Ординатура / Офтальмология / Учебные материалы / Clinical Diagnosis and Management of ocular trauma

Monofilament 10-0 nylon suture material on a fine spatulated design microsurgical needle is used for corneal suturing. Some surgeons even prefer use of 11-0 nylon sutures especially for wounds involving visual axis. A number of strategies for corneal suturing are available. The simplest involves progressively halving the wound with simple interrupted sutures. These definitve corneal sutures should be approximated 1.5 mm long, approximately 90% deep in the stroma, and of equal depth on both sides of the wound. Shallow sutures will cause internal wound gape; sutures that are asymmetric or of unequal depth will result in wound override. On the contrary, full thickness sutures can act as conduit for microbial invasion. In

Corneoscleral Laceration

In cases with corneoscleral laceration, first, a suture is applied to the limbus, and the wound is tightly secured. This suture helps to anatomically approximate the wound. After the first suture is applied, an iris prolapse or a vitreous prolapse is treated. In the presence of an iris prolapsed depending on the viability of iris tissue it is either repositioned or absiccised. In the presence of a vitreous prolapse, a vitrectomy is performed with cellulose sponges or an automated vitrector. During the vitrectomy, traction on the vitreous should be avoided. Any vitreous in the anterior segment may be removed using a vitrectomy machine. After the corneal wound is repaired, the scleral wound

Scleral laceration should be repaired as far posteriorly as possible; far posterior scleral ruptures may be left unsutured. While repairing scleral lacerations, care must be taken to not exert pressure on the globe. In the presence of uveal prolapse, the prolapsed tissue is reposited. The preferred method of sclera wound closure over prolapsed uveal tissue is a zippering technique wherein the sclera wound is closed from anterior end, i.e. limbal end with interrupted sutures placed successively proceeding posteriorly. One should never do excision of the prolapsed uveal tissue unless it is necrotic because it causes excessive bleeding. Vitreous prolapse is managed by performing a vitrectomy with cellulose sponges and scissors or by using an automated vitrector. At every step, care should be taken to prevent iatrogenic damage. The sutures are placed closely together and tied to achieve a watertight closure. The conjunctiva is sutured using 8- 0 or 9-0 Vicryl.

Posterior Scleral Laceration

Scleral laceration without corneal involvement may occur in a variety of settings. Posterior sclera dehiscence or occult sclera dehiscence can be suspected based on history and mode of ocular trauma, poor visual acuity, conjunctival chemosis, deep or shallow anterior chamber, low intraocular pressure, hyphema and/or subconjunctival pigmentation. Lacerations extending beyond equator of the globe can be left unsutured if attempting suturing is causing more trauma to the globe, this sclera perforations will be taken care by delayed secondary healing.

Patch and a Shield

A patch and a shield are applied to the eye. Postoperatively, patients should be carefully monitored for signs of infection. Pain, photophobia, redness, tearing, or a deterioration of vision should alert the physician to look for signs of endophthalmitis. Conjunctival injection, chemosis, corneal edema, and elevated intraocular pressure may be present but are not diagnostic of infection. A more than expected anterior chamber reaction and cells in the vitreous are most suggestive of endophthalmitis.

Fig. 33.1: Corneal laceration operated elsewhere

Fig. 33.2: Corneal laceration repaired under topical anesthesia

Fig. 33.3: Corneal laceration repaired with hypopyon

Introduction

For the treatment of any type of inflammation including iatrogenic, both the steroids and non-steroidal anti-inflammatory drugs may be used.

The corticosteroids are essential drugs in ophthalmological diseases. It is a boon to the patients when it is used with proper indications. It is a two-edged sword, and can cause serious complications and side effects if it is used unwisely. Are we using corticosteroids judiciously? This question must always be kept in mind and answered before instituting this therapy. Before planning the corticosteroid therapy, we must keep in mind its ocular hazards. In clinical practice corticosteroids are often used as shotgun therapy or as a placebo when all is not going well. This practice must be discouraged.

to their use. In experimental studies the available 0.1 percent dexamethasone further diluted as 1:10 or 1:20 dilution had no virus or fungal replications enhancing effect when instilled 10 times a day, while 1:5 dilution or undiluted available dexamethasone drops (0.1%) enhanced virus and fungal growth. Moreover, adequately diluted corticosteroid does not increase the risk of enhancing the collagenase effect.

c.Corticosteroid therapy in vernal conjunctivitis and allergic disorders: The use of corticosteroids locally has a beneficial effect in vernal conjunctivitis. But prolonged use is attended by unwanted side effects like cataracts, glaucoma and secondary keratoconus.

d.Use of corticosteroids in alkali burns of cornea and conjunctiva: The use of corticosteroids in alkali burns is obligatory and seems beneficial.

Topical Application

The route of administration of corticosteroids depends primarily on the site of involvement. Topical therapy is effective in anterior segment diseases, including disorders of lids, conjunctiva, cornea, iris and ciliary body. Ease of application, relatively low cost, and absence of systemic complications strongly favor local routes whenever they are effective.

The course of posterior segment disease (chorioretinitis, optic neuritis, and posterior scleritis) is not appreciably affected by topical corticosteroids and requires systemic therapy.

a.Are diluted corticosteroid drops effective in controlling intraocular inflammation?

It was demonstrated that diluted corticosteroids have therapeutic anti-inflammatory effect in strengths of 0.01 and 0.005 percent.

b.Corticosteroids in infective corneal diseases:

Local installation of corticosteroids in frank suppurative conditions are generally considered as contraindications

e.Use of corticosteroids in pseudophakic bullous keratopathy (PBK): The effects of 5% hypertonic sodium chloride drop and deturgescent drops, prepared by mixing betamethasone eye drops (0.1%) 1 ml; glycerin, 1 ml and artificial tear drops 8 ml, achieving 10% glycerin and 1:0 betamethasone eye drops (0.1%), were compared in a controlled clinical trial in 50 cases of PBK. These were instilled 10 times a day. The deturgescent drops were significantly superior in subjective as well as objective parameters like discomfort, foreign body sensation, corneal clarity and improvement in vision, etc. as compared to 5% hypertonic saline.

f.Ocular hypertensive effect of corticosteroids:

Surgical trauma causes inflammation which demands the use of corticosteroids to prevent the trabecular meshwork, corneal endothelium and other inner structures of the eye from damage by inflammatory response as well as its debris. But, ocular hypertension inducing effects restrict their wide usage. In this regard, 1:10 or 1:20 diluted steroid did not have any ocular hypertensive effect.

Prednisone has become a corticosteroid of choice because it is inexpensive, short acting, and relatively free from sodium retention. It may be used in divided doses, a single daily dose, or a single alternate day dose.

Single daily dose: For long-term low-dosage maintenance (as for chronic uveitis), a single, morning, daily dose of prednisone may be optimal.

Alternate day therapy: The undesirable side effects of systemic corticosteroid therapy can be substantially reduced by using alternate day therapy rather than divided dosage. Briefly stated, the entire total dose of corticosteroid that would have been given during a 2-day period is administered as a single dose every other morning.

Repository Injection

The ophthalmologist who wishes to administer corticosteroids by “subconjunctival” injection should consider use of the repository form of methyl-prednosolone acetate (Depo-Medrol). Thus suspension form of prednisolone provides a constant source of corticosteroid that lasts for 2 to 4 weeks.

Intravitreal Injection

Intravitreal 0.1 ml (Dose 50 mg/ml) is injected to prevent proliferation of fibroblast. It seems helpful to combat proliferative vitreoretinopathy.

Controlled Release Vehicles

Ocusert devices delivering 10 mg of hydrocortisone acetate/hr were used to treat allergic conjunctivitis.

Pulse Therapy

Slow intravenous infusion of 100 mg Prednisolone daily for consecutive three days shows good response in Harada’s disease. If needed, repeat dose can be given after 14 days.

USE IN OCULAR SURGERY

1.Cataract

2.Corneal graft rejection

3.Glaucoma surgery

4.Retinal detachment

5.Vitreous surgery

6.Strabismus

7.Intraocular foreign body.

Contraindications and

Complications

SYSTEMIC COMPLICATIONS

•Peptic ulceration

•Osteoporosis

•Femoral head ischemia necrosis

•Pseudotumor cerebri

•Exophthalmos.

LOCAL CONTRAINDICATIONAND

COMPLICATIONS

•Superinfection

•Activation of tuberculosis

•Uveitis

•Glaucoma

•Corticosteroid mydriasis

•Corticosteroid induced cataract.

The severe scleritis associated with rheumatoid arthritis, an example of immunological disorder does respond to corticosteroid treatment but the patient may suffer structural loss of sclera upto more severe scleromalacia as a result of treatment.

Sympathetic ophthalmia is a classic example of a disease responsive to corticosteroid therapy, but requires prolonged therapy.

Non-specific iridocyclitis and chorio-retinitis, as well as herpetic keratitis do seem to benefit from corticosteroid therapy.

Posterior ocular effects require systemic administration or retrobulbar injection.

Fig. 34.1: Mechanism by which nonsteroidal antiinflammatory drugs produce their clinical effect

MECHANISM OF ACTION

NSAIDs act mainly as anti-inflammatory agents by inhibiting cyclooxygense and lipo-oxygenase enzymes which lead to inhibition of products like prostaglandins, thromboxane and leukotrienes which induce inflammation. Ocular actions of prostaglandins include

TABLE 34.2: Topical nonsteroidal anti-inflammatory agents

an increase in vascular permeability, breakdown of the blood-aqueous barrier and induction of miosis.

Cystoid Macular Edema (CME)

Topical NSAIDs are effective in preventing postsurgical angiographic CME when topical or subtenon’s corticosteroid injections are given concurrently. Only one study (involving 50 patients) has demonstrated similar effect with a topical NSAID in the absence of concurrent corticosteroid therapy.4 Several studies have demonstrated that prophylactic treatment with a topical NSAID has a beneficial effect on visual function. In one study, this effect was shown even in the absence