Improved accuracy of intraocular lens power calculation by preoperative management of dry eye disease

Management of Dry Eye Disease for Intraocular Lens Power Calculation in Cataract Surgery: A Systematic Review

Cataracts are characterized by the crystalline lens of the eye becoming cloudy, and dry eye disease (DED) is a multifactorial disease in which the homeostasis of the tear film is lost. As the prevalence of both diseases increases with age, there is a high prevalence of DED among patients who are candidates for cataract surgery. In recent years, cataract surgery has evolved from vision restoration surgery to refractive surgery. To achieve good surgical outcomes, it is necessary to minimize postoperative refractive error in intraocular lens (IOL) power calculation, which requires accurate preoperative keratometry measurements. A stable tear film is important for the accuracy and reproducibility of keratometry measurements, and DED may have a deleterious effect. In this study, original articles that focused primarily on findings related to this topic were evaluated. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Although appropriate DED diagnoses were not presented in the articles evaluated in this review, it was confirmed that the clinical signs of DED, particularly the shortening of the tear film break-up time (TBUT), negatively impact IOL power calculations. Improvement in these clinical signs might mitigate the negative effects on these calculations.

Effect of Artificial Tears on Preoperative Keratometry and Refractive Precision in Cataract Surgery

Purpose

The primary objective was to investigate if treatment with artificial tears affected the variability of keratometry measurements for subjects with dry eyes prior to cataract surgery. The secondary objectives were to investigate whether treatment with artificial tears improved refractive precision and whether subjects with non-dry eyes had better refractive precision than subjects with dry eyes.

Design

Prospective randomized controlled trial with three arms.

Patients and methods

Dry eye diagnostics according to DEWS II were performed, and subjects with dry eyes were randomized to no treatment (group A1) or treatment with artificial tears two weeks prior to cataract surgery (group A2), with the third group (Group B, non-dry eyes) as a control. Keratometry was performed twice at baseline and twice after two weeks at the time of cataract surgery with three different optical biometers. The change in mean variability of keratometry (average K and magnitude of vector differences) and percentages of outliers after two weeks versus baseline were compared for group A2. The refractive and astigmatism prediction errors were calculated eight weeks after cataract surgery and compared for all three groups.

Results

One hundred thirty-one subjects were available for analysis. There was no statistically significant difference in the mean variability of keratometry or percentages of outliers for group A2 from baseline to the time of cataract surgery. There was no statistically significant difference in refractive precision (absolute error and astigmatism prediction error) between any groups.

Conclusion

Subjects with dry eyes (treated and non-treated) achieved the same refractive precision and percentages of outliers as subjects with non-dry eyes. Treatment with artificial tears for two weeks appeared inadequate to significantly affect variability in biometric measurements for patients with dry eyes prior to cataract surgery. DEWS II criteria for DED may not be optimal in a cataract setting.

Repeatability of biometry in patients with meibomian gland dysfunction before and after vectored thermal pulsation therapy: A randomized, controlled trial

PURPOSE

To evaluate the effect of vectored thermal pulsation therapy (VTPT) on the repeatability of biometry readings of two different optical biometers in patients with meibomian gland dysfunction (MGD).

METHODS

Patients affected by MGD were included in this prospective, randomized, controlled, investigator-masked study. One eye was randomized to VTPT (LipiFlow®, Johnson & Johnson), and the contralateral eye served as a control. Three visits were scheduled at baseline, 2 weeks and 3 months after the treatment. The main outcome parameter of the study was the repeatability of three calculations of emmetropic intraocular lens power (EIOLP) at the 3 months visit as compared to baseline using an optical biometer (IOLMaster® 700, Carl Zeiss Meditec AG). Repeatability of different keratometry values obtained by the optical biometer and a Placido-disc topographer (MS-39®, CSO) served as secondary outcome parameters.

RESULTS

Twenty-nine patients were included in the final analysis. While tear film parameters improved in the study eyes, there were no significant differences regarding the repeatability of three EIOLP measurements between baseline and 3-months-visit in both eyes (p > 0.05) and keratometry measurements in both the optical biometer and the Placido-disc topographer. Remarkably, throughout all study visits, there were some outliers regarding the repeatability of measurements.

CONCLUSION

While both devices showed high repeatability regarding EIOLP and keratometry, future studies are needed to detect high-risk patients for poor repeatability.

Artificial Tear Instillation-Induced Changes in Corneal Topography

This study aims to compare changes of corneal topography (Galilei G4) before and after the instillation of artificial tears in patients with dry eye disease (DED). Corneal topography was performed in patients 1 min before and after artificial tear instillation. Two types of artificial tears were used: 1% polysorbate 80 (PSB) and 0.5% carboxymethylcellulose (CMC). Of 135 patients, PSB and CMC were instilled in 101 and 34 eyes, respectively. The average value of Sim K increased significantly after instillation (44.07 ± 2.26 diopter (D)) compared to before (43.90 ± 2.02 D, p = 0.006) the instillation of artificial tears. Mean Sim K astigmatism was statistically increased after PSB instillation (1.48 ± 2.17 D) compared to before instillation (1.31 ± 2.10 D, p = 0.049). An axis change of astigmatism 10° or more after artificial tear instillation was found in 51.9% of patients, and 30° or more in 20.0% of patients. Increased Sim K value and significant changes in the astigmatic axis in the corneal topography were observed after instillation of artificial tears in DED patients. PSB instillation had a greater effect on corneal keratometry values than CMC instillation.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

Dry Eye Disease as a Cause of Refractive Errors After Cataract Surgery - A Systematic Review

Dry eye disease (DED) is a multifactorial ocular surface disorder characterized by loss of tear film homeostasis with associated ocular symptoms, like dryness, foreign body sensation, and inflammation. Numerous reports confirm an increase in dry eye symptoms after cataract surgery. DED also significantly disturbs preoperative biometric measurements, mainly by changes in keratometry measurements. The purpose of this study is to evaluate the effect of DED on biometric measurements before cataract surgery and postoperative refractive errors. PubMed database was searched for keywords: cataract surgery, dry eye disease, refractive error, refractive outcomes, keratometry, and biometry. Four clinical studies evaluating the effect of DED on refractive errors were included. In all studies, biometry was performed before and after dry eye treatment, and the mean absolute error was compared. Various substances have been used to treat dry eye, such as cyclosporin A, liftitegrast, and loteprednol. The refractive error was significantly lower after treatment in all studies. The results unanimously indicate that refractive errors can be reduced by proper treatment of DED before cataract surgery.

[Enhancement Options after Lens and Corneal Refractive Surgery]

BACKGROUND

 Modern preoperative diagnostics as well as current surgical techniques allow cataract and refractive surgery to deliver precise refractive results.Occasionally, unsatisfactory refractive and visual results occur despite all the care taken. In these cases, subsequent improvement is required to achieve the best final visual outcome. This article shows the therapeutic options for the treatment of residual refractive errors after lens and corneal refractive surgery.

KEY MESSAGES

 The causes of postoperative refractive errors after refractive laser- or lens-based procedures are very diverse and require extensive workup of the cause as well as an individual solution to achieve the desired result. Before any further surgical intervention, specific complications of the primary procedure as well as concomitant ocular diseases must be excluded or treated. The appropriate enhancement after keratorefractive surgery depends primarily on the type of primary surgery, residual stromal thickness, possible complications from the initial surgery, and the patient's personal preference. For enhancements using surface treatments, such as PRK, the use of mitomycin C is recommended for prophylaxis of haze formation. After lens surgery, for low-grade postoperative refractive errors (spherical and astigmatic), keratorefractive enhancements provide the most accurate results. For higher refractive errors, lens-based procedures can be used, with add-on IOLs being safer and more precise compared with one IOL exchange. Low astigmatisms can be successfully treated with LRI or keratorefractive surgery, but higher astigmatisms should be corrected with an IOL exchange in the early postoperative period and with an add-on IOL in the later postoperative period. IOL explantations should be performed very cautiously, especially in cases of pronounced capsular fibrosis, previous posterior capsulotomy, and existing weakness of the zonular apparatus.

Enhancement-Optionen nach Linsen- und refraktiver Hornhautchirurgie

Gelegentlich kommt es trotz aller Sorgfalt und präziser Operationstechnik in der Katarakt- und Refraktivchirurgie zu unbefriedigenden refraktiven und visuellen Ergebnissen. In diesen Fällen ist eine nachträgliche Korrektur erforderlich, um das beste endgültige visuelle Ergebnis zu erzielen. Dieser Beitrag zeigt die Möglichkeiten zur Behandlung residualer Refraktionsfehler nach Linsen- und refraktiver Hornhautchirurgie auf.

Understanding and Optimizing Ocular Biometry for Cataract Surgery in Dry Eye Disease: A Review

PURPOSE

To understand the impact of dry eye disease (DED) on the components of ocular biometry and ways to optimize the visual outcomes of cataract surgery in eyes with DED.

METHODOLOGY

A thorough literature review of the components pertaining to this review was undertaken using the databases, PubMed (from the year 2000), MEDLINE, CENTRAL (including Cochrane Eyes and Vision Trials Register; Cochrane Library: Issue 12 of 12 December 2019), metaRegister of Controlled Trials (mRCT) (www.controlled-trials. com), ClinicalTrials.gov (www.clinicaltrial.gov) and WHO International Clinical Trials Registry Platform (www.who.int/ictrp/search/en). The keywords used for the search included "cataract surgery" or "phacoemulsification" combined with "dry eye", "dry eye disease","biometry", "keratometry".

RESULTS

Publications considered for this review included meta-analysis, systematic reviews, case-control and cohort studies, case series, and laboratory-based studies. Published articles reporting tear film alteration in DED, its impact on the quality of vision and optical aberrations, the effect of topical medications on keratometry variations, and reports on optimizing the ocular surface before cataract surgery were included.

CONCLUSIONS

DED is a common entity seen in patients presenting to routine cataract clinics and is known to impact the accuracy, reliability, and repeatability of ocular biometry and IOL power calculations in them. This review intends to emphasize the preoperative screening for the presence of DED, initiation of appropriate medical management for optimization of the ocular surface before cataract surgery, and recommendations for performing biometry. The algorithmic approach proposed will help the general ophthalmologists in routine practice to provide quality care and acceptable visual outcomes in patients with pre-existing DED.

Investigating the Anti-Inflammatory Effects of RCI001 for Treating Ocular Surface Diseases: Insight Into the Mechanism of Action

The ocular surface is continuously exposed to various environmental factors, and innate and adaptive immunity play crucial roles in ocular surface diseases (OSDs). Previously, we have reported that the topical application of RCI001 affords excellent anti-inflammatory and antioxidant effects in dry eye disease and ocular chemical burn models. In this study, we examined the inhibitory effects of RCI001 on the Rac1 and NLRP3 inflammasomes in vitro and in vivo. Following RCI001 application to RAW264.7 and Swiss 3T3 cells, we measured Rac1 activity using a glutathione-S-transferase (GST) pull-down assay and G-protein activation assay kit. In addition, we quantified the expression of inflammatory cytokines (interleukin [IL]-1β, IL-6, and tumor necrosis factor [TNF]-α) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells using ELISA and real-time PCR. In the mouse ocular alkali burn model, RCI001 was administered via eye drops (10 mg/mL, twice daily) for 5 days, and 1% prednisolone acetate (PDE) ophthalmic suspension was used as a positive control. Corneal epithelial integrity (on days 0-5) and histological examinations were performed, and transcript and protein levels of Rac1, NLRP3, caspase-1, and IL-1β were quantified using real-time PCR and western blotting in corneal tissues collected on days 3 and 5. We observed that RCI001 dose-dependently inhibited Rac1 activity and various inflammatory cytokines in LPS-stimulated murine macrophages. Furthermore, RCI001 restored corneal epithelial integrity more rapidly than corticosteroid treatment in chemically injured corneas. Compared to the saline group, activation of Rac1 and the NLRP3 inflammasome/IL-1β axis was suppressed in the RCI001 group, especially during the early phase of the ocular alkali burn model. Topical RCI001 suppressed the expression of activated Rac1 and inflammatory cytokines in vitro and rapidly restored the injured cornea by inhibiting activation of Rac1 and the NLRP inflammasome/IL-1β axis in vivo. Accordingly, RCI001 could be a promising therapeutic agent for treating OSDs.