Incidence and Associated Factors of Anesthesia-Related Complications in Ophthalmic Surgeries: A 6-Year Retrospective Cohort Study

Surgical intervention rates (SIR) provide a proxy measure of disease burden, surgical capacity, and the relative risk-benefit ratio of surgery. The current study assessed decade trends in ophthalmic surgery and calculated SIRs for all major classes of commonly performed ophthalmic procedures in New Zealand. Retrospective population-based analysis of all ophthalmic surgical procedures performed in New Zealand from 2009 to 2018. National and regional datasets from public and private health sectors and industry were analysed. SIRs were calculated for all major ophthalmic procedures, and subgrouped by patient demographics. There were 410,099 ophthalmic surgical procedures completed with a 25.3% overall increase over 10 years. Procedures were mostly government-funded (51%, n = 210,830) with 71% of patients aged over 64 years. Cataract surgery (78%, n = 318,564) had the highest mean SIR (703/100,000/year) and increased by 25% during the study period, consistent with population growth in the over 64 years old age group. Vitrectomy surgery had the second highest mean SIR (67/100,000/year) and increased by 50%, well above national population growth during the study period. Other SIRs included conjunctival lesion-biopsy (38/100,000/year), glaucoma (33/100,000/year), strabismus (20/100,000/year), dacryocystorhinostomy (10/100,000/year), and keratoplasty surgery (4/100,000/year). This comprehensive review of New Zealand ophthalmic surgery reports increasing SIRs that cannot be explained by population growth alone. Cataract surgery numbers increased year on year consistent with the increase in the over 64 years old population. Vitrectomy surgery growth exceeded that of the national population, including those over 64 years.

Experiencia local con el uso de punción única peribulbar caruncular para anestesia oftálmica

Local experience with caruncular single injection peribulbar anesthesia

Purpose:To discuss the application of mitomycin C (MMC) in ophthalmic surgical procedures, including dosage, method of application, reported complications, and follow-up results.Methods:A comprehensive literature search was conducted on PubMed, Google Scholar, and the Cochrane Library without date limitations using keywords: mitomycin, ophthalmic, and surgery. The original articles used as references were first graded using a 0 to 5 grading scale devised by the authors to ensure the uniformity of reference selection. Only those original articles grading 3 or above based on this grading scale were used as references. The last search was conducted in March 2024.Results:MMC has been widely utilized in ophthalmic surgery due to its effects on the wound-healing process. The main current applications include pterygium surgery, glaucoma filtering surgery, surgical treatment of ocular surface tumors, eye alignment surgeries, dacryocystorhinostomy, and corneal refractive surgery.Conclusions:The dosage and duration of MMC application in ophthalmic surgery depend on the specific procedure, with ongoing controversies regarding the optimal dosage. In addition, it is essential to consider complications when evaluating the cost-benefit of MMC use. Further randomized clinical trials with larger sample sizes and longer follow-up periods are warranted, with a specific focus on reducing long-term side effects, refining dosage guidelines, and exploring MMC’s role in combination therapies for various ophthalmic procedures.

OBJECTIVE To compare complications between healthy horses undergoing general anesthesia for ophthalmic versus non-ophthalmic procedures and identify potential risk factors for the development of complications. DESIGN Retrospective case series. ANIMALS 502 horses (556 anesthetic procedures). PROCEDURES Medical records from January 2012 through December 2014 were reviewed to identify horses undergoing general anesthesia. Signalment, body weight, drugs administered, patient positioning, procedure type (ophthalmic, orthopedic, soft tissue, or diagnostic imaging), specific procedure, procedure time, anesthesia time, recovery time, recovery quality, and postoperative complications were recorded. RESULTS Patients underwent general anesthesia for ophthalmic (n = 106), orthopedic (246), soft tissue (84), diagnostic imaging (110), or combined (10) procedures. Mean procedure, anesthesia, and recovery times were significantly longer for patients undergoing ophthalmic versus non-ophthalmic procedures. Excluding diagnostic imaging procedures, there was a significant positive correlation between surgery time and recovery time. Within ophthalmic procedures, surgery time, anesthesia time, and recovery time were significantly greater for penetrating keratoplasty versus other ophthalmic procedures. There was a significantly higher rate of postoperative colic following penetrating keratoplasty, compared with all other ophthalmic procedures. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that in healthy horses, duration of general anesthesia should be minimized to decrease the risk of postanesthetic complications. Judicious use of orally administered fluconazole is recommended for horses undergoing general anesthesia. For horses undergoing a retrobulbar nerve block during general anesthesia, use of the lowest effective volume is suggested.

Purpose:Since the eye is in close proximity to the oro-nasal cavity, transmission of SARS CoV-2 is higher during ophthalmic surgical procedures, it is vital to ensure the safety of the healthcare team by pre-operative Rapid Antigen Test (RAT) and real-time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) for SARS CoV-2 viral RNA of all patients planned for elective or emergency surgery. Hence, understanding the profile of pre-operative RAT and real-time RT-PCR among patients planned for various ophthalmic procedures, will help us make better decisions for future guidelines, for optimal planning of ophthalmic elective or emergency surgeries, keeping in mind the current scenario.Methods:This is a prospective descriptive study conducted on patients planned for elective or emergency ophthalmic surgeries, who had no COVID-19-related symptoms pre-operatively and were subjected to preoperative RAT and real-time RT-PCR of nasopharyngeal and throat swabs for SARS CoV-2 viral RNA. Data was compiled and statistically analysed.Results:204 patients underwent pre-operative RAT and RT-PCR testing; of which, 85 were females and 119 were males. Mean age of the study population was 51.44 ± 16.501 years. Among the 204, 2 tested positive for SARS CoV-2 with Rapid Antigen testing as well as RT-PCR and 10 patients tested positive via RT-PCR after a negative RAT result of the same sample.Conclusion:Pre-operative testing for COVID-19 disease is indispensable as there is a high chance of transmission from patient to healthcare workers. RAT has the advantage of quick results and may play a role in case of emergency procedures. However, it is prudent to perform the more sensitive real-time RT-PCR before any elective, non-emergency procedures or surgeries to avoid any undue risk to the healthcare team.

THE vast majority of ophthalmic surgeries are performed under regional anesthesia only. However, its use is also described in association with general anesthesia for pediatric cases and for postoperative analgesia. Eye blocks have long been limited to retrobulbar anesthesia (RBA) as performed by surgeons. Surgical technique changes and research on improving patient safety during eye blocks has resulted in the development of alternative techniques, such as peribulbar anesthesia (PBA), followed by low-volume sub-Tenon block (STA) or topical anesthesia (TA).In this review, we present the general requirements necessary for an eye block and then briefly describe each technique, discussing their respective advantages and inconveniences. Although cataract surgery is the most frequent ophthalmic surgical procedure and a large number of articles we cite refer to studies concerning this procedure, implications to regional anesthesia are not limited to cataract surgery; much of the data we review can be extrapolated and reinterpreted for other ophthalmic applications.The orbit is filled mainly by adipose tissue, and the globe is suspended in its anterior part. Four rectus muscles delimit the retrobulbar cone, which is not sealed by an intermuscular membrane.1Sensory innervation of the globe is supplied by the ophthalmic nerve, the first branch of the trigeminal nerve, which passes through the muscular cone. Motor extraocular nerves pass through the muscular cone, except the trochlear nerve. Therefore, injecting local anesthetics inside the cone can logically be expected to provide anesthesia and akinesia of the globe and of the extraocular muscles. Only the motor command of the orbicularis muscle of the eyelids has an extraorbital course because it arises from the superior branch of the facial nerve. Many major structures are located in the muscular conus and are therefore vulnerable to the risk of needle injury, including the optic nerve with its meningeal sheaths; most of the arteries of the orbit; and the autonomic, sensory, and motor innervation of the globe (fig. 1).The fascial sheath of the eyeball—also called the Tenon capsule—is a fibroelastic layer that surrounds the entire scleral portion of the globe. It delimits the episcleral space or sub-Tenon space, a potential space with no actual volume, although fluid can be injected into it. Some experts assimilate it into the articular capsule of the globe. Near the equator, the tendons of the oblique and rectus muscles perforate the Tenon capsule before they insert into the sclera. At this point, there is continuity between the Tenon capsule and the fascial sheath of the muscles. Anteriorly, the Tenon capsule merges with the bulbar conjunctiva before both insert together into the corneal limbus.Ophthalmic surgical procedures have little systemic impact and are associated with a very low rate of general morbidity or mortality. As a result, in some countries, standard safety measures, such as fasting, are sometimes circumvented for eye blocks.2However, when taking into account potential complications, as described in Complications of Injection Blocks, we believe that standard safety measures (preoperative evaluation, fasting, and monitoring) should be applied.The most debated problem concerning usual patient treatment is whether to continue anticoagulant/antiplatelet therapy. Totally "bloodless" superficial procedures, such as cataract surgery, can be performed in the presence of any anticoagulant/antiplatelet agent. A meta-analysis3demonstrated that patients who have a cataract surgery without warfarin interruption (international normalized ratio = 2–3) have a greater risk for bleeding but that such bleeds are not clinically relevant. The bleeds consisted of dot hyphemaeand subconjunctival hemorrhage involving a limited segment of the eye with no impact on postoperative acuity.3Similar results were found in a recent large cohort of more than 2,000 patients taking warfarin.4This study also showed that aspirin use was not associated with bleeding. However, clopidogrel use was associated with a significant increase in observations of posterior capsule rupture, with or without vitreous loss.For those patients, choosing the eye block must take into account TA as a possible option. All injection techniques carry a risk for retrobulbar hemorrhage (very infrequent) or subconjunctival hematoma (short-term esthetic consequences). Benzimra et al. 4demonstrated that there was no significant increase in the overall recording of complications involving sharp needles and sub-Tenon cannula local anesthesia in patients using aspirin or dipyridamole. Similar results were found for those on aspirin used in combination with clopidogrel, warfarin, or dipyridamole.4As concerns hemorrhagic complications, subconjunctival hemorrhaging was significantly increased among patients on clopidogrel or warfarin alone, as well as those on a combination of aspirin and warfarin. No significant increases in the potentially sight-threatening hemorrhagic complications of retrobulbar/peribulbar were found in any of the anticoagulant or antiplatelet groups. Therefore, discontinuation of anticoagulant/antiplatelet therapy for an injection technique is no longer routinely recommended by British and French guidelines.‡ The only drugs for which there are no current recommendations are clopidogrel and the newer antiplatelet agents. In this case, a decision must be made on an individual basis.Requests from the surgeon vary with the procedure. During an open eye surgery, the request from the surgeon is analgesia, akinesia, and hypotonia of the eyeball. Because the eyeball is open, the concept of intraocular pressure cannot exist. However, a "positive vitreous pressure" is commonly caused by the pressure on the outside of the scleral wall (extraocular muscle tension) or a mass (choroidal effusion, hematoma), causing a reduction in scleral cavity volume. Increased positive vitreous pressure is manifested by repeated iris prolapse and can lead to a posterior capsule rupture, vitreous loss, choroidal effusion, or hemorrhage. This increased pressure can be prevented by akinesia of oculorotatory or orbicularis muscle.5Closed intraocular surgery (i.e. , phacoemulsification and anterior vitrectomy) is characterized by some degree of pressurization of the globe. This result is achieved using self-sealing or small incisions while an infusion line pressurizes the eye. Moreover, operating times using this procedure are short, and manipulations of ocular tissues are limited. They do not require the same degree of akinesia as open eye surgery, only anesthesia.The surgeon may also require that other general conditions be prevented. Acute peak arterial hypertension, for instance, may cause catastrophic choroidal expulsive hemorrhage. Tremor and/or restlessness due to anxiety may impair the procedure for obvious reasons. Coughing must be prevented because it results in head movement that increases intraocular pressure to very acute and high peak, which can impair surgery. Sedation may help to obtain optimal "akinesia of the head" but should be used cautiously because of the potential risk of ventilatory depression in a context with no airway accessibility.6Techniques are usually named according to the site at which the needle tip is localized at the time of injection.RBA was the "gold standard" for eye blocks from the beginning of the 20th century until the formalization of PBA and STA in the 1990s. RBA is achieved by injecting a small volume of local anesthetic agent (3–5 ml) inside the muscular cone. The main hazard of RBA is the risk of injury to the globe, the rectus muscles, or one of the many vulnerable elements located in the muscular cone. Near the apex, these structures are packed in a very small volume and are fixed by the tendon of Zinn, which prevents them from moving away from the needle. Currently, RBA is used less frequently because of these potential complications.The long-used technique of PBA was highlighted by the work of Bloomberg et al 7,8in 1986. PBA has a tendency to replace RBA on the theoretical principal of better security. It consists of introducing the needle into the extraconal space to avoid risk of injury to major structures in the intraconal space. See video, Supplemental Digital Content 1, which demonstrates an inferotemporal injection for peribulbar anesthesia, http://links.lww.com/ALN/A653. As much as 12 ml local anesthetic is injected and spreads into the entire corpus adiposum of the orbit, including the intraconal space (figs. 2 and 3).1,9In addition, this large volume allows an anterior spread to the eyelids, providing a block of the orbicularis muscle of the eyelids. The most classic PBA technique involves two injections, one inferiorly and temporally, and the second superiorly and nasally.Alternative techniques have been described but cannot be extensively reported here. However, advances in PBA techniques may be summarized in terms of a few guidelines:Comparative studies have confirmed that, provided the injected volume is sufficient, the single injection technique is as effective as the double injection technique. A second injection should be performed only as a supplement when the first injection has failed.Posterior to the globe, the rectus muscles are in contact with the orbital walls, so that the extraconal space becomes virtual. Increasing the depth of needle insertion is expected to change a PBA into an RBA.10At this level, the distance between the orbital roof and the globe is reduced, theoretically increasing the risk of globe perforation. In addition, the needle may injure the superior oblique muscle. Inferior and temporal puncture remains the "gold standard." An alternative site of puncture for PBA is the medial canthus.11The needle is introduced at the medial junction of the eyelids, nasally to the lacrimalcaruncle in a strictly posterior direction at a depth limited to 15 mm . At this level, the space between the orbital wall and the globe is large and free from blood vessels.Compression has not been clearly shown to enhance the quality of the block. A 30 mmHg pressure applied for 10–15 min is sufficient.In all cases, the spread of local anesthetics in the corpus adiposum of the orbit remains somewhat unpredictable, leading to the common need to increase the injected volume to prevent an imperfect block. Depending on the surgeon's request for akinesia, an additional injection is required in as many as 50% of cases.7,8,12This poor reproducibility in block efficacy is the main disadvantage of PBA.Initially this technique was proposed as an intraoperative complement to RBA. STA is achieved by injecting local anesthetic in the sub-Tenon (or episcleral) space9(fig. 3). Two techniques have been described.Under TA, a buttonhole is opened into the conjunctiva and Tenon capsule 5–10 mm from the limbus. A blunt cannula is then inserted in the episcleral space (fig. 4).13This is the most popular STA, the main advantage being avoidance of a sharp needle technique, which theoretically increases safety. Most articles on STA safety refer to blunt cannula techniques.The needle is introduced between the semilunaris fold of the conjunctiva and the globe, tangentially to the globe. After it has encroached on the conjunctiva, the needle is shifted slightly medially and advanced strictly posteriorly, thereby pulling the globe, which results in directing the gaze medially. See video, Supplemental Digital Content 2, which demonstrates an STA needle technique, http://links.lww.com/ALN/A654. At a 10–15 mm depth, after a small loss of resistance (a "click" is perceived), the globe returns to its primary gaze position.14This technique has not gained a large popularity most likely because it does not avoid the use of a sharp needle.Injecting into the sub-Tenon space allows the local anesthetic to spread circularly around the scleral portion of the globe, thereby achieving high-quality analgesia of the whole globe with the injection of relatively low volumes (2–5 ml). In addition, use of a larger volume (up to 11 ml) means the local anesthetic will spread to the extraocular muscle sheaths (fig. 5), producing an effective and reproducible akinesia.12Chemosis (subconjunctival spread of the local anesthetic) occurs frequently after injection of large volumes. Its occurrence confirms the sub-Tenon location of the injection and may require compression to be resolved.When small volumes are used, STA carries the same limitations as TA. Another limitation of this technique is the relatively high rate of minor complications, which were estimated at 2.5-fold higher using STA compared with RBA or PBA.15Guise16reported that 6% of 6,000 cases had chemosis and 7% had subconjunctival hematoma, with only one case requiring surgery cancellation. However, Kumar et al. 13reported a greater incidence of chemosis and conjunctival hemorrhage, ranging from 25 to 60% and from 20 to 100%, respectively. STA efficacy is excellent for globe analgesia. Guise16reported that 96% of blocks were scored as perfect or good. STA leads to better perioperative analgesia compared with TA. One study reported improved patient and surgeon satisfaction in favor of STA compared with PBA17; however, these results remain somewhat controversial.18,19Finally, safety is the main advantage of the cannula technique, because it avoids the blind introduction of a needle into the orbit.14Some major complications associated with STA, although rare, have been described.20The most common cause of needle block complications is needle (or cannula) misplacement (e.g. , optic nerve damage during RBA). Although some anatomical features may increase the risk of complications, the main risk factor is poor physician training and limited experience using the procedure.First, an inadvertent intra-arterial injection may reverse blood flow in the ophthalmic artery up to the anterior cerebral or the internal carotid artery, such that an injected volume as small as 4 ml can produce seizures. Second, an inadvertent injection under the dura mater sheath of the optic nerve, or directly through the optic foramen, may result in subarachnoid spread of the local anesthetic. This error causes partial or total, progressive, brainstem anesthesia. Symptomatic treatment should result in total recovery.This complication has a poor prognosis, particularly in cases of delayed diagnosis. Perforation incidence was evaluated as 0.9 in 10,000 with RBA and as 1 in 16,000 and 1.4 in 10,000 with PBA.21,22Classic risk factors include physician inexperience and a highly myopic eye (i.e. , long eyeball). In a series of 50,000 cases, Edge and Navon23observed that myopic staphyloma was the most important risk factor for scleral perforation. This finding suggests that isolated high myopia may not be a risk factor per se but acts as a confounding factor because myopic staphyloma occurs only in myopic eyes. The probability of staphyloma is greater in highly myopic, compared with slightly myopic, eyes.24Moreover, staphyloma is more frequently located at the posterior pole of the globe (accounting for perforations after RBA) or in the inferior area of the globe (accounting for perforations after inferior and temporal punctures, both PBA and RBA). As a result, ultrasound measurements of the axial length of the globe (biometry) should be available, at least in myopic patients. A highly myopic eye (axial length more than 26 mm) remains the classic contraindication for eye block. However, this contraindication may be circumvented if B-mode ultrasound is conducted to assess the presence and location of a staphyloma.Several mechanisms can be involved: direct injury by the needle resulting in intramuscular hematoma, high pressure as a result of injection into the muscle sheath, or myotoxicity from the local anesthetic.This complication may lead to a compressive hematoma, which can threaten retinal perfusion. The main risk factor is arterial fragility (diabetes, atheroma) rather than clotting disorders. Venous puncture leads to noncompressive hematoma, the consequences of which are much less severe, and in most cases surgery can be continued.Computed tomography usually shows optic nerve enlargement that is the result of intraneural hematoma.TA consists of the instillation of local anesthetic eye drops on the cornea. The procedure is quick and easy to perform as well as extremely cost-effective. The main advantage of this technique is the avoidance of all potential hazards of injection techniques. TA has thus gained in popularity over the last decade for cataract surgery via phacoemulsification. In the United States, TA use has been documented as occurring in 61% of cataract surgery cases, increasing to 76% among surgeons who perform more than 75 procedures per month.25The use of TA has been reported for many ophthalmic procedures (e.g. , keratoplasty, glaucoma surgery). However, it has its own limitations, chiefly limited duration, limited extension to cornea, and total mobility of the eyeball and lids. First, however, is that analgesia may be incomplete. Despite small differences, less comfort and increased pain are reported when TA is compared with injection blocks.6,26–27Second, the lack of akinesia and pressure (intraocular pressure or positive vitreous pressure) control associated with the short duration of the procedure theoretically makes surgery more hazardous. These operative conditions are not optimal and may lead to perioperative patient movement.26Moreover, a closed claim analysis showed that such movements were associated with 11 of 117 eye injuries.28Acceptably low rates of surgical complications in cataract surgery performed under TA have been described.29One study observed an advantage for TA in terms of surgical complication rates. In a randomized, nonblind, comparative study of unselected patients, Jacobi et al. 30observed only one significant difference between TA and RBA, namely a surprising decrease in vitreous loss rate in the TA group (0.4 vs. 2.5%, P = 0.41). Inversely, in a case-control study, a protective effect of PBA or STA versus TA was identified for displacement of nuclear fragments into vitreous (OR = 0.18 [0.10–0.34]).31However, these data were not confirmed by Srinivasan et al. ,32who compared STA with TA. In their study, TA was associated with a twofold increase in posterior capsule rupture requiring anterior vitrectomy (4.3 vs. 2.1%) but with a nonsignificant difference (P = 0.39). Therefore, TA should be limited to planned, easy procedures performed by experienced surgeons in selected patients. Current research must define criteria for patient selection and surgeon experience. For procedures other than phacoemulsification, such as manual extracapsular cataract extraction, akinesia is still required and the use of TA is questionable.5Efforts have been made to improve TA efficacy in many ways. Use of long-acting local anesthetics such as levobupivacaine or ropivacaine seems more efficient than lidocaine (lignocaine). Intracameral injection of local anesthetics has been proposed to enhance analgesia. This option entails injecting small volumes (0.1 ml) of local anesthetic into the anterior chamber at the beginning of surgery. The safety of this technique in relation to local anesthetic toxicity for corneal endothelium seems to be acceptable but any significant analgesic benefit of intracameral injection versus simple TA is very limited if present.33This result is not surprising because analgesia is not correlated with intracameral local anesthetic concentration. For these reasons, intracameral injection is still debated and cannot be clearly recommended.34The efficacy of sponges soaked with local anesthetic inserted into the conjunctival fornix and soluble local anesthetic inserts needs further documentation. Instilling lidocaine jelly instead of eye drops seems to enhance the quality of analgesia of the anterior segment and is being increasingly used.TA may also be associated with an increased risk for endophthalmitis. One study reported the independent risk for endophthalmitis to be sixfold higher with TA compared with RBA.35The most plausible explanation for this observation is that if the jelly was applied on the eye first, it could have acted as a barrier, preventing disinfectant applied later from reaching the conjunctiva, thereby resulting in insufficient eye disinfection. As a result, the problem is probably related to the wrong sequence of application rather than the jelly itself.Three eye block techniques, PBA, STA, and TA, are widely used. The main disadvantages of PBA are needle-related complications and a lack of reproducibility with a high rate of reinjection. The cannula technique, which gains access to the sub-Tenon space, avoids needle block but does not totally prevent complications. Research is needed to assess the potential benefits of ultrasound guidance for injection techniques to prevent these complications. Using TA, needle-related complications are avoided but at the expense of imperfect surgical conditions. Specific local anesthetic jelly mixtures for topical anesthesia should be developed to ameliorate TA analgesia.The authors thank Carey M. Suehs, M.D., Ph.D., Assistant Professor (Département d'Information Médicale, Groupe Hospitalo-Universitaire Caremeau, CHU Nîmes, France), for the English editing of the manuscript.

Aim: To determine changes in intraocular pressures (IOP) associated with drugs used for general anesthesia (GA) induction in eye surgery. Study design: Observational prospective study Place and duration of study: Department of Ophthalmology, CMH Rawalpindi from 1st March 2015 to 31st May 2016. Methodology: Eighty subjects that were advised to undergone various ophthalmic surgical procedures under GA were included in the study. Visual acuity, intraocular pressure (IOP), extra ocular motility, anterior and dilated posterior segment examination were carried out to determine the ophthalmic status. Mixed anesthetics were used in all patients. IOP was recorded at T1 (10 min before induction of anesthesia), T2 (10 min after intubation), and T3 (at the conclusion of surgery before extudation) using Perkins tonometers. Changes in IOP before induction of GA, after intubation, and just before extubation were recorded. Results: Mean pre-anesthesia IOP for patients of age was 42.3 years with a range of 9-70 years and mean IOP was 16.4 with a range of 10-23 mmHg. There was a significant decrease in the mean IOP at T2 (Perkins: 4-6 mmHg) and T3 (Perkins: 5-8mmHg) as compared to the IOP at T1 (10-18mmHg. The decreases in IOPs at T2 and T3 were similar in both anesthetic groups (T2: P=4-6mmHg; T3: P = 5-8 mmHg). Conclusion: Significant decrease in IOP after GA was observed with mixed anesthetic agents. For management decisions this aspect of general anaesthesia drugs on IOP as noted with currently used anesthetic agents has to be accounted for and decisions are taken accordingly. Keywords: General anesthesia, inhalation anesthetics, intraocular pressure, Perkins tonometers

To investigate antibiotic usage practices in ophthalmic surgeries in Germany. An online questionnaire was sent to veterinary surgeons (general veterinarians and veterinarians with additional qualification in ophthalmology) inquiring about their antibiotic preferences, administration methods, and factors affecting antibiotic usage in ophthalmic surgical procedures. A total of 417 questionnaires were analyzed. Postoperative antibiotics (systemic/topical in percent when used) were used all or most of the time by 69% of veterinarians following enucleation (99/6), by 62% after eyelid surgery (54/69), by 68% after third eyelid (TEL) surgery (19/92) and by 80% after keratectomy (6/99). The most commonly used systemic antibiotic was amoxicillin with clavulanic acid and the most commonly used topical antibiotic was chloramphenicol. WHO "watch-group" antibiotics were infrequently administered systemically but frequently utilized topically; including in 13% of eyelid surgery, 15% of TEL surgery, and 35% of keratectomies. Factors influencing antibiotic use included fear of complications (67%), personal experience (63%), diagnostic uncertainty (21%), and owner expectations (9%). Participants following institutional guidelines used fewer antibiotics in enucleations (p = .002) and were less likely to choose fluoroquinolones post-eyelid surgery (p = .044). The potential for reducing antibiotic use following ophthalmic soft tissue surgery is significant. Addressing barriers such as concerns about postoperative complications and the reliance on individual clinical experience, the implementation of standardized guidelines could facilitate a shift toward more judicious antibiotic practices.

Research progress in surgery-related meibomian gland dysfunction

Micrometer-scale precision is vital for patient safety in ophthalmic surgery. Recent advancements in instrument-integrated optical sensors aim to accurately measure instrument-to-tissue distances. However, the reliability of these measurements is often hindered by segmentation errors caused by artifacts in the signal. We propose a deep learning framework to identify optical coherence tomography (OCT) M-scans that fall outside the expected distribution. Our approach incorporates adaptive remote center of motion (RCM)-informed retinal modeling along with time series analysis to effectively detect and rectify segmentation errors. This method estimates retinal distances and their associated confidence levels by leveraging retinal models, instrument positions, and validated distance data. Validation tests conducted on ex vivo human eyes reveal that our pipeline achieves an 88.8% accuracy in identifying out-of-distribution (OOD) measurements. Furthermore, distance estimation improved by 89% and 93% when compared to two existing methods, resulting in an overall mean absolute error (MAE) of less than 40 μm across diverse conditions, including scans with blood and obstructions. This research enhances the accuracy of instrument-to-retina distance estimation, thereby contributing to improved patient safety in ophthalmic surgical procedures. The proposed method has potential applications beyond ophthalmic surgery, offering benefits to a variety of surgical disciplines and sensorequipped instruments.

Complications of Ophthalmic Surgery in the Horse

Dear Editor, Ambidexterity is necessary for any surgeon where the right-handed surgeon uses the left hand and vice versa (non-dominant hand). Most of the ophthalmic surgical procedures require mixed handedness for a faster, smoother, and better post-operative outcome.[1] Various sporting activities, playing video games, driving a four-wheeler, brushing, combing, eating, and so on have helped surgeons face less difficulty using the non-dominant hand or foot. Hand laterality and ambidexterity have been well explored in general surgery, neurosurgery, and laparoscopic surgery but less in ophthalmic surgery.[2] It is highly imperative to acquire ambidexterity early in a surgeon’s career. Still, on the contrary, non-dominant proficiency may not always be associated with an enhanced surgical outcome, as shown by Saleh et al.[3] The future of ophthalmic surgery is rapidly changing with simulators, robotics, artificial intelligence, and 3D visualization systems and the fusion of technology. Lombana et al. studied the implication of ambidexterity in surgical training by comparing right-handed and left-handed surgeons and found that left-handed individuals have a greater degree of ambidexterity than their right-handed counterparts. They also found that the perceived difference may not be solely because of innate skill or dexterity but may be because of a combination of external influences.[4] We read the interesting article by Ramesh et al.,[5] highlighting the use of ambidexterity in ophthalmic surgical procedures, and we must congratulate the authors on touching on this important aspect of surgery. This article prompted us to explore more on ambidexterity. Here, we have listed various ophthalmology surgical steps requiring ambidexterity which we believe will benefit all the surgeons, especially the young surgeons who have just started training [Table 1]. To the best of our knowledge, this is the first article highlighting ambidexterity in various surgical procedures in ophthalmology.Table 1: Depicting the various common surgical procedures requiring ambidexterityFinancial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

To assess the clinical experience of using a three-dimensional (3D) system for ophthalmic surgical procedures. We retrospectively analysed video recordings of patients who underwent 3D ophthalmic surgery, using the NGENUITY® 3D visualization system, or traditional microsurgery at our hospital, from August 2017 to February 2018. Patients underwent phacoemulsification or phacoemulsification combined with vitrectomy. Diagnoses, operation type, duration of continuous curvilinear capsulorhexis (CCC), number of forceps nips during CCC and capsulorhexis complications were recorded. Five surgeons and four assistants answered a 3D surgery questionnaire. Twenty-six of 46 patients who underwent 3D surgery, and 31 of 51 patients who underwent traditional microsurgery (control group) were enrolled. The mean CCC duration in the study and control groups was 31.2±10.8 and 28.7±13.2seconds (p=0.071), and the mean number of forceps nips was 5±2 and 5±2 (p=0.634), respectively. The anterior capsular rupture rate of phacoemulsification under 3D and traditional conditions was 3.85% (1/26 cases) and 3.23% (1/31 cases), respectively. The complication rate was similar between the two groups (p>0.999). Four of five surgeons and two of four assistants believed the clarity of 3D surgery was similar or better than that of traditional microsurgery. The occurrence of dizziness (p>0.999), shoulder and neck pain (p=0.262), backache (p=0.471) and visual fatigue (p=0.347) did not differ significantly between the two methods. The 3D surgical system facilitated similar operation speed and stability as the traditional microscope and provided reliable support for ophthalmic surgery.

To examine the change in volume and costs of physician services for ophthalmic surgical procedures associated with physician fee cuts. The authors analyzed the physician claims (Part B) data for a 5% random sample of the Medicare population. Number, rate, average allowed charge, and total cost of physician services for ophthalmic surgical procedures were compared for 1988 and 1991. An estimated 3.1 million (98 per 1000) ophthalmic surgical procedures were performed on Medicare beneficiaries in 1991, compared with 2.3 million (76 per 1000) in 1988. There was a 35% increase in number and a 28% increase in rate. The average allowed charge for these services decreased by 26% ($1155 vs $852 per procedure), with an overall cost of $2.6 billion in both years. A reduction in fee for physician services for ophthalmic surgical procedures from 1988 to 1991 was associated with an increase in the volume of the services. The overall costs of physician services for ophthalmic surgical procedures remained consistent between the two years.