Techniques, indications and complications of corneal debridement

Refractory Recurrent Corneal Erosion after Descemet’s Stripping Automated Endothelial Keratoplasty

Purpose: To report a case of refractory recurrent corneal erosion that occurred after Descemet’s stripping automated endothelial keratoplasty (DSAEK) in iridocorneal endothelial syndrome.Case summary: A 62-year-old male patient with iridocorneal endothelial syndrome planned to undergo ultrathin DSAEK. At the surgery, corneal epithelial debridement was performed using a No. 15 blade to enhance the surgical field visibility. Three corneal venting incisions were made before graft insertion in the recipient eye. The corneal epithelium was healed at postoperative 1 week. However, the epithelium detached at 2 weeks postoperatively. The loosened epithelium was peeled off, and a therapeutic bandage contact lens was applied. Thereafter, the corneal epithelial detachment did not improve, despite repeated corneal epithelial debridement, prolonged therapeutic bandage contact lens wear, applications of 5% sodium chloride eyedrops and autoserum eyedrops, and intake of doxycycline, steroids, and valaciclovir. Anterior stromal puncture was performed three times, and the corneal epithelium eventually attached at postoperative 8 weeks. Although recurrent corneal erosion was not observed at postoperative 10 weeks, acute graft rejection occurred but improved with immunosuppressive treatment. The corrected visual acuity was 0.8 after cataract surgery, which was performed at 1 year after DSAEK.Conclusions: Refractory recurrent corneal erosion may occur after DSAEK surgery. In such a case, an aggressive treatment including the repeated anterior stromal puncture technique may be helpful.

Corneal Epithelial Removal with a Newly Designed Epithelial Brush

This study aimed to evaluate and compare the effectiveness of a newly developed epithelial removal brush with conventional methods in a rabbit model of corneal epithelial defects. The corneal epithelia of thirty-seven rabbits were removed by three different methods including blades (blade group), newly developed epithelial brushes (Ocu group), and conventional rotating brushes (Amo group). The defect area was measured with light microscopy immediately and at 4, 18, 24, and 50 hours after removal. Corneas were obtained immediately and at 24 and 50 hours and subjected to hematoxylin and eosin (H&E) and immunofluorescence staining using proliferating cell nuclear antigen (PCNA) and phosphorylated heat shock protein 27 (pHSP27) antibodies. The residual stromal surface was observed by scanning electron microscopy (SEM). In the Ocu group, epithelia were significantly recovered at 18, 24, and 50 hours compared with immediately after removal, and in the blade and Amo groups, epithelia were significantly recovered only at 50 hours after epithelial removal. The expression levels of PCNA and pHSP27 did not differ among three groups. There was significantly more inflammatory cell infiltration in the blade group than in the other groups. SEM showed a more regular and uniform residual stromal surface in the Ocu group than in the other groups. The newly developed epithelial brush showed better polishing ability and led to earlier significant epithelial recovery and a more regular and uniform stromal surface than conventional methods in this rabbit model of epithelial defects. Accumulation of clinical data is expected to expand the scope of application of new brushes for laser surface ablation.

Impact of Intraoperative Ocular Lubricants on Corneal Debridement Rate During Vitreoretinal Surgery

Purpose

To compare surgical parameters among patients receiving Viscoat (sodium chondroitin sulfate 4%–sodium hyaluronate 3%) or Goniosol (hydroxypropyl methylcellulose 2.5%) as topical lubricants for retinal surgery.

Methods

This was a retrospective analysis of patients undergoing retinal surgery between March 2013 and March 2018 using Goniosol or Viscoat as adjuvants. Primary outcome measures were rate of corneal debridement and operative time between groups, compared using χ² and t-tests, respectively.

Results

Compared to Viscoat (n=319), the Goniosol group (n=210) had more frequent intraoperative corneal debridement (21.4% vs 0, p<0.05) and longer surgical times (98 vs 78 minutes, p<0.05). Patients in the Viscoat group had higher rates of complex procedures (34.8% vs 26.7%, p<0.05), but were younger (50.7 vs 55.0 years, p<0.05) and more likely to be phakic (83.4% vs 70.5%, p<0.05).

Conclusion

These findings suggest potential advantages of using Viscoat over Goniosol for corneal lubrication to aid visualization during vitreoretinal surgery.

Evaluation of corneal cross-linking as adjuvant therapy for the management of fungal keratitis

PURPOSE

To evaluate the efficacy of corneal cross-linking (CXL) as adjuvant therapy for the treatment of fungal ulcerative keratitis.

METHODS

Forty-one patients with fungal ulcerative keratitis were recruited and assigned into two randomized controlled groups. These groups were treated with CXL combined with antifungal medications (CXL-M) or antifungal medications alone (M). The ulcers were assessed by slit-lamp biomicroscopy, slit-lamp images, in vivo confocal microscopy (IVCM), and anterior segment optical coherence tomography (AS-OCT). The patients were followed up before surgery/first visit (FV), 1 day after surgery, 1 and 2 weeks, and 1, 2, 3, 4, 5, and 6 months after surgery/FV.

RESULTS

In the cured patients, the area of corneal ulcers, the duration of ulcer healing, the time to non-observed fungal hyphae by IVCM, the number of antifungal medications, the frequency of administered medications, and the maximum ulcer depth decreased significantly after CXL (all P < 0.05) compared with the M group. There were no significant differences in either corneal thickness or epithelial thickness of ulcers after healing between 5 and 6 months after surgery in the CXL-M group, while these were increased significantly at 6 months compared with 5 months after FV in the M group (both P < 0.05).

CONCLUSIONS

In our study, CXL accelerated healing of the fungal ulcers, shortened the treatment duration, and minimized the need for medications and surgery. It appears that CXL is an effective procedure and adjuvant therapy for managing fungal keratitis.

Experimental Study of Diamond Burr Polishing Methods of Bowman’s Membrane

Purpose: to develop the optimal (safe and effective) method of diamond burr polishing of Bowman’s membrane (DBPBM) for the possible use it in the treatment of the recurrent corneal erosion syndrome (RCES) in the experiment.

Material and methods. DBPBM in different modifications of the  method and the mechanical deepithelization were performed in  experiment on 19 human cadaver eyes. We use system Ophtho-Burr  for DBPBM that includes a tip and ophthalmic burrs with diameter  1mm, 2.5 mm, 5 mm, varying the speed of rotation of burr. For 3  eyes — polishing with the application of burr with a diameter of 5  mm, the rotation frequency of 4000 rpm using 2 passes over the  surface of the cornea. For 3 eyes — burr with a diameter of 2.5 mm,  rotation frequency of 4000 rpm in 2 perpendicular passes. For 3 eyes — diameter burr 1 mm at speed of 8000 rpm in 2 perpendicular  passes. For 3 eyes — diameter burr 1 mm at speed 4000 rpm with 4  passes along the surface of the cornea. For 4 eyes — diameter was 1 mm at speed of 4000 rpm in 2 perpendicular passes. For 3 the eyes  was conducted mechanical deepithelization. Subsequent histopathological investigation of the cornea was  performed by method of semi-thin section, with polychrome staining.

Results. The obtained results of histological studies of DBPBM in  different versions on cadaver cornea is allowed to choose the optimal variant of surgical intervention for use in clinical conditions. It  consisted in a selection of burr with a diameter of 1 mm, the rotation frequency of the 4000 rpm and 2 perpendicular passes with a  moderate compression of the cornea. The abovementioned technique of intervention allows removing completely the corneal epithelium  with a basal membrane and save uniform in thickness, fully  deepitelizationed Bowman’s membrane.

Conclusion.Careful and accurate removal of dysplastic corneal epithelium in cases of the recurrent corneal erosion syndrome using  proposed method in clinical conditions should contribute to the  creation optimal environments for adequate reepithelization with  steady epithelial-stromal adhesion. The remaining nearly intact  Bowman’s membrane after procedure can prevent some postoperative complications such as haze and induced refractive disorders.

Corneal Debridement Combined with Intrastromal Voriconazole for Recalcitrant Fungal Keratitis

Background

To analyze the therapeutic effects of corneal debridement combined with intrastromal voriconazole in recalcitrant fungal keratitis.

Methods

This is a retrospective study. Fourteen patients with recalcitrant fungal keratitis were treated by corneal debridement combined with intrastromal voriconazole (50 μg/0.1 ml). This paper reviews and analyzes the patients' basic state, surgical intervention, medicinal treatment, and outcomes.

Results

The mean sizes of infiltration and ulcer were (5.54 ± 1.32)mm and (3.46 ± 1.03)mm, respectively, and the mean depth was (315.43 ± 57.72)μm. Twelve of the patients had satellite lesion, and 2 suffered hypopyon. After intrastromal voriconazole, the size of infiltration decreased significantly to (4.32 ± 1.10)mm (P < 0.001), but there was no significant change in ulcer size ((3.36 ± 0.92)mm, P = 0.082). Thirteen patients were cured after corneal debridement. The mean healing time was (15.38 ± 7.38) days. Excluding one cured patient with optic nerve atrophy and one patient for whom the treatment failed, the mean best-corrected visual acuity after healing was (0.23 ± 0.18)LogMAR, a significant improvement compared to pretreatment (0.87 ± 0.57(LogMAR), P = 0.01). The mean corneal astigmatism was (1.3 ± 1.6)D of 12 cured patients after healing and (1.0 ± 0.7)D at final follow-up, and there was no significant difference (P = 0.374).

Conclusions

Corneal debridement combined with intrastromal voriconazole is a secure and effective treatment for recalcitrant fungal keratitis.

Superior Perilimbal Epitheliopathy in Recurrent Corneal Erosion Syndrome

PURPOSE

To highlight the finding of occult areas of poor epithelial adhesion in the superior perilimbal cornea in a minority of patients with recalcitrant recurrent corneal erosion syndrome presenting with corneal erosion elsewhere on the corneal surface.

PATIENT POPULATION

Thirty-one eyes of 31 consecutive patients with corneal erosion undergoing mechanical debridement of the epithelium before diamond burr keratectomy for recurrent corneal erosion.

METHODS

Thirty-one eyes of 31 consecutive patients with recurrent corneal erosion were examined for poor epithelial adhesion determined by mechanical debridement with a dry microsponge.

RESULTS

During debridement, 8 of 31 eyes (25.8%) displayed a large arcuate area of occult dysfunction of adhesion in the superior perilimbal area. None of these eyes showed recurrence over a mean of 18 months after diamond burr keratectomy (95% confidence interval, 0%-36.9%).

CONCLUSIONS

Mechanical debridement with a microsponge identified a significant minority of patients with poor adhesion in the superior perilimbal cornea away from the area of obvious erosion and increased the target area for diamond burr keratectomy. This 2-pronged approach allowed successful management of this group.

Corneal epithelial debridement for diagnosis and therapy of ocular surface disease

BACKGROUND

There is a wide range of ocular surface conditions that can be diagnosed or treated with epithelial debridement. The purpose of this study is to analyse the indications, instrumentation and outcomes of corneal epithelial debridement for anterior segment pathology.

METHODS

One hundred and thirty-three eyes of 129 patients with ocular surface disease were treated with epithelial debridement. Different methods were used, appropriate to the specific disease, aetiology and outcome measure.

RESULTS

The mean patient age was 56 years and 81 (60.9 per cent) were male. Sixty-two eyes (46.6 per cent) were undertaken for diagnosis and 71 (53.4 per cent) for therapy. Common indications for diagnostic corneal debridement included infective keratitis 48 (36.1 per cent), neoplasia 14 (10.5 per cent), while those for therapeutic corneal debridement included recurrent erosion 30 (22.5 per cent) and band keratopathy 16 (12.0 per cent). The most common post-operative complication was pain, occurring in all patients to some extent. Band keratopathy was seen to recur in two (12.5 per cent) of the treated eyes and there was a single relapse of recurrent erosion during the follow-up period.

CONCLUSION

The techniques presented can be undertaken in the office rather than a day procedural unit, improving time and cost-effectiveness for the ophthalmologist and patient.