Contraindications for Laser Vision Correction

Aug 19, 2021
10 min read
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As with any surgical procedure, it is important to weigh the risks and benefits of laser vision correction to ensure risks do not outweigh the potential benefits. This article will highlight the basic differences between LASIK, PRK, and SMILE as well as the contraindications related to these common LVC procedures. Although most patients will be very satisfied with the results of their refractive surgery, it is important that physicians know to say “no” when encountering relevant contraindications.

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LASIK

LASIK is one of the most popular and commonly performed refractive surgery techniquesdue to its superlative safety and efficacy profile.1 In 2020, despite a global coronavirus pandemic, approximately 718,000 LASIK procedures were performed in the United States.

LASIK involves three fundamental steps:

  1. Create a partial-thickness laminar corneal flap.
  2. Lift the corneal flap and ablate the corneal stromal bed.
  3. Return the corneal flap to its original position.

LASIK corneal flaps are created with a femtosecond laser and corneal stromal bed ablation is carried out with an excimer laser.2

LASIK is efficacious in the treatment of hyperopia, myopia, and astigmatism. It has become the cornerstone of LVC techniques for most patients due to its quick healing time. Studies have shown the mean epithelial healing time to be in the range of three to five days with a known and acceptable safety profile.3

PRK

PRK was developed in 1987 and is defined by a lack of a lamellar corneal flap. Instead, PRK involves removing the top layer of corneal epithelium.4 Once the epithelial layer of the cornea is removed, an excimer laser is used to pertubate the corneal stroma.

The main advantage of PRK lies in the lack of a lamellar corneal flap which is ideal for patients with thinner corneas. The thicker cornea left behind after PRK can be considered a safer alternative to LASIK due to the lower risk for postoperative complications such as ectasia, which is characterized by abnormal asymmetric steepening of the cornea.6 Contrastingly, since the corneal surface is debrided in PRK, patient recovery and healing time are longer.

SMILE

SMILE is a relatively newer LVC technique and was approved by the United States Food and Drug Administration (FDA) to treat myopia in 2018. The main appeal of SMILE, as compared to other more established refractive surgical techniques, is a preferable safety profile with less postoperative incidence of dry eye and faster recovery times.8 Since SMILE was introduced globally, approximately 2 million procedures have been performed.

The SMILE procedure is performed using a femtosecond laser to create a lenticulate (disc-shaped piece of cornea), which is then extracted from the eye through a 2-5 mm corneal incision.8 Unlike LASIK, no corneal flap is required to perform this surgery. It also differs from PRK in that the anterior stromal layer is completely preserved. Although the SMILE technique affords better ocular biomechanical integrity, studies have shown that the postoperative risk of ectasia can vary.9

Contraindications for LASIK, PRK, and SMILE

Contraindications for LVC with LASIK, PRK, and SMILE include medications, abnormal corneal anatomy, autoimmune conditions, and certain specific periods of corneal structure development (e.g., childhood, pregnancy, lactation periods).10 Physicians must inquire prior medical history to ensure informed decision-making with patients.

Medications

Isotretinoin, commonly known as Accutane, is a relative contraindication for LVC. Due to the high prevalence of acne vulgaris, isotretinoin is routinely prescribed.11 Notwithstanding, the ocular ramifications of LVC on patients actively taking isotretinoin are often overlooked. Since the average age of a patient on isotretinoin is 24 years, it creates significant overlap with the major LVC demographic of 18-30 years.12

Specifically, dry eye disease is a major adverse effect of LVC and isotretinoin should not be started if a patient has undergone refractive surgery in the previous six months. Moreover, before performing LVC, ophthalmologists should screen patients for isotretinoin use.12 Due to the serious nature of post-operative dry eye, both ophthalmologists and dermatologists should actively counsel patients on the effects of LVC on patients actively taking isotretinoin.

Amiodarone, an antiarrhythmic cardiac medication, is known to have an adverse effect profile which can cause optic neuropathy and cyanopsia (vision defect resulting in objects appearing to have a blue tint). Cases show patients on amiodarone can develop visual disturbances such as dysphotopsias (flashes and colored rings around lights) after refractive surgery.13 Discontinuation of Amiodarone, in consultation with the patient’s cardiologist, has led to substantial improvements in LVC outcomes.13

Corneal Anatomy Pathology

Patients with a history of rigid contact lenses are more likely to develop corneal topographical anatomical abnormalities. Before LVC is performed, a thorough examination of a patient's cornea is essential to assuring a safe procedure. Contraindicative corneal abnormalities include astigmatism, loss of radial symmetry, and the absence of normal progressive flattening from the center to the periphery of the cornea.14

Rigid contact lenses are a common possible source for these pathogenic corneal abnormalities. It is worth noting that these conditions can also be seen in people who regularly wear soft contact lenses. The topographic changes in the cornea after contact lens removal can affect postoperative wound healing in an unpredictable and irregular manner.15 If abnormalities are present and permanent, LVC should not be performed. Complications of progressive corneal thinning like keratoconus can result in severe vision loss.

Autoimmune Diseases

Collagen vascular diseases(CVD) are a relative contraindication to refractive surgery due to the possible ocular manifestations of these diseases. CVD represents a group of autoimmune diseases including rheumatoid arthritis (RA), Sjogren's Syndrome (SS), and seronegative spondyloarthropathies.16

Dry eye or keratoconjunctivitis sicca is the most common ocular manifestation of disease seen in patients with RA. Studies comparing the outcomes of LVC in patients with and without CVD demonstrate variable and inconclusive conclusions.16,17 Long-term adverse effects of LVC should be extensively discussed between ophthalmologists and their patients with autoimmune conditions. Due to the fact that LASIK has a quicker wound healing time than PRK, it is the preferred form of refractive surgery in patients with autoimmune diseases.

Diabetes mellitus can present with a multitude of ocular manifestations including diabetic keratopathy, diabetic retinopathy, diabetic papillopathy, and refractive instability.16 In diabetes mellitus, defects in insulin sensitivity produce chronic hyperglycemia.18 Patients with uncontrolled diabetes mellitus undergoing LVC show high complication rates of 47% compared to only 6.9% in healthy controls.19 LVC should be avoided on patients with uncontrolled diabetes mellitus or diabetic ocular complications.16

Ocular Development

LVC should be avoided during periods of ocular development and change such as pregnancy and lactation as hormonal changes can lead to changes in refraction.16 Sex hormone receptors can be found in the cornea, and during pregnancy and lactation the overproduction of estrogen can lead to corneal biomechanical instability.21 The evidence suggests that the risk of postoperative corneal ecstasia is significantly elevated during these time periods. Refractive surgeons recommend waiting until after a female's nursing period to perform potential LVC.

Conclusion

Although LVC continues to be a predominantly successful and safe intervention, the need to be cognizant of the relevant contraindications discussed above is paramount. Honest patient-physician rapport is key to effective informed decision making and knowing when to say no to LVC.

References

  1. Bohac M, Koncarevic M, Pasalic A, et al. Incidence and Clinical Characteristics of Post LASIK Ectasia: A Review of over 30,000 LASIK Cases. Seminars in Ophthalmology. 2018;33:1-9. doi:10.1080/08820538.2018.1539183
  2. Kim T-I, Alió del Barrio J, Wilkins M, Cochener B, Ang M. Refractive surgery. The Lancet. 2019;393:2085-2098. doi:10.1016/S0140-6736(18)33209-4
  3. Pallikaris IG, Kalyvianaki MI, Katsanevaki VJ, Ginis HS. Epi-LASIK: Preliminary clinical results of an alternative surface ablation procedure. Journal of Cataract and Refractive Surgery. 2005;31(5):879-885. doi:10.1016/j.jcrs.2004.09.052
  4. Ambrósio R, Wilson SE. LASIK vs LASEK vs PRK: Advantages and indications. Seminars in Ophthalmology. 2003;18(1):2-10. doi:10.1076/soph.18.1.2.14074
  5. Hatch BB, Moshirfar M, Ollerton AJ, Sikder S, Mifflin MD. A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function. Clin Ophthalmol. 2011;5:451-457. doi:10.2147/OPTH.S18967
  6. Heitzmann J, Binder PS, Kassar BS, Nordan LT. The correction of high myopia using the excimer laser. Arch Ophthalmol. 1993;111(12):1627-1634. doi:10.1001/archopht.1993.01090120049021
  7. Ectasia After LASIK - EyeWiki. Accessed July 30, 2021. https://eyewiki.aao.org/Ectasia_After_LASIK#Definition
  8. Doane JF, Cauble JE, Rickstrew JJ, Tuckfield JQ. Small Incision Lenticule Extraction SMILE – The Future of Refractive Surgery is Here. Mo Med. 2018;115(1):82-84.
  9. Seven I, Vahdati A, Pedersen IB, et al. Contralateral Eye Comparison of SMILE and Flap-Based Corneal Refractive Surgery: Computational Analysis of Biomechanical Impact. J Refract Surg. 2017;33(7):444-453. doi:10.3928/1081597X-20170504-01
  10. Messmer JJ. LASIK: A Primer for Family Physicians. AFP. 2010;81(1):42-47.
  11. Ruiz-Lozano RE, Hernández-Camarena JC, Garza-Garza LA, Bustamante-Arias A, Colorado-Zavala MF, Garza JAC la. Isotretinoin and the eye: A review for the dermatologist. Dermatologic Therapy. 2020;33(6):e14029. doi:10.1111/dth.14029
  12. Basheikh A, Alattas A, Alshareef R, Bamahfouz A. Dermatologists’ Knowledge and Attitudes Toward Dry Eye Disease, Refractive Surgery, and Contact Lenses When Prescribing Isotretinoin in Saudi Arabia. Clin Ophthalmol. 2020;14:4519-4522. doi:10.2147/OPTH.S292569
  13. Naser M, Shushtarian SMM, Shojaei A, Adlami-Moghdam F. Visual Disturbance in a Patient with Amiodarone Treatment Following Refractive Surgery. Journal of Ophthalmic and Optometric Sciences. 2017;1(3):39-42. doi:10.22037/joos.v1i3.23351
  14. Ruiz-Montenegro J, Mafra CH, Wilson SE, et al. Corneal topographic alterations in normal contact lens wearers. Ophthalmology 1993; 100:128-34.
  15. Wilson SE, Klyce SD. Screening for Corneal Topographic Abnormalities Prior to Refractive Surgery: Cornea. 1994;13(1):95-96. doi:10.1097/00003226-199401000-00031
  16. AlKharashi M, Bower KS, Stark WJ, Daoud YJ. Refractive Surgery in Systemic and Autoimmune Disease. Middle East Afr J Ophthalmol. 2014;21(1):18-24. doi:10.4103/0974-9233.124082
  17. Smith RJ, Maloney RK. Laser in situ keratomileusis in patients with autoimmune diseases. J Cataract Refract Surg. 2006;32(8):1292-1295. doi:10.1016/j.jcrs.2006.02.059
  18. Kharroubi AT, Darwish HM. Diabetes mellitus: The epidemic of the century. World J Diabetes. 2015;6(6):850-867. doi:10.4239/wjd.v6.i6.850
  19. Fraunfelder FW, Rich LF. Laser-assisted in situ keratomileusis complications in diabetes mellitus. Cornea. 2002;21(3):246-248. doi:10.1097/00003226-200204000-00002
  20. Fraunfelder FW, Rich LF. Laser-assisted in situ keratomileusis complications in diabetes mellitus. Cornea. 2002;21(3):246-248. doi:10.1097/00003226-200204000-00002
  21. Spoerl E, Zubaty V, Raiskup-Wolf F, Pillunat LE. Oestrogen-induced changes in biomechanics in the cornea as a possible reason for keratectasia. Br J Ophthalmol. 2007;91(11):1547-1550. doi:10.1136/bjo.2007.124388
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About Usman Saeedullah

Usman Saeedullah is a medical student at NYIT-College of Osteopathic Medicine. He has been interested in ophthalmology ever since he worked at an ophthalmology clinic observing retinal procedures. Usman graduated from Stony Brook University in 2020 with a Bachelor of …

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