Complication Of Laser In Situ Keratomileusis Research Articles

Complications of laser in situ keratomileusis (LASIK)

Laser-in-situ-keratomileusis (LASIK) is one of the most commonly done refractive surgeries round the globe. It has become a popular technique of refractive surgery because of lower postoperative discomfort, early visual rehabilitation and decreased post-operative haze. This review journal aims to give a brief outline about intra and postoperative complications of LASIK, clinical presentation and management guidelines for these complications. Intraoperative complications include free cap, buttonhole flap, flap tear, decentered ablation, interface debris and femtosecond laser related complications like vertical gas breakthrough and opaque bubble layer. Postoperative complications include flap striae, epithelial ingrowth, diffuse lamellar keratitis, residual refractive error, refractive regression and many more. The knowledge about these complications help the surgeon in early identification and timely intervention for achieving optimal visual outcome.

Flap Thickness and the Risk of Complications in Mechanical Microkeratome and Femtosecond Laser In Situ Keratomileusis: A Literature Review and Statistical Analysis.

Introduction: A recent Cochrane review found no difference in visual acuity outcomes between femtosecond-assisted laser in situ keratomileusis (LASIK) and LASIK using mechanical microkeratomes (MMKs). This study compares the flap thickness and risk of complications related to flap creation using femtosecond lasers and MMKs. Methods: PubMed and the Web of Science are used to search the medical literature. An extensive search is performed to identify the flap thickness and complications of LASIK as reported up to 15 July 2021. The following keywords are used in various combinations: Corneal flap, femtosecond laser, laser in situ keratomileusis, laser-assisted in situ keratomileusis, LASIK, mechanical microkeratome. Results: After removing duplicates and irrelevant studies, 122 articles were included for review. Pooled differences for intended vs. postoperative flap thickness using MMKs and femtosecond laser were −4.07 μm (95% CI: −19.55, 3.24 μm) in studies on the MMK and 5.43 μm (95% CI: 2.30, 7.84 μm; p < 0.001), respectively. After removing the studies evaluating outcomes of the old generation Hansatome MMKs (which had a significantly greater variation of flap thickness), the pooled difference for newer MMKs was 4.97 μm (95% CI: 0.35, 9.58 μm; p < 0.001), but the results still favored the femtosecond laser. Uncommon and mild complications unique for the femtosecond LASIK are epithelial gas breakthrough, opaque bubble layer, transient light sensitivity syndrome, and rainbow glare. A single study reported a very low, but stastically different risk of postoperative flap slippage (0.033% for MMK LASIK, and 0.003% for femtosecond LASIK, respectively). Conclusion: In both manual microkeratome and femtosecond LASIK, intra- and postoperative complications were uncommon. The evidence of the superiority of one technique in terms of complications over another cannot be indisputably stated.

Relevance of Swept-Source Anterior Segment Optical Coherence Tomography for Corneal Imaging in Patients With Flap-Related Complications After LASIK

To evaluate the role of swept-source anterior segment optical coherence tomography (AS-OCT) in the diagnosis and management of laser in situ keratomileusis (LASIK) flap-related complications. This prospective study included 25 eyes with LASIK flap-related complications imaged using swept-source AS-OCT between February and August 2016 at Alforsan Eye Centre, Assiut, Egypt. The images were acquired using a 6-mm line scan. Imaging of flap-related LASIK complications using AS-OCT revealed specific and nonspecific findings. Of note, epithelial ingrowth appeared as highly reflective lesions below the LASIK flap in the form of islands, nests, or a continuous sheet with or without changes in the overlying flap. Macrostriae manifested as dome-shaped irregularities on the stromal surface with regular overlying epithelium, whereas microstriae appeared as corrugations on the stromal surface with regular overlying epithelium. Less common complications included multiple flap macrostriae accompanied by a traumatic folded flap with a flap edge at the interface. Interface debris appeared as a highly reflective interface lesion with or without a surrounding reaction. One eye with a flap that was torn and lost intraoperatively showed epithelialization over a thin residual stroma underlying a contact lens with no stromal infiltration on the second postoperative day. AS-OCT was useful for the assessment of flap thickness and planning of the new flap thickness in the event of an incomplete cut. Swept-source AS-OCT is useful not only for diagnosis but also for management of eyes with LASIK flap-related complications by allowing noninvasive, noncontact, real-time acquisition of cross-sectional AS images.

Sands of Sahara after LASIK in Avellino Corneal Dystrophy

We report the case of a patient diagnosed with Avellino corneal dystrophy (ACD) who developed diffuse interstitial keratitis following excimer laser insitu keratomileusis (LASIK). ACD is an autosomal dominant corneal dystrophy characterized by multiple asymmetric stromal opacities that impair vision. Accepted treatments for this condition include corneal transplantation and phototherapeutic keratectomy (PTK). Our patient underwent LASIK at another institution to correct myopia. LASIK and photorefractive keratectomy (PRK) are usually contraindicated in ACD for the high risk of disease recurrence and postoperative complications. The patient came to our attention lamenting blurry vision, decreased visual acuity, and photophobia. Ophthalmologic examination revealed bilateral interstitial keratitis, also known as “sands of Sahara”, a seldom-seen complication of LASIK characterized by fine and diffuse granular infiltrates at the surgical flap interface.The risk of developing interstitial keratitis, as in the case presented here, represents another valid reason for avoiding LASIK in patients with ACD.

MMP-9 and the perioperative management of LASIK surgery

Hyperosmolarity is a central mechanism causing ocular surface inflammation and eye irritation in typical patients suffering from tear dysfunction. Tear composition in dry eyes, or dysfunctional tear syndrome, may destabilize the tear film and cause ocular surface epithelial disease. Increased activity of matrix metalloproteinases (MMPs), especially MMP-9, plays a critical role in wound healing and inflammation and is primarily responsible for the pathologic alterations to the ocular surface that leads to a dysfunctional tear state. Altered corneal epithelial barrier function is the cause for ocular irritation and visual morbidity in dry eye disease. The increased MMP-9 activity in dry eyes may contribute to deranged corneal epithelial barrier function, increased corneal epithelial desquamation, and corneal surface irregularity. Dry eye is one of the most common complications of photorefractive keratectomy and laser in-situ keratomileusis (LASIK). LASIK has both a neurotrophic effect on the cornea and leads to a physical change in corneal shape that results in a change in tear dynamics, leading to ocular surface desiccation. The reduction in tear function after LASIK may induce an increase in osmolarity and consequently raise the concentration of proinflammatory cytokines and MMP-9 in the tear film, which results in dry eyes and insufficient attachment between the corneal flap and the corneal bed. Appropriate diagnosis and management of dysfunctional tear syndrome may lead to less postoperative LASIK complications.

Salzmann Nodular Degeneration After Laser In Situ Keratomileusis

PURPOSE: To report a case of Salzmann nodular degeneration after laser in situ keratomileusis (LASIK). METHODS: Case report. RESULTS: A 36-year-old woman with no significant medical history underwent routine myopic LASIK in both eyes and 3 months later developed Salzmann nodular degeneration at the inferotemporal and inferonasal flap edges of the left eye only. The visually inconsequential nodules, which did not respond to topical steroids, slowly increased in size and remained 4 years post-LASIK. CONCLUSION: Salzmann nodular degeneration is a rare complication of LASIK.

A retrospective comparison of efficacy and safety of 680 consecutive lasik treatments for high myopia performed with two generations of flying-spot excimer lasers

To compare the visual refractive outcome and complication of laser in situ keratomileusis (LASIK) carried out with a Carl Zeiss-Meditec MEL-70 Excimer laser and a MEL-80 laser for treatment of high myopia. Journal records of 680 consecutive eyes that underwent LASIK with a Schwind Supratome microkeratome and a MEL-70 Excimer laser (Group A), or a Moria M2 microkeratome and a MEL-80 Excimer laser (Group B) were reviewed. Manifest refraction, uncorrected and best spectacle-corrected visual acuity (BSCVA), corneal topography and central corneal thickness (CCT) were recorded before and 3 months after treatment. Pre- and postoperative complications, visual and refractive outcome and frequency of retreatments were registered. Mean preoperative spherical equivalent refraction was -8.52 dioptres (-5.50- -18 dioptres), and the mean attempted laser correction was -8.02 dioptres (-5.50- -11 dioptres). Three months after LASIK, the average treatment error (difference between achieved and attempted correction) was 1.20 (SD=1.19) dioptres of under correction in Group A and 0.52 (SD=1.00) dioptres in Group B. Four eyes lost more than two lines of BSCVA (0.6%). In 110 eyes (16%), a re-LASIK procedure was performed to reduce remaining myopia after the primary procedure. Laser in situ keratomileusis treatment for high myopia can effectively reduce high degrees of myopia. Under correction was observed in both treatment groups but Group B has a slightly better predictability. Significant loss of BSCVA occurs infrequently after LASIK for even considerable grades of myopia (0.6% in each group).

Incidence, Treatment and Visual Outcomes of Non-Infectious Keratitis as a Postoperative Complication of Laser-Assisted in-Situ Keratomileusis (LASIK).

Purpose: To study the incidence, treatment, and visual outcomes of Non-Infectious Keratitis as a Postoperative Complication of Laser in-Situ Keratomileusis (LASIK) at Elite Medical & Surgical Center. K S A Methods: The files of 3500 post-LASIK patients (6326 eyes) were reviewed for the development of Non-Infectious Keratitis. Incidence, management regimens, and final best spectacle corrected visual acuity (BSCVA) were reported. Results: Post-LASIK Non-Infectious Keratitis was diagnosed in 149 eyes (2.35%). The Keratitis was classified as diffuse lamellar keratitis (DLK) in 89 eyes (1.4%) and 60 eyes (0.94%) as localized debris-related Keratitis (LDK). Conclusion: The occurrence of post-LASIK Non-Infectious Keratitis was 2.35%, with DLK being the common diagnosis overall, with 92.6% of patients achieving ≤ 20/20 BSCVA. The best way for prevention of DLK is to eliminate defined predisposing factors for DLK. Close follow-up during the early postoperative period.

Salzmann Nodular Degeneration After Laser In Situ Keratomileusis

To report a case of Salzmann nodular degeneration after laser in situ keratomileusis (LASIK). Case report. A 36-year-old woman with no significant medical history underwent routine myopic LASIK in both eyes and 3 months later developed Salzmann nodular degeneration at the inferotemporal and inferonasal flap edges of the left eye only. The visually inconsequential nodules, which did not respond to topical steroids, slowly increased in size and remained 4 years post-LASIK. Salzmann nodular degeneration is a rare complication of LASIK.

Komplikationen nach Laser-in-Situ-Keratomileusis (LASIK): Ergebnisse einer Metaanalyse zu Inzidenzen und Folgekosten

Laser in situ Keratomileusis (LASIK) is considered to be safe and effective for the treatment of moderate myopia. Nevertheless, the treatment can result in complications, associated with additional costs for treatment of the latter and an associated reduction of the primary treatment's overall cost efficiency. To both identify clinically relevant LASIK-associated complications and to estimate their expectable incidence and treatment cost-profile, a quantitative meta-analysis of trial publications between 1995 - 2004 was implemented. Inclusion criteria were a minimum sample size of 25 eyes, a reported preoperative patient refraction between - 1 und - 14 dioptres and the documentation of an at least 6 months recall period. For each reported complication its "meta incidence" (point estimate and 95 % confidence interval) was estimated. Furthermore, for each complication a clinical pathway for its treatment was modelled assuming a worst case scenario; the treatment costs for this pathway were simulated. The resulting costs for the treatment of one complication were then averaged by the expectable incidence of the respective complication; the maximum "expectable" costs for the respective complication's treatment were then summed up to correct the overall LASIK direct costs. A total of 30 trial reports was included into the meta-analysis; in total, 21 clinically relevant complications were identified (31 % intraoperative complications, among which 19 % were microkeratome-associated, versus 69 % postoperative complications, among which 87 % were classified as long-term postoperative). The most frequent complication was "light sensations" with a meta incidence of 46 % (95 % confidence interval 42 - 50 %), the most cost intensive complications were those requiring clinical re-treatment (overall meta incidence 24 % and expectable cost increase of 449 euro per primary LASIK procedure). In summary the total direct costs of 2426 euro per eye for the initial LASIK procedure may be increased by a total of maximum 648.30 euro, according to a maximum "expectable" cost increase of 27 % per primary LASIK due to complications. At least the worst case scenario introduced into this investigation demonstrated an economically relevant order for the expectable LASIK complications and the associated additional costs for complication treatment.

Hinterabschnittskomplikationen der Laser-in-situ-Keratomileusis (LASIK) - Eine Literaturübersicht

During the past years refractive surgical procedures and particularly laser IN SITU keratomileusis (LASIK) have become established by clinical and experimental studies and are performed worldwide in a high number. This paper provides a survey of the published posterior segment complications of LASIK that may occur albeit very rarely. Additionally, current clinical and experimental hypotheses regarding the pathogenesis of those complications are discussed. Currently a cause-effect relationship between LASIK and reported posterior segment complications has not been proven although a very high number of LASIK procedures have been performed worldwide.

Avoidance, Recognition, and Management of LASIK Complications

To provide important concepts of the latest developments in laser in situ keratomileusis (LASIK) complication avoidance, recognition, and management. A perspective. A comprehensive literature search and review of a total of 816 publications that discussed LASIK complications from 1992 to 2005 was conducted. The risk of visually threatening complications is inherent in any ophthalmologic surgical procedure. Not only does LASIK require the use of several complex medical devices, but there can be significant human variation in response to this surgical intervention. As a result, many potential complications can occur after LASIK. The risk of many complications can be mitigated by appropriate patient selection and preoperative, surgical, and postoperative care. Unforeseen complications will occur, despite meticulous planning, and must be managed. Important current developments in the avoidance, recognition, and management of LASIK complications are reviewed. Complications as a result of LASIK can threaten vision and may cause debilitating symptoms in an otherwise healthy eye. Advancing our understanding of the prevention and management of the complications of LASIK is an endeavor that must be continued as long as refractive surgery is performed.

Transient light sensitivity after femtosecond laser flap creation: Clinical findings and management

To describe the constellation of subjective and objective findings associated with unusual occurrences of photosensitivity after laser in situ keratomileusis (LASIK) with femtosecond flap creation and identify optimal management strategies. Demographic data, laser settings, subjective complaints, clinical findings, treatment, and response to treatment were recorded for suspected cases of transient postoperative photosensitivity from 3 surgeons operating at 3 different sites. All cases were estimated for the period covering the suspected cases at each site to assess incidence. Additional cases were solicited from IntraLase users via a survey. For the 3 sites, 63 eyes from 33 patients were reported of a total estimated case log of 5667 (incidence, 1.1%). Average age was 41 years, and 51.7% of patients were women. Onset of symptoms ranged from 2 to 6 weeks after uneventful LASIK. All patients were treated with prednisolone acetate drops, whereas 1 surgeon also used Restasis (cyclosporine ophthalmic solution 0.05%). Patients noted improvement of symptoms within 1 week of treatment. When the raster and side-cut energy settings were lowered (by an average of 24% and 33%, respectively), significant reductions in incidence were noted. Similar findings were reported by 3 additional surgeons reporting 17 cases in the survey of IntraLase users. This report describes a new complication of LASIK performed with a femtosecond laser keratome that may be related to the pulse energy used for flap creation. Although there is no loss of uncorrected visual acuity, symptoms can be prolonged, especially without prompt steroid therapy. Technical advances that reduced pulse energies appear to decrease the incidence.

Laser in situ Keratomileusis for Correction of Myopia in Eyes After Retinal Detachment Surgery

To evaluate the safety and efficacy of laser in situ keratomileusis (LASIK) for correction of myopia in eyes with previous retinal detachment surgery. A retrospective review was conducted of all consecutive eyes that underwent LASIK after retinal detachment surgery. Data was collected regarding previous ocular surgery and its time prior to LASIK, intra- and postoperative complications, and visual outcome measures pre- and postoperatively. Ten eyes with previous retinal detachment surgery were scheduled for LASIK. One eye was excluded from data analysis as LASIK was aborted due to inadequate microkeratome suction because of conjunctival scarring. Nine eyes underwent an uneventful LASIK procedure. On average, LASIK was performed 130+/-123 months following retinal detachment surgery. Postoperative LASIK follow-up was 14.8+/-12.5 months. No significant intraoperative, postoperative, or retinal complications were observed. The mean preoperative spherical equivalent refraction was -9.00+/-3.00 diopters (D), uncorrected visual acuity (UCVA) was 0.06+/-0.02, and best spectacle-corrected visual acuity (BSCVA) was 0.64+/-0.16. At the end of follow-up, the mean spherical equivalent refraction was 0.65+/-0.88 D, mean UCVA was 0.57+/-0.14, and mean BSCVA was 0.72+/-0.19. Differences between BSCVA before and after LASIK were statistically significant (P=.038). At final follow-up, the safety index was 1.22 and efficacy index was 1.01. Laser in situ keratomileusis was found to be a safe and efficient option for treating refractive errors in eyes with previous retinal detachment surgery.

Complications associated with anterior basement membrane dystrophy after laser in situ keratomileusis

Purpose: To evaluate the complications associated with anterior basement membrane dystrophy (ABMD) after laser in situ keratomileusis (LASIK). Setting: Cornea Service, Wills Eye Hospital, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA. Methods: In this noncontrolled retrospective case series, the medical records of all patients with LASIK complications seen in the Cornea Service at Wills Eye Hospital from January 1, 1998, to December 31, 2002, were reviewed. All patients who presented with ABMD changes after LASIK were included in the study. Patients with a history of trauma before or after surgery were excluded. Results: Thirty-five eyes of 18 patients were included. The mean age was 46.2 years. Thirteen eyes (37.1%) had a flap-lift procedure to remove epithelial ingrowth or for an enhancement. The most common reason for the visit was visual complaints, which were seen in 77.8% of patients. Seven patients (38.9%) had visual complaints alone; 27.8% had visual complaints associated with recurrent erosions and 11.1%, with dry eyes. Four patients (22.2%) had recurrent corneal erosions with no visual complaints. On examination, the most common finding was negative staining with fluorescein dye within the LASIK flap, which was seen in all patients. In addition to the ABMD changes, 25.7% had some degree of epithelial ingrowth and 45.7%, irregular astigmatism. Conclusions: Anterior basement membrane dystrophy changes post LASIK were associated with visual complaints and/or recurrent erosions. Patients should be carefully screened for ABMD. Those who have ABMD signs or symptoms may not be ideal candidates for LASIK.

Progressive Keratectasia After Laser in situ Keratomileusis

We describe ten patients who developed progressive keratectasia following laser in situ keratomileusis (LASIK) and identify possible factors that may lead to ectasia. In this retrospective study, we reviewed the files of 3,634 patients (6941 eyes) who had LASIK between March 2000 and April 2003. Ten patients (14 eyes, 0.2%) developed progressive keratectasia. We also evaluated consequent therapeutic measures and final visual status of these patients. Patients were examined at a mean 24.9 +/- 8.1 months after LASIK. Ectasia developed within a mean 14 +/- 0.3 months after surgery. At baseline, mean keratometric power was 44.7 +/- 2.30 D, mean corneal thickness was 516 +/- 18.9 microm, and mean attempted correction was -10.85 +/- 3.20 D. We found a statistically significant correlation between residual stromal thickness, attempted correction, and occurrence of progressive keratectasia. We also found that preexisting abnormal corneal topography was a risk factor for progressive keratectasia. Ultimately, most patients had reasonable visual acuity after penetrating keratoplasty. Progressive keratectasia is a vision threatening complication of LASIK that may occur in previously healthy or diseased eyes. The most important risk factors are residual stromal thickness and preexisting abnormal corneal topography. Penetrating keratoplasty may be a reasonable therapeutic measure for severe cases of progressive keratectasia.

Clinical course of severe central epithelial defects in laser in situ keratomileusis

Purpose: To report the clinical outcome of laser in situ keratomileusis (LASIK) cases complicated by severe central intraoperative epithelial defects (EDs) caused by the microkeratome cut. Setting: Department of Ophthalmology, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany. Methods: In a retrospective study of 1650 LASIK cases at 1 center, the preoperative data, surgical procedures, and postoperative course in 22 eyes of 14 patients who experienced severe central EDs during the LASIK procedure (1.3%) were reviewed. The surgery was performed using a Technolas® C-LASIK 217 excimer laser (Bausch & Lomb) and a Hansatome® microkeratome (Bausch & Lomb). A follow-up of at least 12 months was available in all but 1 case. The median follow-up was 13.5 months (range 12 to 25 months). In the postoperative period, the following parameters were reviewed: course of refraction, best spectacle-corrected visual acuity (BSCVA), slitlamp findings, and corneal topography. Results: The mean patient age was 42 years (range 27 to 61 years). Eight patients were affected bilaterally. Fifteen eyes (68%) had moderate to severe dry-eye symptoms preoperatively. Almost all eyes lost BSCVA in the postoperative period, and visual acuity improved slowly. By the last follow-up visit, no eye had lost more than 1 line of BSCVA. Diffuse lamellar keratitis (DLK) was observed in 20 eyes (91%), irregular astigmatism in 17 (77%), and microfolds in 12 (55%). In unilaterally affected patients, the refractive outcome was better in the nonaffected eye. Conclusions: A large central ED is a severe intraoperative complication of LASIK that may lead to DLK, irregular astigmatism, flap microfolds, clearly prolonged visual rehabilitation, and temporary loss of BSCVA. The improvement in BSCVA may take several months.

Ulcerative keratitis caused by Serratia marcescens after laser in situ keratomileusis

We report 2 cases of severe corneal infections caused by Serratia marcescens after laser in situ keratomileusis (LASIK). Twenty-four hours after LASIK, 2 patients developed infectious keratitis, 1 bilaterally. In each eye, the corneal flap was edematous, ulcerated, and detached from the stromal bed. Treatment included removal of the necrotic flap and aggressive antibiotic therapy. Cultures from corneal exudates were positive for S marcescens. After 1 year, both patients had a loss of best corrected visual acuity (BCVA) ranging from 20/40 to 20/22 because of irregular astigmatism. Overrefraction with a hard contact lens resulted in a BCVA of 20/20 in the 3 affected eyes. Slitlamp examination showed trace subepithelial haze without severe corneal scarring. Videokeratography disclosed areas of paracentral inferior steepening resembling keratoconus. Refraction and videokeratography remained stable after 6 months of follow-up. Ulcerative keratitis caused by S marcescens is a potential complication of LASIK. Bilateral involvement may occur if bilateral simultaneous surgery is performed.

Laser in situ keratomileusis to correct myopia after scleral buckling for retinal detachment

We describe 5 patients with a previously placed encircling scleral buckle for a retinal detachment who had laser in situ keratomileusis (LASIK) to correct myopia. Uncorrected (UCVA) and best corrected visual acuity, ultrasound pachymetry before and 6 months after LASIK, and development of intraoperative or postoperative complications were measured. In all patients, the UCVA improved and the myopic spherical equivalent decreased after the procedure. The mean ultrasonic pachymetry after LASIK was 413 μm ± 23.1 (SD) (range 380 to 436 μm). No patient had difficulties with LASIK or postoperative complications. To correct myopia in eyes with a previous scleral buckle, LASIK was a feasible and relatively safe procedure.

Corneal ectasia detected 32 months after LASIK for correction of myopia and asymmetric astigmatism

We report a case of corneal ectasia detected 32 months after laser in situ keratomileusis (LASIK) for correction of −4.25 diopters (D) of myopia associated with –2.00 D of regular but slight asymmetric astigmatism. The patient retained stable visual acuity for 15 months postoperatively. The preoperative corneal thickness was 540 μm, and the postablation untouched stroma was assumed to be 290 μm. Although a rare complication of LASIK, corneal ectasia can occur, and there is no consensus regarding how much stroma should be left intact to avoid it. Until we have a better understanding of corneal strength, we think surface photorefractive keratectomy or laser-assisted subepithelial keratectomy ablations should be considered instead of LASIK in borderline cases.