Ocular Injuries Due to Cosmetic Laser
Lasers are a commonly used tool for many cosmetic procedures, with growing popularity and availability around the world. In particular, laser-assisted hair removal is a commonly performed cosmetic procedure for semi-permanent hair reduction. Procedures can be performed by licensed physicians, mid-level practitioners, and aestheticians, generally with self-limited side effects such as mild pain, redness, and edema. While these cosmetic laser procedures are generally considered to be safe, ocular injuries may occur rarely. The risk increases when procedures are performed in the periorbital region, where the chance of a misdirected laser at the eye with inadequate safety precautions is higher.
Some common procedures performed near the eyes include laser epilation (hair removal) of eyebrows, eyeliner tattoo removal, wrinkle reduction, facial resurfacing, xanthelasma ablation, and removal of pigmented or vascular lesions. Awareness of the potential ocular injuries involved can help cosmetic laser procedure providers prevent and recognize the signs of ocular injury, assist patients with making an informed decision about undergoing the procedure, and guide ophthalmologists in assessment and treatment.
Laser Mechanism of Action
Laser use for cosmetic purposes relies on the principle of selective photothermolysis, in which specific wavelengths of light can be targeted toward a chromophore or structure while sparing the surrounding tissue. The wavelength must penetrate deep enough to affect the target. Pulses of laser light are applied to a region, and the target chromophore preferentially absorbs the specific wavelength of light. To cause irreversible damage to the chromophore, the laser should have enough fluence and pulses must be less than or equal to the thermal relaxation time of the chromophore.
For laser epilation, the target chromophore is melanin, causing damage to hair follicles and semi-permanent hair reduction. The outcome of laser treatment depends on multiple factors, including the parameters of the laser used (fluence, wavelength, pulse duration) and the patient profile (skin type and hair color).
Types of Lasers Used
Alexandrite (755 nm)
The alexandrite laser is considered to be a long-wavelength laser, despite having one of the shorter wavelengths in the category. With a long-term efficacy of 65%-80.6%, it is effective at hair removal and is commonly used on people with lighter skin tones (Fitzpatrick Types I-III).
Diode (800-810 nm)
When used at low fluences, diode lasers are 22%-59% effective at long-term hair removal and has one of the best safety profiles for use in darker skin tones (Fitzpatrick Types III-V). For hair removal, alexandrite and diode lasers have been proven to be more effective than other laser systems.
Nd:YAG (1064 nm)
The neodymium-doped yttrium aluminum garnet (Nd:YAG) laser is a long-wavelength laser that is considered to be the best for hair removal on darker skin (Fitzpatrick Types IV-VI). The longer wavelength allows for less melanin absorption by the epidermis, with higher specificity of absorption by hair follicles. Nd:YAG is also the preferred wavelength removal of tattoos with black ink. However, more side effects are reported, such as pain and inflammation, compared to diode and IPL lasers.
Intense Pulsed Light (590-1200 nm)
Although not technically a laser since it uses a broad spectrum approach, intense pulsed light (IPL) is a lower cost light treatment method or hair removal that is commonly used for larger skin areas, such as the back, chest, or legs. It emits wavelengths in the visible and infrared light spectrum.
The carbon dioxide laser (10,600 nm) is the highest-power laser that is currently available. It is effective at removing layers of skin and is used for facial resurfacing, minimizing wrinkles, and removing scars. Ruby lasers (694 nm) are used to treat hyperpigmentation, such as café au lait spots, tattoos, and pigmented lesions. For facial redness, scars, and warts, short wavelength lasers are often used, such as the potassium titanyl phosphate laser (532 nm) and pulsed dye laser (585-595 nm).
Laser Mechanisms of Injury
Rarely, ocular injuries can occur. A misdirected laser beam towards the eye or any reflective surface can penetrate the eye even when the lids are closed. The thickness of eyelids is not sufficient to protect the eye from injury from laser beam exposure, since the light can easily penetrate through. The mechanism of damage to the eye depends on the wavelength of laser used. Short wavelength lasers produce photothermal damage via photocoagulation, while long wavelength lasers can additionally instigate photomechanical damage via photodisruption.
Short wavelength lasers include potassium titanyl phosphate (KTP) and pulsed dye lasers (PDL). KTP and PDL lasers are commonly used to treat facial redness and reduce acne scars. They can cause tissue to generate enough heat to denature proteins. When directed at the eye, retinal temperature can be increased by as much as 40°-60°C, causing thermal damage.
Long wavelength lasers include diode, Nd:YAG lasers, and alexandrite lasers, which are commonly used in hair removal procedures. In addition to causing photothermal damage, they can cause an explosive acoustic shock, where sheared fragments of the chromophore can perforate surrounding tissue, causing mechanical damage.
The most frequently reported laser causing ocular damage is the carbon dioxide laser, which has a very high wavelength of 10,600 nm. Carbon dioxide is followed by alexandrite, diode, and Nd:YAG in most common lasers implicated in ocular injury. Notably, these are all long wavelength lasers that cause both photothermal and photomechanical damage to the eye.
Lack of adherence to safety precautions and accidental misdirecting of lasers can cause ocular injury during periorbital laser treatments. In a study of 40 patients with ocular injury, only 15% were wearing protective eyewear. Providers often ask patients to remove protective eyewear during eyebrow epilation or eyeliner tattoo removal, adding to the risk of laser exposure to the eye. especially high. Furthermore, Bell’s phenomenon (where the eye naturally rolls upward upon eyelid closure) increases the risk of damage to the iris by bringing anterior eye structures closer to the laser’s radiation range.
Laser parameters, patient profile (eye, skin, and hair type), and safety protocols all play a role in the outcome of laser treatment.
The severity of ocular injury from cosmetic lasers depends on the duration of the exposure, distance from the exposure, and the amount of energy delivered. More severe injuries are associated with longer exposure durations, shorter exposure distances, and higher fluences. Longer wavelength lasers, such as carbon dioxide, Alexandrite, Nd:YAG lasers, can penetrate deeper layers of the skin and have been the cause of more reported ocular injuries.
In patients with light-colored eyes, the laser is more likely to penetrate past the iris and cause damage in the posterior eye structures. As a result, the laser is absorbed by the retinal pigment epithelium, leading to visual changes. Patients with darker eyes will more often report pupillary abnormalities such as iris atrophy, since the melanin in the iris absorbs most of the radiation.
Having a pupil size of 2-3mm and having a history of ocular abnormalities are associated with an increased risk of ocular injury from cosmetic lasers. Patients with higher initial visual acuity are also more likely to report ocular issues, likely due to the increased chance of noticing acute vision changes.
Skin and Hair Color
For laser epilation, the target chromophore is melanin in the hair follicle. However, the melanin in the epidermis competes with the hair follicle for absorption of light absorption. While ocular injuries are not directly linked skin and hair color, different skin types are better suited for specific wavelengths of lasers. Lasers with higher wavelengths (such as diode and Nd:YAG) which are more likely to cause ocular damage, are better suited for effective hair and pigment removal from people with darker skin.
The patient, provider, and observers are all at risk for ocular damage due to incidental exposure of lasers. The majority of cases of ocular damage due to cosmetic exposure have occurred when safety precautions were evaded. However, in a review of 21 case reports, 33% of cases had severe ocular injury even when proper use of wavelength-specific goggles and intraocular corneal shields were used.
Symptoms and Exam Findings
Signs of ocular injury due to cosmetic laser procedures are typically easy to identify due to the short temporal relationship between laser exposure and symptom onset. Listed in order of most to least common, patients report the following ocular symptoms after laser therapy:
- Visual abnormality (includes decreased visual acuity, blurriness, shadow, scotoma, and metamorphopsia)
- Pain, discomfort, irritation
- Erythema or hyperemia
- Pupil irregularity
- Flashing light
On initial ophthalmologic exam, findings may include the following conditions, listed in order of decreasing incidence:
- Corneal abnormality (includes swelling, abrasion, ulceration, and epithelial defects)
- Evidence of thermal injury
- Pupillary irregularity (includes iris atrophy)
- Conjunctival/ciliary infection
- Increased intraocular pressure or glaucoma
- Vitreous hemorrhage
- Choroidal neovascularization.
Cosmetic laser providers are not immune to ocular injury. One case report described a dermatologist who experienced central scotoma after performing a procedure using a Nd:YAG laser without wearing protective eyewear. The dermatologist had held a glass slide to the treatment area, incidentally reflecting the laser beam off the reflective surface. Foveal choroidal neovascularization was detected two weeks after the procedure.
Complications have also been reported due to incidental laser exposure with use of metal corneal shields. For example, one patient developed bilateral bullous keratopathy following CO2 laser facial resurfacing, most likely due to overheating of the metal shields from inadequate cooling time between laser pulses. A more recent case report described a patient wearing metal corneal shields who developed corneal ulceration and scarring, iris deformity, cataract, and burned eyelashes after CO2 laser resurfacing for periocular rhytides. The study found that cataract can form when corneal temperatures reach 80°C for 14 seconds, and that the eye injuries sustained by the patient were caused by heating of the metal corneal shields by at least 10 consecutive incidental laser impacts.
While there are numerous case reports describing the initial symptoms and clinical findings of patients with ocular injury following a cosmetic laser procedure, there is little consensus on the long-term sequelae and outcomes of these patients. Depression has been reported in cases with reduced vision after cosmetic laser procedures.
Anterior Segment Injury
Diode laser epilation to the eyelid area has led to reported cases of nuclear cataracts and iris atrophy. Patients may present weeks after receiving the laser treatment with decreased visual acuity and increased light sensitivity, along with a history of pain during the laser procedure. It can be concluded from these cases that diode laser can be cataractogenic.
Alexandrite laser treatment of the eyelid has resulted in iritis, pupillary distortion, iris atrophy, and anterior uveitis.   Patients may present with photophobia, pain, tearing, irregular pupil, glare, and blurred vision.   On examination, there may be injected conjunctiva, superficial punctate keratopathy, transillumination defects, and poor pupillary response.   Intraocular pressure and the posterior pole are usually spared.  
Damage to the iris is irreversible and patients can suffer long-term effects on vision. Steroids and cycloplegics have been found to be beneficial in restoring vision.  
Posterior Segment Injury
Inappropriate use of alexandrite lasers for hair removal has led to reports of subfoveal and intraretinal hemorrhages. Patient presentation may vary from eye discomfort with 20/20 vision to decreased visual acuity reaching 20/200. One patient reported seeing a black shadow immediately after the laser session. Anterior segment examination is expected to be within normal limits. On fundus examination, subfoveal or intraretinal hemorrhage can be noted. Macular SD-OCT would reveal hyper-reflective lesions.
Choroidal neovascularization can occur as an adverse event. Fundus fluorescein angiography would reveal hyperfluorescence in the early phase and late leakage, which are characteristics of a choroidal neovascular membrane. Intravitreal bevacizumab 1.25mg/0.05mL was found to be highly effective in these cases, restoring vision back to 20/20 with complete involution of the membrane.
Non-Ocular Side Effects of Cosmetic Lasers
Post-operative complications may occur that impact the periorbital region. Some common complications include erythema in the treated region, scarring, bacterial infection, and hyper- or hypopigmentation.
The treatment of ocular damage due to cosmetic lasers depends on the extent and type of injury sustained. A few treatments for common laser-induced injuries are discussed below.
For superficial lesions, topical antibiotics, topical steroids, and contact lens or patching may be indicated. For corneal lesions involving the endothelium, surgical intervention with corneal transplantation may be necessary, since endothelial involvement can lead to bullous changes, corneal thickening, or vision loss.
Topical, injectable, implantable, or systemic corticosteroids are indicated for laser-induced retinal injury. Corticosteroids help in reducing inflammation, healing the retinal pigment epithelium, reducing macrophage activity, mitigating photoreceptor damage, and re-establishing retinal and choroidal vasculature.
Topical or oral ascorbic acid is often prescribed to promote fibroblast activity to minimize ocular damage. Other drugs that may be considered are topical prostaglandin analogs, topical antibiotics, injectable anti-vascular endothelial growth factor drugs, and appropriate surgical intervention.
Laser providers are trained to recognize signs of ocular injury and refer patients to an ophthalmologist. There are currently no guidelines on dosing and preferred medications for ophthalmologists specifically for cosmetic laser-induced ocular injury. However, obtaining a thorough history and physical exam can help ophthalmologists determine the appropriate treatment regimen for the patient.
While cases of ocular injury due to cosmetic lasers remain rare, they can be minimized by adhering to proper safety protocols before, during, and after the procedure. In a review of 21 case reports of ocular injuries due to cosmetic lasers, 62% involved no protective eyewear or the removal of goggles when treating periorbital regions. Safety precautions must be followed to protect both the provider and patient throughout the laser procedure.
Wavelength-specific goggles that block laser radiation should be worn by the operating personnel, the patient, and any observers to reduce the risk of ocular damage. Goggles should fit snugly but comfortably, and should remain on at all times, especially during laser alignment. Providers often ask patients to remove their protective eyewear when targeting periorbital regions, such as during eyebrow epilation, to have easier access to the target area. However, it is crucial to have goggles on during these periorbital procedures, as there is high risk of laser exposure to the eye. In one study of 40 patients with ocular injury, 34 did not wear protective eyewear, and 5 wore goggles that were not wavelength-specific. Since laser radiation can reflect from shiny surfaces, it is imperative that the provider also wear protective goggles.
Corneal shields are especially important for the patient to wear when protective goggles are unfeasible, such as during eyeliner tattoo removal or eyelash cauterization. After applying a topical anesthetic to the eyes, corneal shields can be placed like a contact lens over the eyeball. The largest shield possible should be used to maximize the area of the cornea that is covered and to reduce the risk of shifting during the procedure. While both metal and plastic corneal shields exist, metal corneal shields are preferred, since there is reduced risk of thermal damage. One study found that plastic shields melted or caught fire when radiation from long-wavelength Nd:YAG and carbon dioxide lasers were applied. It is important for providers to wear wave-specific goggles while operating on patients wearing metal corneal shields, since laser radiation can reflect off the surface. In addition, risk of corneal abrasion from wearing corneal shields is possible, but can be minimized with appropriate lubrication.
Corneal and Periorbital Cooling
In some ophthalmologic laser procedures, corneal cooling via eye irrigation with a chilled balanced saline solution is performed and has been found to be effective in preventing ocular injury. While this may not be necessary in cosmetic laser procedures, cooling of periorbital regions can help protect against epidermal injury. This can be achieved using contact methods, such as an ice pack, or non-contact methods, such as cold air or cryogen spray.
Patient and Provider Education
The increase in popularity of home-use laser epilation devices further necessitates that patients who are self-administering cosmetic laser treatments be aware of safety protocols and potential complications. Lasers are especially dangerous when the light is not in the visible spectrum, since it is unclear when the device is on. While these FDA-approved devices have built-in safety mechanisms that only allow laser radiation when in contact with the skin, risk of device failure may occur. Users must understand the importance of wearing proper eye protection, avoiding direct gaze, and avoiding use of the laser in a room with highly reflective surfaces such as mirrors.
Reported laser accidents from the British Medical Laser Association in 2003 revealed that 66.6% of cases were due to operator error. In US legal cases filed after laser surgery, almost half had non-physicians listed as the primary laser operator. This suggests that mid-level providers or aestheticians comprise a large proportion of cosmetic laser operators. It is critical that all cosmetic laser providers have sufficient medical knowledge to counsel patients on postoperative complications, and should be able to recognize the common signs of ocular damage.
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Gan SD, Graber EM. Laser hair removal: A review. Dermatologic Surgery. 2013; 39(5):823-38.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Brilakis HS, Holland EJ. Diode-laser-induced cataract and iris atrophy as a complication of eyelid hair removal. Am J Ophthalmol. 2004; 137(4):762-3.
- ↑ Yates B, Que SK, D'Souza L, Suchecki J, Finch JJ. Laser treatment of periocular skin conditions. Clin Dermatol. 2015;33(2):197-206.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 Huang A, Phillips A, Adar T, Hui A. Ocular Injury in Cosmetic Laser Treatments of the Face. J Clin Aesthet Dermatol. 2018;11(2):15-18.
- ↑ Anderson RR, Parrish JA. Selective photothermolysis: precise microsurgery by selective absorption of pulsed radiation. Science. 1983;220(4596):524–527.
- ↑ 6.0 6.1 Arsiwala SZ, Majid IM. Methods to overcome poor responses and challenges of laser hair removal in dark skin. Indian J Dermatol Venereol Leprol. 2019;85(1):3-9.
- ↑ Khoury JG, Saluja R, Goldman MP. Comparative evaluation of long-pulse alexandrite and long-pulse Nd:YAG laser systems used individually and in combination for axillary hair removal. Dermatologic Surg. 2008;34(5): 665-71.
- ↑ 8.0 8.1 8.2 Mu YZ, Jiang L, Yang H. The efficacy of fractional ablative carbon dioxide laser combined with other therapies in acne scars. Dermatol Ther. 2019;32(6):e13084.
- ↑ 9.0 9.1 9.2 9.3 Mainster MA, Stuck BE, Brown J Jr. Assessment of alleged retinal laser injuries. Arch Ophthalmol. 2004;122(8):1210-1217.
- ↑ 10.0 10.1 10.2 10.3 Shum JW, Iu LP, Cheung DN, Wong IY. A case of accidental ocular injury from cosmetic laser burn. Retin Cases Brief Rep. 2016;10(2):115-120.
- ↑ 11.0 11.1 11.2 11.3 11.4 11.5 Juhasz M, Zachary C, Cohen JL. Ocular Complications After Laser or Light-Based Therapy-Dangers Dermatologists Should Know [published online ahead of print, 2021 Mar 9]. Dermatol Surg. 2021;10.1097.
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- ↑ 13.0 13.1 13.2 13.3 13.4 13.5 Lin CC, Tseng PC, Chen CC, Woung LC, Liou SW. Iritis and pupillary distortion after periorbital cosmetic alexandrite laser. Graefes Arch Clin Exp Ophthalmol. 2011;249(5):783-785.
- ↑ Barkana Y, Belkin M. Laser eye injuries. Surv Ophthalmol 2000;44: 459–78
- ↑ 15.0 15.1 Milsom PK, Till SJ, Rowlands G. The effect of ocular aberrations on retinal laser damage thresholds in the human eye. Health Phys. 2006; 91:20–8.
- ↑ 16.0 16.1 16.2 16.3 16.4 Lee YH, Kim YC. Foveal choroidal neovascularization secondary to accidental laser exposure in a dermatologist: A case report. Medicine (Baltimore). 2019;98(18):e15429.
- ↑ Widder RA, Severin M, Kirchhof B, et al. Corneal injury after carbon dioxide laser skin resurfacing. Am J Ophthalmol. 1998;125(3):392–394.
- ↑ 18.0 18.1 van Gemert MJC, Bloemen PR, Wang WY, et al. Periocular CO2 laser resurfacing: severe ocular complications from multiple unintentional laser impacts on the protective metal eye shields. Lasers Surg Med. 2018;50(10):980-986.
- ↑ Balyen L. Inadvertent macular burns and consecutive psychological depression secondary to Alexandrite laser epilation: A case report. Saudi J Ophthalmol. 2019;33(1):105-108.
- ↑ 20.0 20.1 20.2 20.3 20.4 Elkin Z, Ranka MP, Kim ET, Kahanowicz R, Whitmore WG. Iritis and iris atrophy after eyebrow epilation with alexandrite laser. Clin Ophthalmol. 2011;5(1):1733-5.
- ↑ 21.0 21.1 21.2 21.3 21.4 21.5 Lin LT, Liang CM, Chiang SY, Yang HM, Chang CJ. Traumatic macular hole secondary to a Q-switch Alexandrite laser. Retina. 2005;25(5):662-665.
- ↑ 22.00 22.01 22.02 22.03 22.04 22.05 22.06 22.07 22.08 22.09 22.10 22.11 22.12 Asiri MS, Alharbi M, Alkadi T, Abouammoh M, Al-Amry M, Al Zahrani Y, et al. Ocular injuries secondary to alexandrite laser-assisted hair removal. Can J Ophthalmol. 2017;52(2):e71-e75.
- ↑ 23.0 23.1 Bowman PH, Fosko SW, Hartstein ME. Periocular reconstruction. Semin Cutan Med Surg. 2003 Dec;22(4):263-72
- ↑ Gulmez Sevim D, Oner AO, Unlu M, Mirza GE. Ocular complications after cosmetic periocular diode laser application to the eyelids. J Cosmet Laser Ther. 2018;20(7-8):447-448.
- ↑ Nordqvist C, Fracheboud S, Guex-Crosier Y. Intense Pulsed Light Eyebrow Epilation and Iris Lesion. Klin Monbl Augenheilkd. 2018;235(4):450-452.
- ↑ Kataoka T, Zako M, Takeyama M, et al. Cooling prevents induction of corneal damage by argon laser peripheral iridotomy. Jpn J Ophthalmol. 2007;51(5):317–324.
- ↑ AlTaleb RM, Alsharif HM, Younis AS, Alsulaiman SM, Abouammoh MA. Adherence to optical safety guidelines for laser-assisted hair removal. Photodermatol Photoimmunol Photomed. 2019;35(5):313–7.
- ↑ Moseley H. Operator error is the key factor contributing to medical laser accidents. Lasers Med Sci 2004;19:105–11.
- ↑ Jalian HR, Jalian CA, Avram MM. Common causes of injury and legal action in laser surgery. JAMA Dermatol 2013;149:188–93.