Common Diagnostic Tests:

  • Fundus Photography
    Color photographs of the back of the eye
  • Fluorescein Angiography (FFA) -Spectralis HRA system
    A diagnostic procedure that photographs the blood circulation of the retina. This involves injection of a dye called fluorescein into a vein in the arm or hand.
  • Indocyanine Green Angiography (ICG) -Spectralis HRA system
    A diagnostic procedure that photographs the blood circulation of the choroid. (Choroid is a layer of blood vessels behind the retina). This procedure is very similar to fluorescein angiography and involves injection of the indocyanine green dye into a vein in the arm or hand.
  • Spectral Domain Optical Coherence Tomography (SD-OCT) – Spectralis
    This is a diagnostic procedure similar to the CT scan of the brain. It uses a beam of light and its reflection to obtain cross-sectional images that provide information about the different layers of the retina.
  • Ultrasonography (B-Scan)
    This procedure involves use of high-frequency sound waves to examine the eye when the normal view is obscured by hemorrhage or cataracts.
  • Electroretinogram (ERG,mfERG, EOG, VEP)
    Electrophysiological measure of retinal function after light stimulation of the retina.
  • Visual Field Analysis
    Measurement of the full extent of the area visible to an eye that is fixating straight ahead.

Common OPD Procedures


PASCAL (Pattern Scan Laser)
Narayana Nethralaya boasts of an advanced version of laser photocoagulation system. The PASCAL (Pattern Scan Laser) Photocoagulator is a new system designed to treat retinal diseases. There are several benefits with the Pascal laser compared to the conventional laser. Most of the laser can be done in one sitting, unlike the conventional laser which requires two to three sessions. This in turn reduces the number of patient-visits to the hospital. The procedure also significantly reduces the discomfort associated with conventional laser, and therefore patient tolerance is much better. Pascal laser can be used in most situations where conventional laser is indicated.


Indirect Ophthalmoscopic Laser Delivery System (LIO)
This laser delivery system is mainly used for peripheral retinal lesions, e.g. horse shoe tear (HST), lattice degeneration, retinal holes, Retinopathy of prematurity (ROP) or pan retinal photocoagulation for vascular retinopathy in a hazymedia.


Photodynamic Therapy (PDT)
Photodynamic therapy is a specialised form of laser treatment used for patients with age related macular degeneration (AMD). A light- sensitive drug is injected into a vein and travels to the abnormal blood vessels in the macula. This is activated by the laser. The light-activated drug then destroys the abnormal vessels.


Cryotherapy is a second way of treating retinal tears apart from laser. An extremely cold probe is used to “freeze-burn” a small area on the outside of the eyeball that overlies the retinal tears. The purpose is to seal the tears and create an eventual scar that will “stick” the retina to that spot.


Pneumoretinopexy is a method of treating selected cases of retinal detachments. A gas bubble is injected into the eye after applying cryo spots to the area of retinal tear. The patient is expected to maintain a certain posture after the procedure for about a week to ten days. Also, he is not allowed to travel by air during this period.

Anterior Chamber / Vitreous tap

A very small amount of fluid from inside the eye is removed in cases of suspected infection or persistent inflammationin the eye. This fluid is then analyzed microbiologically and biochemically to aid in the diagnosis.