Systematic evaluation of machine learning-enhanced trifocal IOL power selection for axial myopia cataract patients

PURPOSE

This study aimed to evaluate and optimize intraocular lens (IOL) power selection for cataract patients with high axial myopia receiving trifocal IOLs.

DESIGN

A multi-center, retrospective observational case series was conducted. Patients having an axial length ≥26 mm and undergoing cataract surgery with trifocal IOL implanted were studied.

METHODS

Preoperative biometric and postoperative outcome data from 139 eyes were collected to train and test various machine learning (ML) models (support vector machine, linear regression, and stacking regressor) using five-fold cross-validation. The models' performance was further validated externally using data from 48 eyes enrolled from other hospitals. Performance of seven IOL calculation formulas (BUII, Kane, EVO, K6, DGS, Holladay I, and SRK/T) were examined with and without ML models.

RESULTS

The results of cross-validation revealed improvements across all IOL calculation formulas, especially for K6 and Holladay I. The model increased the percentage of eyes with a prediction error (PE) within ±0.50 D from 71.94% to 79.14% for K6, and from 35.25% to 51.80% for Holladay I. In external validation involving 48 patients from other centers, six out of seven formulas demonstrated a reduction in the mean absolute error (MAE). K6's PE within ±0.50 D improved from 62.50% to 77.08%, and Holladay I from 16.67% to 58.33%.

CONCLUSIONS

In this study, we conducted a comprehensive evaluation of seven IOL power calculation formulas in high axial myopia cases and explored the effectiveness of the Stacking Regressor model in augmenting their accuracy. Of these formulas, K6 and Holladay I exhibited the most significant improvements, suggesting that integrating ML may have varying levels of effectiveness across different formulas but holds substantial promise in improving the predictability of IOL power calculations in patients with long eyes.

Retinal complications post posterior chamber phakic intraocular lens implantation at a tertiary eye hospital in the Eastern Province of Saudi Arabia

PURPOSE

Phakic intraocular lenses treat higher degrees of myopia not possible previously with conventional refractive surgery. The aim of this study is to report the incidence and risk factors of retinal complications after posterior chamber PIOL implantation and assess the differences in biometric parameters between patients who developed such complications versus those who did not.

METHODS

This retrospective study recruited 514 patients who underwent ICL implantation to correct myopia at a tertiary eye hospital center in the Eastern province of Saudi Arabia. Follow up period was at least one year. Medical records of the patients were reviewed to obtain the required data. Associations between respondents' characteristics and retinal complications were evaluated using the Chi-squared test.

RESULTS

The mean (SD) age was 27.7 (± 6.5) years ranging from 18 to 47. Laser treatment was performed in 14 cases (2.7%). Retinal complications occurred in six cases (1.2%). The risk of retinal complication was significantly higher among patients with high axial length (OR = 1.3, 95% CI 1.2, 1.4) and patients with high pre-spherical equivalent before ICL (OR = 1.09, 95% CI 1.03, 1.4).

CONCLUSION

Patients with higher axial length and higher pre-spherical equivalent before ICL implantation are at high risk of retinal complications.

6PPD and its metabolite 6PPDQ induce different developmental toxicities and phenotypes in embryonic zebrafish

The automobile tire antioxidant N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) and its quinone metabolite 6PPDQ have recently received much attention for their acute aquatic toxicity. The present study investigated the mechanistic developmental toxicity of 6PPD and 6PPDQ in embryonic zebrafish. Neither compound induced significant mortality but significantly decreased spontaneous embryo movement and heart rate. Both compounds induced malformations with different phenotypes; the 6PPD-exposed larvae manifested a myopia-like phenotype with a convex eyeball and fusion vessels, while the 6PPDQ-exposed embryonic zebrafish manifested enlarged intestine and blood-coagulated gut, activated neutrophils, and overexpressed enteric neurons. mRNA-Seq and quantitative real-time PCR assays showed that 6PPD- and 6PPDQ-induced distinct differential gene expression aligned with their toxic phenotype. 6PPD activated the retinoic acid metabolic gene cyp26a, but 6PPDQ activated adaptive cellular response to xenobiotics gene cyp1a. 6PPD suppressed the gene expression of the eye involved in retinoic acid metabolism, phototransduction, photoreceptor function and visual perception. In contrast, 6PPDQ perturbed genes involved in inward rectifier K+ and voltage-gated ion channels activities, K+ import across the plasma membrane, iron ion binding, and intestinal immune network for IgA production. The current study advances the present understanding the reason of why many fish species are so adversely impacted by 6PPD and 6PPDQ.

Myopic macular Bruch's membrane defects

Purpose

To examine histologic characteristics of macular Bruchś membrane defects (BMD) in axially elongated eyes.

Design

Histomorphometric study.

Methods

Using light microscopy, we examined enucleated human globes for BMDs.

Results

In 247 eyes, BMDs were detected in 15 (6.1%) eyes (axial length:27.0-36.0 mm), in 10 of them in the macular region. Prevalence and size of BMDs (mean:1.93 ± 1.62 mm; range:0.22mm-6.24 mm) correlated with longer axial length (OR:1.52; 95%CI:1.19,1.94; P = 0.001) and higher prevalence of scleral staphylomas (OR:16.3; 95%CI:2.67,99.3; P < 0.001). The BMDs were smaller than corresponding gaps in the retinal pigment epithelium (RPE) (1.93 ± 1.62 mm versus 2.61 mm ± 1.73 mm; P = 0.003), and larger than corresponding gaps in the inner nuclear layer (0.43 ± 0.76 mm; P = 0.008) and inner limiting membrane bridges (0.13 ± 0.33 mm; P = 0.001). Choriocapillaris thickness, BM thickness and RPE cell density did not vary (all P > 0.05) between the BDM border and adjacent areas. In the BMD, choriocapillaris and RPE were absent. The sclera was thinner in the BDM area than in adjacent areas (0.28 ± 0.19 mm versus 0.36 ± 0.13 mm; P = 0.006).

Conclusions

BMDs as hallmarks of myopic macular degeneration are characterized by longer gaps in the RPE and smaller gaps in the outer nuclear layer and inner nuclear layer, by localized scleral thinning, and by a spatial association with scleral staphylomas. Thickness of the choriocapillaris and density of the RPE cell layer, both absent within the BDMs, do not vary between the BMD border and adjacent regions. The results suggest an association between BDMs and absolute scotomas, stretching of the adjacent retinal nerve fiver layer, and an axial elongation-associated stretching effect on BM as etiology of the BDMs.

Efficacy of low-concentration atropine (0.01%) eye drops for prevention of axial myopic progression in premyopes

Purpose

Low-concentration atropine (LCA; 0.01%) is known to reduce the progression of myopia in axial myopes. The purpose of this study was to understand the role of LCA in premyopic children in preventing progression.

Methods

A randomized case-control study of known premyopes was done between the use of LCA and no intervention. A total of 30 children were included in both groups.

Results

The mean age in the LCA group was 7.7 ± 2.1 years (5-12 years), and in the control group, it was 7.2 ± 1.9 years (4-12 years). The mean baseline progression per year in the LCA group (before starting the eye drops) was - 0.72 ± 0.3 D, and in the control group, it was - 0.69 ± 0.4 D. At the end of the first year, the mean progression in the LCA group was - 0.31 ± 0.3 D versus - 0.76 ± 0.4 D, and the axial length increase was 0.12 ± 0.1 mm in the LCA group and 0.21 ± 0.2 mm in the control group. At the end of the second year, the mean progression compared with the baseline in the LCA group was - 0.6 ± 0.3 D versus - 1.75 ± 0.4 D, and the axial length showed an increase from baseline in the LCA group by 0.21 ± 0.2 mm, and in the control group, the increase was 0.48 ± 0.2 mm in 2 years.

Conclusion

Low-concentration eye drops (0.01%) work in preventing the progression of axial myopia in premyopic children.

Percaruncular single injection peribulbar anaesthesia in patients with axial myopia for phacoemulsification

BACKGROUND

Myopia has been identified as a risk factor for globe perforation during regional anaesthesia for cataract surgery. We conducted this study to evaluate efficacy of single injection percaruncular peribulbar anaesthesia for phacoemulsification in patients with axial myopia.

METHODS

Eighty patients with axial myopia received percaruncular peribulbar anaesthesia and were evaluated for incidence of major or minor complications. Also surgeon and patients' satisfaction and their comment on operative conditions were noted.

RESULTS

Of the 80 patients 51 patients had posterior staphylomas. About three quarters of the patients developed adequate akinesia in 10 min. Remaining 25% received second injection with the same technique but with less volume after which the percent of patients with adequate akinesia rose to 91%. Adequate analgesia developed in almost all patients and only in one patient, intravenous analgesia was necessary to complete the operation. All operations were completed uneventfully. No perforations or penetrations were recorded and no other major complications were encountered. About 97% of the surgeons and 96% of the patients found the operative conditions satisfactory.

CONCLUSION

Using single injection percaruncular peribulbar local anaesthesia for phacoemulsification in patients with axial myopia is an effective technique.