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| COMMENTARY |
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| Year : 2022 | Volume
: 2
| Issue : 2 | Page : 397-398 |
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Commentary: Intraocular lens opacification: Study by advanced microscopy and spectroscopy
Dipankar Das1, Harsha Bhattacharjee2, Obaidur Rehman2
1 Department of Ocular Pathology, Uveitis and Neuroophthalmology Services, Sri Sankaradeva Nethralaya, Guwahati, Assam, India
2 Department of Ophthalmology, Sri Sankaradeva Nethralaya, Guwahati, Assam, India
| Date of Web Publication | 13-Apr-2022 |
Correspondence Address:
Dipankar Das
Department of Ocular Pathology, Uveitis and Neuro-Ophthalmology Services, Sri Sankaradeva Nethralaya, Guwahati, Assam
India
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/ijo.IJO_3214_21
How to cite this article:
Das D, Bhattacharjee H, Rehman O. Commentary: Intraocular lens opacification: Study by advanced microscopy and spectroscopy. Indian J Ophthalmol Case Rep 2022;2:397-8 |
How to cite this URL:
Das D, Bhattacharjee H, Rehman O. Commentary: Intraocular lens opacification: Study by advanced microscopy and spectroscopy. Indian J Ophthalmol Case Rep [serial online] 2022 [cited 2023 Jun 2];2:397-8. Available from: https://www.ijoreports.in/text.asp?2022/2/2/397/342994 |
Opacification in an intraocular lens (IOL) may occur as a complication of cataract surgery with IOL implantation and can cause various visual problems in an operated eye.[1] This phenomenon happens mostly in the optics, and sometimes in the haptics of the IOLs.[2] Different types of opacification patterns may be observed, based on the IOL make-up, for instance, polymethylmethacrylate (PMMA) IOLs have various intricate snowflake deposits on its surface.[2] These snowflake crystals have different sizes and are sometimes seen overlapping each other, causing irregular and diffuse refraction to the spectrum of light.[2] The cause of snowflakes is not known exactly but temperature variation in intraocular microenvironment may lead to formation of these circular and hexagonal crystals.[2] Electrostatic property of aqueous and vitreous in close proximity to a PMMA IOL surface may play a role in the formation of these snowflake crystals. Scanning electron microscopy (SEM) and atomic force microscopy observations of the crystals would be interesting in future studies. Discoloration may be seen in silicone IOLs, and calcification of different grades may be noted in hydrophilic acrylic IOLs.[3] Discoloration of silicone IOLs made from different silicone materials has been described in eyes with asteroid hyalosis, and that too without the presence of any predisposing cause.[3] Prof. David J. Apple and his team have performed extensive studies on IOL calcifications and have grouped them into two varieties in acrylic IOLs.[4] The primary calcifications, according to them, were due to inadequate structural formulation of acrylic polymer, which had inherent issues in the fabrication process of acrylic IOL manufacturing.[4] Primary calcifications in the studied IOLs did not have any other disease process association.[4] Secondary calcifications, on the other hand, had calcium deposits on acrylic IOLs and were mostly due to intraocular microenvironmental causes.[4] In secondary calcifications, the manufacturing problem of acrylic IOLs was not entertained.[4] The glistening of IOLs has been reported in hydrophobic acrylic IOLs; however, this can even be seen in other IOLs.[5],[6] The glistening of IOLs is more common than gross calcifications.[5],[6] The glistening of IOLs can have multiple causative factors which include manufacturing of IOLs, packaging of IOLs, and surgical procedures, particularly those employing viscoelastic substances during the cataract surgery.[5] Various corneal and vitreoretinal surgeries might precipitate these opacities on IOLs, particularly when intraocular gas and silicon oils are used.[5] Temperature variation can cause clouding of IOLs during the operative procedure, but it seems to be transient and reversible.[5] The glistening of hydrophobic IOLs is due to fluid-filled microvacuoles measuring 1–25μ and is thought to be a result of biodegradable change in the polymer of hydrophobic acrylic lens.[6] IOL calcifications can also be attributed to the breakdown of a blood aqueous barrier.[5],[6] The glistening of IOLs can produce a glare effect in the patients' vision, which may be distressing and in very rare situation may require IOL explantation and exchange.[5],[6]
In recent years, extensive research has been conducted on IOL opacification.[1],[2],[3],[4],[5],[6] In the present article,[1] opacification has been described as a rare phenomenon in Indian scenario. In this case report, the author(s) have performed SEM analysis with energy-dispersive X-ray spectroscopy (EDXS) and observed that the opacities consisted of the elements calcium, carbon and potassium.[1] Author(s) have reported a case of a 45-year-old diabetic patient who had undergone uncomplicated cataract surgery 1-year back and then subsequently developed dimness of vision in that eye.[1] An opaque IOL was seen, which was explanted and replaced.[1] The patient did not have any previous surgical procedure or local disease to initiate such opacification.[1] The expression of potassium in EDXS was unique in this study.[1] Bhattacharjee et al.[5] have shown hydrolytic biodegradation on the surface of a hydrophobic IOL and noted sodium as well as chloride spikes in their SEM and EDXS study.
There are other extensive IOL studies with light microscopy[7] and SEM.[1],[2],[3],[4],[5],[6] Microvacuoles can be picked up on an IOL by diffraction microscopy or with fluorescein staining of the IOL.[8] Alizarin Red or Von Kossa stain can be used for IOL staining, to pick up calcium deposition. We can explore IOL microvacuoles with ruthenium red stain[9] in SEM for better documentation; however, ruthenium red stain should avoided, if the researcher intends to do EDXS study in their specimen as it can alter the results of element identification.[9] IOL opacification can lead to high level of light scattering, which may affect the photon transmittance, causing actual glare and also affecting the contrast sensitivity, in the process.[10] Various spectroscopy studies can be done to understand IOL opacities, particularly the study of Raman spectroscopy on microvacuoles and IOL polymers that can open the maiden notion of this complex pathology of IOL opacification.[10],[11] The intensity of glistening can have a linear correlation with light scattering as reported by few researchers in literature.[10],[11] Researchers have also pointed toward newer IOLs, which might be resistant to such microopacification, but they need long-term follow-up to comment on it with authority, particularly in pediatric cases of IOL implantation.[6]
| References | |  |
| 1. | Jyoti K, Vats MS. Electron microscopic analysis of explanted opacified posterior chamber intraocular lens. Indian J Ophthalmol Case Rep 2022;2:395-6.  [Full text] |
| 2. | Werner L, Stover JC, Schwiegerling J, Das KK. Effects of intraocular lens opacification on light scatter, stray light, and overall optical quality/performance. Invest Ophthalmol Vis Sci 2016;57:3239–47. |
| 3. | Stringham J, Werner L, Monson B, Theodosis R, Mamalis N. Calcification of different designs of silicone intraocular lenses in eyes with asteroid hyalosis. Ophthalmology 2010;117:1486–92. |
| 4. | Neuhann IM, Werner L, Izak AM, Pandey SK, Kleinmann G, Mamalis N, et al. Late postoperative opacification of a hydrophilic acrylic (hydrogel) intraocular lens: A clinicopathological analysis of 106 explants. Ophthalmology 2004;111:2094–101. |
| 5. | Bhattacharjee H, Buragohain S, Javeri HJ, Das D. Scanning electron microscopic feature of explanted degraded hydrophobic acrylic intraocular lens which were in vivo for a prolonged period. Indian J Ophthalmol 2020;68:1086-9. [ PUBMED] [Full text] |
| 6. | Grzybowski A, Markeviciute A, Zemaitiene R. A narrative review of intraocular lens opacifications: Update 2020. Ann Transl Med 2020;8:1547. |
| 7. | Biswas J, Kumar SK. Cytopathology of explanted intraocular lenses and the clinical correlation. J Cataract Refract Surg 2002;28:538-43. |
| 8. | Das D, Deka P, Bhattacharjee H, Deshmukh S, Gupta P, Deka A, et al. Fluorescein dye as a novel cost-effective approach for staining raw specimens in ophthalmic pathology. Indian J Ophthalmol 2020;68:2175-8. [ PUBMED] [Full text] |
| 9. | Dierichs R. Ruthenium red as a stain for electron microscopy. Some new aspects of its application and mode of action. Histochemistry 1979;64:171-87. |
| 10. | Michelson J, Werner L, Ollerton A, Leishman L, Bodnar Z. Light scattering and light transmittance in intraocular lenses explanted because of optic opacification. J Cataract Refract Surg 2012;38:1476-85. |
| 11. | Xu X, Ming H, Zhang Q, Zhang Y. Properties of Raman Spectra and Laser induced birefringence in polymethyl methacrylate optical fibres. J Opt A Pure Appl Opt 2002;4:237-42. |
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