.

CONCLUSIONS

The Haigis-L formula was relatively accurate in predicting extreme long axis (>29.0 mm) eyes after myopic LASIK surgery but less accurate for eyes with extremely flat corneas (<35 D). SRK/Tcorrected K and Shammas-PL performed better than the other methods for refractive prediction in this type of eyes.

SYNOPSIS

Haigis-L performed worse than SRK/Tcorrected K and Shammas-PL in predicting IOL power in extremely long axis (>29.0 mm) eyes after myopic LASIK, especially with extremely flat corneas (K < 35 D).

Cataract Surgery after Radial Keratotomy with Non-Diffractive Extended Depth of Focus Lens Implantation

Radial keratotomy was a popular surgical procedure used to treat myopia. Patients who underwent radial keratotomy several years ago, are currently reporting to the ophthalmologist due to worsening of vision associated with age-related cataracts. In this case report we present a case of a 60-year-old woman who underwent radial keratotomy with 16 incisions in the right eye and 12 incisions in the left eye. The patient reported to an ophthalmologist due to a deterioration of vision caused by a cataract. We described, in detail, the difficulties encountered during the diagnostic procedures, differences in the calculation of intraocular lens, and intraoperative difficulties as compared to patients who had not undergone radial keratotomy. We also present the obtained postoperative results.

Trifocal IOL Implantation in Eyes With Previous Laser Corneal Refractive Surgery: The Impact of Corneal Spherical Aberration on Postoperative Visual Outcomes

PURPOSE

To analyze corneal aberrations and factors affecting visual outcomes after implantation of a trifocal intraocular lens (IOL) in eyes previously treated with laser corneal refractive surgery.

METHODS

This retrospective case series included 222 consecutive eyes implanted with the trifocal FineVision Micro-F IOL (PhysIOL) after laser corneal refractive surgery. The series was divided into two groups according to safety outcomes after lensectomy: eyes with loss of one or more lines of corrected distance visual acuity (CDVA) [n = 59, 26.5%]) (failed eyes group) and eyes with no loss or gain in CDVA lines (n = 163, 73.4%]) (successful eyes group). Distribution of tomographic corneal aberrations (spherical aberration [Z⁴₀], comatic and root mean square of higher order aberrations [RMS-HOA]), laser corneal refractive surgery error, kappa angle, and CDVA after laser corneal refractive surgery were compared among both groups.

RESULTS

Mean CDVA after lensectomy was 0.15 ± 0.07 logMAR (range: 0.05 to 0.30 logMAR) versus 0.03 ± 0.04 logMAR (range: 0.00 to 0.15 logMAR) in the failed and successful eyes groups, respectively (P < .001). Comparison of both groups showed that failed eyes had a statistically significantly higher grade of hyperopic laser corneal refractive surgery than successful eyes measured as mean sphere (+0.71 ± 3.10 diopters [D] [range: -7.75 to +6.00 D] vs -0.46 ± 3.70 D [range: -10.75 to +6.00 D], P < .01), spherical equivalent (+0.27 ± 3.10 D [range: -8.00 to +5.50 D] vs -0.97 ± 3.60 D [range: -12.50 to +4.90 D], P < .05), and percentage of hyperopic laser corneal refractive surgery (64% vs 43.5%, P < .05). Corneal aberration analysis showed that mean Z⁴₀ values were significantly more negative in the failed eyes group than in the successful eyes group (+0.07 ± 0.40 mm [range: -0.82 to +0.65 mm] vs +0.18 ± 0.37 mm [range: -0.79 to +0.87 mm], P < .05). Laser corneal refractive surgery cylinder was distributed homogeneously between both groups, as well as coma and RMS-HOA, kappa angle, and CDVA after laser corneal refractive surgery that were not statistically significant.

CONCLUSIONS

Surgeons should consider tomographic corneal spherical aberration after implantation of a trifocal IOL in eyes after keratorefractive surgery, particularly in eyes previously treated with hyperopic laser corneal refractive surgery, to prevent loss of lines of visual acuity after lensectomy. [J Refract Surg. 2022:38(4):222-228.].

Presbyopia correction after previous Intracor treatment: Combined implantation of a small-aperture and a non-diffractive extended-depth-of-focus lens

PURPOSE

We present the case of implantation of two different Extended depth of focus intraocular lenses (EDoF IOLs) in a patient with a history of unilateral intrastromal femtosecond laser treatment for presbyopia correction (Intracor).

OBSERVATIONS

The patient reported decreasing visual acuity at near distance and increasing spectacle dependence. Ten years earlier, he had Intracor treatment for presbyopia correction in his left eye. Corrected distance visual acuity (CDVA) was 0.08 logMAR for the right eye and 0.16 logMAR for the left eye. Apart from dysfunctional lens syndrome, the examination results were unremarkable. Phacoemulsification and subsequent IOL implantation was performed in both eyes. The left eye was implanted with an IC-8 (AcuFocus, Irvine, CA, USA), whereas the fellow eye was implanted with an AcrySof IQ Vivity IOL (Alcon, Fort Worth, TX, USA). Postoperatively, CDVA improved to 0.02 and 0.04 logMAR for the right and left eye. Uncorrected intermediate visual acuity (UIVA) was 0.24 logMAR for the right eye and -0.04 logMAR for the left eye, binocular UIVA was -0.04 logMAR. The patient reported a low level of photic phenomena and spectacle independence for far and intermediate distance.

CONCLUSIONS AND IMPORTANCE

Combined implantation of a non-diffractive and a small-aperture EDoF lens after previous unilateral Intracor treatment could successfully improve visual acuity at far and intermediate distance.

Trifocal intraocular lens implantation in eyes with previous corneal refractive surgery for myopia and hyperopia

PURPOSE

To evaluate the visual and refractive outcomes of trifocal intraocular lens (IOL) implantation in eyes previously treated with myopic and hyperopic corneal refractive laser surgery.

SETTING

Clinica Baviera-AIER-Eye group, Spain.

DESIGN

Retrospective comparative case series.

METHODS

The series was divided into 2 groups according to the type of corneal laser refraction (myopic and hyperopic). The main visual and refractive outcome measures included corrected distance visual acuity (CDVA) and uncorrected distance and near visual acuity, safety, efficacy, and predictability. The secondary outcome measures were percentage of enhancement and Nd:YAG capsulotomy and influence of prelaser magnitude of myopia and hyperopia on the outcome of trifocal IOL implantation.

RESULTS

The sample comprised 868 eyes (543 patients): myopic, n = 319 eyes (36.7%); and hyperopic, n = 549 eyes (63.2%). Three months postoperatively, visual outcomes were poorer in the hyperopic group than those in the myopic group for mean CDVA (0.06 ± 0.05 vs 0.04 ± 0.04, P < .01) and safety (21% vs 12% of CDVA line loss, P < .05) outcomes. However, precision outcomes were worse in the myopic group than those in the hyperopic group, with a mean spherical equivalent of -0.38 ± 0.3 vs -0.17 ± 0.3 (P < .01). Stratification by magnitude of primary laser treatment revealed poorer visual and safety results in the high hyperopia subgroup (>+3.0 diopters [D]) and poorer precision in the high myopia subgroup (<-5.0 D).

CONCLUSIONS

Trifocal IOL implantation after photorefractive surgery in eyes previously treated with myopic ablation achieved good visual outcomes but less predictability in the high myopia subgroup. However, eyes with a previous hyperopic corneal ablation achieved excellent precision but worse visual and safety outcomes in the high hyperopia subgroup.

Extended depth-of-focus intraocular lenses: power calculation and outcomes

The extended depth-of-focus intraocular lenses (EDOF IOLs) represent one of the most exciting advancements in the field of lens surgery. EDOF IOLs promise an excellent visual experience, minimizing visual disturbances (ie, halos and glare) commonly associated with multifocal IOLs. The pros and cons of EDOF IOLs should be evaluated in comparison with other more traditional multifocal or monofocal IOLs. The aim of this review is to provide the most current information regarding EDOF IOLs for power calculating formulas, refractive outcomes, incidence of photic phenomena, and patient satisfaction.

Unintended changes in ocular biometric parameters during a 6-month follow-up period after FS-LASIK and SMILE

Background

Corneal refractive surgery has become reliable for correcting refractive errors, but it can induce unintended ocular changes that alter refractive outcomes. This study is to evaluate the unintended changes in ocular biometric parameters over a 6-month follow-up period after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE).

Methods

156 consecutive myopic patients scheduled for FS-LASIK and SMILE were included in this study. Central corneal thickness (CCT), mean curvature of the corneal posterior surface (K_pm), internal anterior chamber depth (IACD) and the length from corneal endothelium to retina (ER) were evaluated before and after surgery over a 6-month period.

Results

Both the FS-LASIK and SMILE groups (closely matched at the pre-surgery stage) experienced flatter K_pm, shallower IACD and decreased ER 1 week post-surgery (P < 0.01), and these changes were larger in FS-LASIK than in SMILE group. During the 1 week to 6 months follow up period, K_pm, IACD and ER remained stable unlike CCT which increased significantly (P < 0.05), more in the FS-LASIK group.

Conclusions

During the follow up, the posterior corneal surface became flatter and shifted posteriorly, the anterior chamber depth and the length from the corneal endothelium to retina decreased significantly compared with the pre-surgery stage. These unintended changes in ocular biometric parameters were greater in patients undergoing FS-LASIK than SMILE. The changes present clear challenges for IOL power calculations and should be considered to avoid affecting the outcome of cataract surgery.

Comparison of intraocular lens calculation methods after myopic laser-assisted in situ keratomileusis and radial keratotomy without prior refractive data

AIM

To compare intraocular lens (IOL) calculation methods not requiring refraction data prior to myopic laser-assisted in situ keratomileusis (LASIK) and radial keratotomy (RK).

METHODS

In post-LASIK eyes, the methods not requiring prior refraction data were Hagis-L; Shammas; Barrett True-K no-history; Wang-Koch-Maloney; 'average', 'minimum' and 'maximum' IOL power on the American Society of Cataract and Refractive Surgeons (ASCRS) IOL calculator. Double-K method and Barrett True-K no-history, 'average', 'minimum' and 'maximum' IOL power on ASCRS IOL calculator were evaluated in post-RK eyes. The predicted IOL power was calculated with each method using the manifest postoperative refraction. Arithmetic and absolute IOL prediction errors (PE) (implanted-predicted IOL powers), variances in arithmetic IOL PE and percentage of eyes within ±0.50 and ±1.00 D of refractive PE were calculated.

RESULTS

Arithmetic or absolute IOL PE were not significantly different between the methods in post-LASIK and post-RK eyes. In post-LASIK eyes, 'average' showed the highest and 'minimum' showed the least variance, whereas 'average' and 'minimum' had highest percentage of eyes within ±0.5 D and 'minimum' had the highest percentage of eyes within ±1.0 D. In the post-RK eyes, 'minimum' had highest variance, and 'average' had the least variance and highest percentage of eyes within ±0.5 D and ±1.0 D.

CONCLUSION

In post-LASIK and post-RK eyes, there are no significant differences in IOL PE between the methods not requiring prior refraction data. 'Minimum' showed least variance in PEs and more chances of eyes to be within ±1.0 D postoperatively in post-LASIK eyes. 'Average' had least variance and more chance of eyes within ±1.0 D in post-RK eyes.

Artificial Intelligence for Cataract Detection and Management

The rising popularity of artificial intelligence (AI) in ophthalmology is fuelled by the ever-increasing clinical "big data" that can be used for algorithm development. Cataract is one of the leading causes of visual impairment worldwide. However, compared with other major age-related eye diseases, such as diabetic retinopathy, age-related macular degeneration, and glaucoma, AI development in the domain of cataract is still relatively underexplored. In this regard, several previous studies explored algorithms for automated cataract assessment using either slit lamp of color fundus photographs. However, several other study groups proposed or derived new AI-based calculation for pre-cataract surgery intraocular lens power. Along with advancements in digitization of clinical data, data curation for future cataract-related AI developmental work is bound to undergo significant improvements in the foreseeable future. Even though most of these previous studies reported early promising performances, limitations such as lack of robust, high-quality training data, and lack of external validations remain. In the next phase of work, apart from algorithm's performance, it will also be pertinent to evaluate deployment angles, feasibility, efficiency, and cost-effectiveness of these new cataract-related AI systems.

Methods for Intraocular Lens Power Calculation in Cataract Surgery after Radial Keratotomy

PURPOSE

To compare methods of calculating the required intraocular lens (IOL) power for patients undergoing cataract surgery after radial keratotomy (RK), including the 2016 update of the True K formula.

DESIGN

Retrospective case series.

PARTICIPANTS

A total of 52 eyes of 34 patients who had sequential RK and cataract surgery performed in the same institution by 1 of 2 surgeons.

METHODS

Seven IOL calculation formulae were evaluated: True K [History], True K [Partial History], True K [No History], Double-K Holladay 1 (DK-Holladay-IOLM), Potvin-Hill, Haigis, and Haigis with a -0.50 diopter (D) offset. Biometry was obtained with the IOLMaster 500 (Carl Zeiss Meditec AG, Jena, Germany) and Pentacam (OCULUS Inc, Arlington, WA) devices. Subjective refraction was performed at 4 to 6 weeks postoperatively. The achieved spherical equivalent outcome was compared with the target outcome to calculate the absolute error for each eye with each formula.

MAIN OUTCOME MEASURES

Median absolute error (MedAE) and mean absolute error (MAE), and percentage of patients within ±0.50 D, ±0.75 D, and ±1.00 D of refractive target. Mean error (ME) was also calculated to demonstrate whether a formula tended toward more myopic or hyperopic outcomes.

RESULTS

Best results were achieved with the True K [History]. The MedAE was higher (0.382 vs. 0.275) with the True K [Partial History], but a similar percentage of patients (75.0%-76.6%) achieved within ±0.50 D of target. Of the methods that do not require refractive history, the True K [No History] and unadjusted Haigis were most accurate (69.2% within ±0.50 D of target), with the True K [No History] returning the lowest MedAE but also more of a tendency toward hyperopia (ME +0.269 vs. -0.006 for Haigis). The DK-Holladay-IOLM and Potvin-Hill methods were the least accurate.

CONCLUSIONS

Knowledge of the refractive history significantly improves the accuracy of IOL calculations in patients undergoing cataract surgery after previous RK. The post-RK refraction appears to be the most important parameter, with inclusion of the pre-RK refraction offering a further slight improvement in MedAE. When no refractive history is available, the True K [No History] and Haigis formulae both perform well, with the added advantage of not requiring data from separate biometric devices.

Refractive predictability and visual outcomes of an extended range of vision intraocular lens in eyes with previous myopic laser in situ keratomileusis

Purpose:

To evaluate the refractive predictability obtained with an extended range of vision intraocular lens in eyes with previous myopic laser in situ keratomileusis, confirming which intraocular lens power formula provides the most accurate calculation.

Methods:

The study enrolled 71 eyes with previous successful myopic laser in situ keratomileusis surgery of 43 patients undergoing cataract surgery with implantation of the extended range of vision intraocular lens TECNIS Symfony (Johnson and Johnson Vision). Intraocular lens power was calculated using all American Society of Cataract and Refractive Surgeons formulas, and their average value was selected for implantation. Refractive outcomes were evaluated at 3 months postoperatively.

Results:

Postoperative spherical equivalent within ±0.50 and ±1.00 D was found in 61.6% and 86.3% of eyes, respectively. In eyes with pre-laser in situ keratomileusis data available, no significant correlation was found between pre-laser in situ keratomileusis spherical equivalent and post-cataract surgery spherical equivalent (r = 0.237, p = 0.114). A postoperative spherical equivalent within ±0.50 D was found in 65.2% and 55.6% of eyes in the subgroups with and without pre-laser in situ keratomileusis data available, respectively (p = 0.480). Statistically significantly higher differences between the intraocular lens power implanted and the calculation provided by the Potvin–Hill (p = 0.028) and Barrett True K No History formulas (p = 0.022) were found in those eyes with postoperative spherical equivalent > 0.50 D.

Conclusion:

The extended range of vision intraocular lens evaluated can provide a predictable refractive correction in eyes with previous laser in situ keratomileusis surgery. The Potvin–Hill and Barrett True K No History are the most adequate formulas to perform intraocular lens power calculations in these cases.

Femtosecond laser-assisted cataract surgery with implantation of a diffractive trifocal intraocular lens after laser in situ keratomileusis: a case report

Background

We report for the first time, a case of femtosecond laser-assisted cataract surgery (FLACS) with implantation of a diffractive trifocal intraocular lens (IOL) after laser in situ keratomileusis (LASIK).

Case presentation

A 60-year-old man underwent FLACS uneventfully 15 years after myopic LASIK. An AT Lisa tri 839MP IOL was implanted with the expectation of spectacle independence. The Haigis-L formula was chosen for calculation of the IOL power and it provided reliable results. Three months postoperatively, the uncorrected visual acuities were 0.00 logMAR for distance, 0.10 logMAR for intermediate, and 0.10 logMAR for near.

Conclusions

This case suggested that FLACS presents a feasible surgical technique for post-LASIK eyes and that implantation of trifocal IOL can achieve good visual performance in strictly selected cases after myopic LASIK.

Comparative analysis of clinical outcomes of a monofocal and an extended-range-of-vision intraocular lens in eyes with previous myopic laser in situ keratomileusis

PURPOSE

To compare the clinical outcomes after cataract surgery with implantation of a monofocal or an extended-range-of-vision intraocular lens (IOL).

SETTING

Hospital da Luz, Lisbon Portugal.

DESIGN

Prospective case series.

METHODS

Patients who previously had myopic laser in situ keratomileusis (LASIK) had cataract surgery with bilateral implantation of an extended-range-of-vision IOL (Tecnis Symfony) or a monofocal IOL (Tecnis ZCB00). Visual acuity, refraction, defocus curve, contrast sensitivity, photic phenomena, spectacle independence, and patient satisfaction were evaluated at 4 months postoperatively.

RESULTS

The study comprised 44 patients (88 eyes), with 22 patients in each IOL group. No significant differences between groups were found postoperatively for most visual and refractive parameters (all P ≥ .27). However, binocular uncorrected intermediate and near visual acuities were significantly better in the extended-range-of-vision group (P < .01). The defocus curve of both IOLs differed more with increasing negative defocus (P < .01). No significant differences between IOLs were found in contrast sensitivity for any spatial frequency evaluated (P ≥ .05). Most of the patients did not perceive photic phenomena with either IOL. Mild glare was reported in 22.7% of the extended-range-of-vision patients and 9.1% of the monofocal group; mild halos were comparable with 13.6% in both groups. Spectacle dependence for intermediate vision and near vision was higher in the monofocal IOL group.

CONCLUSION

The extended-range-of-vision IOL was a useful option to restore visual function after cataract surgery in eyes that previously had myopic LASIK surgery, offering levels of visual quality comparable to those achieved with the monofocal IOL.

Clinical outcomes with distance-dominant multifocal and monofocal intraocular lenses in post-LASIK cataract surgery planned using an intraoperative aberrometer

IMPORTANCE

Studies evaluating the clinical benefits of intraoperative aberrometry (IA) in cataract surgery are limited.

BACKGROUND

The study was designed to determine whether IA improved clinical outcomes of post-laser in situ keratomileusis (LASIK) cataract surgery with different intraocular lenses (IOLs) implanted.

DESIGN

A retrospective chart review of clinical outcomes from one surgeon at one surgical centre was conducted. It included post-LASIK cataract surgeries where IA was used for the confirmation of IOL power, with either a distant-dominant multifocal IOL or a monofocal IOL implanted.

PARTICIPANTS

Records for 44 eyes of 31 patients were analysed.

METHODS

Differences in visual acuity (VA) and refractions by lens type were compared, and the effects of IA were evaluated.

MAIN OUTCOME MEASURES

Uncorrected distance VA and the percentage of eyes with a spherical equivalent refraction within 0.5D of the intended correction were the primary outcome measures.

RESULTS

There was no statistically significant difference in the percentage of eyes with uncorrected distance VA of 20/25 or better between IOL groups (P = 0.41). More eyes in the multifocal group had a refraction within 0.50D of intended (P = 0.03). In 39% of cases, the preoperative and IA power calculations suggested the same IOL power. When not equal, the IA results were not significantly more likely to be 'best' (P = 0.08).

CONCLUSIONS AND RELEVANCE

Results suggest that a history of previous LASIK is not a contraindication to use of distant-dominant multifocal IOLs. IA did not appear to improve clinical outcomes in post-LASIK eyes, although a positive trend was evident.

Management of cataract in uveitis patients

PURPOSE OF REVIEW

This review is timely because the outcomes of surgical invention in uveitic eyes with cataract can be optimized with adherence to strict anti-inflammatory principles.

RECENT FINDINGS

All eyes should be free of any cell/ flare for a minimum of 3 months preoperatively. Another helpful maneuver is to place dexamethasone in the infusion fluid or triamcinolone intracamerally at the end of surgery. Recent reports about the choice of intraocular lens material or lens design are germane to the best surgical outcome. Integrating these findings will promote better visual outcomes and allow advancement in research to further refine these surgical interventions in high-risk uveitic eyes.

SUMMARY

Control of inflammation has been shown to greatly improve postoperative outcomes in patients with uveitis. Despite better outcomes, more scientific research needs to be done regarding lens placement and materials and further research needs to adhere to the standardized reporting of uveitis nomenclature. Future studies should improve postoperative outcomes in eyes with uveitis so that they approach those of eyes undergoing routine cataract procedures.