Pseudoexfoliation Syndrome was first described by Lindberg in 1917
]. Several studies have reported differences between eyes with and without PEX. Our study was aimed at documenting this difference in patients from Kashmir.
Significantly more eyes in Group 1 had hard cataract i.e. Grade 3 to Grade 4. Also the nuclei were found to be harder intraoperatively at the time of phacoemulsification than the preoperative LOCS III classification. This was consistent with the study of Shastri and Vasavada
We noted higher preoperative IOP in patients with PEX. This was consistent with previous studies – Shingleton et al.
] and Damji
] who reported a mean baseline IOP higher in PEX (17.60
mmHg) versus 16.08
mmHg in the control group.
A good mydriatic pupil is one of the main requirements for a safe and successful phacoemulsification surgery. This is even more important in eyes with PEX syndrome, in which surgery is more complicated because of the risks associated with loss of zonular integrity and poor pupillary dilatation
]. In our study, the mean pupil diameter achieved after maximal mydriasis was significantly less in the PEX Group. This necessitated the use of iris hooks, mechanical pupil stretching and viscomydriasis to facilitate surgical maneuvers.
Cataract surgery in eyes with PEX syndrome is considered a challenge because of weakened zonules and poor pupillary dilatation. Initial case reports document increased rate of complications during cataract extraction in patients with PEX syndrome. Drolsum and co-authors
] found a frequency of 9.6% of capsular tear, zonular tear or vitreous loss in eyes with PEX. In the study by Shingleton and co-authors
], the rate of vitreous loss was 4% in the PEX eyes and 0% in non-PEX group.
However recent reports by Shastri and Vasavada
], Michael Hyams et al.
] and others report no significant difference in the rate of complications between patients with and without PEX. Raymond J. Nagashima
] reported no cases of posterior capsular tears and zonulo-dialysis. In our study, though intraoperative complications were comparable between the two groups, the occurrence of zonular dehiscence and sulcus fixated lens was more in Group 1.
Various factors that explain the difference between our intraoperative result and the lesser complications in the recent reports are:
1. Surgical experience being a crucial factor. Comparatively we are in the initial phase of phacoemulsification. It is to be stressed here that the rate of complications was more in patients operated in the earlier part of our study whereas it was significantly less in the later part of the study. We attributed this to the increasing experience of surgeons which acted as a crucial factor when operating on eyes with PEX.
2. With experience we learnt that gentle multi-quadrant hydrodissection with very gentle in-the-bag nuclear rotation is advocated to avoid zonular stress and dehiscence in PEX cases.
3. It was also found that rather than doing in-the- bag nucleotomy with its inherent danger of further damaging the already weak zonules, it is safer to do a supra-capsular pulsed phaco with soft shell visco-technique to protect the corneal endothelium after dividing the nucleus into two halves as the stress on the zonules by this technique is much less, and all the maneuvers therein are outside the bag reducing any stress on the zonules.
4. Michael Hyams et al.
] implanted an anterior chamber IOL in higher number of patients with PEX. This may act as a surrogate for complications.
5. Also degree of PEX was not graded in any of the studies. It was observed in grading the degree of PEX, intraoperative complications were seen more in cases with severe exfoliation i.e. PEX present on the lens capsule and zonules.
We noted a higher inflammatory response postoperatively in patients with PEX in the form of flare, cells, corneal edema and inflammatory membranes. The significantly higher postoperative inflammatory response in patients with PEX can be attributed to the transient breakdown of the blood-aqueous barrier that occurs during phacoemulsification in patients with PEX
]. In addition iris vessels are pathological with an increased permeability for protein in eyes with PEX
The literature has shown a decrease in IOP after phacoemulsification that is more pronounced in eyes with a higher preoperative IOP. It is speculated that phacoemulsification removes a source of PEX material (the anterior lens capsule) and results in or stimulates clearance of PEX and pigment debris from the anterior segment, in particular the trabecular meshwork
]. This was supported by other studies by DJ Cimetta
] and Shingleton
]. Our study too showed a decrease in IOP after phacoemulsification which was more pronounced in patients with PEX than in controls thus being consistent with other studies.
The UCVA in the early postoperative period was significantly better in the control group as compared to the group with PEX. This was attributed to the higher postoperative inflammatory response which affected the visual acuity in patients with PEX. However the UCVA later was comparable between the two groups. This was attributed to the clearance of inflammatory reaction that had caused a significant drop in visual acuity previously. Though the difference in BCVA at 6
months between the two groups was not statistically significant yet visual acuity in the PEX group was less on account of the occurrence of posterior capsular haze and opacity which was more in this group. This was consistent with Akinci et al.
] and Shastri and Vasavada
] who reported no significant difference in the visual acuity gain between the two groups (p
0.05). However Streho M
] reported a mean postoperative visual acuity of 0.4
0.6 LogMar in the PEX group and 0.2
0.1 LogMar in the control group. Drolsum et al.
] reported a visual acuity of 0.5 (6/12) or better achieved in 86.5% of eyes with PEX and 92.4% in control group (P
0.02) at 4