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Clinical Outcomes at SNEC

Cataract Surgery

Cataract extraction and intraocular lens implantation is the most common operation performed at the Singapore National Eye Centre (SNEC). More than 10,000 cataract procedures are performed in SNEC each year, by a team of 52 full-time ophthalmology specialists.

In a report on Cataract Surgery by the Ministry of Health of Singapore in 2006, 11,532 of the 16,310 cases of cataract surgeries performed at three participating centres in 2004 were done at SNEC.

Cataract surgeries performed by consultants at SNEC have a consistent overall visual success rate of 97 - 98%. This means 97-98% of all our cataract surgeries attain a Snellen visual acuity of 6/12 (internationally-accepted visual requirement for driving) or better. Our visual success rate compares favourably with those from international eye centres such as those in the US (93%) and the UK (92%). Cataract surgeries at SNEC performed by the phacoemulsifi cation technique have a success rate of 99.5%.

Another important yardstick of success in cataract surgery is the rate of endophthalmitis, a sightthreatening microbial infection of the content of the eye. At SNEC, we take great pains to reduce and eliminate the risks of endophthalmitis. As a result, our cataract operations enjoy a very low rate of post-operative endophthalmitis. Of our 99,655 cases of cataract operations over a 10-year period (2001-2010), the average endophthalmitis incidence rate was 0.027%, well below the international advisory of 0.1%.

Corneal Transplants

Corneal Surgery in General
The success rate for routine uncomplicated corneal transplants is about 91% in the fi rst year. This rate of corneal graft survival matches the results of other renown centres in the West. Success rates for Anterior Lamellar Keratoplasty and Endothelial Keratoplasty now range closer to 100% as less risk of rejection occurs in these new procedures.

However, complications can occur following a transplant. The more common complications that can occur include raised eye pressure, which can cause damage to the eye nerve (glaucoma), and corneal graft rejection. Most of the complications occur in the first year after transplantation, but most can still be treated successfully if detected early. Our results for Asian Eyes are equivalent to that of the mainly Caucasian eyes in the West, and we are the only major database monitoring success in Asian eyes.

Lamellar Keratoplasty (LK)
In SNEC, nearly 75 cases of Lamellar Keratoplasty are performed yearly. As Anterior Lamellar Keratoplasty (ALK) retains the innermost corneal layer, it greatly reduces the risk of corneal graft rejection, a signifi cant cause of corneal transplant failure, to almost zero.

Compared with the 20% overall risk of rejection after Penetrating Keratoplasty (PK), rejection risk following ALK is less than 1%. There is better long-term graft survival following ALK. Our results show that the overall one-year graft survival for ALK in SNEC is 94%.

In terms of recovery of vision, with the newer surgical techniques, we have been able to achieve equal if not better visual outcomes following ALK as compared with PK performed for similar indications.

Endothelial Keratoplasty (EK or DSAEK)
In SNEC, more than 100 cases of Endothelial Keratoplasty are performed yearly.

EK offers several advantages over a fullthickness procedure like PK in patients who have selective damage to the inner layers of the cornea (endothelium):

1. No suture-related problems. As EK does not involve any sutures it does not have the risk of suture-related problems like suture-related abscess. There is also reduced astigmatism, resulting in better vision when compared with PK.

2. Lower risk of graft rejection. Early results have shown that the risk of rejection is much lower with EK. Compared with the 20% overall risk of rejection after PK, rejection risk following EK is just 7.6% in the fi rst year. This is probably because far less donor tissue is transplanted, compared to conventional PK, where the whole cornea is transplanted.

In SNEC we have performed over 300 EK procedures and have had only three eyes with graft rejection (2%).

3. Excellent graft survival. There has been no failure to-date in the SNEC series. Graft survival appears to be better than conventional PK surgery. This may be related to the lower risk of graft rejection.

4. Faster visual recovery. The visual recovery is much faster following an EK procedure with reduced astigmatism compared with PK.

Retinal Surgeries

The SNEC surgical retina team treats common conditions such as retinal tears and detachments, advanced diabetic eye disease, vitreous haemorrhage, giant retinal tears, macular holes, macular puckers, vitreomacular traction, myopic foveoschisis, trauma, proliferative vitreoretinopathy.

The various surgical procedures which are done include lasers, pneumoretinopexy, scleral buckling and vitrectomies. The vitreoretinal operating theaters are equipped with equipment to perform scleral buckling surgery, vitrectomies and lensectomies.

The surgical volume averages about 1,000 each year. The three most commonly treated conditions are retinal detachments, diabetic retinopathy and disorders of the vitreomacular interface such as macular holes and puckers.

Our surgical success rate for retinal detachment is 97.5%.


As the local and regional referral centre for secondary and tertiary management of glaucoma, the SNEC Glaucoma Service manages over 40,000 glaucoma attendances annually - including over 2,000 attendances from the region. Our glaucoma consultants manage paediatric and adult glaucomas with more than 600 glaucoma surgeries performed every year.

We practise independent annual audits. It has calculated our surgical success rate at achieving an intraocular pressure of less than 21mmHg for primary glaucoma at one year. With trabeculectomy this is 97.3% to 99%. For combined cataract and trabeculectomy surgeries for primary glaucoma our success rate is 96.7% to 99.6%. The success rate for tube-shunt surgery for refractory and complex glaucoma cases is 89.3% to 93.3%.

Oculoplastic / Aesthetic Eyeplastic

This is a tertiary service that deals with a wide range of conditions including droopy lids, entropion and ectropion, blocked nasolacrimal ducts that cause tearing disorders, orbital fractures and tumours, and thyroid eye disease. We perform over 700 oculoplastic procedures annually. We recognise the increasing demand for aesthetic surgery to the eyelids and surrounding tissues. This includes blepharoplasty, endoscopic or small incision brow-lifts and mid-face lifts. Aesthetic eyeplastic procedures such as botox injections and fi ller treatments are increasingly combined and performed by oculoplastic surgeons as older individuals look for ways to rejuvenate their appearance. The Aesthetic Eyeplastic service was set up to cater to this demand.

Dacryocystorhinostomy (DCR)
Dacryocystorhinostomy (DCR) is a surgical procedure that restores the fl ow of tears into the nose in patients with blocked nasolacrimal ducts. It refers to the creation of a new drainage pathway between the naso-lacrimal sac and the nose and involves the removal of intervening bone. There are two methods of DCR:

  • Externally, through a small incision on the side of the nasal bridge with direct visualisation of the nasolacrimal sac and the nasal cavity
  • Endoscopically, with a nasoendoscope to fashion an opening in the naso-lacrimal sac from within the nasal cavity.

Both external DCR and endoscopic DCR surgeries are performed at SNEC. Our success rate for both procedures ranges from 94 – 95%.

Entropion refers to the abnormal in-turning of the eyelid with the resultant irritation of the cornea by the lashes. This can result in persistent red and teary eyes. Entropion occurs most commonly with ageing but can be due to scarring of the conjunctiva or inner lid margin.

Surgery is usually required to solve this problem. Improvement of the eyelid position relative to the eye will prevent the constant rubbing of the cornea and relieve the symptoms of redness and discomfort.

Our success rate for entropion surgery is 94.3%.