OPHTHALMOLOGY CASE PRESENTATION

Partial Central Retinal Artery Occlusion

A Clinical Case Study

Indraprastha Apollo Hospital

May 2026

01

Central Retinal Artery Occlusion

Definition

Central Retinal Artery Occlusion (CRAO) is an ophthalmic emergency characterized by sudden, painless vision loss due to obstruction of blood flow through the central retinal artery, which supplies blood to the inner layers of the retina.

Classification

  • Complete CRAO: Total occlusion with severe vision loss (counting fingers to light perception)
  • Incomplete/Partial CRAO: Partial occlusion with variable vision loss and characteristic fundus findings
  • Transient CRAO: Amaurosis fugax - temporary episodes of vision loss

Key Clinical Features

  • Sudden, painless monocular vision loss
  • Relative afferent pupillary defect (RAPD)
  • Cherry-red spot at macula
  • Pale, edematous retina
  • Box-carring of blood vessels

⚠️ Ophthalmic Emergency

CRAO is considered an ocular stroke. The retina can survive only 90-100 minutes of ischemia. Immediate intervention is crucial.

02

Pathophysiology & Etiology

Mechanism of Injury

1
Arterial Occlusion

Embolus or thrombus blocks the central retinal artery

↓
2
Ischemia

Inner retinal layers lose blood supply

↓
3
Edema

Retinal swelling and opacification

↓
4
Vision Loss

Photoreceptor dysfunction and cell death

Common Causes

🫀

Cardiac

Atrial fibrillation, valvular disease, endocarditis

🩸

Hematologic

Hypercoagulable states, thrombophilia

🧠

Vascular

Carotid atherosclerosis, giant cell arteritis

💊

Iatrogenic

Retrobulbar anesthesia, orbital trauma

03

Case Presentation

Patient ID: 0012098127
Indraprastha Apollo Hospital

Chief Complaint

Painless, diminished vision in Left Eye (OS)

Patient Demographics

Age 56 years
Gender Male
Date of Examination May 15, 2026

History of Present Illness

The patient presented with complaints of painless, progressive diminution of vision in the left eye. No history of trauma, pain, redness, or photophobia reported. No similar episodes in the past.

Relevant History

  • No known history of diabetes mellitus
  • No known history of hypertension
  • No previous ocular surgery
  • No family history of ocular diseases
04

Visual Acuity & Intraocular Pressure

Visual Acuity Assessment

Eye Uncorrected VA Best Corrected VA
Right Eye (OD) 6/6 6/6
Left Eye (OS) 6/24 6/12

Key Finding: Significant improvement with refraction in the left eye, suggesting the presence of retinal pathology affecting visual acuity.

Intraocular Pressure (IOP)

Initial
OD 30 mmHg
OS 30 mmHg
↓
After Brinzemic B
OD 15 mmHg
OS 16 mmHg

Response: Excellent response to Brinzemic B (Brinzolamide + Brimonidine), with IOP normalized in both eyes.

05

Fundus Examination

Color Fundus Photography
Color Fundus Photography - Both Eyes

Clinical Findings

Right Eye (OD)

  • Normal optic disc appearance
  • Healthy retinal vasculature
  • No signs of ischemia or edema
  • Normal macular reflex

Left Eye (OS) - Affected Eye

  • Superior quadrant: Pale, yellowish discoloration
  • Retinal whitening in affected area
  • Attenuated arterioles in superior arcade
  • Partial involvement suggests incomplete occlusion

Clinical Significance

The pale yellowish appearance in the superior quadrant is characteristic of retinal ischemia secondary to arterial occlusion. The partial nature of the findings suggests a branch or incomplete central retinal artery occlusion.

06

OCT Findings

OCT Macular Scan
OCT Macular Scan - Left Eye

OCT Analysis

📊

Macular Thickening

Increased retinal thickness observed in the macular region, consistent with retinal edema secondary to ischemia.

🔍

Inner Retinal Hyperreflectivity

Increased reflectivity in the inner retinal layers, indicating ischemic changes and cellular edema.

⚠️

Loss of Layer Definition

Partial loss of normal retinal layer architecture in affected areas, suggesting acute ischemic injury.

OCT Interpretation

OCT findings confirm the clinical suspicion of retinal ischemia. The macular thickening and inner retinal changes are characteristic of acute arterial occlusion. The partial nature of these changes supports the diagnosis of Partial CRAO rather than complete occlusion.

07

Electrophysiological Assessment

Visual Evoked Potential (VEP)

Normal Response Patient Response (Delayed)
ABNORMAL

Delayed Conduction

Prolonged P100 latency observed in the left eye, indicating delayed transmission of visual signals from the retina to the visual cortex.

Additional Investigations

🫀

Cardiac Evaluation

ECG, Echocardiography to rule out embolic source

🩸

Laboratory Tests

CBC, ESR, Lipid profile, Blood glucose

🧠

Carotid Doppler

To assess carotid artery patency and plaque

📋

Systemic Workup

Complete evaluation for stroke risk factors

08

Diagnosis

🔬

Final Diagnosis

Partial Central Retinal Artery Occlusion Left Eye (OS)
ICD-10: H34.12

Supporting Evidence

✓

Clinical Presentation

Painless, diminished vision in left eye with partial improvement on refraction

✓

Fundus Findings

Pale yellowish superior quadrant indicating retinal ischemia

✓

OCT Findings

Macular thickening with inner retinal hyperreflectivity

✓

VEP Findings

Delayed conduction confirming optic pathway dysfunction

Differential Diagnosis Considered

Complete CRAO Rejected: Preserved central vision, partial fundus changes
Branch Retinal Artery Occlusion Considered: Similar presentation, but extent suggests central involvement
Retinal Vein Occlusion Rejected: No hemorrhages, venous engorgement absent
Optic Neuritis Rejected: Painless presentation, no disc edema
09

Management & Treatment

Immediate Management

0-24 hours

Ocular Massage

Digital ocular massage to dislodge embolus

Immediate

Paracentesis

Anterior chamber paracentesis to lower IOP

Ongoing

Hypotensive Agents

Brinzolamide + Brimonidine (Brinzemic B)

Systemic Management

Antiplatelet Therapy

Aspirin 75-150 mg daily

Statin Therapy

Atorvastatin for vascular protection

Carotid Evaluation

Doppler ultrasound to assess stenosis

Cardiac Workup

Rule out atrial fibrillation, valvular disease

Prognosis & Follow-up

📈

Visual Prognosis

Variable; partial CRAO has better prognosis than complete occlusion. Final VA depends on duration of ischemia and area of retina affected.

🔄

Follow-up

Regular monitoring of visual acuity, IOP, and fundus examination. Systemic evaluation for stroke prevention.

10

Case Summary

Key Learning Points

  • Partial CRAO presents with variable vision loss and characteristic fundus findings
  • Early recognition is crucial for optimal visual outcomes
  • Multimodal imaging (Fundus + OCT + VEP) aids in diagnosis
  • Systemic evaluation is essential to prevent future vascular events
  • Prompt treatment with ocular massage, IOP reduction, and systemic workup

Clinical Pearl

Always consider CRAO in patients with sudden painless vision loss, even when vision is partially preserved. The presence of a pale retina on fundus examination is pathognomonic.

Diagnostic Approach

Combine clinical examination with OCT and VEP to confirm diagnosis and assess extent of ischemic damage.

Thank You

Questions & Discussion

Indraprastha Apollo Hospital, Delhi

1 / 11