Acute Angle-Closure Glaucoma Secondary to a Phakic Intraocular Lens, an Ophthalmic Emergency

Influence of anterior chamber depth and vault on anterior chamber angle morphology after phakic posterior chamber intraocular lens implantation

PURPOSE

This study aims to investigate the influence of anterior chamber depth (ACD) and vault on the anterior chamber angle (ACA) morphology in myopic individuals implanted with posterior chamber phakic intraocular lenses.

METHODS

This retrospective case series involved 231 eyes receiving a 13.2-mm implantable collamer lens (ICL). Preoperative anterior chamber anatomy was assessed using anterior segment optical coherence tomography (AS-OCT) and optical tomography, while postoperative evaluation employed AS-OCT. ACA morphology was characterized pre- and postoperatively through trabecular iris angle (TIA750), ACA distance opening (AOD750) and trabecular iris space area (TISA750). The influence of ACD and vault was examined by categorizing the sample into ACD (shallow, average and deep) and vault (low, optimal and high) groups.

RESULTS

Preoperative ACA morphology varied based on ACD, with shallower ACDs exhibiting narrower TIA750, smaller AOD750 and TISA750. ICL implantation induced greater ACA narrowing more in the deep ACD group (TIA750 = 20.1 degrees; AOD750 = 0.82 mm and TISA750 = 0.44 mm2) compared to the shallow ACD group (TIA750 = 15.2 degrees; AOD750 = 0.44 mm and TISA750 = 0.21 mm2). Postoperatively, deeper ACDs showed larger ACAs. Increasing vault magnitude led to increased ACA narrowing, with the low vault group exhibiting smaller closure (TIA750 = 14.3 degrees; AOD750 = 0.56 mm and TISA750 = 0.29 mm2) compared to the high vault group (TIA750 = 20.8 degrees; AOD750 = 0.73 mm and TISA750 = 0.36 mm2). The magnitude of ACA narrowing associated with the vault had a consistent effect across different ACD groups.

CONCLUSIONS

Posterior chamber intraocular lens implantation results in ACA narrowing, the extent of which is contingent upon preoperative anterior chamber and ACA morphology, with additional influence from vault magnitude.

Analysis of vault prediction in phakic implantable phakic collamer lenses: manufacturer's calculator vs theoretical formulae vs clinical practice

BACKGROUND

Implantable collamer phakic (ICL) intraocular lens sizing calculations are necessary to avoid complications associated to inadequate sizing. Historically, Holladay R, Dougherty, Hernández-Matamoros, and other authors have tried to create new formulas that solve calculation problems and provide higher reliability. In addition, in recent years, the appearance of new equipment, parameters, and formulas have led to significant progress. This paper compares the sizing according to manufacturer's method and other methods.

METHODS

Forty-three eyes of 24 patients with EVO ICL implanted, with at least 1 year of follow-up, were analysed. The analysed variables were white to white (WTW), anterior chamber depth (ACD), ACW (angle-to-angle), crystalline lens rise (CLR), ICL size, vault measured at 1 week and 1 year after surgery, ICL size, and vault predicted by Nakamura-2 as well as vault size predicted by Igarashi.

RESULTS

Sizing calculation with Online Calculation and Ordering System according to WTW and ACD is a good indicator with 86% success rate. The calculation with Nakamura 2 suggests larger ICL sizes in 32.5% of cases and smaller in 18.6% of cases, while the resulting Vault according to Igarashi obtains better results without significant differences.

CONCLUSIONS

ICL sizing according WTW and ACD, using the manufacturer's algorithm, seems to be the most predictable method compared to other algorithms using other variables. The surgeon's expertise also has a high importance in the final ICL size election.

Prediction model of the horizontal trabecular iris angle after phakic posterior chamber implantable intraocular lens surgery

PURPOSE

To determine the predictors of the postoperative horizontal trabecular iris angle (TIA 750 ) after phakic posterior chamber implantable intraocular lens (IOL) surgery.

SETTING

Ophthalmology Clinic Vista Sánchez Trancón, Badajoz, Spain.

DESIGN

Retrospective case series.

METHODS

330 eyes implanted with spherical/toric implantable collamer lens (ICL) were included in this study. From 230 eyes implanted with 13.2 mm ICL, these were divided in modeling (n = 180) and evaluation group (n = 50). Two groups implanted with 12.6 mm and 13.7 mm (n = 50 each) were also used as evaluation. Anterior-segment optical coherence tomography was used preoperatively to perform anterior chamber biometry (angle-to-angle [ATA] distance, crystalline lens rise, anterior chamber depth [ACD], cornea sagittal depth, pupil diameter, nasal/temporal TIA 750 ); postoperatively for measuring the vault, pupil diameter and nasal/temporal TIA 750 . Corneal curvature and horizontal visible iris diameter were measured using optical tomography. Bivariate correlation analysis was used to determine associations between preoperative and postoperative horizontal TIA 750 with anterior chamber biometry, ICL-related parameters and age. Finally, a multivariate linear regression model was constructed for predicting the postoperative TIA 750 .

RESULTS

Horizontal TIA 750 reduced from 42.9 ± 8.0 degrees preoperatively to 24.4 ± 5.6 degrees postoperatively. Postoperative TIA 750 was positively correlated with the preoperative TIA 750 , cornea sagittal depth and ACD, and negatively associated with the vault. The main predictors of the postoperative TIA 750 were the preoperative parameters, TIA 750 , ICLsize - ATA and pupil diameter (adjusted- R2 = 0.39). The limits of agreement between predicted and real TIA 750 were close to ±10 degrees.

CONCLUSIONS

Implantation of a phakic posterior chamber implantable IOL leads to a reduction in TIA 750 and the main factors contributing for this are the preoperative TIA 750 aperture and the vault.

Automatic measurement of anterior chamber angle parameters in AS-OCT images using deep learning

The early assessment of angle closure is of great significance for the timely diagnosis and treatment of primary angle-closure glaucoma (PACG). Anterior segment optical coherence tomography (AS-OCT) provides a fast and non-contact way to evaluate the angle close using the iris root (IR) and scleral spur (SS) information. The objective of this study was to develop a deep learning method to automatically detect IR and SS in AS-OCT for measuring anterior chamber (AC) angle parameters including angle opening distance (AOD), trabecular iris space area (TISA), trabecular iris angle (TIA), and anterior chamber angle (ACA). 3305 AS-OCT images from 362 eyes and 203 patients were collected and analyzed. Based on the recently proposed transformer-based architecture that learns to capture long-range dependencies by leveraging the self-attention mechanism, a hybrid convolutional neural network (CNN) and transformer model to encode both local and global features was developed to automatically detect IR and SS in AS-OCT images. Experiments demonstrated that our algorithm achieved a significantly better performance than state-of-the-art methods for AS-OCT and medical image analysis with a precision of 0.941, a sensitivity of 0.914, an F1 score of 0.927, and a mean absolute error (MAE) of 37.1±25.3 µm for IR, and a precision of 0.805, a sensitivity of 0.847, an F1 score of 0.826, and an MAE of 41.4±29.4 µm for SS, and a high agreement with expert human analysts for AC angle parameter measurement. We further demonstrated the application of the proposed method to evaluate the effect of cataract surgery with IOL implantation in a PACG patient and to assess the outcome of ICL implantation in a patient with high myopia with a potential risk of developing PACG. The proposed method can accurately detect IR and SS in AS-OCT images and effectively facilitate the AC angle parameter measurement for pre- and post-operative management of PACG.

Validation of the vault prediction model based on the sulcus-to-sulcus diameter and lens thickness: a 925-eye prospective study

BACKGROUND

To verify the accuracy and stability of the prediction formula based on the ciliary sulcus diameter and lens thickness and to analyse factors influencing the prediction results.

METHODS

In total, 925 eyes from 506 subjects were enrolled in this prospective study between July 1, 2020, and June 30, 2021. Subjects were divided into four seasons, each spanning three months. The target vault was set to be between 300 μm and 700 μm according the prediction formula. The actual vault was measured one month postoperatively. The Bland-Altman test, 95% confidence intervals (95% CI) and 95% limits of agreement (95% LoA) were used to evaluate the agreement between the predicted vault and the actual vault. Eyes with absolute prediction errors greater than 300 μm were further analysed.

RESULTS

The mean predicted vaults for the four seasons were 503 ± 99, 494 ± 96, 481 ± 92 and 502 ± 93 μm, while the mean actual vaults were 531 ± 189, 491 ± 179, 464 ± 179 and 529 ± 162 μm, respectively. The predicted and actual vaults of the overall subjects were 493 ± 95 and 500 ± 180 μm, respectively. Of the 925 eyes, 861 eyes (93.08%), 42 eyes (4.54%), and 22 eyes (2.38%) showed a normal vault, high vault, and low vault, respectively. Bland-Altman plots showed that the mean difference between the actual vault and predicted vault overall (± 95% LoA) was 6.43 ± 176.2 μm (-339 to 352 μm). Three UBM features may lead to large prediction errors (more than 300 μm): wide iris-ciliary angle (ICA), iris concavity and anteriorly positioned ciliary body.

CONCLUSIONS

This study demonstrated the accuracy and stability of the prediction formula through the validation of a large sample size and a long time span. Wide ICA, iris concavity and anteriorly positioned ciliary body may have an effect on vault.

Analysis of perioperative problems related to intraocular Implantable Collamer Lens (ICL) implantation

PURPOSE

To introduce a modified procedure of ICL implantation, to summarize the perioperative problems and their corresponding treatment after myopia correction with Implantable Collamer Lens (ICL), and to compare the difference of complications between the no-hole ICL and hole ICL.

METHODS

We searched all articles on ICL-related perioperative problems and their corresponding treatment in Scopus, Embase, PubMed and Web of Science databases for the last 22 years.

RESULTS

ICL implantation is safe, effective, stable and predictable in the correction of myopia, hyperopia and astigmatism, but can also cause a series of perioperative problems, including intraoperative and postoperative complications.

CONCLUSION

There are many kinds of complications related to ICL, but the common intraoperative and postoperative complications mainly include abnormality of arch height, abnormal position of ICL, loss of corneal endothelial cells and corneal decompensation, high intraocular pressure and secondary glaucoma, cataract and night vision symptoms. Compared with ICL without central pore, the incidence of complications such as loss of corneal endothelial cells and corneal decompensation, high intraocular pressure and secondary glaucoma and cataract was relatively lower in central hole ICL, while postoperative complications such as night vision symptoms were obvious.

Phakic intraocular lenses: an update and review for the treatment of myopia and myopic astigmatism in the United States

PURPOSE OF REVIEW

To review all phakic intraocular lenses (pIOLs) available in the United States for the correction of myopia or myopic astigmatism and offer a clinical approach to their proper use, postoperative follow-up, and analysis of visual and adverse outcomes.

RECENT FINDINGS

In March 2022, the FDA approved the EVO/EVO+ Visian ICL for widespread use, adding this lens to the two others available (Verisyse, Visian ICL). Cataract formation, endothelial cell loss (ECL) and surgical reintervention remain the most common adverse events. There are discrepancies between studies on ECL following implantation with pIOLs, although trends can be deduced with meta-analysis. Posterior Chamber-pIOLs (PC-pIOLs), especially the EVO/EVO+, have an overall lower mean adverse effect and subjective patient symptom profile when compared to Iris Fixated-pIOLS (IF-pIOLs). Advancements in PC-pIOL sizing have provided a noticeable difference in visual and safety outcomes.

SUMMARY

All pIOLs available in the United States provide high-quality visual correction of moderate to high myopia and/or myopia with astigmatism. Proper follow-up for ECL and cataract formation is warranted.

Needle decompression of the eye! Emergent management of a vision threatening surgical complication

Acute angle-closure glaucoma (AACG) is a medical emergency that can cause permanent visual deficits without prompt recognition. From 2006 to 2011, nearly 12 million visits to emergency departments (ED) in the United States were ophthalmologic in nature, making it crucial for emergency physicians to be familiar with the diagnosis and treatment of ophthalmologic emergencies. AACG can be precipitated by several mechanisms including pupillary block, anticholinergic medications, and sympathomimetic medications. We present a rare case of angle-closure glaucoma status post pneumatic retinopexy with cryotherapy due to migration of an intravitreal gas bubble into the anterior chamber with emphasis on understanding how retinal surgery types lead to significant differences in management.