Posterior capsular opacification in diabetic and nondiabetic canine patients following cataract surgery

Effects of intracameral tissue plasminogen activator injection on posterior capsular opacification, fibrin formation, and intraocular pressure in dogs after phacoemulsification

OBJECTIVE

To evaluate whether intracameral tissue plasminogen activator (tPA) injection is effective in regulating posterior capsular opacification (PCO), fibrin formation and intraocular pressure (IOP) after cataract surgery.

ANIMAL STUDIED

Prospective study involving 30 eyes of 21 dogs that underwent phacoemulsification.

PROCEDURES

Thirty eyes were randomly divided into two groups of 15 eyes (control and tPA groups). Intracameral tPA (25 μg/0.1 mL) was injected into tPA group eyes before corneal incision closure but not into the eyes of the control group. The grades of anterior fibrin formation and PCO were compared based on slit lamp biomicroscope examination at 1 and 2 weeks, 1 month, and 2-3 months postoperatively. IOP was measured using applanation tonometry every 30 min for 4 h immediately after operation and on the following morning. The IOP of the two groups at each time was compared.

RESULTS

The grade of anterior fibrin formation and that of PCO were not significantly different between the two groups at any time point (p > .05). However, the IOP of the tPA group was significantly lower than that of the control group at each point on the day of surgery (p < .05). No complications were observed with tPA injection, except for temporary hyphema (for 3 days) in one eye.

CONCLUSIONS

Although the intracameral tPA injection did not affect anterior fibrin formation and PCO, it effectively maintained normal IOP immediately after phacoemulsification. Thus, our findings provide valuable insights into the potential benefits of intracameral tPA injection in achieving immediate IOP control after phacoemulsification.

Phacoemulsification Combined with Pars Plana Vitrectomy: Outcome in Horses with Acquired Cataracts Associated with Uveitis

BACKGROUND

Cataracts resulting from equine recurrent uveitis (ERU) or other forms of uveitis are usually associated with rapid progression. ERU is the most common ocular disease cause of blindness and cause of cataracts in horses. The necessity for the posterior capsulorhexis (PC) during phacoemulsification (PE) is controversial. This study aimed to evaluate vision and complications after PE combined with pars plana vitrectomy (PPV) in horses with uveitis-associated cataracts and compare the PE technique with and without posterior capsulorhexis.

METHODS

Thirty-two eyes of 28 horses with uveitis-associated cataracts aged 14 months to 19.6 years were treated with PE-PPV under identical conditions. Twenty-three eyes of 21 horses were affected by an ERU-associated (ERU group), and nine eyes of 7 horses were affected by cataracts related to uveitis with pathogenesis different to ERU (non-ERU group). PE-PPV was performed in 12 eyes of 10 horses (PC group) and 20 eyes of 18 horses without posterior capsulorhexis (NPC group). Follow-up examination was performed at a mean of 1.7 ± 1.8 years postoperatively (range: 1 month-6.4 years).

RESULTS

In the period up to 1 month postoperatively, 17/20 (85%) NPC-eyes and 8/12 (67%) PC-eyes (total: 25/32 [78%]) were visual. From 1-6 months postoperatively, 16/20 (80%) NPC-eyes and 7/12 (58.3%) PC-eyes (total: 23/32 [72%]), and from 6-12 months, 7/11 (63.6%) NPC-eyes and 3/8 (37.5%) PC-eyes (total: 10/19 [52.6%]) were visual. From 12-18 months postoperatively, 3/7 (42.9%) NPC-eyes and 2/9 (22.2%) PC-eyes (total: 5/16 [31.3%]), and from 18-24 months, 3/8 (37.5%) NPC-eyes and 1/8 (12.5%) PC-eyes (total: 4/16 [25%]) were visual. After 24 months postoperatively, 2/7 (28.6%) NPC-eyes and 1/8 (12.5%) PC-eyes (total: 3/15 [20%]) were visual. Despite the higher number of visual eyes in the NPC group at each time point, differences were not significant. No obvious differences regarding postsurgical vision were observed between the ERU- and non-ERU groups at each time point. In the overall population, a significant decrease in the number of eyes with postoperative active uveitis was observed during the follow-up examinations (p < 0.001). A significant increase in the number of eyes that were blind due to retinal detachment was observed in the overall patient population as the examination period progressed (p < 0.001). Retinal detachment was the sole long-term cause of blindness.

CONCLUSIONS

In horses diagnosed with uveitis-associated cataracts and treated with PE-PPV, no persistent active uveitis was observed in the present study during follow-up examinations. However, the proportion of eyes that were blind due to retinal detachment increased. Whilst PE-PPV may prevent postsurgical persistent active uveitis and remove lens opacity, the prognosis for a visual outcome is guarded. A superior outcome in postsurgical vision was observed in the NPC group. However, caution is required when interpreting these results due to several factors that affect the independent comparison of the surgical groups.

Hyperproliferation of Elschnig pearl-type posterior capsule opacification and spontaneous regression in two pseudophakic canine eyes

OBJECTIVE

To describe the hyperproliferation of Elschnig pearl-type posterior capsule opacification and concurrent uveitis in two canine eyes after phacoemulsification, followed by spontaneous resolution of the Elschnig pearls.

ANIMAL STUDIED

A 10-year-old castrated male Spitz (Case 1) and a 4-year-old spayed female Bichon Frise (Case 2).

PROCEDURE

Elschnig pearls proliferating beyond the anterior capsulotomy site were observed in the right eye 10 months after bilateral diabetic cataract surgery (Case 1) and 7 months after unilateral cataract surgery (Case 2). In both cases, hyperproliferation occurred where the anterior capsule did not overlap with the intraocular lens (IOL), and was accompanied by aqueous flare. In Case 1, the pearls extended from the anterior capsule and adhered to the iris, causing focal posterior synechia. No other possible causes of uveitis were apparent.

RESULTS

Initially, uveitis severity improved after the administration of topical and systemic anti-inflammatory drugs. However, uveitis recurred when the dosage of anti-inflammatory treatment was reduced. The Elschnig pearls underwent morphological changes throughout the follow-up period. In both cases, the pearls beyond the anterior capsulotomy resolved spontaneously after 5 months. Only a few pearls remained between the IOL and posterior capsule, and no recurrence of pearl proliferation was observed at the last follow-up.

CONCLUSIONS

To the best of our knowledge, this is the first report of spontaneous Elschnig pearl regression in dogs. Lens-induced uveitis (LIU) may have been caused by anterior chamber hyperproliferative pearls. LIU associated with hyperproliferative pearls may be managed with appropriate anti-inflammatory treatment and monitoring.

Comparison of the outcomes of phacoemulsification versus topical medication alone in canine diabetic cataracts: a retrospective study

BACKGROUND

Long-term comparisons of phacoemulsification with topical medication are limited in canine diabetic cataracts.

OBJECTIVES

To compare outcomes of eyes submitted to phacoemulsification with those of topical medication for canine diabetic cataracts and identify risk factors for complications.

METHODS

Through medical records review, 150 eyes (76 dogs) with diabetic cataracts were included; 58 eyes (31 dogs) underwent phacoemulsification (phaco-group) and 92 eyes (48 dogs) received ophthalmic solution alone (medication-group). The medication-group was divided into owner-led and vet-led groups depending on who elected not to perform surgery. Comparisons involved time-to-complications, vision, and the number and type of ophthalmic solutions administered. The association between complications and pretreatment clinical findings was investigated.

RESULTS

No difference was found in complication risk between the phaco and owner-led medication groups. Conversely, the vet-led medication-group had a higher complication risk than the other groups. At the last follow-up, 94.8% of the phaco-group had vision, whereas 7.6% of the medication-group restored some visual axis. Poor glycemic control in the medication-group and younger age in the phaco-group increased complication risk. At 1-year post-treatment, the average number of ophthalmic solutions administered was 1.7 and 2.6 in the phaco and medication groups, respectively. The medication-group used anti-inflammatories the most throughout the follow-up, whereas the phaco-group used anti-inflammatories the most until 1-year post-treatment and lacrimostimulants at 1.5-year post-treatment.

CONCLUSIONS

For canine diabetic cataracts, phacoemulsification is recommended because it is superior to topical management alone in terms of maintaining vision and reducing the number of ophthalmic solutions required in the long term.

How study of naturally occurring ocular disease in animals improves ocular health globally

In this article, which is part of the Currents in One Health series, the role of naturally occurring ocular disease in animals is reviewed with emphasis on how the understanding of these ocular diseases contributes to one health initiatives, particularly the pathogenesis and treatment of ocular diseases common to animals and humans. Animals spontaneously develop ocular diseases that closely mimic those in humans, especially dry eye disease, herpes virus infection (cats), fungal keratitis (horses), bacterial keratoconjunctivitis, uveitis, and glaucoma. Both uveitis and glaucoma are common in domestic animals and humans, and many similarities exist in pathogenesis, genetics, and response to therapy. Furthermore, the study of inherited retinal disease in animals has particularly epitomized the one health concept, specifically the collaborative efforts of multiple disciplines working to attain optimal health for people and animals. Through this study of retinal disease in dogs, innovative therapies such as gene therapy have been developed. A unique opportunity exists to study ocular disease in shared environments to better understand the interplay between the environment, genetics, and ocular disease in both animals and humans. The companion Currents in One Health by Gilger, AJVR, December 2022, addresses in more detail recent studies of noninfectious immune-mediated animal ocular disease and their role in advancing ocular health globally.

Pro-inflammatory cytokines in aqueous humor from dogs with anterior uveitis and post-operative ocular hypertension following phacoemulsification, primary glaucoma, and normal healthy eyes

Background

The aim of this study was to evaluate the levels of pro-inflammatory cytokines in aqueous humor (AH) from dogs with anterior uveitis and post-operative ocular hypertension (POH) following phacoemulsification, in AH from dogs with primary glaucoma, and in normal healthy eyes with no signs of anterior uveitis or other ocular diseases.

Methods

An exploratory study including 21 samples of AH collected from 15 dogs; post-phacoemulsification with anterior uveitis and POH (‘POH group’, n = 10 samples), primary glaucoma (‘glaucoma group’, n = 6 samples), and normal (‘normal group’, n = 5 samples). Target mass spectrometry via multiple reaction monitoring (MRM-MS) with the Canine Cytokine SpikeMix™ as internal standard was used to measure the pro-inflammatory cytokine levels.

Results

The MRM-MS method measured 15 pro-inflammatory cytokines. Tumor-necrosis-factor-alpha (TNFα) and interleukin-18 (IL-18) levels in AH were different between all three groups (glaucoma>POH>normal) (p = .05, p = .02, respectively). Additionally, IL-6 was higher in the ‘POH group’ compared to the ‘glaucoma group’ (p = .04) and IL-4 was higher in the ‘POH group’ compared to the ‘normal group’ (p = .04). Intraocular pressure (IOP) was positively associated with increased AH levels of IL-18 (Spearman correlation = .64, p = .03).

Conclusions

MRM-MS using the Canine Cytokine SpikeMix™ as an internal standard was established as a method to detect pro-inflammatory cytokine levels in canine AH. The study demonstrated increased levels of IL-4, IL-6, IL-18, and TNFα in AH from canines with POH following phacoemulsification. Primary glaucomatous eyes had the highest levels of IL-18 and TNFα which may indicate that inflammation plays a role in the pathogenesis of primary glaucoma in dogs.

Post-operative outcomes in canine eyes receiving a rhexis-fixated prosthetic intra-ocular lens: 30 cases (2014-2020)

OBJECTIVES

To report the outcomes following the insertion of a rhexis-fixated prosthetic intraocular lens (IOL) in dogs undergoing lens removal.

MATERIALS AND METHODS

The results are from 30 eyes of 28 dogs, undergoing lendectomy, in which the lens capsule could not accommodate a conventional prosthetic endo-capsular IOL. The reported cases had sustained either spontaneous or traumatic lens capsule rupture, or accidental intra-operative iatrogenic lens capsule disruption, or had required a planned, large, anterior or posterior continuous curvilinear capsulorhexis, all of which precluded insertion of a prosthetic IOL within the lens capsule. An acrylic IOL (XVET; Medicontur) was modified and positioned across the anterior and/or posterior capsulorhexes.

RESULTS

Other than haptic luxation in three cases, no complications were seen that were directly attributable to the rhexis-fixated lens. Over a follow-up period from three to 76 months (mean 20.7 months) 26/30 eyes remained visual. Blindness developed in three eyes due to retinal detachment and one eye was enucleated due to regrowth of a ciliary body adenoma.

CLINICAL SIGNIFICANCE

Rhexis fixation provided an alternative method to implant a prosthetic IOL when the lens capsule was unable to accommodate a conventional endo-capsular IOL.

Efficacy of long-term topical flurbiprofen in limiting lens capsule opacities following phacoemulsification in dogs

OBJECTIVE

To assess lens capsule opacity (LCO) following phacoemulsification in dogs receiving long-term topical ophthalmic flurbiprofen sodium 0.03%.

ANIMAL STUDIED

Twenty-five client owned dogs undergoing phacoemulsification surgery for either diabetic or nondiabetic cataracts.

METHODS

Prospective, randomized, masked clinical study assessing two groups of dogs for twelve months following phacoemulsification. All dogs underwent a complete eye examination and were photographed at each visit, beginning three weeks post-surgery, and repeated at 2, 3, 6, and 12 months post-surgery. Post-operative treatment protocols were similar for both groups, except that Group F received topical flurbiprofen once daily for 12 months and Group A received artificial tears once daily for 12 months. Digital photographs were analyzed for LCO using a subjective grading scale (0-4). The change in capsular opacities from 3 weeks to 12 months post-surgery was evaluated for each dog, and the groups were compared.

RESULTS

There were 25 dogs evaluated post-phacoemulsification at each designated time point of the study. There were 12 dogs in Group A and 13 dogs in Group F. There was no significant statistical difference in LCO score between Groups A and F at baseline (3 weeks post-surgery), 6 months post-surgery, or 12 months post-surgery. Scores did not change significantly from baseline to 12 months within or between groups.

CONCLUSIONS

Topical ophthalmic flurbiprofen sodium 0.03% solution applied once daily for 12 months following phacoemulsification does not appear to lead to a decrease in LCO formation as compared to artificial tears control.

Determination of trypan blue efficacy in the mitigation of ex vivo canine PCO formation

PURPOSE

To determine whether trypan blue (TB) reduces canine lens epithelial cell (LEC) or corneal endothelial cell (CEC) viability in vitro; if cell death is noted, to subsequently evaluate the molecular mechanism.

METHODS

Cellular viability was determined using a lactate dehydrogenase (LDH) assay. In TB-treated LECs, caspase 3/7 activity was assessed to evaluate apoptosis; autophagy was evaluated using immunoblotting against LC3 and p62. To evaluate the effects of TB on ex vivo posterior capsule opacification (PCO), following mock cataract surgery, lens capsules were treated with TB and subsequently maintained in culture to determine LEC migration and proliferation.

RESULTS

Following acute exposure, TB did not significantly reduce LEC or CEC viability at any of the concentrations tested. Increased caspase 3/7 activity was found in LEC cultures treated with TB for an extended period of time; no change in LC3 or p62 expression was noted. Ex vivo PCO formation was not significantly altered by TB treatment.

CONCLUSIONS

Acute exposure to TB did not reduce LEC or CEC viability, and only longer exposure to TB was able to initiate apoptosis. Treatment with intraocular TB at the time of cataract surgery is likely safe to the CECs but will not prevent PCO formation.

Effect of immediate postoperative intracameral tissue plasminogen activator (tPA) on anterior chamber fibrin formation in dogs undergoing phacoemulsification

OBJECTIVE

To evaluate the postoperative effect of intracameral tPA (alteplase; Activase®, Genentech, San Francisco, CA), administered at immediate conclusion of phacoemulsification, on anterior chamber fibrin formation in dogs.

PROCEDURES

Forty-one dogs (82 eyes) undergoing bilateral phacoemulsification received 25 μg/0.1 mL intracameral tPA in one eye and 0.1 mL unmedicated aqueous vehicle in the contralateral eye immediately after corneal incision closure. Intraocular pressure (IOP) was measured, and severity of anterior chamber fibrin formation, aqueous flare, pigment precipitates on the intraocular lens (IOL) implant, posterior capsular opacification (PCO), and corneal edema were graded at approximately 1 week, 2-3 weeks, 4-6 weeks, 8-12 weeks, and greater than 3 months postoperatively.

RESULTS

Anterior chamber fibrin developed postoperatively in 68.3% of dogs (28/41) and 50% of eyes (41/82). In tPA-treated eyes, 53.7% (22/41) developed fibrin compared to 46.3% of control eyes (19/41). Some degree of postoperative ocular hypertension (POH) occurred in 53.7% of dogs (22/41) and 36.5% of eyes (30/82). In tPA-treated eyes, 34.1% (14/41) experienced POH compared to 39% of control eyes (16/41). Additional intracameral tPA injection was later required in 29.3% of both tPA-treated (12/41) and control eyes (12/41).

CONCLUSIONS

Administration of intracameral tPA at immediate conclusion of canine phacoemulsification had no clinically observable effect on anterior chamber fibrin incidence at any time point. tPA-treated eyes showed no prophylaxis against POH or secondary glaucoma compared to control eyes and received late postoperative tPA injections at the same frequency as control eyes.

Effects of grape seed extract, lutein, and fish oil on responses of canine lens epithelial cells in vitro

OBJECTIVE To determine the effects of grape seed extract (GSE), lutein, and fish oil containing omega-3 fatty acids on oxidative stress, migration, proliferation, and viability of lens epithelial cells (LECs). SAMPLE Lens capsules or cultured LECs obtained from canine cadavers. PROCEDURES An antioxidant reductive capacity assay was used to determine reducing capability of each substance. The LECs were cultured and incubated with various substances, including N-acetyl cysteine (NAC), when appropriate, and dimethyl sulfoxide (DMSO) as positive and vehicle control substances, respectively. A dichlorofluorescein assay was used to evaluate reactive oxygen species (ROS) production, and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine cell viability. Ex vivo posterior capsule opacification (PCO) was used to evaluate LEC migration and proliferation. RESULTS Antioxidant reductive effects of GSE surpassed those of NAC, lutein, and fish oil containing omega-3 fatty acids. The GSE reduced ROS production in LECs, compared with the DMSO vehicle control, whereas lutein was pro-oxidative. All test substances reduced cell viability. Ex vivo PCO was not altered by GSE, was decreased by lutein, and was increased by fish oil containing omega-3 fatty acids, compared with results for the DMSO vehicle control. CONCLUSIONS AND CLINICAL RELEVANCE Only GSE had significant antioxidant capabilities and reduced ROS production; however, no effect on ex vivo PCO was detected. Fish oil containing omega-3 fatty acids increased ex vivo PCO. No conclusions could be made regarding antioxidant effects of these substances on LECs. These findings suggested that the substances will not decrease PCO.

Technique, postoperative complications, and visual outcomes of phacoemulsification cataract surgery in 21 penguins (27 eyes): 2011-2015

OBJECTIVE

To describe surgical technique, postoperative complications, and visual outcome in penguins after phacoemulsification lens extraction surgery.

ANIMALS STUDIED

Twenty-one penguins (27 eyes) that had phacoemulsification from 2011 to 2015 at Animal Eye Associates. Species included are as follows: 14 southern Rockhopper (18 eyes, 66.6%), 4 Gentoo (4 eyes, 19%), 2 King (3 eyes, 9.5%), and 1 Chinstrap penguin (2 eyes, 4.8%). Eleven of the penguins were females, and 10 were males with average age at the time of surgery being 27.5 years (range of 22-31 years).

PROCEDURE

This is a retrospective study of phacoemulsification cataract surgery patients from 2011 to 2015. Visual outcome was evaluated by veterinary ophthalmologists at postoperative recheck examinations and subjectively by penguin keepers using individual bird surveys and paired t tests for statistical analysis.

RESULTS

All eyes were functionally visual after surgery and at the time of last follow-up. Based on keeper surveys, 81% (17/21) of penguins showed immediate improvements in overall quality of life and 90% (19/21) of penguins exhibited improvement in mobility and behavior within their exhibit following cataract removal. Of the 14 penguins that received 1:5 intracameral atracurium during surgery, 10 (71.4%) had moderate mydriasis, 1 (7.1%) had minimal mydriasis, and 3 (21.4%) showed no effect to the pupil. Seventy percent of the cases had phacoemulsification times less than 60 seconds/eye; the mean time was 72 seconds. Sixteen eyes (59.3%) underwent anterior capsulotomy only, planned anterior and posterior capsulotomies were performed in 3 eyes (11.1%), and the entire lens capsule was removed due to capsular fibrosis and wrinkling in 8 eyes (29.6%). The most common short-term postoperative complication was temporary mild blepharospasm and/or epiphora, reported in 8 eyes (29.6%) from 7 penguins (33.3%). Long-term complications, 2-6 years postoperatively, included posterior synechiation resulting in dyscoria (10 of 24 eyes, 41.7%) and capsular fibrosis in all penguins with residual lens capsule (19/19, 100%).

CONCLUSION

The prognosis for vision and behavioral improvement after phacoemulsification surgery in penguins is good, with low incidence of vision-threatening complications.

Cyclosporine A prevents ex vivo PCO formation through induction of autophagy-mediated cell death

The purpose of this study was to determine the Cyclosporine A (CsA) dose and minimum drug delivery time needed to prevent posterior capsule opacification (PCO) in an ex vivo canine model and evaluate the mechanism of CsA-induced cell death. Canine lens epithelial cells (LEC) were treated with CsA and changes in cell migration, proliferation, and density were monitored over time. CsA-treated LEC underwent transmission electron microscopy (TEM), immunofluorescence, and immunoblotting in the presence or absence of autophagy inhibitors to evaluate the mechanism of cell death. Lens capsules were harvested from canine cadaver eyes for an ex vivo model of PCO. Lens capsules were treated with CsA for 1, 2, 3, 4, 5, 6, or 7 days, and subsequently maintained in culture for a total of 28 days in the absence of drug. CsA reduced LEC viability in a dose dependent manner. Morphologically, CsA-treated LEC were swollen, had intact nuclei, lacked peripheral chromatin condensation, and demonstrated prominent vacuolization; TEM revealed autophagosomes. LC3-II protein expression and acridine orange fluorescence increased in CsA-treated cells. A small non-significant induction of cleaved caspase-3 was observed in CsA-treated LEC. Lens capsules treated with 5, 6, or 7 days of 10 μg/mL CsA showed a significant decrease in ex vivo PCO formation; 6 days of drug delivery prevented PCO. This study finds that morphologic changes, formation of acidic vesicles, and increased expression of LC3-II supports the hypothesis that CsA mediates LEC death via autophagy; this is a novel finding in the lens. Induction of CsA-induced apoptosis was minimal. Six days of intracapsular CsA drug delivery prevented ex vivo PCO formation.

Efficacy of COX-2 inhibitors in controlling inflammation and capsular opacification after phacoemulsification cataract removal

OBJECTIVE

To evaluate the efficacy of 0.9% bromfenac (Xibrom™) or a celecoxib-impregnated intraocular lens (celecoxib-IOL) compared with 1% prednisolone acetate (PA) in controlling postoperative inflammation and posterior capsule opacification (PCO).

ANIMAL STUDIED

Fifty-nine dogs undergoing cataract extraction by phacoemulsification.

PROCEDURE

Bilateral patients received bromfenac or celecoxib-IOL plus PA in one eye, and PA in the contralateral eye. Unilateral patients received bromfenac or PA. Complete ophthalmic examination including tonometry, slit-lamp grading of flare and PCO, and digital image acquisition for masked PCO evaluation was performed within 24 h and 1, 4, 12, 24, and 56 weeks following surgery.

RESULTS

Celecoxib-IOL/PA-treated eyes had significantly less flare than PA-treated eyes, which had significantly less flare than bromfenac-treated eyes 24 h postoperatively. There was no significant difference in intraocular pressure (IOP) postoperatively, or at 1, 24, or 56 weeks. Celecoxib-IOL/PA-treated eyes had significantly lower IOP measurements than bromfenac and PA-treated eyes at 4 and 12 weeks. There was no significant difference in PCO level between groups using slit-lamp biomicroscopy at any time point. Masked evaluation of digital images revealed significantly less PCO in celecoxib-IOL/PA- vs. bromfenac-treated eyes at 4 weeks, and in bromfenac- vs. PA-treated eyes at 56 weeks.

CONCLUSIONS

Eyes receiving celecoxib-IOL/PA had better initial control of inflammation. Bromfenac was equally effective compared with PA in controlling inflammation. There was no association between COX-2 inhibitor administration and ocular hypertension. Celecoxib-IOL/PA-treated eyes showed better initial control of PCO (up to 12 weeks), while eyes receiving bromfenac had better long-term control of PCO (56 weeks).

In vivo effects of adjunctive tetracycline treatment on refractory corneal ulcers in dogs

OBJECTIVE

To evaluate effect of adjunctive treatment with tetracycline analogues on time to complete corneal reepithelialization in dogs with nonhealing (ie, refractory) corneal ulcers.

DESIGN

Randomized controlled clinical trial.

ANIMALS

89 dogs with refractory corneal ulcers.

PROCEDURES

Corneal ulcers were treated via debridement and grid keratotomy. Dogs were assigned to receive 1 of 3 treatment regimens for up to 6 weeks: doxycycline (5 mg/kg [2.27 mg/lb], PO, q 12 h) with topically applied ophthalmic ointment containing neomycin, polymyxin B, and bacitracin (ie, triple antibiotic ointment; q 8 h); cephalexin (22 mg/kg [10 mg/lb], PO, q 12 h) with topically applied oxytetracycline ophthalmic ointment (q 8 h); or a control treatment of cephalexin (22 mg/kg, PO, q 12 h) with topically applied triple antibiotic ointment (q 8 h). Healing was monitored via measurements of the wound with calipers and evaluation of photographs obtained every 2 weeks. Treatment effectiveness was evaluated by wound healing and decreased signs of pain.

RESULTS

The Boxer breed was overrepresented in all groups. At the 2-week time point, wound healing was significantly more common in small-breed dogs, compared with large-breed dogs. Dogs treated with oxytetracycline ophthalmic ointment had a significantly shorter healing time than did dogs receiving the control treatment. Corneal ulcers in dogs that received doxycycline PO healed more rapidly than did ulcers in dogs in the control treatment group; however, this difference was not significant.

CONCLUSIONS AND CLINICAL RELEVANCE

Topical tetracycline ophthalmic ointment was a safe, inexpensive, and effective adjunctive treatment for refractory corneal ulcers in dogs.

A and B mode ultrasonography in preoperative evaluation of lens and posterior segment of dogs eyes with cataract

Ultrasonography of the lens and posterior segment is an indispensable step in the preoperative evaluation of dogs with cataracts, since ophthalmoscopy is not feasible when there is opacification of the lens. This study evaluated the echographic conditions of cataractous lens and fundus of the eye in dogs affected by cataracts. The study was conducted in 30 dogs (56 eyes), 10 males and 20 females, with different types of cataracts at different stages of development. Echography in A and B modes, simultaneously, was carried out for the examination of the lens and posterior segment. The examinations revealed anterior cortical, posterior cortical and nuclear cataract in 12 eyes (21.4%), anterior cortical, posterior cortical, nuclear and posterior capsular in 23 eyes (41%), anterior cortical, posterior cortical and posterior capsular cataract in one eye (1.7%), anterior cortical and nuclear cataract in one eye (1.7%), anterior cortical, nuclear and posterior capsular cataract in five eyes (8.9%), and anterior cortical cataract in seven eyes (12.5%). Abnormal ultrasonographic alterations were observed in the posterior segment in 26 eyes evaluated (46.4%). Vitreal degeneration was detected in 12 eyes (21.4%), images of vitreal exudate or hemorrhage in seven eyes (12.5%), persistence of hyaloid artery in four eyes (7.1%) and lens subluxation in three eyes (5.3%). The results obtained reiterate the importance of ultrasonography in canine patients presented for cataract surgery given that alterations of the posterior segment are difficult to identify in a clinical examination when the lens is opacified.

Update on veterinary cataract surgery

PURPOSE OF REVIEW

The purpose of this review is not to specifically discuss the techniques of veterinary cataract surgery, but rather to emphasize some of the differences between the veterinary and human cataract patients, procedures and outcomes.

RECENT FINDINGS

In general, veterinary cataract surgery has more similarities than differences when compared to its human counterpart. This is especially true when comparing pediatric cataract patients. Veterinary cataract surgery has changed dramatically in recent years with regards to surgical technique, ocular pharmacology, viscoelastic devices, phacoemulsification, and the most recent advancement, intraocular lens implantation for dogs, cats, and horses.

SUMMARY

It is hoped that the exchange of information between the human and veterinary specialties can be of benefit to both groups as we all work to improve outcomes and resolve complications.