The lens has a nucleus in the center, surrounded by epinucleus and then cortex with “capsule” around it and a continuous round hole of approximately 5-6mm (the CCC or
Continuous curvilinear CAPSULORRHEXIS) is made so that the phaco tip can directly come into contact with the nucleus to emulsify it.
EYE-DROP ANAESTHESIA FOR PHACO
Anaesthetic eye drops are used prior to the procedure to numb the eye. Sometimes a diluted 1% lidocaine is irrigated into the anterior part of the eye to numb the sensitive iris in case the phaco tip touches it.
Since phaco is a short time painless procedure and there is very little handling of the eye, this no-injection eye drop anaesthesia is enough for a total comfort of the patient.
One should also remember that eye drop anaesthesia is safer than injection which can cause complications like drug reaction and peforation of the eye.
THE NO-STITCH PHACO
Phacoemulsification is done with a thin probe which can enter the eye through a 3.2 mm incision. This incision is made in such a manner that a small tunnel is formed with a length of approximately 2.5 mm. The configuration of the tunnel is such that it closes when the eye pressure is increased and so does not need any stitch to keep it closed.
BEST TIME FOR PHACO CATARACT SURGERY
Today the life style of every person is such that eyes are used extensively for reading/writing/driving during day and night/ watching television etc. and cataract surgery has become very patient friendly. The recovery is quick and discomfort is minimal. Also as the cataract “matures” , it becomes harder and difficult to emulsify with phacoemulsification.
It is therefore, advisable to get the phco-cataract surgery done as early as possible. Definitely when the person is able to read the top letter indicating cataract is sufficiently ready for operation.
PRECAUTIONS BEFORE & AFTER PHACO CATARACT SURGERY
It is advisable to maintain proper hygiene and cleanliness. No cosmetics should be used on the eye or face.
There are no dietary restrictions required before or after cataract operation. Dietary restrictions for other systemic diseases should be observed.
Splashing water in the eye to wash it is not to be done. Face can be washed and head bath can be taken with the eyes closed.
PHACO CATARACT SURGERY IN DIABETICS
Control of blood sugar is essential. A post prandial blood sugar level of up to 180 mg % should be maintained before and after cataract operation.
PHACO CATARACT SURGERY IN HIGH BLOOD PRESSURE
Blood pressure control should be maintained with appropriate medications before/ during and after surgery.
PHACO CATARACT SURGERY IN OTHER DISEASES
Other diseases like Bronchial Asthma, Rheumatoid Arthritis, Dependance on steroids should be discussed and appropriate measures should be taken.
THE COLD PHACO
New phacoemulsification probe produce less heat during ultrasonic vibration thus prteventing heat induced damage to the incision and cornea. This can even be used without infusion sleeve through a smaller incision of 1 – 1.4 mm.
MICRO-INCISION CATARACT SURGERY (MICS)
Phacoemulsification through a smaller incision of around 1 mm with a sleeveless phaco tip and irrigation through a separate side port provides an advantage of speedy recovery, faster healing and lesser surgery induced astigmatism. The surgery involves insertion of a rollable lens of 5.5mm dia which can be inserted through 1.2 mm incision (The microincision).
SPECIAL LENSES
1. MULTI-FOCAL IOL
2. ACCOMODATIVE IOL
3. ROLLABLE IOL
4. BLUE BLOCKING IOL
5. LIGHT ADJUSTABLE IOL
GLAUCOMA
Glaucoma is complex disease of the eye involving irreversible damage to the optic nerve because of increased intraocular pressure. It is common after 5th decade of life, is genetically determined and is more prevalent in Diabetics. Glaucoma can occur in new born , young children and young adults also.
Glaucoma can be broadly divided into 2 types: 1. Acute Glaucoma characterized by sudden increase in eye pressure, painful and red eye, decrease in vision, appearance of coloured haloes around lights and rapid deterioration in vision if not treated in time.
2. Chronic Glaucoma characterized by slow increase in eye pressure causing irreversible damage to the optic nerve associated with slow deterioration in vision and defects in the visual field.
Diagnosis of Glaucoma depends on
1.Complete eye examination including eye pressure,
2.Fundus examination for optic nerve head,
3. Gonioscopy (Study of angle of eye),
4.Pachymetry (Corneal Thickness),
5.SWAP Perimetry (Field test) and
6.Retinal Nerve fibre analysis.
Heidelberg Retinal Tomograph ( HRT 3 ) Retinal Nerve Fibre Analysis determines the thickness of the retinal nerve fibres, which reduces in Glaucoma. Thinning of retinal nerve fibres occurs much before the damage to the fibres and optic nerve causing field defects.
HRT analysis can detect the possibility of glaucoma 3 to 7 years before the appearance of field defects and detection of Glaucoma with other diagnostic procedures.
Treatment of Glaucoma is possible both with medicines and operation. HRT 3 and Perimetry determine the efficacy of medical treatment in preventing the progress of disease and HRT 3 acts as a guide to maintaining good vision. These tests should be repeated at appropriate interval to judge the efficacy.
Bharti Eye Foundation has the first HRT3 in India. |