Associated Problems Corneal Hypoxia

Hypoxia is the condition of low oxygen (hypo-, meaning low, and -oxia, referring to oxygen). Oxygen supply to the cornea is critical in contact lens wear, particularly with soft contacts. Slit lamp findings of the hypoxic cornea can include neovascularization (especially in the superior quadrant), generalized corneal edema (best viewed with sclerotic scatter), edematous corneal formations (ECF), vertical striae, and corneal infiltrates. These findings are noted in the patient's chart and graded...

External Ocular Adnexa

By definition, the ocular adnexa includes the lids, lacrimal system, orbit, and surrounding tissue (Figure 3-1). We will explore only those structures visible with the slit lamp. These external structures are screened with a moderately wide or full beam and 6X or 10X magnification. A beam angle of about 45 degrees is good, with the light directed from the left to examine the patient's lateral right eye and medial left eye, and directed from the right to examine the patient's lateral left eye...

Protocol and Documentation

It is important to develop your own slit lamp examination protocol. Performing the exam the same way, in the same order, on every patient, will increase the quality of your examination by ensuring that nothing is missed. Table 2-1 is a typical protocol. This protocol might be modified depending on the patient and the situation. For example, if the patient is uncooperative, select the structures that are most vital and examine them first. In addition, each examiner may modify this plan to suit...

Retroillumination

Retroillumination is used to evaluate the optical qualities of a structure. The light strikes the object of interest from a point behind the object and is then reflected back to the observer. Thus, it is similar to a silhouette. Some professionals advocate setting the slit beam slightly off center (via the slit scanning control ring or the slit centering knob) for these techniques. The authors prefer to leave the slit beam in its usual position. Direct Retroillumination From the Iris This...

TABLE 91 Soft Contact Lens Evaluation

Contact Lens Related Overuse Limbus

hygiene cleanliness look for deposits, film. Doc note, describe, grade 1+ to 4+ coverage generally, a soft contact lens will extend beyond the limbus in every direction the edge will not be on the cornea. Doc note, describe (limbal touch nasally, etc) movement a soft lens will generally move about 1.00 mm with a blink. If it does not, have the patient look up you should see a 1.00 mm downward slide of the lens. If it still does not move, have the patient blink while looking up there should now...

Cornea

A system of documenting corneal pathology by hand-drawn illustrations has been described by several authors. Waring and Laibson suggest the following color scheme solid line - sutures dotted line - contact lens dots - guttata wavy lines - Descemet's folds tiny circles - epithelial edema thin solid line - superficial vessels thick solid line - stromal vessels dotted line - ghost vessels green fluorescein, lens, vitreous yellow infiltrate, hypopyon, keratitic precipitates In addition, the...

The Subjective Grading System

An important but confusing part of documenting abnormalities is the subjective grading system. Even the term subjective causes confusion because such grading occurs during the objective examination. Some clarification seems to be in order. First, many of the patient's symptoms are subjective. These are symptoms that the patient tells us about but that we cannot see, such as pain. Other findings are objective, which do not involve the patient's ability to report them. We can see them ourselves...

Arteriosclerosis arcus senilis

Asthma conjunctivitis, cataract (secondary to corticosteroid treatment). Bell's Palsy incomplete or absent lid closure, exposure keratitis. breast cancer metastatic lesion to angle, metastatic lesion to iris, other metastatic lesions (visible mass, redness), symptoms of metastatic lesions (exophthalmus, hyphema). cancer (see Breast Cancer, Colon Cancer, Leukemia, Lung Cancer, Melanoma). Candida albicans (yeast) swelling of lacrimal gland, lid thrush, conjunctivitis, stringy mucus, keratitis,...

Anterior Chamber Aqueous and Angle

Open Angle Slit Lamp

The anterior chamber of the eye is filled with a clear fluid called aqueous. The normal anterior chamber is optically empty. The aqueous that fills the anterior chamber is constantly being formed and drained out. The aqueous drainage area is found in the angle, the area formed where the posterior corneal surface meets the anterior iris root. (The angle itself cannot be viewed directly unless a gonio lens is used.) This dynamic creates a pressure within the eye, the IOP. Average IOP is around...

Specular Reflection

Specular reflection is used to visualize the integrity of the corneal and lens surfaces. If the surface is smooth, the reflection will be smooth and regular if the surface is broken or rough, the reflection will likewise be irregular or appear to be textured. Its most common use is in evaluating the general appearance of the corneal endothelium. In this technique, position the illuminator about 30 degrees to one side and the microscope 30 degrees to the other side. The angle of the illuminator...

TABLE 58 Types of Cataracts

Posterior Capsular Opacification Grading

Congenital (formed in utero or during infancy) 1. Polar Anterior or posterior (axial area) of the lens capsule appears as fine white dots Gray round opacities surrounded by a dark, clear zone can occur in pre- or postnatal development Presenile (formed during early childhood young adulthood) 1. Coronary Wreath of opacities in periphery of cortex Senile (appearance generally following ages 30 to 40) 1. Nuclear Sclerosis (NS) Lens nucleus normally hardens with age index of refraction of nucleus...

Posterior Chamber Intraocular Lens Implant

As mentioned above, most IOLs are placed into the posterior chamber, behind the pupil. Unless the pupil is dilated, you probably will not be able to see the haptics. The haptics look like blue nylon fish line. Only the center of the IOL's optic should be visible through the normal undilated pupil. The entire lens assembly should be in the posterior chamber, and the optic should be on a level plane with the iris. Documentation if PC IOL is present PC IOL clear and in place Posterior Lens Capsule...

Measuring

Measuring the size of a finding can be an important part of the slit lamp examination. A record of a lesion's size from one exam to the next allows us to monitor for growth or resolution. Obviously, a lesion may be measured using a hand held ruler with one hand while observing through the slit lamp. Admittedly, this is awkward. It is far easier to use an ocular that has a ruler built in to the reticule. A third method is possible with vertical illumination source models. First, the slit is...

Instrumentation

The eye is one of the most fascinating structures of the body. A great deal of this fascination hinges on the fact that it is the only organ that we can look directly into without having to cut and or insert a special scope. The slit lamp is a microscope designed specifically to examine the eye. It is composed of a microscope and a light source. The microscope is binocular that is, it has two eyepieces, giving the binocular observer a stereoscopic 3-dimensional view of the eye. Thus, another...

Movement and Centration

High Ride Rgp

A rigid lens is smaller than a soft lens and, thus, will not cover the cornea. The old PMMA hard contact lenses were designed to have an interpalpebral fit. That is, the centered lens lies entirely between the lids. The more modern method of fitting gas permeable lenses which are larger than PMMA contacts is the alignment fit, where the upper third of the lens stays under the upper lid Figure 9-7 . The movement of a rigid lens is much different from that of a soft lens. The rigid lens will move...

Slit Lamp Exam of the Prospective Contact Lens Patient

The result of the slit lamp examination is one of the determining factors in whether or not a patient can try contact lenses. Here is a basic list of things that the fitter will want to know 1. Tear film Is the tear film clear, or is there evidence of oil and or debris What is the tear BUT Is there evidence of dry eye 2. Eyelids What is the blink rate Do the lids close completely with each blink Are the lid margins smooth Is exophthalmus present Are the lids and lashes clean, or is there...

TABLE 55 Grading Corneal Staining

Narrow Angle Left Eye

Minimal superficial staining or stippling 1 Regional or diffuse punctate staining 2 Significant dense coalesced staining, corneal abrasion, or 3 foreign body tracks Severe abrasions gt 2.00 mm diameter, ulcerations, epithelial 4 loss, or full thickness abrasion Adapted from FDA document Premarket Notification Guidance Document for Daily Wear Contact Lenses. Figure 5-19. Herpetic dendrite. Photo by Val Sanders. Figure 5-20. Dry eye stained with rose bengal lower left quadrant . Photo by Val...