Refractive lens exchange and piggyback intraocular lens implantation in nanophthalmos: Visual and structural outcomes

Application of Femtosecond Laser + Piggyback Multifocal Intraocular Lens Implantation in Patients with Super-High Myopia Complicated with Cataract

OBJECTIVE

To observe the clinical effect of piggyback multifocal intraocular lens (IOL) implantation in treating patients with high myopia complicated with cataract.

METHODS

This was a prospective controlled study. We compared 32 eyes of 32 patients who underwent femtosecond laser-assisted cataract surgery with piggyback IOL implantation (two IOLs were implanted into the capsule) with 32 eyes of 32 patients who also underwent the same surgery (one IOL implanted into the capsule) due to high myopia complicated with cataract at the Wuhan Aier Eye Expert Hospital between January 2019 and October 2020. All patients were followed up for three months after surgery. Uncorrected distance visual acuity (UCDVA), uncorrected intermediate visual acuity (UCIVA), uncorrected near visual acuity (UCNVA), best-corrected distance visual acuity, distance-corrected intermediate visual acuity (DCIVA), distance-corrected near visual acuity (DCNVA), postoperative spectacle independence, postoperative visual interference, equivalent spherical lens, defocus curve, and IOL tilt and eccentricity were evaluated.

RESULTS

Three months after surgery, the patients' UCIVA, UCNVA, DCIVA, and DCNVA were 0.49 ± 0.07, 0.38 ± 0.15, 0.47 ± 0.09, and 0.36 ± 0.12, respectively, in the research group and 0.56 ± 0.18, 0.72 ± 0.22, 0.55 ± 0.13, and 0.69 ± 0.15, respectively, in the control group; the differences between the two groups were statistically significant (P < .05). The spectacle independence rate was higher in the research group (93%) than in the control group (13%). The overall satisfaction regarding postoperative visual quality was also higher in the research group than in the control group. The absolute mean value of the spherical equivalents was 0.48 ± 0.28 D in the research group and 0.62 ± 0.33 D in the control group; the difference between the two groups was statistically significant (P < .05).

CONCLUSION

Piggyback multifocal IOL implantation can expand the multifocal IOL application range, and satisfy the desire of patients with high myopia complicated with cataract to see both near and far.

Heterozygous variants c.781G>A and c.1066dup of serine protease 56 cause familial nanophthalmos by impairing serine-type endopeptidase activity

BACKGROUND/AIMS

Nanophthalmos is a rare developmental, bilateral, sporadic or hereditary form of microphthalmos. In this study, the heterozygous variants c.781G>A and c.1066dup of the PRSS56 gene were identified in two patients with nanophthalmos. This study reports the clinical manifestation and the underlying pathogenic mechanism.

METHODS

Whole-exome sequencing was performed to identify the pathogenic genes in a Chinese family with nanophthalmos. The molecular simulation was used to predict the structures of wild-type or mutant PRSS56. The PRSS56 wild-type or mutation overexpression cellular models have been constructed accordingly. The subcellular localisation was then observed using immunofluorescence and Western-blot techniques. The Folin-Ciocalteu assay was carried out to evaluate serine-type endopeptidase activity, and a wound-healing assay was used to examine the cellular migratory ability.

RESULTS

The whole-exome sequencing revealed that heterozygous variants c.781G>A and c.1066dup of the PRSS56 gene might contribute to nanophthalmos. Both variants were not identified in the dbSNP, 1000 Genome project or ESP6500 databases. Furthermore, the variants were highly conserved and were involved in biological functions. The mutations result in destructive protein structure and impede serine-type endopeptidase activity, thereby impairing subcellular localisation and cellular migration.

CONCLUSION

The c.781G>A and c.1066dup variants of the PRSS56 gene might negatively affect protein structures, subcellular localisation, serine-type endopeptidase activity and cellular migratory ability. Together, these changes could lead to the development of nanophthalmos. This study identifies the PRSS56 gene as a potential target for nanophthalmos diagnosis and treatment.

Combining primary and sulcus piggyback IOLs for the correction of a spherical-cylindrical defect in an eye with abnormal cornea

INTRODUCTION

Piggyback IntraOcular Lenses (IOLs), or supplementary secondary implant lenses, have been developed to provide a sufficient dioptric power in eyes with high refractive defects, which are not fully correctable after cataract surgery with single IOL in the range of powers available. These lenses can also be used for the correction of refractive errors that occurred for a wrong choice of the IOL power after cataract surgery.

CASE DESCRIPTION

We report the case of a complete refractive success obtained in a patient with an abnormal cornea, with a central stable ectasia, with thinning, high myopic astigmatism and cataract, obtained with the implant of a primary posterior chamber IOL at the time of cataract surgery and a subsequent implant of a secondary piggyback, sulcus-based customized toric IOL (Camellens FIL 622-2 Toric Monofocal IOL, Soleko, Rome, Italy).

CONCLUSIONS

This brief report demonstrates the utility of combining primary and piggyback IOLs implant for the correction of a complex spherical-cylindrical refractive defect in a case of abnormal cornea and cataract.

[Evolution of IOL exchange. Part 1. Development of methods for IOL exchange]

The review presents the history of development and improvement of methods for intraocular lens (IOL) exchange. Existing techniques of IOL exchange are comparatively analyzed.

The Pathogenesis and Treatment of Complications in Nanophthalmos

Microphthalmos is a type of developmental disorder ophthalmopathy, which can occur isolated or combined with other ocular malformations and can occur secondary to a systemic syndrome. Nanophthalmos is one of the clinical phenotypes of microphthalmos. Due to the special and complex structure of nanophthalmic eyes, the disorder is often associated with many complications, including high hyperopia, angle-closure glaucoma, and uveal effusion syndrome. The management of these complications is challenging, and conventional therapeutic methods are often ineffective in treating them. The purpose of this paper was to review the concept of nanophthalmos and present the latest progress in the study of the pathogenesis and treatment of its complications. As it is considerably challenging for ophthalmologists to prevent or treat these nanophthalmos complications, timely diagnosis and a suitable clinical treatment plan are vital to ensure that nanophthalmos patients are treated and managed effectively.