Corneal Anesthesia Research Articles

Combined deep anterior lamellar keratoplasty and sural nerve transplant in a child with corneal anesthesia and maculo-leucomatous opacity

Sural nerve transplantation is an established procedure for neurotization in patients with corneal anaesthesia. In a child presenting with corneal anesthesia and maculo-leucomatous opacity, a combined deep anterior lamellar keratoplasty (DALK) and sural nerve transplant procedure was done. Under general anesthesia, a sural nerve graft was obtained from the child's own foot and co-apted with contra-lateral supra-orbital nerve. Simultaneously, lamellar dissection of host corneal bed, followed by the apposition of the graft was done. At 1 year follow up, visual acuity had improved, the graft was clear, avascular and the corneal epithelium was healthy. The corneal sensations were appreciated in all quadrants. The child was started on amblyopia therapy. Combined keratoplasty with neurotization surgery is a feasible alternative to staged surgical procedure. It helps achieve faster visual and anatomical recovery.

Retrobulbar lidocaine injection via the supraorbital fossa is safe in adult horses but produces regionally variable periocular anaesthesia.

Injection techniques for retrobulbar anaesthesia are published in horses, but neither safety nor anaesthetic efficacy and duration have been evaluated objectively in vivo. To characterise the safety and efficacy of one published technique for retrobulbar anaesthesia. Randomised, controlled descriptive experiment. Unilateral retrobulbar injection with 10mL lidocaine (2%) was performed in eight sedated adult mares. Contralateral eyes served as untreated controls. Neurophthalmic parameters, intraocular pressure (IOP), and corneal and periocular sensation were measured awake, post-sedation and at periodic time points for 24hours following injection. Adverse effects were documented. Injection of 10mL lidocaine significantly increased IOP for up to 2hours (P<.05) maximally at 30min (mean [95% CI]: 6.0 [2.7, 9.2] mmHg, P<.001). Six of the eight treated eyes developed mild to moderate reversible chemosis for 2 to 24hours. One eye developed severe chemosis and superficial corneal ulceration at 24 and 48hours following injection respectively. Corneal sensitivity significantly decreased for 6hours (P<.05), maximally at 10min (-44.4 [-34.6, -54.1] mm, P<.001). Periocular sensitivity (measured as increase in applied force) significantly decreased dorsally and medially for up to 2hours (maximal at 2hours (367.1 [238.5, 495.7] g, P<.001, and at 30min: 345.8 [202.6, 488.9] g, P<.001) respectively). Ventral and lateral sensitivity were not effectively decreased beyond 30min. Optic nerve function was not consistently reduced following injection. Investigators were not masked to the treated eye. Retrobulbar injection using 10mL lidocaine is safe in normal eyes of adult horses, but carries risk in structurally compromised or glaucomatous eyes due to transient IOP increase. Reversible chemosis commonly develops 2-4h following injection, and may be severe in some horses with risk for corneal ulceration. Corneal anaesthesia is rapid and prolonged, but all periocular regions are not consistently anaesthetised. Retrobulbar injection should be combined with other local anaesthetic injections for eyelid surgeries or enucleations.

Evaluation of corneal anaesthesia after the application of topical 0.5% bupivacaine, 2% lidocaine and 0.4% oxybuprocaine in normal horses

ObjectiveTo compare the corneal anaesthetic effect of 0.5% bupivacaine, 2% lidocaine and 0.4% oxybuprocaine on normal equine eyes. Study designProspective, blinded crossover study. AnimalsA group of 10 clinically healthy horses. MethodsCorneal sensitivity was determined in each eye by measuring corneal touch threshold (CTT). The study had three phases. Each subject was randomly given one of the three treatments followed by a 72 hour washout period. Every horse received all treatments. Baseline CTT was recorded prior to anaesthetic instillation (T0) then CTT was measured 5 and 10 minutes after (T1 and T2, respectively), then 20 to 90 minutes (T3 to T10) at 10 minute intervals. CTT data were compared among treatments at each time point using the Friedman test p < 0.05. ResultsMedian (range) baseline CTT was 51.3 (25.0–60.0) mm for bupivacaine, 50.0 (40.0–55.0) mm for oxybuprocaine and 55.0 (30.0–60.0) mm for lidocaine. All treatments caused a significant decrease in CTT at T1. The lowest CTT was observed at T3 with bupivacaine and oxybuprocaine treatments. Median CTTs at this time point were 18.7 (5.0–25.0) mm and 28.7 (25.0–40.0) mm, respectively. The lowest CTT with lidocaine treatment was 28.7 (20.0–50.0) mm at T6 (50 minutes). At T3, CTT was significantly lower with the bupivacaine treatment compared with oxybuprocaine and lidocaine treatments (p < 0.0074). There was no significant difference in CTT values between T1 and T6 for bupivacaine, between T1 and T7 for lidocaine, and between T1 and T8 for oxybuprocaine. Duration of the maximum effect was 45 minutes for the bupivacaine, 55 minutes for the lidocaine and 65 minutes for the oxybuprocaine treatment. Conclusions and clinical relevanceAdministration of a 0.5% injectable solution of bupivacaine or a 2% lidocaine had similar anaesthetic effect to the commonly used oxybuprocaine. Therefore, they might be used as alternatives for corneal anaesthesia.

Facial-onset sensory-motor neuronopathy, a rare variant of Huntington’s disease or chance association?

Objectives: To describe a patient with facial-onset sensory-motor neuronopathy (FOSMN) that later developed Huntington’s disease (HD). Case report: A 62-year-old woman complained of progressive dysphagia 8 years before referral. At initial evaluation, there was excessive salivation, dysphagia, and sensory-motor trigeminal impairment. Denervation was noted on the upper limbs and the tongue. Blink reflexes were abolished. Genetic study of amyotrophic lateral sclerosis (ALS)-related genes was normal. She was diagnosed with FOSMN syndrome. Her clinical state progressively worsened with corneal anesthesia, severe denutrition, right arm and axial weakness. Seven years after referral, she was unable walk and developed generalized chorea. Abnormal huntingtin gene repeat expansion confirmed the diagnosis of HD. She died 16 years after onset of dysphagia. Conclusion: Cases with both HD and ALS have already been reported but not FOSMN and HD, to our knowledge. Some FOSMN cases have been linked to ALS-related gene mutations and HD phenocopies have been associated with C9ORF72 repeat expansions. Recently, huntingtin repeat expansions were described in the ALS population. Although a chance association cannot be excluded, data from the literature are in favor of a pathogenic relationship between FOSMN and HD in this particular case. We suggest that huntingtin gene be more systematically studied in patients with FOSMN.

Corneal sensitivity is required for orientation in free-flying migratory bats

The exact anatomical location for an iron particle-based magnetic sense remains enigmatic in vertebrates. For mammals, findings from a cornea anaesthesia experiment in mole rats suggest that it carries the primary sensors for magnetoreception. Yet, this has never been tested in a free-ranging mammal. Here, we investigated whether intact corneal sensation is crucial for navigation in migrating Nathusius’ bats, Pipistrellus nathusii, translocated from their migratory corridor. We found that bats treated with corneal anaesthesia in both eyes flew in random directions after translocation and release, contrasting bats with a single eye treated, and the control group, which both oriented in the seasonally appropriate direction. Using a Y-maze test, we confirmed that light detection remained unaffected by topical anaesthesia. Therefore our results suggest the cornea as a possible site of magnetoreception in bats, although other conceivable effects of the anaesthetic are also explored. Furthermore, we demonstrate that the corneal based sense is of bilateral nature but can function in a single eye if necessary.

Quantitative corneal neural imaging using in vivo confocal microscopy in cases of congenital corneal anesthesia: A prospective analysis and clinical correlation.

Purpose:Congenital corneal anesthesia (CCA) is a rare clinical entity that poses a diagnostic dilemma, particularly in the pediatric age group with very little literature on this. Accurate initial diagnosis, evaluation, early identification of risk factors, aggressive systemic workup, and appropriate therapy are paramount to prevent visual loss due to long-term complications of corneal anesthesia. The purpose of the study was to estimate and compare the corneal neural architecture using real time, in vivo confocal microscopy (IVCM) in patients with CCA as against a control population.Methods:This was a retrospective nonconsecutive, comparative clinical case series in a tertiary hospital in South India from June 2015 to December 2018.Methods:IVCM was accomplished in cooperative children in whom central cornea was relatively clear. The clearest three to five images from each eye were selected, and the nerves were analyzed for length, thickness, density, dichotomous pattern, and beading. Statistical analysis was done using Origin v7.0 (Origin Lab Corporation, Northampton, MA, USA).Results:In total, 15 eyes of 11 cases and 20 eyes of 10 controls were imaged. Measurements on corneal nerve density showed a significant difference (P = 0.0005), cases having a lower mean (3.85 ± 1.38 mm per mm2) compared to the controls (6.74 ± 1.75 mm per mm2). Measurements on corneal nerve length (P = 0.28), thickness (P = 0.45), and presence of beading (P = 0.97) and dichotomous pattern (P = 0.07) did not reveal a significant difference between cases and controls.Conclusion:There is a strong relationship between the functional loss (absent corneal sensation) and anatomical decrease (reduced subbasal nerve density) of corneal nerves in congenital corneal anaesthesia.

Management of Ocular Surface Squamous Neoplasia in Association with Fungal Keratitis in a HIV Positive Individual

Ocular Surface Squamous Neoplasia (OSSN) co-existent with fungal keratitis in an immunodeficient individual has rarely been talked about in literature. Risk factors for fungal keratitis are trauma with vegetative matter, topical steroid abuse, poor ocular surface, corneal anaesthesia, systemic immunosuppression, etc., and for OSSN a major risk factor is immunodeficiency. In current report, patient had multiple risk factors. This report highlights the management of HIV positive 42-year-old male with OSSN and fungal keratitis. A comprehensive evaluation helps clinician decide on treatment priority and achieve good clinical outcome.

Commentary: Congenital corneal anesthesia.

Commentary: Congenital corneal anesthesia.

The surgical management of extra-cranial trigeminal nerve palsies: A retrospective case series

To assess for functional improvement in outcomes following supermicrosurgical restoration across a cohort of patients with a spectrum of trigeminal nerve disorders. In a retrospective case series over three years (2016-18), twenty patients were included in a cohort of trigeminal nerve palsy patients. Eleven patients with corneal anaesthesia underwent corneal neurotisation procedures and were followed up using Cochet-Bonnet aesthesiometry. Six patients with sensory trigeminal nerve injuries had direct nerve coaptation and neuroma excision. Three patients with trigeminal motor nerve palsies were followed up with photography for contour improvement. Regarding corneal neurotisation, there was evidence of significant improvement in protective corneal sensation and also blinking frequency. Regarding facial sensory disturbances, all patients had full resolution of painful trigeminal neuroma symptoms. In two cases of iatrogenic trigeminal motor palsies with contour defects, adipo-fascial variants of the superficial circumflex iliac artery (SCIP) free flap achieved excellent restoration of facial contour in lieu of facial lipofilling. In another case of a necrotising infection of the head and neck with loss of all masticatory muscles, a free functional muscle using a chimaeric vastus lateralis-ALT flap was used to restore masticatory and facial movement in a single stage procedure. Using combinations and permutations of current surgical techniques, it is possible to successfully restore both form and function for patients with sensory as well as motor trigeminal nerve palsies. This sets a precedent for the expansion of cranial nerve surgery as an evolving sub-speciality.

Efficacy of Oral Alprazolam and Mefenamic Acid in Relieving Pain During Pan Retinal Photocoagulation

.&#x0D; Purpose: To find out the efficacy of oral Alprazolam and Mefenamic acid in relieving pain during pan retinal photocoagulation in patients with proliferative diabetic retinopathy.&#x0D; Study Design: Quasi experimental study.&#x0D; Place and Duration of Study: Department of Ophthalmology, Al-Ehsan Eye Hospital, Lahore, from January 2018 to December 2018.&#x0D; Methods: Patients were divided into two groups; groups A received one tablet of Xanax (Alprazolam 0.5 mg) and 2 tablets of Ponston Forte (Mefenamic acid 500 mg) an hour before PRP. In group B no pain relieving medicines were prescribed. Proparacaine hydrochloride 0.5% eye drops were instilled in the eye to achieve corneal anesthesia before the procedure in both the groups. Pain was scored, 15 minutes after PRP, using standard verbal rating scale and results were analyzed. Paired sample t-test was used to measure the mean difference in pain between the two groups. A p value of less than 0.01% was considered significant.&#x0D; Results: Five hundred and sixty patients with proliferative diabetic retinopathy (PDR) requiring Pan Retinal Photocoagulation (PRP) were enrolled. There were 272 males and 288 females. Mean age of patients was 64.0 ± 6.8 years. Mean pain score for group A was 4.0 ± 0.6 and for group B was 2.1 ± 0.3. Difference in pain score felt by each group was -1.93 ± 0.7 with significant p value of ˂ 0.01%.&#x0D; Conclusion: Oral administration of Alprazolam and Mefenamic acid one hour before PRP in patients with proliferative diabetic retinopathy was effective in reducing pain and in attaining patient cooperation during the procedure.&#x0D; Key Words: Pan Retinal Photocoagulation, Pain, Proliferative Diabetic Retinopathy, Alprazolam, Mefenamic acid.

Outcomes of corneal neurotisation using processed nerve allografts: a multicentre case series

BackgroundCorneal neurotisation is a rapidly evolving procedure treating neurotrophic keratopathy. The variety of surgical techniques used and corresponding outcomes after corneal neurotisation are not well understood. This study describes the...

Effects of topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution and 1% ropivacaine hydrochloride on corneal sensitivity in rats

The aim of the present study was to determine and compare the degree and duration of corneal anesthesia following topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution and 1% ropivacaine hydrochloride treatment in healthy rats. A randomized, blinded, crossover study was conducted on 20 healthy adult Wistar rats, following complete physical and ophthalmological examination. Baseline corneal touch threshold (CTT) was determined in the central corneal area of both eyes with a Cochet–Bonnet aesthesiometer, in mm filament length. Oxybuprocaine was randomly applied to one eye and 0.9% sterile sodium chloride solution was instilled into the contralateral eye. Subsequent CTT measurements were performed in both eyes 5 minutes after topical application and at 5-minute intervals thereafter for 75-minutes in the anesthetized eye. Following a 2-week washout period, this protocol was repeated with ropivacaine. Quantitative data were summarized as mean ± standard deviation, median and inter-quartile range (Q1–Q3). Repeated measures data were analyzed over time and between treatments using Friedman test and Wilcoxon signed-rank test with Bonferroni adjustment (p < 0.05). Baseline CTT values were 60 mm in all eyes. With oxybuprocaine, CTT values decreased significantly for 65 minutes (0–55 mm; p = 0.002) when compared with baseline; the maximal anesthetic effect (no blink response at 5 mm filament length) was maintained for up to 15 minutes (p < 0.0001). With ropivacaine, CTT values were significantly lower than baseline for 30 minutes (0–55 mm; p = 0.002), with a maximal anesthetic effect recorded at 5 minutes in 18 eyes (p < 0.0001). Oxybuprocaine induced a significantly lower CTT than ropivacaine (p = 0.002) from 10 to 65 minutes following topical application. Both anesthetic agents induced significant corneal anesthesia; however, oxybuprocaine provided a greater and longer anesthetic effect, making it more suitable for potentially painful ophthalmologic procedures.

Therapeutic Contact Lenses in the Treatment of Corneal and Ocular Surface Diseases-A Review.

Therapeutic contact lenses (TCLs) are often used in the management of a wide variety of corneal and ocular surface diseases (OSDs). Indications of TCL include pain relief, enhancing corneal healing, corneal sealing, corneal protection, and drug delivery. For painful corneal diseases such as bullous keratopathy, epidermolysis bullosa, and epithelial abrasions/erosions, bandage contact lenses (BCLs) provide symptomatic relief. Postoperatively in photorefractive keratectomy or laser epithelial keratomileusis, BCLs also alleviate pain. In severe OSDs such as severe dry eye, Stevens-Johnson syndrome/toxic epidermal necrolysis, gas-permeable scleral contact lenses are often used to enhance corneal healing. BCLs are used post-keratoplasty, post-trabeculectomy, and post-amniotic membrane transplantation to enhance healing. BCLs, with or without glue adhesives, are used to seal small corneal perforations and sometimes also used as bridging treatment before penetrating keratoplasty in larger corneal perforations. In patients with eyelid conditions such as trichiasis, ptosis, and tarsal scarring, BCLs are also effective in forming a mechanical barrier to protect the cornea. A relatively new use for TCLs is in ocular drug delivery where TCLs are used to maintain therapeutic concentrations of medication on the ocular surface. Contraindications of the use of TCLs include infective keratitis, corneal anesthesia, and significant exposure keratopathy with inadequate eyelid position or movement. Complications of TCL include infective keratitis, corneal hypoxia and associated complications, corneal allergies and inflammation, and poor lens fit. Overall, TCLs are effective in the treatment of corneal and OSDs but contraindications and complications must be considered.

Effects of topical application of tramadol with/without dexmedetomidine and proparacaine on corneal sensitivity in rats.

To evaluate the corneal anesthetic effect following topical application of tramadol alone and in combination with dexmedetomidine, and compare it to proparacaine, in clinically healthy rats. A randomized, crossover study was performed. Twenty Wistar albino rats (n = 40 eyes) were used. Corneal touch threshold (CTT) measurements (in mm) were obtained using a Cochet-Bonnet aesthesiometer. CTT measurements were obtained at baseline, 1-min following application of the topical anesthetic agent, and repeated at 5-min intervals up to 75min. The topical protocol involved 3 treatment conditions, separated by a 2-week washout period: proparacaine, tramadol alone, and tramadol in combination with dexmedetomidine. CTT values were significantly decreased compared to baseline at each timepoint until completion of the 75-min evaluation in all treated eyes, regardless of the assigned treatment (p < 0.0083). With tramadol, complete corneal anesthesia (CTT = 0) was achieved within 1-5min in 18 eyes and ranged from 5 to 25min. Co-administration of dexmedetomidine to tramadol resulted in significantly increased CTT values from 5 to 20min following topical application, compared to tramadol alone (p < 0.0083), and complete corneal anesthesia was achieved in only 14 out of 20 treated eyes. Tramadol might be a useful alternative to topical anesthetic agents, providing a dose-related corneal anesthetic effect. Co-administration of dexmedetomidine does not potentiate its anesthetic effect. The underlying mechanism(s) of drug antagonism between tramadol and dexmedetomidine remains to be determined.

Clinical and confocal imaging findings in congenital corneal anaesthesia

Background/AimsCongenital corneal anaesthesia (CCA) is an uncommon cause of corneal ulceration in young patients, with a reported poor visual prognosis. We correlated clinical findings in patients with CCA with corneal...

Effect of four local anesthetics (tetracaine, bupivacaine, lidocaine and proparacaine) on intraocular pressure in rabbits- Comparison of an applanation and a rebound tonometer

The type of device used, the type of local anesthetic agents, and the animal species may affect the intraocular pressure(IOP). Therefore, in order to determine these issues, the effects of four local anesthetics were investigated in 10 adult rabbits by ICare TA01i and Tono-Pen Vet tonometers. In the right eye of half of the rabbits and in the left eye of the other half of the rabbits, one drop of tetracaine was instilled. The IOP in each rabbit was measured using two tonometers, ICare and Tono-Pen Vet, before and each 5 minutes until 40 minutes later. The effects of other drugs were also studied at least with one-week interval. Based on the results of ICare tonometer, tetracaine significantly reduced the IOP immediately and 25 minutes after instillation. IOP changes after instillation of bupivacaine, lidocaine and proparacaine were not significant at any time compared to baseline values (p > 0.05). Based on the results of Tono-Pen Vet tonometer, all drugs reduced the IOP immediately after use; however, the effects of bupivacaine and lidocaine on IOP were much lower than that of tetracaine and proparacaine. The average duration of corneal anesthesia were 20, 15.5, 7.5 and 21 minutes for tetracaine, bupivacaine, lidocaine, and proparacaine, respectively. It is concluded that IOP reduction by local anesthetics when Tono-Pen Vet is used is much greater than the ICare tonometer measurements. Also, the reduction of IOP with each of the devices when tetracaine or proparacaine is used is greater than when bupivacaine or lidocaine is used.

Corneal anesthesia associated with topical application of 2% lidocaine nonophthalmic gel to healthy canine eyes.

To assess the degree and duration of corneal anesthesia induced by topical application of 2% lidocaine gel to the healthy canine eye. Nineteen adult Beagles free of ocular abnormalities. Baseline corneal touch threshold (CTT) was measured bilaterally with a Cochet-Bonnet aesthesiometer. The 2% lidocaine gel (0.1mL) was applied to one eye, randomly assigned, and the same volume of a lubricant gel was applied to the opposite eye. The CTT measurements were repeated bilaterally within 1minute, after drug application, and every 5minutes, until the baseline corneal sensitivity was restored. The potential for local adverse effects was evaluated. Complete desensitization of the cornea (CTT=0) was achieved one minute after lidocaine gel application and was maintained during 25.3±12.5minutes. Overall, the corneal sensitivity was significantly decreased for 58.4±16.6minutes compared with baseline level. Minor and reversible punctate epithelial erosions of the cornea were observed in the two treatment groups and were attributed to the anesthetic effect and the aesthesiometry procedure. In the current study, the 2% lidocaine gel provided a sustained, deep and well-tolerated corneal anesthesia in ophthalmically normal dogs.

Corneal perforation: the most feared complication of corneal abscess.

We report the case of a 60-year-old patient who consults for eye pain after 3-months of trauma to the right eye. The examination finds a visual acuity with light perception, a perforated cornea in the center with hernia of the iris and a corneal halos abscessed all around (A, B). Corneal abscesses are a serious pathology and potentially blinding, their risk factors are multiple: contact lens wear, corneal trauma, dry eye with blepharitis, corneal anesthesia and keratoplasties. The severity factors requiring hospitalization with corneal harvesting and treatment with fortified antibiotic eye drops adapted to the antibiogram are: an abscess 3mm or more long axis, a central location or less than 2mm from the center, an inflammatory reaction of the anterior chamber. Corneal abscesses appearing at a distance from trauma, as the case we describe are often of fungal origin and are generally of very poor prognosis.

Effect of fentanyl addition to local anesthetic mixture in peribulbar block for cataract surgery

Background In peribulbar regional anesthetic blocks, injection of local anesthetic mixtures alone provide unsatisfactory surgical conditions as regards block intensity and duration especially for relatively lengthy operations. So, additives may improve the quality of the block and provide good postoperative analgesia. Aim To examine the effect of adding fentanyl to local anesthetics in peribulbar block on the onset and duration of lid and globe akinesia (primary outcome) and postoperative analgesia (secondary outcome). Patients and methods Patients were classified randomly allocated in a blind manner into two groups; each group contained 30 patients. The control group received a measure of 7 ml [3 ml lidocaine 2%+0.5 ml hyaluronidase (150 U)+2.5 ml bupivacaine 0.5%+1 ml saline] which was used locally and the fentanyl group received a measure of 7 ml [3 ml lidocine2%+0.5 ml hyaluronidase (150 U)+2.5 ml bupivacaine 0.5%+1 ml saline containing 20 μg fentanyl] which was used locally. Results Statistically significant decreased mean time of complete akinesia decreases the mean time to sensory block in the fentanyl group compared with the control group. Conclusion Fentanyl is an effective drug as an additive to local anesthetic mixture in peribulbar anesthesia, as it shortens the onset time of corneal anesthesia and globe akinesia, prolongs block duration, and good postoperative analgesia.

Normal reference ranges of ocular physiology and sonographic biometry of Latvian Hunting dogs.

Background and Aim:The Latvian Hunting dog is the only national dog breed in Latvia and so far, there are no data on the important ophthalmological data pertaining to clinical tests and ocular biometry. The aim of this study was to improve the ocular examination and to document normal reference ranges of the globe axial length (AXL), anterior chamber depth (ACD), lens thickness (LT), intraocular pressure (IOP), and Schirmer tear test (STT).Materials and Methods:Sixteen Latvian Hunting dogs (32 eyes) of varying age and sex were included in this study. All dogs underwent an ophthalmic examination followed by tear production (STT) and IOP (TonoVet®) measurements. Biometric examination using A-mode ultrasonography was done under topical corneal anesthesia using 0.5% proparacaine hydrochloride. The eyes were scanned using A-mode ultrasonography with a 10 MHz transducer by transcorneal approach. The reference values of IOP, STT, AXL, ACD, and LT are expressed as mean ± standard deviation (SD).Results:Statistical analysis using the SPSS v.23 and Microsoft Excel 2013 showed no statistically significant differences between the right and left eyes for either of the tests. The mean±SD value of STT and IOP values was 20.9±3.2 mm/min and 17.7±3.2 mmHg, respectively. The mean±SD of the AXL, ACD, and LT obtained by A-mode ultrasound was 2.21±0.1 cm, 0.35±0.1cm, and 0.42±0.06cm, respectively.Conclusion:This study documents the normal reference ranges of important ophthalmological clinical tests (IOP and STT) and ocular biometry (AXL, ACD, and LT) in Latvian Hunting dogs.