Diamond burr debridement of calcific band keratopathy in 24 eyes of 22 horses

PURPOSE

To evaluate the safety and effectiveness of diamond burr debridement (DBD) for the treatment of calcific band keratopathy (CBK) in horses.

METHODS

Medical records from horses with CBK were reviewed over a period of 4 years. Diagnosis of CBK was based on slit-lamp examination findings, and DBD was performed on standing sedated horses. Follow-up was obtained by clinical reevaluation of the treated eyes or a telephone survey with the referring veterinarian.

RESULTS

Twenty-two horses of different ages (median: 11 years; range: 5-23) representing 24 CBK-affected eyes (14 left eyes and 10 right eyes) were included in the study. The patients had a medical history of chronic and recurrent uveitis, which required repeated long-term treatments with various combinations of ophthalmic corticosteroids. DBD alone cleared the cornea in 22 affected eyes (92%), but it was combined with blade scraping in two cases with thick calcium plaques. The postoperative medication included a topical antibiotic, atropine drops, and oral flunixin meglumine. Corneal healing was achieved in 21 eyes (87%), 5-21 days (median time 13 days) postoperatively. The three remaining horses were lost to follow-up. Recurrence occurred in 5 of the 21 (24%) reexamined eyes, 3-12.5 weeks (median 8 weeks) postoperatively, and required a second DBD. Four of the 21 eyes ended up being enucleated due to sequelae of uveitis. The main limitations of the study include those inherent to all retrospective clinical data collections.

CONCLUSION

Mechanical DBD can readily and safely clear the cornea in horses with CBK, but recurrence of calcium deposition is possible.

Commercial amniotic membrane extract for treatment of corneal ulcers in adult horses

BACKGROUND

Amniotic membrane extract enhances the rate of epithelialisation after corneal ulceration in several species but has not been studied in the equine cornea.

OBJECTIVES

To evaluate the effect of amniotic membrane extract on re-epithelialisation of equine corneal ulcers compared with ulcers treated with antibiotic, antifungal and mydriatic medical therapy alone, and to evaluate equine corneal healing after experimentally induced superficial ulceration.

STUDY DESIGN

Masked, randomised, controlled experimental trial.

METHODS

Superficial, 8 mm corneal ulcers were created bilaterally in each horse. One eye was treated with amniotic membrane extract and the opposite was control. Both eyes were treated with medical therapy. Treatment eyes received amniotic membrane extract, and control eyes received the amniotic membrane extract vehicle. Ulcers were stained with fluorescein and photographed in 12-hour increments until completely healed. Ulcer surface area was determined by analysing photographs with ImageJ. A mixed linear model was used to compare ulcer surface area and hours until healing between treatment groups. A regression model was also used to calculate corneal re-epithelialisation rate over time.

RESULTS

Regardless of therapy, healing occurred in two phases: an initial rapid phase of 0.88 mm² /hr (95% CI: 0.81-0.94 mm² /hr) for approximately 48-54 hours followed by a second, slow phase of 0.07 mm² /hr (95% CI: 0.04-0.09 mm² /hr). Most eyes healed within 135.5 ± 48.5 hours. Treatment (amniotic membrane extract vs. control) was not significantly associated with size of ulcers over time (P = .984). Discomfort was minimal to absent in all horses.

MAIN LIMITATIONS

Results achieved experimental studies may differ from outcomes in the clinical setting.

CONCLUSIONS

There was no significant difference in healing rate with addition of amniotic membrane extract to medical therapy for equine superficial corneal ulcers. A biphasic corneal healing process was observed, with an initial rapid phase followed by a slow phase. Further study will be needed to determine whether amniotic membrane extract will be helpful for infected or malacic equine corneal ulcers.

Immediate effects of diamond burr debridement in patients with spontaneous chronic corneal epithelial defects, light and electron microscopic evaluation

PURPOSE

To evaluate immediate effects of diamond burr debridement (DBD) on the cornea of canine patients diagnosed with spontaneous chronic corneal epithelial defects (SCCEDs).

ANIMALS STUDIED

Eight client owned dogs with SCCEDs.

METHODS

Nine eyes from eight dogs with SCCEDs underwent superficial keratectomy (SK). The ulcerated area was divided into quadrants with a 300-micron restricted depth knife. Two of four quadrants underwent DBD for 40-60 s. A SK followed immediately. One burred section and one nonburred section were fixed with formaldehyde 10% and underwent light microscopy (LM). The remaining quadrants from five eyes were fixed with glutaraldehyde 2.5% and underwent transmission electron microscopy (TEM). Masked pathologists evaluated the samples. A student's paired t-test was used to analyze the data.

RESULTS

With LM all nonburred samples had a superficial stromal hyaline acellular zone (HAZ), seven of the burred samples had an intermittent HAZ and in two burred samples this zone was absent. The HAZ thickness of burred samples (1.062 ± 0.664 μm) was significantly thinner than that of the nonburred samples (4.309 ± 1.348 μm) (P < 0.0001). Transmission electron microscopy showed an absence of basement membrane and the presence of an amorphous, fine fibrillar material in the superficial stroma in nonburred samples. This material was intermittent or absent in burred samples.

CONCLUSION

DBD significantly reduces the superficial stromal HAZ in SCCEDs. A reduction of its thickness may be responsible for the healing rates reported with DBD.

Diamond burr debridement of 34 canine corneas with presumed corneal calcareous degeneration

OBJECTIVES

To describe the signalment, presence of systemic and/or ocular comorbidities, times to detected healing and probabilities of recurrence after diamond burr debridement (DBD) of eyes with presumed corneal calcareous degeneration and secondary ulceration and/or ocular pain.

ANIMALS STUDIED

Twenty-six dogs with 42 eyes affected, 34 eyes treated with DBD.

METHODS

A case series was conducted using medical records from a private veterinary ophthalmology referral practice. Dogs were included if they had white or gray corneal opacity consistent with corneal calcareous degeneration with either erosive or superficial ulceration and/or ocular pain in at least one eye and had at least one such eye treated with DBD. DBD was performed with a battery-operated handheld motorized burr (The Alger Company, Inc. Lago Vista, TX, USA), and a bandage contact lens was placed in the majority of eyes (30/34). Eyes were considered healed when the cornea was fluorescein negative, and there were no signs of ocular pain. Patient data (signalment, recurrence) were extracted from medical records.

RESULTS

Dogs were first re-examined 7-62 days after treatment (median: 13 days). All DBD-treated eyes healed within 62 days (% healed: 100%; one-sided 97.5% CI: 90-100%, median: 14 days), 82% of eyes (28/34) were healed at first re-examination (median: 13 days after treatment), and all were healed by their second examination (median: 24 days). Of the 34 treated eyes, 11 were lost to follow up; 11 of the remaining 23 eyes recurred. Estimated 1-year recurrence probability was 58% (95% CI: 35-83%). Seven dogs had systemic disease; 7 had a history of prior ocular disease or intraocular surgery.

CONCLUSIONS

Diamond burr debridement is a safe and effective treatment for rapid resolution of superficial corneal ulceration and ocular pain secondary to presumed corneal calcareous degeneration in dogs.

Treatment of nonhealing corneal ulcers in 60 horses with diamond burr debridement (2010-2013)

OBJECTIVE

To review the signalment, clinical characteristics, and outcome of horses with nonhealing corneal ulcers treated with diamond burr debridement (DBD); and to evaluate the role of ulcer duration, size and location, and bandage contact lens (BCL) placement on healing.

ANIMALS

From January 2012-April 2013, 60 horses were diagnosed with ulcers classified as nonhealing based on the presence of raised epithelial margins and duration of at least 7 days.

PROCEDURE

Retrospective record review.

RESULTS

Average age of included horses was 14.68 years, SD 8.17 years. There were three times as many males (45) as females (15), (χ12 = 15, P = 0.001). Forty-eight horses (80%) had nonhealing ulcers uncomplicated by associated corneal disease. In the remaining horses, associated corneal disease included esinophilic keratitis (10%), calcific band keratopathy (5%), endothelial decompensation (1.67%), habronemiasis(1.67%), and lid suture abrasion (1.67%). Average corneal ulcer duration prior to diamond burr debridement (DBD) was 29.0 days (n = 56). Ulcers occurred most commonly in the axial cornea (41%). Fifty-five of 60 horses (92%) healed with DBD. Healing time, defined as time to epithelialization following DBD, averaged 15.5 days, SD 9.32 days, and was not correlated with patient age or ulcer duration, location, or size prior to or following DBD. Healing time was significantly longer for eyes in which a BCL had been placed (n = 28, 19.0 days) than for eyes without a BCL (n = 32, 12.9 days), F(1,58) = 5.543, P = 0.02. DBD was considered a failure for five horses (8%).

CONCLUSIONS

DBD may be an effective treatment for nonhealing corneal ulcers in horses.

Lateral nasal osteotomy: a comparative study between the use of osteotome and a diamond surgical burr - a cadaver study

BACKGROUND

The ultimate goal of rhinoplasty is to achieve a controllable, reliable and an aesthetically pleasing result. Various approaches and instruments have been introduced for the correction of the bony walls of the nose to improve predictability of the procedure and to minimize the associated trauma. We conducted a cadaveric study comparing the results of osteotomy of the nasal wall using a diamond surgical burr with those using a 2-mm osteotome.

MATERIAL AND METHODS

Bilateral osteotomy of the nasal wall was performed on 10 cadavers. The 20 lateral nasal osteotomies were carried out on 7 females and 3 males of an age range between 61-91 years. A 2-mm osteotome was used percutaneously to perforate the lateral nasal wall of the right side. On the left side a 2-mm diamond surgical burr was introduced via an intraoral approach to thin out the lateral nasal wall. The in-fracture of the nasal bone was accomplished by controlled finger pressure. The nasal mucosa was inspected endoscopically and also dissected to identify any perforations or lacerations. The pattern of nasal fracture and the presence of any fragmentation of the bony segments were assessed clinically.

RESULTS

The in-fracturing of the nasal bone was accomplished by gentle pressure on the left side, but required more force on the contra lateral side. On the left side the in-fractured lateral nasal wall remained as one piece and no irregularities were seen. On the right side 3-5 bony fragments of irregular sizes and shapes were detected. There were 3-4 tears of the nasal mucosa, where the osteotome was applied. However, no mucosal tears were detected at the side, where the surgical burr was used.

CONCLUSION

Osteotomy of the lateral nasal wall with a diamond burr via intraoral approach is more precise and associated with fewer complications in comparison with the use of the osteotome.

Diamond burr superficial keratectomy for recurrent corneal erosions

AIMS

To evaluate the efficacy and safety of diamond burr superficial keratectomy in the treatment of recurrent corneal erosions.

METHODS

A retrospective review of 54 eyes (47 patients) with recurrent corneal erosions treated with diamond burr superficial keratectomy. Preoperative and postoperative visual acuities and refractions, slit lamp examination findings, and the incidence of recurrent erosion after keratectomy were studied. Specular microscopy was also performed in six patients before and after surgery.

RESULTS

30 eyes had underlying map dot fingerprint anterior basement membrane corneal dystrophy, while 24 eyes did not. Postoperative follow up time ranged from 3 to 53 months (mean 12.3 months). Corneal erosion recurred in three eyes (6%) after diamond burr superficial keratectomy. This procedure improved the best corrected visual acuity from 20/26 to 20/22 by logMAR statistical evaluation (p=0.002) and caused very little change in the refractive spherical equivalent. No endothelial cell loss or changes in morphology were noted on specular microscopy.

CONCLUSION

Diamond burr superficial keratectomy appears to be an effective and safe method of treating recurrent erosions and is a good alternative therapy to needle stromal micropuncture, Nd:YAG induced epithelial adhesion, and excimer laser surface ablation.