MSc Clinical Optometry: Therapeutics Lab Quiz
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Questions and Answers

Which of the following is NOT typically included in a pathology request form?

  • Results of the laboratory analysis (correct)
  • Patient's identification details
  • Clinical history
  • Relevant medications

When collecting a microbiology specimen, what specific information about the patient's current medications is essential to include on the request form?

  • Any antibiotics they are currently prescribed (correct)
  • The family history of reactions to any antibiotics
  • The start date of their current medication
  • A list of all medications they have ever taken

In addition to clinical examination, what can medical laboratories provide, to aid in the diagnosis of ocular disease?

  • Objective information (correct)
  • Inferred diagnosis
  • Historical medical records
  • Subjective patient reports

Which of the following investigations is NOT typically carried out in a pathology laboratory?

<p>Radiology (A)</p> Signup and view all the answers

What additional information is specifically required on a request form when blood is being collected for drug level monitoring?

<p>Drug dosage and time of collection (D)</p> Signup and view all the answers

For what type of ocular disease is a fasting blood sample particularly important to note on the request form?

<p>Ocular vascular diseases (D)</p> Signup and view all the answers

What is the primary reason for including clinical history and examination findings on the pathology request form?

<p>To aid in accurate interpretation of test results. (C)</p> Signup and view all the answers

What is the role of the reference values that are provided alongside laboratory test results?

<p>To offer context for the medical professional to interpret the results (B)</p> Signup and view all the answers

Why is the timing of specimen collection important, especially for blood samples?

<p>To ensure the specimen is collected before the next dose of medication, to measure trough levels. (A)</p> Signup and view all the answers

What is the primary reason for repeating the surgical process when a lesion extends to the margin of a section?

<p>To ensure an adequate, clear margin is achieved. (B)</p> Signup and view all the answers

Which of the following is NOT a typical step in handling and transporting specimens?

<p>Transporting the specimen without a request form. (C)</p> Signup and view all the answers

Which of the following lid lesions is considered a premalignant condition?

<p>Actinic keratosis (C)</p> Signup and view all the answers

Why are blood samples for electrolyte studies not generally refrigerated if there is a delay?

<p>Refrigeration can invalidate the accuracy of electrolyte results. (A)</p> Signup and view all the answers

Apart from basal cell carcinoma, which of the following malignant lid lesions is mentioned as less common?

<p>Sebaceous gland carcinoma (C)</p> Signup and view all the answers

What is the primary purpose of fixing tissue specimens in 10% formalin prior to light microscopy?

<p>To preserve tissue structure and prevent degradation. (A)</p> Signup and view all the answers

What is a key feature of Moh’s micrographic surgery that distinguishes it from frozen section?

<p>It uses histological drawings for a 3D view of the lesion. (A)</p> Signup and view all the answers

Which of these specimens are MOST likely to be transported fresh without fixation?

<p>Specimens for frozen sections, Moh's surgery, or flow cytometry. (B)</p> Signup and view all the answers

Which of these scenarios require a biopsy?

<p>Any reoccurence of a lesion. (B)</p> Signup and view all the answers

What is the main purpose of a frozen section in surgical procedures?

<p>To confirm complete excision of a potentially malignant lesion with adequate margins. (D)</p> Signup and view all the answers

How should tissue specimens be prepared for electron microscopy (EM)?

<p>Transported fresh or rapidly fixed in glutaraldehyde. (A)</p> Signup and view all the answers

What is the immediate next step after a specimen is excised during surgery for a frozen section?

<p>Rapid freezing to form hard tissue blocks. (B)</p> Signup and view all the answers

Why is it important to consult with the pathology laboratory if there is uncertainty about specimen handling?

<p>To ensure correct procedures are followed to prevent artefactual results. (A)</p> Signup and view all the answers

What is the most common treatment method for persistent or symptomatic chalazia?

<p>Surgical removal (D)</p> Signup and view all the answers

What is the purpose of an incisional biopsy compared to an excisional biopsy?

<p>An incisional biopsy takes a portion of the lesion whereas an excisional biopsy removes the whole lesion. (A)</p> Signup and view all the answers

Which thyroid function test is affected by changes in serum binding proteins?

<p>Total T4 (D)</p> Signup and view all the answers

Which of the following tests directly measures the amount of unbound thyroxine in the bloodstream?

<p>Free T4 (C)</p> Signup and view all the answers

What is a key clinical feature, consistent with thyroid dysfunction, but may be difficult to recognize?

<p>Eyelid retraction (B)</p> Signup and view all the answers

What is the primary diagnostic objective when using Thyroid-stimulating hormone receptor antibody testing?

<p>Diagnosing and monitoring thyroid dysfunction (A)</p> Signup and view all the answers

Which blood test is used as a non-specific marker of inflammation in cases of Giant Cell Arteritis?

<p>Erythrocyte sedimentation rate (B)</p> Signup and view all the answers

Which of the following is a specific symptom associated with Giant Cell Arteritis?

<p>Throbbing headache (B)</p> Signup and view all the answers

In hypothyroidism, which of the following changes in test results is most likely?

<p>Decreased total T4, Decreased THBR (D)</p> Signup and view all the answers

If a patient has hyperthyroidism, what would be the expected change in Free T4 level?

<p>Increased (C)</p> Signup and view all the answers

What is the primary measurement used to determine the Erythrocyte Sedimentation Rate (ESR)?

<p>The length of the plasma column above settled red blood cells at one hour. (D)</p> Signup and view all the answers

For a 60-year-old woman, what would be considered the maximum normal ESR?

<p>35 mm/hr (B)</p> Signup and view all the answers

Which condition is NOT typically associated with an elevated ESR?

<p>Hypothyroidism (D)</p> Signup and view all the answers

In the context of thyroid function, when is T3 level measurement most appropriate?

<p>When T4 levels are normal and there is clinical suspicion of hyperthyroidism. (A)</p> Signup and view all the answers

What is the most sensitive initial screening test for thyroid dysfunction in ambulatory patients?

<p>TSH level measurement. (D)</p> Signup and view all the answers

According to the content, what effect does inflammation have on red blood cells in relation to ESR?

<p>It causes them to clump together and settle out of solution faster. (B)</p> Signup and view all the answers

Why is C-reactive protein (CRP) considered more useful than ESR in some instances?

<p>It is more sensitive and increases more rapidly during inflammation. (D)</p> Signup and view all the answers

What is the typical normal range for haemoglobin in a female, as shown in the reference values?

<p>12-16 g/dL (A)</p> Signup and view all the answers

What does the measurement of antithyroid antibodies primarily indicate?

<p>The presence of an autoimmune disorder of the thyroid. (D)</p> Signup and view all the answers

If a patient has a red blood cell count of 5.8 x 10^12 /L, and is female, is this value within the normal range?

<p>Yes, it's within the normal range. (C)</p> Signup and view all the answers

Which of the following is NOT typically measured in a full blood count?

<p>Electrolytes (B)</p> Signup and view all the answers

Which of the following conditions will show elevated antimicrosomal antibodies?

<p>Hashimoto’s disease (C)</p> Signup and view all the answers

If a patient has presumed thyroid disease, but their thyroid function tests are within normal limits, how often does this occur?

<p>10-20% of the time (A)</p> Signup and view all the answers

If a patient has a haemoglobin level of 13 g/dL, and a haematocrit of 42%, which of these statements is correct?

<p>They are both within the normal range for females. (B)</p> Signup and view all the answers

What is the normal range for white blood cells (WBC) according to the provided table?

<p>4.5–11.0 x 10^9 /L (A)</p> Signup and view all the answers

What is measured by 'Mean cell haemoglobin concentration' (MCHC) within a full blood count?

<p>The concentration of haemoglobin in a red blood cell. (D)</p> Signup and view all the answers

Flashcards

Anatomical Pathology

Lab tests that examine tissue samples to diagnose diseases.

Haematology

Lab tests that examine blood cells to diagnose diseases.

Chemical Pathology

Lab tests that examine blood chemistry to diagnose diseases.

Immunopathology

Lab tests that examine immune system components to diagnose diseases.

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Genetics

Lab tests that examine genetic material to diagnose diseases.

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Microbiology

Lab tests that examine microorganisms to diagnose diseases.

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Special Tests

Lab tests that are not typically categorized under other branches of pathology.

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Pathology Request Form

A form that accompanies a lab specimen, containing patient information, clinical history, findings and medications.

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Incisional biopsy

Surgical procedure where a small portion of a lesion is removed for examination.

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Excisional biopsy

Surgical procedure where the entire lesion is removed for examination.

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Moh's micrographic surgery

A type of surgery used for skin cancers, where the tissue is examined under a microscope during the procedure to ensure clear margins.

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Electron microscopy (EM)

A type of microscopy that uses a beam of electrons to view very small structures.

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Glutaraldehyde

A chemical used to preserve tissue for examination under a microscope.

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Seborrheic keratosis

A type of benign tumor of the eyelid.

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Actinic keratosis

A type of precancerous skin lesion.

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Basal cell carcinoma

A type of skin cancer that originates from the basal cells.

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Trough drug level

Collecting a sample at the lowest point of a drug's concentration in the body, typically before the next dose, to assess its effectiveness.

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Frozen section

A technique used to rapidly freeze and slice tissue for microscopic examination, often used to determine the extent of a tumor.

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Formalin

A common fixative used to preserve tissue for light microscopy, allowing for detailed examination of structures.

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Tissue processing

The process of preparing a sample for microscopic analysis, including fixation, embedding, sectioning, and staining.

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Light microscopy (LM)

A type of microscopy that uses visible light to illuminate and magnify a sample, allowing for the observation of cells and tissues.

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Biohazard

Any substance or organism that could cause contamination or infection.

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Biohazard warning plastic bag

A plastic bag with a warning label indicating potentially hazardous biological materials.

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Request form

A form used to provide detailed information about the specimen being submitted for analysis, including patient details, clinical history, and requested tests.

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Thyroid function tests

This test is used to diagnose and monitor thyroid function, alongside clinical assessment.

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Thyroxine (T4)

T4 is a thyroid hormone involved in regulating metabolism.

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Triiodothyronine (T3)

Triiodothyronine is another thyroid hormone regulating metabolism, with even stronger effects than T4.

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Thyroid-stimulating hormone (TSH)

Thyroid-stimulating hormone is produced by the pituitary gland and stimulates the thyroid to produce T4 and T3.

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Thyroid function tests: how they work

This test is used to measure the levels of T4, T3, and TSH in blood.

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Hyperthyroidism

A condition where the thyroid gland is overactive, producing excessive thyroid hormones.

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Hypothyroidism

A condition where the thyroid gland is underactive, producing insufficient thyroid hormones.

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TSH receptor antibody test

This is a test to measure the amount of thyroid antibodies in the blood, which can be helpful in diagnosing certain thyroid disorders.

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Full Blood Count (FBC)

A blood test that measures the different components of blood, including red blood cells, white blood cells, and platelets.

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Pre-septal cellulitis

A type of cellulitis that affects the tissues around the eye, but is not life-threatening.

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Hashimoto's Disease

An autoimmune disorder that destroys thyroid tissue, leading to hypothyroidism.

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Antimicrosomal Antibodies

Abnormal antibodies found in Hashimoto's disease that target thyroid cell components.

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Euthyroid

A condition where the thyroid gland is not functioning properly, but hormone levels may be within the normal range.

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Presumed Thyroid Eye Disease

A condition where thyroid eye disease is suspected, but thyroid function tests are normal.

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Erythrocyte Sedimentation Rate (ESR)

A blood test that measures the rate at which red blood cells settle to the bottom of a test tube. It's often used to detect inflammation in the body.

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C-Reactive Protein (CRP)

A sensitive blood test that detects the presence of inflammation. It's often used to monitor the progress of infections and inflammatory conditions.

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T3 Toxicosis

A form of hyperthyroidism where only T3 levels are elevated, often seen in Graves' disease patients with normal T4.

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Antithyroid Antibodies

Specific antibodies against thyroid tissue that can be measured in the blood. They are often elevated in thyroid autoimmune diseases, such as Graves' disease.

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Giant Cell Arteritis (GCA)

A common condition characterized by inflammation of the large arteries, particularly the temporal artery.

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Thyroid Ophthalmopathy

Inflammation of the tissues surrounding the eye, often associated with thyroid disease.

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Study Notes

MSc in Clinical Optometry: Principles of Therapeutics - Laboratory Investigation in Ocular Disease

  • This unit reviews common laboratory investigations in ocular disease, outlining specimen collection, processing, and interpretation methods.
  • Eight hours of study.
  • Learning outcomes include identifying common laboratory tests for ocular diseases and understanding their indications and results.

Introduction

  • Ocular and systemic diseases are initially assessed via thorough medical history and clinical examination.
  • Laboratory tests help determine disease stage, severity, and aid in differential diagnosis.
  • Laboratory investigations are categorised as anatomical pathology, haematology, chemical pathology, immunopathology, genetics, microbiology, and special tests.
  • Specimen collection, transportation, and analysis are critical. Pathology request forms must include patient details, history, examination findings, and medications.
  • Timing of specimen collection is important (e.g., blood for drug level monitoring should be taken before the next dose).
  • Results often come with normative data or reference values.

Specimen Handling and Transport

  • Specimens are placed in sterile containers, labeled immediately.
  • Care is taken to prevent contamination of the specimen and the safety of staff handling it.
  • Specimens are transported promptly to the laboratory and handled carefully according to each specific test requirements (e.g., tissue for EM might need rapid fixation).

Tissue Specimens

  • Fresh specimens are useful for frozen sections, Mohs micrographic surgery, and flow cytometry.
  • 10% formalin is common for light microscopy.
  • Frozen sections are used for complete excision margin control, especially for malignant lesions, with adequate margins.
  • Mohs micrographic surgery is specifically recommended for canthal cancers, focusing on rigorous margin control.
  • Histological examinations are often required, particularly for surgical decisions related to margins of excision.

Investigation of Ocular Disease: Eylids and Orbit

  • Investigations can be via biopsy, cytology, ophthalmic radiology, or ophthalmic ultrasonography.
  • Benign lid tumours, including papillomas, seborrhoeic keratosis, keratoacanthoma, naevi, and vascular lesions, are possible.
  • Premalignant tumours are actinic keratosis. The most common malignant eyelid lesion is basal cell carcinoma, followed by rarer squamous cell and sebaceous gland carcinomas.
  • Chalazia are common and often resolve spontaneously, but persistent or symptomatic ones may need surgical treatment, requiring biopsy for accurate diagnosis.
  • Incisional and excisional biopsies differ in how much of the lesion is removed.
  • Electron microscopy may be necessary for undifferentiated tumours.
  • Immunohistochemical investigations may be performed with tissue collected by biopsy fixed in formalin.

Investigation of Orbital and Pre-septal Cellulitis

  • Pre-septal cellulitis and orbital cellulitis are significant ocular infections.
  • CT imaging is crucial for differentiation based on tissue location front or behind the septum orbitale.
  • Investigation for orbital cellulitis often includes body temperature, full blood count, blood culture, and connective tissue (CT) scan of the orbit, sinuses, and brain.

Full Blood Count

  • The full blood count (FBC) includes red blood cell (RBC) count, haematocrit, haemoglobin, mean cell haemoglobin concentration, mean cell haemoglobin, white blood cell (WBC) count with differential, and platelet count, using automated analysers.
  • Specific reference ranges for male and female are cited in the table.

Investigation of Thyroid Disease

  • Chemical pathology, including hormone tests, is frequently used to assess thyroid function.
  • Total T4/T3, thyroid hormone binding ratio (THBR), and thyroid-stimulating hormone (TSH) are measured.
  • Free T4/T3 can be calculated using THBR.
  • T3 levels are used in conjunction with normal T4 levels, if there's a clinical suspicion of hyperthyroidism.

Investigation of Giant Cell (Temporal) Arteritis

  • Giant cell arteritis (GCA) is inflammation of blood vessels supplying the head.
  • Erythrocyte Sedimentation Rate (ESR) and C-Reactive protein (CRP) are non-specific inflammatory markers, with elevated values suggesting active disease.

Investigation of Microbial Keratitis

  • Microbial keratitis is chiefly bacterial, often caused by contact lens wear.
  • Investigating include anatomical pathology (biopsy) and microbiology (cultures e.g. Gram stain, culture).

Investigation of Herpes Simplex Keratitis

  • Diagnosis is often clinical, but viral culture could be used for confirmation if unsure.

Investigation of Lacrimal Disorders

  • Tears can be collected via micropipettes or Schirmer strips for biochemical analysis (osmolality, lactoferrin, lysozyme).
  • Hyperosmolality is a sensitive, but not specific, marker for keratoconjunctivitis sicca (KCS).

Investigation of Conjunctival Disease

  • Anatomical pathology (biopsy) is the gold standard for conjunctiva disease diagnosis; it is performed when other tests are inconclusive.

Investigation of Uveitis

  • Uveitis is inflammation of the middle eye layer; anterior uveitis is generally non-systemic and resolves with treatment.
  • Posterior uveitis, panuveitis, or intermediate uveitis might warrant investigations for potential systemic causes.
  • Diagnosing and assessing different forms of uveitis (anterior, intermediate, posterior, and panuveitis) is dependent on the clinical symptoms but is often assisted by blood studies.
  • Investigations focus on identifying systemic disease factors when uveitis remains non-responsive to treatment for prolonged periods.

Investigation of Scleritis

  • Scleritis is a chronic, inflammatory sclera disease; in over 50% of cases, an associated systemic illness could be diagnosed.
  • Laboratory tests (e.g., blood counts, ESR, RF, ANCA, CRP, ACE, uric acid) may be used to find potential associated systemic diseases.

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Unit 5 Part 4: Laboratory Investigation in Ocular Disease PDF

Description

This quiz assesses your understanding of common laboratory investigations in ocular diseases, including specimen collection, processing, and interpretation methods. You will explore the importance of laboratory tests in determining disease severity and aiding in differential diagnosis. Prepare to identify key tests and their indications as part of your learning outcomes.

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