Interface fluid associated with diffuse lamellar keratitis and epithelial ingrowth after laser in situ keratomileusis

Clinical Applications of Anterior Segment Optical Coherence Tomography: An Updated Review

Since its introduction, optical coherence tomography (OCT) has revolutionized the field of ophthalmology and has now become an indispensable, noninvasive tool in daily practice. Most ophthalmologists are familiar with its use in the assessment and monitoring of retinal and optic nerve diseases. However, it also has important applications in the assessment of anterior segment structures, including the cornea, conjunctiva, sclera, anterior chamber, and iris, and has the potential to transform the clinical examination of these structures. In this review, we aim to provide a comprehensive overview of the potential clinical utility of anterior segment OCT (AS-OCT) for a wide range of anterior segment pathologies, such as conjunctival neoplasia, pterygium, scleritis, keratoconus, corneal dystrophies, and infectious/noninfectious keratitis. In addition, the clinical applications of AS-OCT (including epithelial mapping) in preoperative planning and postoperative monitoring for corneal and refractive surgeries are discussed.

Amantadine induced interface fluid formation after LASIK. A case report

Purpose

To describe a case of bilateral interface fluid formation 2 years after laser-assisted in situ keratomileusis (LASIK) surgery caused by the side effect of amantadine.

Observations

A 47-year-old male patient with a history of Parkinson's disease treated with amantadine who had uneventful LASIK surgery in both eyes 2 years ago, presented with a decline in vision over the past 6 weeks. Results: Best corrected vision was 20/200 and 20/400 in the right and left eye respectively. Intraocular pressures were measured within the normal range. Biomicroscopic exam showed bilateral corneal edema. Anterior segment optical coherence tomography (AS-OCT) revealed fluid accumulation within the LASIK flap interface in both corneas. The patient's corneal edema and fluid in the interface began to gradually resolve, and vision improved 2 weeks after discontinuing amantadine.

Conclusions and Importance

Although there is no previous report, it is possible that amantadine may cause interface fluid formation in patients with LASIK surgery.

Interface Fluid Syndrome After Descemet Membrane Endothelial Keratoplasty in Patients With History of LASIK

PURPOSE

The aim of this study was to evaluate the visual, pachymetric, tomographic, and biomicroscopic findings in a series of cases with laser in situ keratomileusis (LASIK) flap interface fluid syndrome (IFS) after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Six cases were included in this study; all patients had a history of LASIK and underwent DMEK for the treatment of bullous keratopathy. After uneventful surgery, all patients presented with corneal edema and IFS under the LASIK flap, which was demonstrated with anterior segment optical coherence tomography (AS-OCT). Visual acuity, clinical findings, pachymetry, endothelial cell count, and AS-OCT were documented during the management of these cases.

RESULTS

IFS appears 2.33 days (±1.03) after DMEK. One case improved with conservative treatment. In 5 cases, the LASIK flap was lifted, the fluid was drained, and the flap was replaced. The mean best-corrected visual acuity after fluid drainage was 0.44 logMAR (range 0.18-1.0) and mean central corneal thickness was 538 μm ± 160. Total resolution of the IFS was achieved at 14.5 days (range 4-30) after DMEK. AS-OCT showed resolution of the flap interface in 5 of 6 cases, while 1 patient required second DMEK due to reaccumulation of the interface fluid.

CONCLUSIONS

IFS can occur after DMEK in patients with previous LASIK. AS-OCT is a valuable tool for monitoring these cases preoperatively and postoperatively. Early surgical management is often needed to achieve resolution.

Interface fluid syndrome after small incision lenticule extraction surgery secondary to posner schlossman syndrome - A case report

Purpose

This report describes a case of interface fluid syndrome (IFS) secondary to Posner Schlossman Syndrome (PSS) following small incision lenticule extraction (SMILE) surgery.

Case presentation

A 19-year-old male was diagnosed with IFS secondary to PSS in his left eye 1 month after undergoing SMILE. Detailed patient history and clinical findings, auxiliary examination results, and short-term follow-up are reported. In this patient, the IFS was caused by elevated intraocular pressure (IOP) due to PSS. Treatment with topical steroids in combination with anti-glaucoma drops led to complete regression of the fluid, and there was no recurrence during a 7-month follow-up period.

Conclusion

IFS is a potential complication of SMILE, and anterior segment ocular coherence tomography (AS-OCT) can definitively diagnose the condition. This case demonstrates that the treatment for IFS should be based on the underlying cause, and requires prompt and vigorous management for resolution.

Interface Fluid Syndrome Masquerading as Diffuse Lamellar Keratitis After Small Incision Lenticule Extraction

A 34-year-old male with no past medical or ocular history underwent bilateral uncomplicated small incision lenticule extraction (SMILE). On day 1, uncorrected distance visual acuity (UDVA) was 20/25 in the right eye (OD) and 20/20 in the left eye (OS). The intraocular pressure (IOP) was 12 mmHg in both eyes (OU). On day 17, UDVA was 20/70 OD and 20/30+2 OS. Slit-lamp examination (SLE) revealed diffuse 2+ haze at the interface suspicious for diffuse lamellar keratitis (DLK). Topical difluprednate was added twice a day (BID). Vision decreased by day 20 with a significant myopic shift and 3+ interface haze OU. A washout of the interface was performed. Topical steroids were increased with oral prednisone. One day after the washout, vision and interface haze improved. On day 3 status post washout, UDVA decreased to 20/70 OD and 20/50 OS. IOP was 42 mmHg OU. A diagnosis of interface fluid syndrome (IFS) was confirmed. All steroids were stopped while adding ocular hypotensive medication. One month later, visual acuity was 20/20 OU with a complete resolution of interface haze. Only a handful of IFS has been documented in SMILE, an incidence that may increase as SMILE becomes more common. Among all SMILE cases, IFS was most commonly associated with steroid-induced ocular hypertension and a myopic shift around 21 days postoperatively. A fluid cleft at the interface may not always be visible with SLE, masquerading as DLK. Scheimpflug densitometry and anterior segment optical coherence tomography (AS-OCT) may aid in quantifying interface edema needed to confirm a diagnosis when IOP is unclear. A corneal washout can immediately improve corneal edema, but the preferred treatment is discontinuing all steroid medication and starting glaucoma drops.

Late-onset interface fluid syndrome: A case report and literature review

PURPOSE

To present a case of late-onset interface fluid syndrome (IFS) and a literature review on this rare clinical entity.

INTRODUCTION

IFS is an uncommon complication of laser in situ keratomileusis (LASIK). Although generally appearing in the early postoperative period, IFS has been reported even years after LASIK.

METHODS

A case report of IFS manifesting 19 years after uneventful LASIK, which prompted a literature search for similar, late-onset cases in MEDLINE PubMed. This article reports on a case of IFS appearing 19 years after LASIK surgery, including extensive patient history and analytical presentation of clinical findings, ancillary testing, and short-term follow-up. Furthermore, a literature search for similar cases was performed on MEDLINE, focusing on the etiology and management of late-onset IFS.

RESULTS

Through thorough ancillary testing, the interface fluid was attributed to elevated intraocular pressure (IOP) arising from primary open-angle glaucoma. Antiglaucoma drops resulted in complete fluid regression. A narrative review was conducted based on the 29 case reports that were recovered from the literature search.

CONCLUSION

IFS represents an uncommon complication that could appear years after LASIK. Careful clinical examination and anterior segment optical coherence tomography promote early diagnosis. Similar cases may manifest due to elevated IOP of variable etiology or as a result of endothelial dysfunction. Depending on the etiology, IOP control or keratoplasty may resolve the condition.

Suture-Related Fungal Interstitial Interface Keratitis in Deep Anterior Lamellar Keratoplasty: A Case Report

Interstitial interface keratitis (IIK) in lamellar keratoplasty is a term used to describe infectious keratitis that primarily involves the graft-host interface. It poses specific challenges due to impaired access for microbiological testing and poor penetration of antimicrobial drugs, as well as ease of deeper extension of the microorganism. A 33-year-old male with a medical history of left eye deep anterior lamellar keratoplasty (DALK) with keratoconus, subsequently complicated with steroid-induced glaucoma controlled with Xen tube insertion, presented with acute left eye pain and redness for two days due to one broken corneal graft suture at 5 o’clock position with infiltrate at the graft-host junction. He was treated for suture-related bacterial keratitis (culture-negative) with intensive single broad-spectrum topical antibiotic after suture removal. However, the condition worsened, with dense stromal infiltrate extending into the graft-host interface junction which further progressed to an endothelial plaque. Systemic and topical antifungal treatments were started with adjunctive intracameral and subconjunctival voriconazole before improvement was observed. The condition was resolved with localized scarring without the need for repeat keratoplasty. The best-corrected vision was maintained at 6/36 due to residual sutured-related astigmatism with no signs of corneal graft rejection. Lamellar keratoplasty poses an increased risk of fungal IIK even after several years if there is a predisposing factor e.g., steroid usage and broken suture. Timely diagnosis and intervention are the keys to ensure an optimal outcome.

A Case Report of Diffuse Lamellar Keratitis after FemtoSMILE Refractive Surgery

Diffuse lamellar keratitis (DLK) is not an uncommon complication of the small-incision lenticule extraction (SMILE) operation. Instrumental causes, such as contamination, are usually the underlying etiological route. Herein, we present an atypical case of DLK with numerous foci of cellular infiltrates on day 1. No evidence of any diffuse inflammatory response was reported. On the other hand, the multifocal response began to improve starting on the third day, after the administration of systemic steroids, with pain and discomfort significantly disappearing on the second day. Antibiotics were given as well, in the case of secondary infections. After 1 week of treatment and close monitoring, significant improvement was reported, and the slit-lamp examination was unremarkable.

Management of acute corneal hydrops after laser in situ keratomileusis

A 43-year-old man developed acute corneal hydrops after laser in situ keratomileusis (LASIK). A persistently fluid-filled interface between the corneal flap and stroma (without flap dehiscence or wound leakage) did not respond to the conservative treatment. To avoid keratoplasty, the subflap fluid was drained by an air injection into the anterior chamber; the surgery also included suturing of the corneal flap and stroma. The corrected distance visual acuity improved rapidly after resolution of the fluid-filled interface and corneal stromal edema, and no leakage was observed. Thus, a minimally invasive surgery to drain the subflap fluid by an air injection was effective for treating a persistently fluid-filled interface in a case of acute corneal hydrops after LASIK.

Risk factors for early flap misalignment following microkeratome-assisted laser in situ keratomileusis: A retrospective large database analysis

PURPOSE

To determine factors associated with early flap misalignment following microkeratome-assisted laser in situ keratomileusis.

MATERIALS AND METHODS

This retrospective study included the right eyes of consecutive patients who underwent laser in situ keratomileusis procedure between 2005 and 2016 at Care-Vision Laser Centers, Tel-Aviv, Israel. Patients were divided into two groups according to whether or not they subsequently developed early flap misalignment.

RESULTS

A total of 14,582 eyes (mean age of patients: 32.4 ± 10.3 years) were included. Post-laser in situ keratomileusis early flap misalignment developed in 158 eyes (1.1%). Misalignment was more frequent during the spring (32.3% vs 22.8%, p = 0.003) and in a higher operating room temperature (23.34 ± 1.06 vs 22.98 ± 1.26, p < 0.001). In addition, in the misalignment group, there was a higher rate with the of use of the a Moria M2 microkeratome (rather than sub-Bowman's keratomileusis microkeratome) head (55.2% vs 40.5%, respectively, p < 0.001). In a multivariable analysis adjusted for surgeon and year of surgery, high operating room temperature (odds ratio = 1.22, p = 0.006), treatment zone of 9.0 mm (as opposed to smaller treatment zones, odds ratio = 1.54, p = 0.04), and springtime (odds ratio = 1.58, p = 0.02) were associated with flap misalignment. There was a significant difference in misalignment rates between surgeons (p = 0.02).

CONCLUSION

This study found that larger treatment zones, higher operating room temperature, operating during the spring, and the use of Moria M2 microkeratome were associated with increased flap misalignment rates. The association with operating room temperature and seasonal variation is of interest and merits further research.

Urrets-Zavalia syndrome with interface fluid syndrome following laser in situ keratomileusis

Purpose

We describe the case of a 41-year-old male that underwent laser in situ keratomileusis (LASIK) complicated by Urrets-Zavalia syndrome with interface fluid syndrome and epithelial ingrowth.

Observation

The patient presented at our institution with headache and blurred vision three weeks after a right microkeratome-assisted LASIK procedure. On examination, the visual acuity was hand movements and the intraocular pressure (IOP) was 45 mmHg with fluid in the flap interface, a fixed pupil in moderate mydriasis, iris transillumination and cells in the anterior chamber. A Baerveldt tube implant was necessary to control the IOP. After three months, the corrected visual acuity was 20/40 with normal IOP and an early cataract.

Conclusion and importance

To our knowledge this is the first report of a case of combined Urrets-Zavalia syndrome and interface fluid syndrome after LASIK. We speculate that steroid induced ocular hypertension was the primary cause.

Incidence, Indications, and Outcomes of Eyes Needing Early Flap Lifting After LASIK

PURPOSE

To analyze the incidence, indications, and outcomes associated with early flap relifting after uncomplicated laser in situ keratomileusis (LASIK).

METHODS

All LASIK cases from a single surgical center between 2007 and 2015 were reviewed. Early postoperative flap lift cases (<15 d after surgery) were identified.

RESULTS

Overall, 25,712 eyes were included, of which 366 (1.42%) underwent early postoperative flap lifting. There was a significant reduction in early postoperative flap lifting rates from 2006 (2.46%) to 2015 (0.92%) (P = 0.001). Reasons for early flap lifting included striae (n = 301, 1.17%), diffuse lamellar keratitis (n = 62, 0.24%), flap dislocation (n = 20, 0.08%), epithelial ingrowth (n = 18, 0.07%), and interface debris (n = 15, 0.06%). There was a significant difference in rates and outcomes of flap relifting among high-volume surgeons (P < 0.001). The flap lift group had a significantly lower final safety index (0.95 ± 0.16 vs. 1.01 ± 0.15, P < 0.001), efficacy index (0.85 ± 0.26 vs. 0.94 ± 0.26, P < 0.001), and a higher distance from target refraction (0.39 ± 0.61 vs. 0.21 ± 0.46 D). In unilateral cases, the study eye had a lower safety index (P < 0.001), efficacy index (P < 0.001), and greater distance from target refraction (P = 0.003) compared with the fellow eye. After intervention, 81.1% of cases achieved full resolution, 10.1% achieved partial resolution, 4.1% required additional flap relifting, and 4.7% were nonresolved by the end of follow-up.

CONCLUSIONS

The main indication for early flap relifting after LASIK was striae, and most cases achieved full resolution. Although refractive and visual outcomes are lower in this group, they are, nevertheless, satisfactory.

Pressure-induced stromal keratopathy after laser in situ keratomileusis: Acute and late-onset presentations

We present a series of 4 cases of pressure-induced stromal keratopathy after laser in situ keratomileusis (LASIK). Four patients (5 eyes) with previous LASIK presented for poor visual acuity and ocular pain because of ocular hypertension. At examination, all cases revealed corneal haze and a space filled with fluid between the surgical flap and the residual stroma. All cases were managed with topical hypotensive treatment and one of them was also treated with a valve drainage device. Topical steroids restriction was indicated in all cases. Intraocular pressure (IOP) was normalized in all cases with subsequent interface fluid resolution and significant improvement of vision in most cases. Early recognition and appropriate treatment for pressure-induced stromal keratopathy is essential to avoid complications associated with prolonged elevated IOP. It is extremely important to measure the IOP in the peripheral cornea because IOP in the central cornea can be incorrectly measured with the characteristic interface fluid developed in this entity.

Interface Fluid Syndrome (IFS) following Toxic Anterior Segment Syndrome (TASS): not related to high intraocular pressure but to endothelial failure

We describe the case of a 52-year-old female with past history of LASIK, 21 years earlier, without Fuchs’ endothelial dystrophy, who underwent phacoemulsification and intraocular lens (IOL) implantation. During the early postoperative period severe corneal edema, anterior chamber cellularity and iris inflammation presented, accompanied by a clear space along the LASIK interface. Those findings were interpreted as part of a Toxic Anterior Segment Syndrome (TASS) and secondary interface fluid syndrome (IFS). When interface fluid was present, intraocular pressure (IOP) measured in the center of the cornea yielded very low values. In addition, applanation tonometry performed in the corneal periphery, as well as Schiotz tonometry and digital tonometry also indicated that the IOP was not high. Fluid in the interface persisted until a DMEK was carried out 11 months after the phacoemulsification surgery. Five days postoperatively the IFS resolved, confirmed by OCT imaging. The origin of IFS in this case was corneal edema secondary to endothelial cell dysfunction and it was not related to high IOP. This is the first reported case of IFS following TASS, the third case published of DMEK procedure used to solve endothelial failure-related IFS, and the case with the longest time of presentation after LASIK.

Nd:YAG laser for epithelial ingrowth after laser in situ keratomileusis

PURPOSE

To evaluate the efficacy of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser for treatment of epithelial ingrowth after laser in situ keratomileusis (LASIK).

PATIENTS AND METHODS

Fifty-eight patients with epithelial ingrowth presented to Sohag refractive center, Sohag, Egypt, between January 2015 and March 2017. Only 41 patients (18 females and 23 males, mean age: 33.4 years) involving 41 eyes were indicated for treatment by Nd:YAG laser as the rest of the eyes were only under observation. Patients with epithelial ingrowth were recognized at a mean of 6 months after primary LASIK procedure (range: 2-16 months). Four eyes had undergone previous LASIK enhancements. Four eyes had the epithelial ingrowth removed by flap lift and scrapping. The mean intensity of the spots used was 0.8 mJ with variable number of shots depending on the size and density of the epithelial ingrowth area. Twenty-eight eyes showed complete regression after one session, while the rest necessitated 2-3 sessions for complete resolution. Mean follow-up period was 8 months (range 5-12 months).

RESULTS

Epithelial ingrowth was treated successfully in all 41 eyes. The uncorrected visual acuities were 20/20, and there was no evidence of recurrent epithelial ingrowth after 6 months with no complications reported.

CONCLUSION

YAG laser is a simple, effective outpatient procedure for the management of epithelial ingrowth after LASIK.

Pharmacologic Management of Pressure-Induced Stromal Keratopathy after LASIK

PURPOSE

To emphasize the importance of anticipation of pressure-induced stromal keratopathy (PISK) in eyes with a previous history of LASIK.

CASE REPORT

A 40-year-old man developed LASIK-related pressure-induced stromal keratopathy after uneventful phacoemulsification (Phaco) and intraocular lens (IOL) implantation in his left eye. With immediate discontinuation of the steroid drops and initiation of antiglaucoma medication, his visual acuity, interface edema, and haze improved rapidly. One year later, during Phaco with IOL implantation in his other eye, with anticipation of a similar LASIK-related pressure-induced stromal keratopathy, a very brief course of soft steroid therapy was given together with antiglaucoma medication. Intraocular pressure elevation was avoided, and no interface edema or haze was observed.

CONCLUSIONS

This case illustrates that the risk for LASIK-related pressure-induced stromal keratopathy may be reduced with appropriate precautions.

Incidence of interface fluid syndrome after laser in situ keratomileusis in Egyptian patients

Purpose

To determine the incidence of interface fluid syndrome (IFS) secondary to steroid-induced elevation of intraocular pressure (IOP) following laser in situ keratomileusis (LASIK) in myopic Egyptian patients.

Methods

This retrospective case series study was conducted at El-Gowhara Private Eye Center. The medical records of 1,807 patients (3,489 eyes), who underwent LASIK to correct myopia from April 2012 to December 2015 were included. The patients were operated on and reviewed by one surgeon (AAG) for IFS after LASIK associated with elevation of IOP (as compared to preoperative values).

Results

This paper reports the incidence of 2.9% (54 patients) (102 eyes) of IFS induced by increased IOP after LASIK in Egyptian patients. The medical records of 1,807 patients (3,489 eyes) with mean age ± standard deviation (SD) 26.4±2.7 years, who presented with mean myopia ± SD −4.50±1.3 D, mean astigmatism ± SD −1.43±0.8, mean IOP ± SD 15.2±1.2 mmHg, and mean central corneal thickness ± SD 549±25.6 μm, were included. The preoperative anterior and posterior segments, corneal topography, and Schirmer’s test were unremarkable.

Conclusion

Limiting topical steroids and routinely measuring the IOP post-LASIK are necessary steps to prevent IFS, especially in case of myopia. A high index of suspicion is required to make a diagnosis. High-resolution optical coherence tomography is helpful to confirm the diagnosis.

Corneal densitometry changes in a patient with interface fluid syndrome after small incision lenticule extraction

Background

To report a case of interface fluid syndrome (IFS) following small incision lenticule extraction (SMILE) evaluated with corneal densitometry and optical coherence tomography (OCT).

Case presentation

An 18-year-old man reported sudden vision loss 24 days after SMILE procedure. Intraocular pressure (IOP) was 36.3 mmHg (OD) and 36.7 mmHg (OS) by noncontact tonometry. Moderate corneal edema, interface fluid pocket and haze were observed by OCT and confirmed by corneal densitometry values. Discontinuation of steroids and addition of hypotensive medication were offered immediately. The symptoms were cured after the medication. Changes of corneal densitometry were consistent with the clinical course of IFS.

Conclusion

This case illustrates that it is crucial to be aware that a history of SMILE can also cause IFS. Both OCT and corneal densitometry can serve as auxiliary means to evaluate the clinical course of IFS, and appropriate IOP management is an effective approach.

Interface Fluid Syndrome Induced by Uncontrolled Intraocular Pressure Without Triggering Factors After LASIK in a Glaucoma Patient: A Case Report

This study sought to describe a glaucoma patient with interface fluid syndrome (IFS) induced by uncontrolled intraocular pressure (IOP) without triggering factors after laser in situ keratomileusis (LASIK). Case report and review of the literature. A 23-year-old man with open-angle glaucoma underwent bilateral LASIK for myopia in 2009. Two years later, the patient reported sudden vision loss. The IOP in the right eye was not measurable using Goldmann applanation tonometry (GAT), but was determined to be 33.7 mm Hg using a noncontact tonometer. IFS was diagnosed based on the presence of space-occupying interface fluid on anterior segment optical coherence tomography images. After a trabeculectomy was performed, the IOP decreased to 10 mm Hg, and GAT measurement became possible. However, the corneal fold remained visible in the flap interface. Six months later, the IOP in the left eye increased, and a trabeculectomy was performed during the early stages of this increase in IOP. Following this procedure, the IOP decreased, and visual acuity remained stable. In glaucoma cases that involve a prior increase in IOP, IOP can continue to increase during the disease course even if temporary control of IOP has been achieved. If LASIK is performed in such cases, the treatment of glaucoma becomes insufficient because of underestimation of the typical IOP. In fact, the measurement of IOP can become difficult because of high-IOP levels. Therefore, LASIK should not be performed on patients with glaucoma who are at high risk of elevated IOP.

Central toxic keratopathy after laser in situ keratomileusis

PURPOSE

To review cases of central toxic keratopathy (CTK) occurring over a period of 46 days.

SETTING

Moorfields Eye Hospital, London, United Kingdom.

DESIGN

Retrospective consecutive case series.

METHODS

This was a review of patients with CTK after uneventful laser in situ keratomileusis (LASIK) performed by 1 of 5 surgeons at a single institute. The following parameters were analyzed: corrected distance visual acuity (CDVA), manifest refraction, and central corneal thickness from Scheimpflug pachymetry readings (Pentacam).

RESULTS

The cohort consisted of 15 eyes of 9 patients. Thirteen eyes were diagnosed within 7 days after LASIK, while the remaining 2 eyes developed CTK 12 days postoperatively. In 10 eyes, the time to resolution was 1 to 8 months. Five eyes still had residual signs at the last outpatient visit. At the final follow-up, 3 eyes (20%) had a CDVA worse than 0.0 logMAR.

CONCLUSIONS

Although a rare entity, CTK can occur in clusters. Although a cause was not fully isolated, ultimately each eye achieved excellent CDVA (all better than 0.2 logMAR) at the last follow-up.

Post-LASIK interface fluid syndrome caused by steroid drops

Interface fluid syndrome after laser in situ keratomileusis (LASIK) is a rare but visually threatening postoperative complication. In this case series we present 8 post-LASIK eyes that developed interface fluid syndrome after prolonged steroid use. Patients presented with signs mimicking diffuse lamellar keratitis (DLK) that worsened with steroid treatment. Slit-lamp examination revealed corneal haze and an optically clear fluid-filled space between the flap and stroma. The IOP was high in all cases. Topical steroids were stopped and replaced with topical and systemic anti-glaucoma medications resulting in a dramatic improvement in visual acuity.

Post-LASIK edema-induced keratopathy (PLEK), a new name based on pathophysiology of the condition

A 33-year-old man who underwent uneventful laser in situ keratomileusis (LASIK) developed pressure-induced stromal edema resulting in an interface haze in both eyes and a pocket of fluid under the flap of the right eye 10 days after surgery, while receiving topical fluorometholone. Intraocular pressure by applanation tonometry was 16 mm Hg in his right eye (erroneous result due to the fluid in the interface) and 34 mm Hg in his left eye. After discontinuation of steroids and addition of ocular hypotensive medication, interface fluid collection disappeared in his right eye. Visual acuity improved and haze diminished in both eyes. This case illustrates that in the same patient a post-LASIK edema induced syndrome may be present with or without fluid in the interface, suggesting that both clinical pictures could be manifestations of a broad spectrum of the same condition. We suggest a new name for this non-inflammatory disorder: post-LASIK edema-induced keratopathy (PLEK).

Refractive surgery and the glaucoma patient

PURPOSE OF REVIEW

Patients considering corneal refractive surgery undergo extensive preoperative testing, but current protocols may not address the management of glaucoma appropriately. This review outlines the current body of literature on the diagnostic and management challenges that exist in the treatment of glaucoma patients undergoing laser ablative surgery, and makes recommendations to improve current perioperative protocols.

RECENT FINDINGS

As permanent structural alterations to the cornea after laser-assisted in-situ keratomileusis surgery make Goldmann applanation tonometry inaccurate, the advent of new diagnostic modalities and recommendations to accurately measure postoperative intraocular pressure (IOP) and subtle damage to the optic nerve have been further analyzed and tested.

SUMMARY

As IOP is the only modifiable risk factor in the treatment of glaucoma to date, traditional diagnostic and treatment algorithms may not be appropriate for refractive surgery patients. Glaucoma remains a relative contraindication to refractive procedures, but as new diagnostic modalities emerge, our ability to diagnose and manage these patients may improve. More uniform recommendations need to be implemented to improve our long-term management of these patients.

Interface fluid syndrome after bioptics

PURPOSE

To report an unusual case of interface fluid syndrome after refractive surgery.

METHODS

A 37-year-old man with high myopia underwent a planned bioptics procedure including creation of a corneal flap using a mechanical microkeratome and concurrent anterior chamber phakic intraocular lens implantation; excimer laser ablation was not performed at this time.

RESULTS

Postoperatively, the patient developed corneal edema and was referred to our department. Interface fluid syndrome was confirmed using optical coherence tomography; the mechanism was due to endothelial cell pump dysfunction.

CONCLUSIONS

This is the first report to document interface fluid syndrome following a planned bioptics procedure.

Interface Fluid Syndrome in Human Eye Bank Corneas after LASIK

PURPOSE

To evaluate the effects of corneal edema on human donor corneas that had previous LASIK using a laboratory model with histologic and ultrastructural correlations.

DESIGN

Experimental study.

PARTICIPANTS

Thirty human eye bank corneas from 15 donors (mean age +/- standard deviation, 49.9+/-8.9 years) who had had previous LASIK surgery (2-8 years before death).

METHODS

The corneas were mounted in an artificial anterior chamber and the corneal endothelium was perfused for up to 5.0 hours with 0.9% saline solution (endothelial cell damage group) or BSS Plus at a pressure of 15 mmHg (control group), or BSS Plus at a pressure of 55 mmHg (high-pressure group). The corneas were evaluated by confocal and specular microscopy before, during, and at the end of the experimental period. Subsequently, the specimens were evaluated by light and electron microscopy.

MAIN OUTCOME MEASURES

Corneal thickness, reflectivity, histology, and ultrastructure.

RESULTS

Endothelial cell damage resulted in an increased (141.5+/-38.8 microm) total corneal thickness relative to controls (52.3+/-33.7 microm), whereas high pressure resulted in a decreased thickness (24.8+/-14.1 microm) relative to controls. This ultimately was due to swelling of the LASIK interface in both groups and swelling of the residual stromal bed (RSB) in the endothelial cell damage group or compression of the RSB and, possibly, the flap in the high-pressure group. A significant increase in corneal reflectivity at the LASIK interface occurred in both groups, primarily due to varying degrees of fluid accumulation and associated hydropic keratocyte degeneration, as well as increased corneal reflectivity in the RSB only in the endothelial cell damage group.

CONCLUSIONS

After LASIK surgery, edematous corneas preferentially hydrate and swell in the paracentral and central interface wound, commonly resulting in a hazy corneal appearance primarily due to keratocyte hydropic degeneration. More severe corneal edema is characterized by the formation of an optically empty space corresponding to an interface fluid pocket. The spectrum of interface fluid syndrome can be described in 3 stages.

Interlamellar flap edema due to steroid-induced ocular hypertension after laser in situ keratomileusis

BACKGROUND

Several recent studies have reported post-laser in situ keratomileusis (LASIK) complications related to a steroid-induced increase in intraocular pressure, including interface fluid and elevated intraocular pressure-induced interlamellar stromal keratitis.

CASES

We examined two cases of interlamellar flap edema due to steroid-induced ocular hypertension after uneventful laser in situ keratomileusis.

OBSERVATIONS

Oral acetazolamide and discontinuance of topical steroids were effective for treating interlamellar stromal edema in both cases.

CONCLUSION

A rise in intraocular pressure should be considered a cause of interlamellar stromal edema after LASIK.

Surgical-glove-related diffuse lamellar keratitis after laser in situ keratomileusis: long-term outcomes

PURPOSE

To study the long-term refractive results in eyes that developed surgical-glove-related diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK).

SETTING

Department of Ophthalmology, Hospital Provincial, Toledo, Spain.

METHODS

This retrospective review analyzed an epidemic of surgical-glove-related DLK over a 5-month period at a single hospital. Twenty-four eyes (24 patients) that developed DLK (DLK group) were compared to 30 eyes (30 consecutive patients) that had surgery during the same time but had an uneventful postoperative course (control group). Follow-up was 12 months in all cases.

RESULTS

Twelve months after LASIK, the mean spherical equivalent was 0.14 diopter (D) +/- 0.36 (SD) in the DLK group and -0.07 +/- 0.33 D in the control group (P=.03). The mean uncorrected visual acuity was 0.91 +/- 0.18 and 0.90 +/- 0.17, respectively (P = .81). The mean best spectacle-corrected visual acuity (BSCVA) was 0.97 +/- 0.08 in the DLK group and 0.99 +/- 0.06 in the control group (P = .42). At 1 year, 91.7% of eyes in the DLK group and 93.3% of eyes in the control group were within +/-0.50 D of the attempted correction (P = .82). The BSCVA was 1.0 or better in 87.5% and 93.3%, respectively (P =.46).

CONCLUSIONS

Early diagnosis and appropriate treatment of glove-related DLK provided visual outcomes that were similar to those in eyes with an uneventful postoperative course. These good results are consistent with those in studies of classic DLK.

In vivo confocal microscopic findings of interlamellar stromal keratopathy induced by elevated intraocular pressure

We report the confocal microscopic findings in a case of interlamellar stromal keratopathy induced by elevated intraocular pressure (IOP) after laser in situ keratomileusis (LASIK). In vivo confocal microscopy showed swollen and enlarged cellular structures and the presence of microlacunae separating the stromal collagen lamellae. Inflammatory mononuclear cells and granulocytes typically seen in patients with diffuse lamellar keratitis (DLK) were absent. Stopping the topical steroids with concurrent lowering of the IOP resulted in improvement in the uncorrected and best corrected visual acuities and was associated with resolution of the corneal findings. In vivo confocal microscopy is a useful tool to study interlamellar stromal keratopathy induced by elevated IOP after LASIK in humans and the response to treatment and to differentiate interlamellar stromal keratopathy from DLK.

Interface fluid syndrome in laser in situ keratomileusis after complicated trabeculectomy

A 69-year-old man developed stromal edema and a pocket of fluid in the laser in situ keratomileusis (LASIK) interface wound in the left eye after acute endothelial cell loss from complicated trabeculectomy. He eventually required penetrating keratoplasty along with cataract surgery. Histologic examination of the corneal button showed an edematous 720 microm central residual stromal bed, a 54 microm empty space at the level of the central interface wound, and a 154 microm LASIK flap. The endothelial cell count was 0 to 2 cells per high-power field, corresponding to a cell density of 450 to 500 cells/mm(2). Four years after LASIK, the central interface wound was susceptible to forming a pocket of serous fluid after the corneal endothelial function was compromised.

Interface Corneal Edema Secondary to Steroid-induced Elevation of Intraocular Pressure Simulating Diffuse Lamellar Keratitis

PURPOSE

To describe interface corneal edema secondary to steroid-induced elevation of intraocular pressure (IOP) following LASIK.

METHODS

Retrospective observational case series. Diffuse interface edema secondary to steroid-induced elevation of IOP was observed after LASIK simulating diffuse lamellar keratitis (DLK) in 13 eyes. Mean patient age was 31.4 +/- 5.3 years. Patients were divided into two groups according to provisional misdiagnosis: DLK group (group 1) comprised 11 eyes and infection group (group 2) comprised 2 eyes (microbial keratitis). Mean follow-up was 8.1 +/- 0.5 weeks.

RESULTS

In the DLK group, typical diffuse haze was confined to the interface and extended to the visual axis, impairing vision in all eyes. Provisional diagnosis was late-onset DLK and topical steroids were started. Repeat examination showed elevated IOP as measured at the corneal center and periphery using applanation tonometry (mean 19.1 mmHg and 39.5 mmHg, respectively), causing interface edema with evident interface fluid pockets. Steroids were stopped and topical anti-glaucoma therapy was started. The interface edema decreased and at the end of follow-up the corneal transparency was restored and IOP dropped to normal values. The infection group demonstrated a microbial keratitis-like reaction and underwent flap lifting and interface wound debridement and biopsy with administration of fortified antibiotics and steroids. After elevated IOP was detected, steroids and antibiotics were stopped and topical anti-glaucoma therapy was started, resulting in the resolution of the interface edema.

CONCLUSIONS

Interface fluid syndrome secondary to steroid-induced elevation of IOP might develop in steroid responders after LASIK with a misleading clinical picture simulating DLK or infectious keratitis. Management includes stopping topical steroids and starting topical antiglaucoma therapy.