Exposing the LASIK Scam

Exp Eye Res. 2004 Mar;78(3):513-25.

Neural basis of sensation in intact and injured corneas.

Belmonte C, Acosta MC, Gallar J.

Instituto de Neurociencias de Alicante, Universidad Miguel Hern?ndez-CSIC, Apdo correos 18, 03550 San Juan de Alicante, Spain. carlos.belmonte@umh.es

Excerpts:

In humans, the magnitude of stromal nerve injury and the temporal pattern of regeneration consecutive to the various refractive surgery procedures (radial keratotomy, photorefractive keratectomy, laser-assisted in situ keratomileusis) seem also to be variable. Nonetheless, in all circumstances in which stromal and epithelial nerves were destroyed, the injured area in the cornea was first entered by sprouts of intact neurons, some of them that had their receptive field limited originally to the conjunctiva (de Felipe and Belmonte, 1999), followed in the next weeks by the advance of regenerating axons of the severed nerves. Only a proportion of regenerated axons succeed in penetrating the denervated, injured corneal tissue. Microneuromas and nerves presenting a random and disorderly distribution pattern, with hyperregeneration and abnormal shapes, were often observed in the scar region and in the reinnervated territory long time after the lesion (Wolter, 1966; Chan et al., 1990; Trabucchi et al., 1994).



The differences in sensitivity disturbances as well as the variability found among individuals in the degree and time course of sensibility recovery after PRK or LASIK are not surprising considering the variability among studies in the type of lesion, excision depth, extension of nerve damage, etc. The reduced discrimination capacity of the Cochet? Bonnet esthesiometer is also a limiting factor.When the more sensitive gas esthesiometer (Belmonte et al., 1999) was employed and corneal mechanical and chemical sensitivity was measured at variable times after LASIK surgery (Gallar et al., 2003b) corneal sensitivity to mechanical and chemical stimulation was noted to be seriously reduced in the first week after surgery, appeared enhanced around the flap and in the hinge area 2 weeks later, and then dropped remarkably and remained significantly below control levels, 3 and 6 months post-LASIK. Sensitivity to both types of stimuli was close to normal only 2 years post-surgically (Fig. 5).



It is worth noting that the incidence of long-lasting discomfort symptoms attributable to nerve damage that was reported by patients subjected to this type of surgery is surprisingly high. A study with 231 PRK patients and 550 LASIK patients performed by Hovanesian et al. (2001) revealed an incidence of dryness symptoms in 43 and 48%, respectively. Soreness of the eye to touch was reported by 26.8% and 6.7%, respectively (P <.0001). Sharp pains occurred in 20.4% of PRK patients and 8.0% of LASIK patients (P =.0001). Complaints of the eyelid sticking to the eyeball occurred in 14.7% and 5.6%, respectively (P =.0001).



In LASIK surgery, the lamellar incision made with the microkeratome to create the flap, cuts the nerve fibre bundles of the superficial stroma and the subbasal nerve plexus at the flap. Nerve fibre bundles in the corneal bed located in the middle-third of the stroma are spared but suffer a variable degree of injury during photoablation.



Link to the full text:
http://www.lasikfraud.com/articles/neur ... sation.pdf

J Cataract Refract Surg. 2001 Apr;27(4):577-84.

Symptoms of dry eye and recurrent erosion syndrome after refractive surgery.

Hovanesian JA, Shah SS, Maloney RK.
Jules Stein Eye Institute and the Department of Ophthalmology, UCLA School of Medicine, Los Angeles, California, USA.

PURPOSE: To determine the incidence and severity of patient complaints typical of dry eye and recurrent erosion syndrome after excimer laser refractive surgery and to compare the incidence of these symptoms after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).

SETTING: Outpatient university practice.

METHODS: A questionnaire was mailed to 1731 patients who had had primary myopic PRK or LASIK at least 6 months previously. Questions were designed to determine the incidence and character of ocular dryness and recurrent erosion symptoms and their impact on patient satisfaction and willingness to have surgery again. Responses from PRK and LASIK patients were compared.

RESULTS: Responses from 231 PRK patients and 550 LASIK patients revealed an incidence of dryness symptoms in 43% and 48%, respectively (P >.05). Soreness of the eye to touch was reported by 26.8% and 6.7%, respectively (P <.0001). Sharp pains occurred in 20.4% of PRK patients and 8.0% of LASIK patients (P =.0001). Complaints of the eyelid sticking to the eyeball occurred in 14.7% and 5.6%, respectively (P =.0001). All symptoms occurred predominantly on waking. Frequency of eyelid sticking (P <.0005) and sharp pain (P <.005) symptoms, as well as severity of sharp pain symptoms (P <.0001), were significantly greater in PRK patients than in LASIK patients. On a scale of 0 to 10 (10 high), median overall patient satisfaction with surgery was 9 in both groups. Soreness of the eyelid to touch occurred significantly more frequently among patients with symptoms of sharp pains on waking (P <.001) and the sensation of the eyelid sticking to the eyeball (P <.001). Patients with 1 or more symptoms were twice as likely as asymptomatic patients to have a satisfaction score of less than 8 (P <.001).

CONCLUSIONS: Ocular dryness symptoms occurred commonly after PRK and LASIK. Symptoms suggestive of mild recurrent erosions included sharp pains, the sensation of the eyelid sticking to the eyeball, and soreness of the eyelid to touch, a previously unrecognized symptom of this condition. These symptoms occurred commonly after excimer laser procedures but were significantly more common, more severe, and more prolonged after PRK. The presence of these symptoms had a significant effect on patient satisfaction.

I am going to try to get the full text of this (no abstract available):

Arch Ophthalmol. 2007 Oct;125(10):1423-5.
Laser in situ keratomileusis flap necrosis after trigeminal nerve palsy.
Rocha GA, Acera A, Dur?n JA.
Instituto Cl?nico-Quir?rgico de Oftalmolog?a, Virgen de Bego?a 34, 48006 Bilbao, Spain. duran@icqo.org.

Am J Ophthalmol. 2002 Aug;134(2):264-5.

Infraorbital nerve palsy: a complication of laser in situ keratomileusis.

McCulley TJ, Eifrig CW, Schatz NJ, Rosenfeld SI, Lam BL.
Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA.

PURPOSE: To report infraorbital nerve dysfunction after laser in situ keratomileusis.

DESIGN: Observational case report.

METHODS: Neuro-ophthalmologic examination with brain and orbital magnetic resonance imaging (MRI) and orbital computed tomography (CT).

RESULTS: During laser in situ keratomileusis, two healthy women, aged 42 and 46 years, experienced acute onset of sharp ipsilateral cheek pain. Both cases occurred during manipulation of the eyelid speculum. Postoperatively, ipsilateral numbness and tingling or pain of the upper cheek was reported, and examination showed decreased sensation in the distribution of the infraorbital nerve. In both cases, brain and orbit MRI and orbit CT were normal. Both patients were managed medically. In one patient, mild symptoms persisted 1 year postoperatively, and in the second patient, moderate discomfort persisted 8 months postoperatively.

CONCLUSION: Infraorbital nerve palsy is a potential complication of laser in situ keratomileusis. Symptoms improve but may persist.